Improvements in Breech Mechanism for Rapid Fire Guns.
Year: 1899

page_text: COMPLETE SPECIFICATION.
Improvements in Breech Mechanism for Rapid Fire Guns.
I, JOHN WESLEY STOCKETT, of No. 312, Fourth Street, South-East, in the
City of Washington, District of Columbia, United States of America, Engineer,
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:-
”
-
My invention relates to breech mechanism for rapid fire guns and more particu-
larly to that general class of breech mechanism known as the interrupted
screw type and in which but a single motion is required to unscrew, withdraw
and swing the breech-block free of the gun and to restore it to its normal position.
The general object of my invention is to improve and simplify the construction
of such guns, and to these ends my invention consists in various features of
construction and arrangement of parts having the general mode of operation
substantially as hereinafter more particularly set forth.
Referring to the accompanying drawings wherein I have illustrated a preferred
embodiment of my invention; Fig. 1 is a horizontal section of the breech of a
gun, showing the mechanism applied thereto; Fig. 2 is a rear elevation of the
same; Fig. 3 is a vertical section; Figs, 4, 5 and 6 are respectively rear elevation,
plan and sectional views of a circular plate attached to the breech-block; Figs. T
and 8 are respectively plan and sectional views of the operating lever and pinion;
Figs. 9 and 10 are sectional views of portions of the mechanism, showing the
locking pin; Fig. 11 is a side view of a portion of the breech block and attach-
ments; Figs. 12, 13 and 14 are rear and sectional views of the automatic safety
extractor and firing attachment.
One of the principal objects of my invention is to provide a mechanism of the
class described, which is adapted to be used without the employment of fixed
ammunition and which, therefore, provides for the use of a plastic pad as a gas-
check. Another important feature of my invention consists in arranging the

page_text: mechanism of this class of guns so that a minimum amount of withdrawal or
translation of the breech-block in a right line is necessary in order that the
block may be swung clear of the breech of the gun. Another feature of invention
resides in the construction and arrangement of parts to accomplish the above in
such a manner that the walls of the breech of the gun about the screw-box are
not weakened by cutting through the same or otherwise. Other features of inven-
tion will appear from the following description taken in connection with the
accompanying drawings.
In the drawings A represents the breech portion of a rapid fire gun of
any usual construction and B the breech-block provided with the usual
interrupted screw-threads fitting similar screw-threads in the screw-box of the
breech in the usual manner. Mounted on the breech-block is a gas-check, C,
shown in the form of a plastic pad fitting the rear portion of the bore of the gun.
Mounted on the breech of the gun is a block carrier D, shown as pivotally
mounted on the side of the breech at D¹ and adapted to swing backward and
laterally, and while this is the preferred position of the carrier it, of course,
can be differently arranged with relation to the breech without departing from
the invention.
The breech-block, B, is shown as provided with a reduced rearward exten-
sion, B, fitting and passing through the opening in the block-carrier and moving
therein to permit the motion of translation so-called, that is, the longitudinal
movement of the breech-block in the carrier. The rear face of the breech-block
is grooved at 133, to receive a forwardly projecting annular flange, D2, of the
block-carrier which closely fits into said groove in order to assist in supporting
the block when open, and the carrier is grooved at D5 to receive the flange, B3,
and form a large surfaced stop limiting the movement of translation of the block
and avoiding danger of upsetting the usual lock bolt. In order to permit this
movement without producing an air cushion in the groove, B2, at the inner
end thereof are drilled several small holes, b.
This
Outside of the central extension of the breech-block and projecting beyond
the block carrier ring is a detachable attachment shown in the form of a circular
plate, E, illustrated in detail in Figs. 4-6, and this plate may be attached to the
breech-block in any suitable way, as by dove-tailed portions or bolts, e.
attachment is provided with turning and translating devices co-operating with
the operating lever and pinion and is made separable from the block so that in
case of accident or otherwise this attachment may be readily removed and another
substituted and in the present instance the plate, E, is shown as having an
extension, E, provided with teeth, e¹.
As in this construuction there is relatively a small movement of translation
of the breech-block, only sufficient to withdraw the plastic pad from the bore of
gun, it is only necessary to have practically two feeth,, on the extension, E
as best shown in Fig. 6.
the
In order to produce the rotation of the breech-block necessary to disengage the
interrupted screw-threads from the breech I have shown as formed with or
mounted on the circular plate, E, an extension in the form of a rotating gear
sector, F, provided with gear teeth, f, adapted to be engaged by a sector on the
operating pinion, as hereinafter described, and this is so arranged that the gear
teeth of the gear sector are practically housed at all times and are protected from
injury and at the same time the teeth of the operating pinion are also protected.
Mounted on the block carrier, D, and on a rearward extension, D3, thereof is
the operating lever, G, formed with or carrying an operating pinion, H, and con-
veniently held in position by a screw pin, G¹. In the present instance, as shown
in Figs. 7 and 8, the operating pinion is made separate from the operating lever
and is secured thereto by a squared extension, H, fitting a similar recess in the
end of the lever, the pinion thus forming a bearing for the lever and the screw
pin forming a bearing for the operating pinion. The operating pinion, H, is
provided on one side with two spur teeth, 1, adapted to engage the teeth, e,

page_text: on the extension, E', of the circular plate, E, to produce the movement of trans-
lation. The operating pinion is also provided with a sector, He, having a number
of teeth. 2, adapted to engage the teeth, f, and this sector is preferably less
than a quadrant, the teeth being so arranged (as indicated in Fig. 7) that they
will engage the teeth of the rotating gear sector F and turn the breech-block
sufficiently to disengage the interrupted screws to allow the breech-block to be
moved outward and so as not to interfere with such movement. Thus as shown
the tooth, , for instance, is practically in the central vertical plane of the
breech mechanism and normally engages a corresponding tooth, f, of the rotating
gear sector, F, when the breech-block is in its normal closed position. I find
it an advantage to make the operating pinion separate from the lever and to
secure them togther in the manner shown, as it is impracticable to cut the teeth
on the operating pinion if made an integral part of the lever, and the construc-
tion furnishes a strong union between the parts and a ready means for attaching
them to the breech of the gun.
An important feature of my invention is found in the construction and arrange-
ment of the teeth on the operating pinion and the rotating rack plate. It is
well known that in breech mechanisms of this class as the breech block is un-
screwed to disengage the mutilated screws it moves outward from the gun to a
greater or less extent and the amount of this outward motion of the breech-
block is determined by the pitch of the threads on the block and the amount of
circular motion required to disengage the mutilated threads on the block from
those of the breech, and as above described while the teeth, or one of them at
least, of the sector normally engages the teeth of the rotating rack plate when the
breech block is in its normal closed position this outward movement of the
block due to its rotation, as above set forth, tends to produce lost motion or
varying strains on the teeth of the sector and plate. In order to overcome this
the teeth on the rotating gear sector F, are cut on an incline equal to the
pitch of the thread on the breech-block and have an inward inclination with
reference to a line parallel with the face of the breech of the gun, as indicated
by the pitch line 2 The teeth on the sector H2 of the pinion and those on the
rotating gear sector F are set so that when the breech-block is closed their pitch
lines are coincident or intermesh and the pitch line of the teeth on the rotating
gear sector being cut on an inclination toward the block, as indicated by the
line f, as the block moves backward, it will necessarily present a constant and
uniform working surface between the teeth on the rotating gear sector and those
on the sector of the pinion, and there will consequently be no lost motion or
varying strains between the teeth, so that the block will be uniformly rotated
and under the most advantageous conditions.
Arranged on the end of the breech of the gun and co-operating with the
breech block is an automatic locking bolt, I of usual construction, the details of
which need not be herein set forth, as they form no part of my present invention
and it is simply shown as one well-known means of locking the breech block in
the usual manner and serves to limit the rotation of the block and hold it in
position in the block carrier while it is being swung out of the breech of
the gun.
Another feature of my invention comprises the automatic safety extractor
and firing attachment shown more in detail in Figs. 12 and 13, and this com-
prises a lever K, mounted on a movable fulcrum K¹, connected to the block
carrier and shown in the present instance in the shape of a bearing pin for the
lever, K, sliding in an opening D in the carrier so that it can move in and out
in accordance with the movements of the breech-block and still be properly
supported with relation to the block carrier. This lever K is provided with an
elongated slot K³, through which passes a stud shown in the form of a screw K³,
engaging the circular plate E. Also connected to the circular plate in the present
instance is a screw K, the head of which is adapted to engage the end of the
lever K. forming what may be termed a blow back latch, that is, serving to

page_text: maintain the lever K in the position shown in Fig. 12 when the gun is
fired. It will be seen that not only does the lever have a longitudinal movement
on its fulcrum K¹, but that it is rotated thereon by the screw K³ as the circular
plate E is rotated, its two extreme positions being shown in Fig. 12 in full and
dotted lines. This lever is further provided with extensions K³, having on their
adjacent faces inclined lugs k, arranged as shown and adapted to engage the
head of the primer P, as the lever K is moved upward and to force the primer
out of position ready to receive a fresh primer. The inner edge of the lever
adjacent the primer is also inclined, as at k¹, so that as the lever K is returned
to its normal full line position it engages the fresh primer put in place and insures
its being forced home to its normal position ready for firing.
Also carried by the lever K is the firing attachment L, which may be of any
usual or preferred construction, either electrical or mechanical. As shown it
comprises a pin L¹, mounted in an adjustable case L², but insulated therefrom
and pressed forward by a spring L³, and having an electre conductor L, con-
nected therewith, being adapted for electric firing. If, however, a mechanical
fuse or primer is used this can be replaced by the ordinary mechanical device.
Having now briefly described the general construction and arrangement of
the parts the operation will be largely understood therefrom by those skilled in
the art and may be briefly described as follows:
The parts being in the positions shown in Figs. 1, 2 and 3, the lever G, is
swung rearward and laterally and the sector, H2, of the operating pinion being
in engagement with the rotating gear sector F', the breech-block is rotated suffi-
ciently to disengage the interrupted screws and is thereby unlocked when the
teeth of the operating pinion engage the teeth e¹ of the extension E¹, of the
circular plate E, and produce a longitudinal movement of translation of the
block sufficient to withdraw the plastic pad from the bore of the gun. In doing
this the extension B of the breech-block moves through the opening in the
breech-block carrier and the inwardly extending ring or flange 12 passes into
the groove 12 of the breech-block. As the movement of translation is accom-
plished the locking bolt I operates to secure the block in the carrier, and on a
further movement of the operating lever G the breech-block is swung outward
and laterally away from the breech. In order that this may be done without
friction the block and the screw box of the breech are cut away slightly at
points ab, as best indicated in Fig. 1. Meanwhile, as the breech-block was
rotated the screw K has operated the lever K, causing the lugs to engage the
head of the primer P, and extract the same.
When the new charge is in place a reverse movement of the lever G first
swings the breech block within the screw box, then the teeth h¹, co-operating
with the teeth e, produce the necessary movement of translation to force the
plastic pad into the bore of the gun and a further movement of the lever through
the medium of the sector engaging the rotating gear sector turns the block
to lock the same and produce the final longitudinal movement. In doing this
the lever K is restored to its normal position, its inclined face ¹, forcing the
fresh primer P into position and bringing the firing pin into proper relation
therewith to operate the gun, and the end of the lever K engages the blow back
latch K
It will be seen that these operations are very simple yet positive and effective;
and that the longitudinal movement of translation of the breech-block is relatively
small and yet sufficient to allow the use of the plastic pad or gas-check. It will
further be seen that it is impossible to fire the gun until the parts are firmly
in their normal positions and completely locked, as the firing pin is not brought
into operative position until the breech-block is screwed home.
It will further be observed that all the parts are simple of construction and
not liable to get out of order; and that the gearing is properly housed and
protected from injury, but if perchance it should be injured it is only necessary

page_text: to remove the circular plate E, and repair the same or substitute another, and
the whole apparatus has been found exceedingly effective and satisfactory in
its operation. Furthermore, the rotating and translating devices are outside of
or beyond the elements of the gun.
It is evident that the extensions E and F, of the circular plate may be joined
together at their adjacent sides so as to more fully house the gear. It may be
observed that in a breech mechanism having 45° angular motion to disengage the
interrupted threads the last tooth on the sector may be omitted so that the sector
is less than a quadrant.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is―
1. The combination with a breech-block carrier having an opening, of a
breech-block having an extension sliding in said opening, a circular plate attached
to said extension, said plate having two sets of teeth, and means co-operating with
said teeth for rotating and translating the breech-block, substantially as
described.
2. The combination with a breech-block carrier having an opening, of a breech-
block having an extension sliding in said opening, a circular plate attached
to said extension, said plate having two sets of teeth formed and housed thereon,
and means co-operating with said teeth for rotating and translating the breech-
block, substantially as described.
3. The combination with a breech-block carrier having an opening, of a
breech-block having an extension sliding in said opening, a circular plate
attached to said extension, said plate having an extension provided with a tooth,
and a gear sector provided with teeth on its inner face, all the teeth being
housed, and means co-operating with the teeth for rotating and translating the
breech-block, substantially as described.
4. The combination with a breech-block carrier having an opening, of a breech-
block having an extension sliding in said opening, a circular plate attached
to said extension, said plate having two sets of teeth formed and housed thereon,
an operating pinion provided with spur teeth, and a gear sector co-operating with
the teeth on the circular plate to translate and rotate the breech-block, sub-
stantially as described.
5. The combination with a breech-block carrier having an opening, of a breech-
block having an extension sliding in said opening, a circular plate attached
to said extension, said plate having two sets of teeth formed and housed thereon,
an operating pinion attached to the block-carrier and provided with spur teeth,
and a gear sector co-operating with the teeth on the circular plate to translate and
rotate the breech-block, all the teeth being housed by the plate, substantially as
described.
6. The combination with a breech-block carrier having an opening, of a breech-
block having an extension sliding in said opening, a circular plate attached
to said extension, said plate having two sets of teeth formed and housed thereon,
and an operating pinion provided with two sets of teeth co-operating with the
teeth on the circular plate to translate and rotate the breech-block, the rotating
and translating devices being outside of and beyond the elements of the gun,
substantially as described.
7. The combination with a block-carrier, of a breech-block provided with
interrupted screw-threads, and having a rotating rack-plate provided with
gear-teeth, the pitch-line of the gear-teeth inclining inwardly equal to the pitch
of the screw-threads on the breech-block, substantially as described.
8. The combination with a block-carrier and breech-block rotating and sliding
therein, of an automatic extractor comprising a lever connected to and operated
by the breech-block, and a movable fulcrum connected to the carrier for said
lever, substantially as described.

page_text: 9. The combination with a carrier and breech-block rotating and sliding
therein, of an extractor comprising a slotted lever, a movable fulcrum therefor,
and a stud connected to the breech-block and engaging the slot in the lever
for operating the same, substantially as described.
10. The combination with a carrier and breech-block rotating and sliding
therein, of an extractor comprising a slotted lever, a movable fulcrum for the
lever, a stud connected to the breech-block and engaging the slot in the lever, and
a firing attachment mounted on the lever, substantially as described.
11. The combination with a breech-block, of an automatic extractor comprising
a lever having extensions provided with oppositely inclined lugs for engaging the
primer to extract the same or force it into position, substantially as described.
12. The combination with a block-carrier and a breech-block sliding therein, of
an automatic extractor movably attached to the block-carrier and moved in and
out with and operated by the breech-block, substantially as described.
13. The combination with a block-carrier and a breech-block sliding therein,
of an automatic loader and extractor having a longitudinally movable fulcrum
on the block-carrier and connected to be operated by the breech-block, sub-
stantially as described.
14. The combination with a block-carrier and a breech-block sliding therein,
of an automatic extractor provided with a firing-pin and moved in and out with
and operated by the breech-block, substantially as described.
15. The combination with a block-carrier and a breech-block sliding therein,
of an automatic extractor provided with a firing-pin, and means for positively
locking the extractor on opposite sides of the firing-pin, substantially as described.
16. The combination with a block-carrier and a breech-block sliding therein,
of an automatic extractor movably fulcrumed on the block-carrier and provided
with a firing-pin, and connections between the breech-block and extractor
whereby the latter is operated by the breech-block and locked when in position
for firing, substantially as described.
17. The combination with a block-carrier, of a breech-block, an automatic
loader and extractor comprising a lever movably fulcrumed on the block-carrier
and having a slot, a stud on the breech-block engaging the slot to operate the
lever, and a lock on the breech-block adapted to engage the free end of the lever
when in position for firing, substantially as described.
18. The combination with a block-carrier, of a breech-block, an automatic
loader and extractor comprising a lever movably fulcrumed on the block-carrier
and having a slot, a firing-pin mounted on the lever, a stud on the breech block
engaging the slot to operate the lever, and a lock on the breech-block adapted to
engage the free end of the lever when in position for firing, substantially as
described.
19. In a breech mechanism, the combination with a lever having a squared
opening therein, of an operating-pinion carrying rotating and translating gear-
teeth and having a squared extension fitting the opening in the lever, sub-
stantially as described.
20. In a breech mechanism, the combination with a lever having a squared
opening therein, of an operating-pinion carrying rotating and translating gear-
teeth and having a squared extension fitting the opening in the lever, and a
pivot passing through the operating-pinion and holding the pinion and lever
in place, on the block-carrier, substantially as described.
21. The combination with a block-carrier, of a breech-block having a central
rearward extension formed integrally thereon passing through the block-carrier,
and devices whereby the breech-block may be rotated and translated attached
to the outer end of said extension, substantially as described.
22. The combination with a block-carrier having an opening and an inwardly-
projecting flange, of a breech block having a central rearward extension formed
integrally thereon passing through the opening and having a groove receiving
the flange of the block-carrier, a plate attached to the outer end of said extension,

page_text: said plate being provided with devices whereby the breech-block may be rotated
and translated, and means co-operating with said devices, substantially as
described.
Dated this 12th day of June 1899.
PHILIP M. JUSTICE,
Chartered Patent Agent, London, For the Applicant.