Improvements in Breech-loading Cannon.
Year: 1892

page_text: COMPLETE SPECIFICATION.
Improvements in Breech-loading Cannon.
I, SAMUEL SEABURY, Lieutenant United States Navy, of Schuyler Place,
Bergen Point, in the County of Hudson and State of New Jersey, United States
of America, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement:—
This invention relates particularly to breech-loading cannon in which, according
to my British Letters Patent No. 5697, dated April 15th 1890, a screw breech
block movable directly back and forth into the breech of the gun is employed in
combination with a swinging carrier which is hinged to the breech of the gun, and
into which the said block is received when withdrawn from the breech, and with
the swinging retractor which is hinged to the breech, to move independently of the
said carrier, for the purpose of withdrawing the said block from the breech into
the said carrier, and pushing it therefrom into the breech.
I will first describe my invention with reference to the accompanying drawings
of the breech portion of the gun to which it is applied, and will afterwards
specifically point out its novelty in claims.
Fig. 1 represents a central vertical section of the breech and carrier, and shows
the breech block partly in section and partly in side view, and screwed up.
Fig. 2 is a rear view corresponding with Fig. 1.
Fig. 3 is a rear view of a portion of the breech, and of the breech block and
its operating mechanism, shewing the breech block unscrewed and ready to be
withdrawn.
Fig. 4 is a side view of the pin which constitutes the pivot of the hinge of the
carrier and retractor, the said pin having affixed to its upper end, a crank for
operating the retractor.
Fig. 5 is an inverted plan of the pin and crank.
Fig. 6 represents a horizontal section of the breech of the gun, and a plan of the
breech block and its operating mechanism.
Fig. 7 is a plan view, partly in section, of the rotator by which the turning of
the breech-block is effected.
Fig. 8 is a plan of the breech block retractor.
Similar letters of reference designate corresponding parts in all the figures.
A is the breech, bored, screw threaded, and grooved to receive a mutilated
screw-threaded breech block B, which is represented as of ordinary pattern
externally, the said breech and block having preferably four longitudinal grooves,
that the block may be unscrewed and screwed up by an eighth of a turn.
C, C, C, C, designate a hinge bracket affixed to the breech, for the purpose
of attaching the breech-block carrier D, D1, D2, and the breech block retractor E,
the said bracket consisting of a plate C, which is dovetailed into the breech, two
arms C, C projecting rearwardly from said plate, and a strengthening web C³
between said plate and arms. The dove-tailed plate C of the said bracket is
secured to the breech by screws a a.
Fis the hinge pin upon which the breech block carrier D, D', D², and breech
block retractor E, are fitted to swing freely, the said pin having forged in the same
piece with it, or otherwise affixed to its upper end, a crank arm G, which carries
two wrist pins bb, one above and the other below, the upper one, b, being for the
purpose of unscrewing and screwing the breech block, and the lower one, b, being
for the purpose of operating the breech block retractor E. The said pin Fis
fitted to turn freely in the fixed arms C1, C2 of the hinge plate. The lower end of

page_text: the said pin is represented as having securely affixed to it, a worm gear H, which
engages, for the purpose of turning it, with an endless screw I on the horizontal
shaft which is fitted to bearings c, e¹, c, on the breech, the said bearings c² c
consisting of lugs projecting from the lower arm C of the hinge bracket. This
shaft is represented as furnished with a hand crank 12, by which it is turned, for
the purpose of turning the hinge pin to produce the operations of the breech
mechanism. J is what I term the breech-block-rotator, for screwing up and
unscrewing the breech-block.
This rotator consists of a rod or bar for connecting the breech block with the
upper wrist pin of the crank G, the said rod or bar having, at one end, a curved
hook or slotted yokej with an open mouth, and being permanently attached to the
upper part of the rear of the breech-block by a pivot k, which is screwed into the
block. The hook or yokej receives within it, and engages with, the crank wrist
pin b. The sides of this pin have a rounded profile, and the transverse section of
the sides of the hook or yoke j are made of corresponding form to accommodate
the slight vertical oscillation which the rotator J has upon the pivot in the
turning movement of the breech block produced through it by the action of the
crank G.
In order to give the hook or yoke the necessary strength, I prefer that its
curved slot, which receives the wrist pin b, shall not extend right through it, but
that a portion of the metal of which it is constructed, shall be continuous across
the said slot, as may be understood by reference to Fig. 7, where the web across
the said slot is indicated in dotted outline. As, during the movement of the hinge
pin F and crank G, which takes place after the unscrewing of the breech block,
and prior to screwing it in again, the rotator Jis disengaged from, and unsupported
by the crank, I provide on the back of the breech block, for the support of the
said rotator, at such times, a projection g, represented as a pin screwed into the
block. This pin supports the rotator as shown in Fig. 3, in position for its
re-engagement with the crank G, by the entry of the wrist pin into the open
mouth of its hook or yoke.
From that end of the rotator J which is connected with the breech-block, there
projects downwards a tail piece or extension p, to serve as a safety cover for the
vent in the breech block or gas check.
The rear end of the breech block is shown as having a central recess d to receive
the nuts ee on the stem of the gas-check; and inside of this recess is a circumferential
groove, shown in section in Fig. 1, and also shown in Fig. 3, by breaking away
part of the rear of the block, and shown in Figures 2 and 6 in dotted outline, for
the reception and engagement of a wrist or pin 9, which projects upwards from the
extremity of the breech block retractor E, the said wrist or pin, by operating in
the said groove, serving to retract the block, and the groove providing for the
turning of the block to unscrew it, and screw it up, without interference with the
said retractor which consists of an arm fitted to swing horizontally upon the hinge
pin F, and which is represented in Figs. 2 and 3 as bifurcated, or having two
leaves, where the hinge pin passes through it, so that it connects with the said pin
above and below the upper arm C of the stationary hinge bracket. The said
retractor is moved back to withdraw the breech block by the pressure of crank
wrist against its front edge, but as the said wrist will not operate to return the
retractor, here provide, as described in my herein before mentioned Letters Patent,
the return bolt o, which works up and down through guide holes for it in the two
leaves of the retractor arm, and into and from a hole provided for it in the crank G,
the said movement being produced by a lateral projection on the said bolt working
in a cam groove in the rounded end of the bracket arm C. I have shown a spring n
applied to the said bolt to push it upward.
The breech block carrier D, D1, D2, consists of a tray D, of a common form, to
serve as a seat for the breech block, arms, D' D', to the end of which the said tray
is attached, and a hub D' from which the said arms project, and which is fitted to
turn on the hinge pin between the retractor E and the arm C₁ of the stationary

page_text: hinge bracket. The said tray D has, at its sides, as is common, longitudinal parallel
guides h, for the purpose of guiding the breech block during its withdrawal from,
and return to the breech, the said block being provided with grooves ii, which
come opposite the said guides when the breech block is unlocked. For locking the
carrier to the breech of the gun at all times except when it is required to take the
breech block away therefrom, and for locking the breech block in the tray of
the carrier after it has been withdrawn from the breech into said tray, I provide
a tray latch such as is well known and is described in my herein before mentioned
Letters Patent, consisting of a hooked lever K which is pivoted by a pin to the
tray D of the carrier, and engaging with a hooks affixed to the breech, the said
latch being disengaged from the said hook, to liberate the carrier by the rear end
of the breech block passing over its upward projection t, which projects through
an opening in the tray, and the block being afterwards locked in the tray by the
entrance of the said projection t into the notch w provided in the block for its
reception.
To lock the breech block when it is screwed up, I provide what I term a gravity
locking latch, consisting of a bolt L having dovetailed edges, and fitted to work
easily in a nearly radial groove of corresponding dove-tail form in the rear face of
the breech block. The outer end of this bolt, when the breech-block is screwed
up, drops into a notch in the counter bore or screw box of the breech, as shewn
in Fig. 2. Before the unscrewing of the breech block, the said bolt or latch has
to be lifted up out of the notch by a handle, provided on it for the purpose,
aud held so lifted while the block is turned far enough for the end of the
said bolt or latch to be supported within the counterbore of the breech, as shown
in Fig. 3.
Having now described the construction and separate operations of the several
parts of the breech-block, and its operating mechanism, I will now proceed to
describe the operations for loading and firing the gun.
The gun having been fired and left with the parts of the mechanism in the
position in which they are represented in Fig. 2 and in bold outline in Fig. 6, to
open the breech, first raise the latch L out of the recess u, then turn the shaft I',
by means of the hand crank 12, in the direction to cause the endless screw I to
turn the worm gear H and the hinge pin F and crank G in the direction of the
arrow shown near the hinge in Fig. 6.
During the first portion of this movement of the hinge pin, the upper crank
wrist b, working in the yoke or hook j of the rotator J, produces the turning of
the breech block to the left, as indicated by the arrow shown near it in Fig. 2.
When, by this movement, the block is unscrewed and ready to be withdrawn from
the breech, the lower wrist of the crank comes against the retractor E, and the
continued turning of the hinge pin and crank produces, through the operations of
the said wrist on the retractor, and of the wrist g of the retractor in the slot f
of the breech-block, a complete withdrawal of the said block from the breech into
the tray D of the carrier, which is now first unlocked from the breech by the
passage of the block over the projection of the tray latch K, and then locked to
the breech-block by the entrance of the projection into the notch w. By the
further continued turning of the hinge pin, the wrist b', continuing in action on the
retractor, pulls back the breech block, and with it the carrier, until the block and
the whole of the mechanism are thrown aside to the position shown in dotted
outline in Fig. 6, leaving the breech completely open for loading. Prior to the
commencement of the movements above described for opening the breech, the tail
piece p of the rotator J left the vent uncovered, as shown at Fig. 2, but by the
unscrewing of the breech block, the vent is brought behind the said tail piece, as
shown in Fig. 3, where it remains during the remainder of the opening movements,
and until the breech block has been again inserted into and screwed up within the
breech, the tail piece thus serving as a safety cover to the vent at all times but
when the breech block is screwed up.
When, in the movement of the crank G, the lower crank wrist has come into

page_text: contact with the retractor, and begins to move it and the breech block, the
rotator J, owing to its superior speed, due to the difference in radial length
between the retractor and the crank, disengages itself from the wrist b, the yoke
or hook in the rotator being made open at the end, to allow the said wrist to pass
out. During that part of the movement of the crank G which takes place before
the wrist begins to act on the retractor, the return bolt o is held down by the
groove m in the arm C² of the hinge bracket, and the crank passes over the upper
end of said bolt, until, as the wrist arrives at the retractor, the hole in the
crank arrives over the said bolt, which, as the retractor moves back, is raised by
its lateral projection running in the said groove m, and is thereby caused to
engage the retractor with the crank, ready for the return movement of the breech
block.
To close the breech, the movement of the hand crank J' is reversed. The
return movement then takes place as follows:-
The whole of the breech-block-operating mechanism swings back, and as the
tray D of the carrier with the breech block in it, arrives at the breech of the gun,
the tray latch Kis tripped from the block by the hook stud, s, and the continued
movement of the retractor E with the hinge pin F and its crank G pushes the
breech block back into the gun. When this position is reached, the return bolt o
has been nearly withdrawn from the crank arm by its movement in the groove m
of the hinge bracket arm C³, and the further turning movement causes the return
bolt to be withdrawn from the crank G. As the crank is thus released from the
retractor, its wrist operates in the yoke or hook j of the rotator J (the rotator
having overtaken the crank wrist while the block was being pushed into the gun),
and pulling the latter to the right, turns the block from the position shown in
Fig. 3 to that shown in Fig. 2, thus completing the closing of the breech.
As soon as the breech block is screwed up, the gravity latch L drops into its
notch in the gun, and upon firing the gun, takes the strain of the turning effort,
thus relieving the various parts of the breech-block operating mechanism.
The endless screw 1 and worm wheel H effect another lock always in action
should its latch L be dispensed with.
The vent is uncovered as shown in Fig. 2, by the final movement of the breech
block, and the rotator during the operation of screwing up, and a primer may then
be inserted in the vent. Although the vent is covered by the rotator, at all times
except when the breech block is screwed up, it is not thus rendered inaccessible
for clearing when the breech is open, for should the clearing be necessary, by lifting
the hooked end of the rotator, the tail piece or safety cover may be carried clear
of the vent. Only design, however, will enable this to be done. It cannot occur
through accident.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
1. The combination with a breech-loading cannon and a breech-block for the
same, which has both a rotary and a backward and forward movement, a swinging
carrier for said breech block, and a hinge pin attached to the breech, and con-
stituting a pivot upon which the said carrier swings, of a crank on said pin, and a
bar or rod pivoted to the breech block and having a hook or slotted yoke
engaging with a wrist of said crank, substantially as and for the purpose herein
set forth.
2. The combination with a breech-loading cannon and a breech block for the
same, which has both a rotary and a backward and forward movement, a swinging
carrier for said breech-block, a swinging retractor for drawing the breech block
into the carrier and pushing it therefrom into the gun, and a hinge pin attached to
the breech, and constituting a pivot on which said carrier and retractor swing
independently of each other, of a bar or rod pivoted to the said breech block, and
having a curved slotted yoke or hook, and a crank on the hinge pin having two

page_text: wrists, one of which engages with the said slotted yoke or hook, for turning the
breech block, and the other engages with the retractor for withdrawing the breech
block from the gun, substantially as herein set forth.
3. The combination with the breech-loading cannon and a breech block which
has both a rotary movement and a backward and forward movement in the breech
thereof, and in which there is a circumferential groove, of a breech block retractor
hinged to the breech, and engaging in said groove in the breech-block, substan-
tially as and for the purpose herein set forth.
4. The combination with a breech-loading cannon, and a breech block having a
turning movement therein, of a pin pivoted to the breech, a crank on said pin, and
a bar or rod which is pivoted to the breech block, and connects the crank there-
with, and a portion of which covers, and leaves uncovered, the vent in the breech
block, as the latter is turned in one direction or the other, substantially as herein
set forth.
5. The combination with the breech of a breech-loading cannon and a screw
breech block fitted to the same, of a locking bolt fitted to slide in a substantially
radial groove in the said block, and engaging in a notch within the breech, when
the block is screwed up, substantially as herein specified.
Dated this 29th day of July 1892.
NEWTON & SON,
Agents for the Applicant.