Improvements in Breech-mechanism for Ordnance.
Year: 1893

page_text: Date of Application, 23rd Dec., 1893
Complete Specification Left, 19th Oct., 1894-Accepted, 24th Nov., 1894
Improvements in Breech-mechanism for Ordnance.
I, AXEL BREMBERG, 32 Victoria Street, in the City of Westminster, Engineer,
do hereby declare the nature of this invention to be as follows:-
My invention relates to breech-mechanism for ordnance and comprises the
improvements hereinafter described.
The chief feature of my said invention relates to the construction of the breech-
block which is formed with interrupted screw-threads arranged in spiral sections in
a well-known manner, but instead of having a tapering surface or a cylindrical
surface of uniform diameter throughout its whole length, it is according to my
invention made in steps, decreasing in diameter from the outer to the inner end
thereof, each part however between the steps being cylindrical in shape. There
may be two or more such cylindrical portions of different diameters, but in most
cases it will be found that two such parts, that is to say, one step about the middle
of the block, will be sufficient. The breech of the gun is of course also formed in
steps to suit the block. One of the plain spiral parts between the interrupted
screw threads is furnished with a spiral groove with which engages a pin fixed in
the carrier ring, in the now well known manner, so that when the breech-block is
turned, its screw-threads first become unlocked from those of the breech, and then
the continued rotation operates to withdraw it from the breech. Owing to the
peculiar construction of my improved block it is not necessary to withdraw the
block entirely from the breech as has heretofore been the case before it can be
rotated about the pivot of the carrier ring, but a partial withdrawal is sufficient, as
owing to the reduced diameter of the inner end of the block the turning movement
is possible after such partial withdrawal.
Another important feature of my invention relates to improved mechanism for
opening the breech during the running-out of the gun after recoil. For this
purpose provide on the rear end of the block a toothed segment which gears with
a long toothed pinion mounted on a shaft that extends rearwardly parallel with the
axis of the gun. Said toothed segment remains in gear with the pinion during the
to and fro axial movements of the block when opening and closing the breech.
Formed in one with or secured to the toothed pinion aforesaid is a bevel wheel
which gears with a similar wheel fixed on the hinge-pin, and on the hinge-pin is
also fixed a pinion which gears with a rack that is connected with a hydraulic
buffer device, comprising a piston working in a closed cylinder containing liquid
and having a non-return valve fitted to allow the liquid to pass freely in one
direction from one side of the piston to the other, but not in the other direction, the
liquid passing back during the return movement of the piston by way of a small
channel of varying area provided in the cylinder or preferably in a liner fitted
therein. The said closed cylinder is secured to a non-recoiling part of the
mounting. The piston rod works through a stuffing-box in the cylinder and is
suitably guided outside the cylinder. This mechanism operates as follows, that is
to say, when the gun recoils, the rack is drawn out by the pinion that gears
therewith, the non-return valve above mentioned opening to allow of the requisite
transfer of liquid from one to the other side of the piston. When the recoil is
complete and the running out movement commences, the aforesaid non-return valve
closes and prevents the liquid returning by way of the valve. The liquid thus
locked can then only return by way of the channel beforementioned and as this is
very small the rate at which the liquid can flow therethrough is limited. The

page_text: result is that the forward movement of the piston is retarded-and lags behind the
forward movement of the gun, whereupon the wheel in gear with the rack rolls on
said rack and thus operates to open the breech by turning the hinge pin thereof.
The first part of the movement unlocks the breech-block, the second part withdraws
it as far as necessary from the breech, and the third part swings the block and
carrier ring away from the breech. When the breech-block is fully open, it is
preferably held open by a suitable catch until it is required to be closed again.
This is effected by a spring that moves the rack forward again as soon as the
aforesaid catch is moved out of gear with the block, and thereby turns back the
hinge pin to its initial position, and closes the breech.
I provide the usual locking devices on the gun and carrier ring to ensure that
the various stages of the opening and closing movements shall take place in proper
sequence.
I also provide a system of hinged or pivoted links connected with the gun and
the carrier ring to limit the turning movement of the latter when opening. One of
said links is preferably formed with a long eye to allow of a certain amount of
play to ensure that the links shall not jam and lock the breech-block when the
latter is required to close.
The controlling channel in the closed cylinder before mentioned is preferably so
shaped that a comparatively large opening is provided for the escape of the liquid
at the point where the piston first presses against the liquid so as to reduce the
shock as much as possible. Afterwards it contracts very considerably to increase
the resistance sufficiently to ensure the opening of the breech, and then enlarges
gradually to the end, to reduce said resistance as required.
For smaller guns 1 sometimes provide for operating such a breech-block in
accordance with my invention a hand mechanism which comprises a bevel wheel
fixed to the rear of the breech-block and gearing with a second wheel also carried
by the breech-block but constructed with a bearing which slides to and fro in a
slot in the carrier ring, as the block moves in and out. Said slot is parallel with
the axis of the gun. I provide a handle for turning said wheel in either direction
as required to open and close the breech.
In a still simpler arrangement for a small field gun for example, the breech is
rotated by hand by means of a handle attached directly to the back thereof.
The above described improvements can obviously be applied to breech-blocks
having obturators.
Dated this 23rd day of December 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Breech-mechanism for Ordnance.
I, AXEL BREMBERG, of 32 Victoria Street, in the City of Westminster,
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 ordnance and comprises the
improvements hereinafter described.
The chief feature of my said invention is the provision of a screw breech-block
which, instead of having a uniformly tapering surface or a cylindrical surface of
uniform diameter throughout its whole length as heretofore is made with a stepped
surface, that is to say, a surlace which has a sudden change of diameter at one,
two or more places, the inner end being smaller than the outer end. Each part of
the breech-block between the steps is cylindrical in shape. There may be as

page_text: above indicated two or more such cylindrical portions of different diameters, but in
most cases it will be found sufficient for the purpose of my invention to have two
cylindrical portions only, that is to say, to have one step which will usually be
situated about the middle of the block. The breech of the gun is stepped in the
same manner to fit the block. Each part of the breech-block has interrupted
screw-threads arranged in helicoidal or spiral segments for engaging with corre-
sponding interrupted screw threads formed in the breech. This construction, allows
the breech to be opened and closed without requiring that the block shall be
entirely withdrawn from the breech before it can be turned about its hinge. For
example a block having one step as above described will be free to turn about its
hinge when it has been withdrawn about one half its length, whereas an ordinary
cylindrical block must be withdrawn the whole or nearly the whole of its length
before it can be turned about its hinge. It will thus be seen that my improved
construction of block facilitates the opening and closing of the breech by shortening
the time and lessening the labour necessary for performing one of the required
operations namely that one wherein the block is moved axially to withdraw it
from the breech or to insert it therein.
One of the plain spiral parts between the interrupted screw threads or each of
two or more of such plain parts is furnished with a spiral groove; one portion of
this groove has the same pitch as the screw threads of the block and another
portion has the same pitch as the spiral parts or sections of the block. The two
parts of the groove merge into each other. Fixed in the carrier-ring that supports
the block is a pin that projects into the aforesaid groove, and engages with the
sides thereof. When the breech-block is turned about its axis to open the breech
its screw-threads first become unlocked from those of the breech, and then the
continued rotation operates through the pin and groove to withdraw the block
from the breech in a manner that is now well understood. After the breech-block is
drawn back as far as necessary it is swung with the carrier-bracket clear of the
breech.
My invention also provides improved mechanism for opening the breech by
hand, and it also provides improved mechanism for opening it automatically during
the running out of the gun after recoil.
I will now proceed to describe my invention more fully with reference to the
accompanying drawings in which
Figure 1 is a plan of a breech-block constructed according to my invention.
Figure 2 is a rear elevation, and
Figure 3 is a horizontal central section, of the breech end of a small gun fitted
with my improved block.
Figures 4 and 5 are views similar to Figures 2 and 3 but showing breech
mechanism intended for a larger gun; the open position of the block is indicated
by dotted lines in Figure 5.
Figure 6 is a plan, and
Figure 7 is a rear elevation, partly in section, showing a modified form of
breech-mechanism adapted for my improved block.
Figure 8 is a rear elevation, and
Figure 9 is a side elevation of the breech end of a gun fitted with a further
modified form of breech mechanism adapted for my improved block, the same being
shown in section in the latter figure.
Figure 10 is a side elevation of the breech end of a gun fitted with my improved
mechanism, shown partly in section for automatically. opening the breech during
the running out of the gun after recoil.
Figure 1 is a rear view of the same.
Figure 12 is a plan of the same, showing by dotted lines the position of the
breech-block when open.
Figure 13 is a section of the non-recoiling frame, taken on the line x, x of
Figure 10.
Figure 14 is a detail, partly in section, hereinafter described.

page_text: Figure 15 is a side elevation partly in section of similar mechanism to that
shown by Figure 10 but provided with means for opening the breech by hand.
Figure 16 is a plan of the same showing the parts in the positions they occupy
when the breech has been opened by hand.
Like letters of reference denote corresponding parts throughout the drawings.
A is the breech-block; C is the carrier-ring or bracket hinged on the pin D ;
E is the handle for operating the block.
The block A shown in the drawings has two cylindrical parts A¹ A² the inner
or forward part being smaller than the outer or rear part for the purpose above
specified. The breech-chamber is constructed to fit the block. Both parts of the
block are furnished with interrupted screw-threads arranged in spiral sections or
segments. In each of two or more of the plain spiral sections or segments of the
large end of the block is formed a spiral groove F. The forward portion of the
said groove is parallel to the centre line of the said plain spiral section, that is
to say, it has the same pitch as the said section, and the rear portion of the groove
has the same pitch as the screw-threads.
The inner circumference of the carrier-ring C is furnished with pins or studs G
Figures 3, 4 and 8 which project into the grooves F, that is to say, one pin or
stud projects into each groove F and engages with the sides of the said groove.
During that part of the rotation of the block which is necessary to lock or unlock
the block, the pins G are in engagement with the rear parts of the grooves F, and
t other times during the opening and closing of the breech they are in engagement
with the forward parts of the grooves, as is well understood. The forward part of
each groove F is sufficiently long to permit the block to move axially for a distance
equal to about half of the length of the block, although in some instances a shorter
movement than this will suffice to allow the block to clear the breech when turned
with the carrier-ring about the hinge pin.
Figures 2 and 3 show my improved block applied to a small gun. The operating
handle E is secured directly to the rear end of the block. By raising the handle
from the lowest to the highest position shown in Figure 2 and thus turning the
block the latter is first unlocked, and then partially withdrawn; a pull on the
handle will then cause the block to swing with the carrier-ring or bracket clear of
the breech. The four positions of the handle corresponding with (1) the block
locked, (2) the block unlocked, (3) the block unlocked and partially withdrawn,
and (4) the block swung clear of the breech are indicated in Figures 2 and 3. The
mechanism is provided with the usual locking devices to ensure that the block shall
not be turned about its axis while out of the breech and that the carrier-ring shall
be locked to the gun as long as the block is not withdrawn sufficiently to clear
the breech. The handle is also furnished with the usual locking catch to prevent
accidental movement thereof.
The block will as before stated clear the breech when rotated about the hinge-
pin after it has been withdrawn from the breech for about half its length. This
result is made possible by the smaller part of the block being then situated in the
larger part of the breech. The hinge pin is preferably placed well forward as
shown in Figure 3.
In Figures 4 and 5 I have shown a block having an extension at its rear end
ou which extension are formed a number of teeth H, but in other respects the block
is constructed as above described. The operating handle E is in this case mounted
to turn freely on the binge pin D and is formed with, or rigidly connected to, a
bevelled toothed wheel or sector J. With this sector there gears another toothed
sector or wheel K which is supported by the carrier bracket and which is rigidly
connected with a third toothed sector or wheel L. The latter is in gear with the
teeth H of the breech-block. When the handle E is drawn backwards it operates
through the gearing above described to turn the block as far as it will go, thus
unlocking and partially withdrawing it, and then turns the block and carrier-ring
together about the hinge pin away from the breech. The teeth H are sufficiently
long to allow the block to slide in and out of the breech while remaining in gear

page_text: with the sector L. The positions of the handle and block when the breech is
fully open are indicated by dotted lines in Figure 5. The part ƒ of the groove F
(see Figure 5) allows the block to enter the carrier ring and be withdrawn
therefrom when required.
The mechanism shown in Figures 6 and 7 is combined with a breech-block similar
to the block shewn in Figures 1, 4, 5 but having right handed screw threads.
This mechanism is applicable for larger guns and comprises a rack M which gears
with the teeth H and which can slide transversely to the axis of the gun in a
part of the carrier-bracket prepared to receive it. The rack is connected by a
link N to an arm which is secured to the hinge pin D. P is a worm wheel also
secured to or formed on the hinge pin. The said worm wheel is driven through
the worm P, and shaft P2 by the handle E. The worm, worm-shaft, and operating
handle are omitted from Figure 6. The dotted lines in this figure indicate that
the block is furnished with an obturator two positions of which are shown, viz. one
when the block is fully home in the breech, and the other when the block is partially
withdrawn and ready to be swung clear of the breech.
In the mechanism shown in Figures 8 and 9 the handle E is mounted to turn
loosely on a vertical pin Q which is carried by a piece Q' that is fitted into a
recess Qin the rear end of the block. Q³ is a tooth or projection which is formed
on the periphery of the piece Q' and which engages with an annular groove Q in
the block. This tooth ensures that the breech-block and piece Q shall not be
separated when moving axially, and allows the block to turn while the piece Q¹
remains stationary. The lower end of the pin Q projects into a slot C' formed in
a projection C2 of the carrier ring and is furnished with a loose sleeve Q. The
slot is parallel to the axis of the breech-block. Formed with or secured to the
haudle E is a bevelled toothed sector R which gears with another toothed sector R'
formed on or secured to the rear end of the breech-block. The latter sector is
furnished with a rearwardly extending central projection R2 that forms an internal
bearing for the piece Q. The operation of this mechanism is as follows, that is to
say, when the handle E is pulled rearwardly, the block is first rotated through the
gearing R, R', and unlocked from the breech; then while continuing its rotation it
is withdrawn by the pins or studs G which at such time engage the forward parts
of the grooves. During these movements the pin Q slides in the slot C'; then,
when the block is sufficiently withdrawn and the carrier-ring is unlocked the continued
pull on the handle turns the block and carrier-ring about the hinge piu clear of the
breech.
My improved mechanism for opening the breech automatically during the running
out of the gun after recoil shown in Figures 10 to 16 is as follows. The carrier
bracket C, rack M, link N, and arm O are similar to the corresponding parts above
described with reference to Figures 6 and 7. But in lieu of the worm wheel P in
Figure 7 employ a spur pinion S which gears with a rack S¹ connected with the
piston rod T of a hydraulic brake apparatus. The cylinder T of the said apparatus
is secured to or formed on a non-recoiling part of the mounting and is filled with
liquid. T is a spring, compressed between the rear end of the cylinder T¹ and
the piston T3. A portion only of this spring is shown. T' is a non-return valve
fitted to the forward face of the piston and controlled by a spring To which is
compressed between the valve and a collar T° on the piston rod. T°, Te are
apertures in the piston, which apertures are closed by the valve T when the latter
is on its seat. T7 is a channel or groove formed in the side of the cylinder. This
groove or channel may be conveniently provided as follows, that is to say, the
cylinder may be furnished with a thin lining T which lining is slotted at T7 to
form the channel. The channel is much wider at each end than at the middle
for a purpose hereinafter specified. U is a part of the non-recoiling frame in
which are formed the cylinders U, U to receive the recoil buffers or brake as
shown in Figure 13, and the cylinder T' above described. U2, U Figure 10 are
spring buffer casings.
This mechanism operates as follows, that is to say, when the gun recoils, the

page_text: rack S' recoils therewith by reason of its being in gear with the pinion S that
cannot turn in the direction it would be required to do to allow the rack S' to
remain stationary during the recoil of the gun. The rod T is thus drawn out of
the cylinder and its piston T3 compresses the spring T2. During this movement
of the rod the valve T' opens to allow the liquid to pass freely from the rear to the
forward side of the piston through the apertures T. When the recoil energy is
expended and the running out movement commences under the action of the recoil
springs, the valve T immediately closes and prevents the liquid from returning
through the piston. The liquid thus retained can then only return by way of the
channel T' and as this passage is a small one the liquid can only flow through it
slowly, consequently the forward movement of the piston is retarded relatively to
the forward movement of the gun, whereupon the pinion S travels along the rack
and is rotated in the proper direction for opening the breech in the manner described
with reference to Figures 6 and 7. When the gun has run out and the breech is
fully open the piston T will be about at the middle of the channel T' and the piston
if free would then by the pressure of the spring T2 continue to move forward and
would close the breech. It is however necessary to prevent such action. until the
gun is loaded and for this purpose I provide a catch V Figure 14 carried by the
gun or other recoiling part and a number of notches V₁ formed in the lower side
of the rack S with one or other of which notches the catch V engages when the
breech is opened. The catch thus operates to lock the rack and prevent the forward
movement of the latter till the catch is again raised. V is a handle secured to
the rod or spindle V3 on which the catch is mounted. V is a spring that
keeps the handle depressed. To release the rack S' it is necessary to raise the
handle V2, whereupon the spring T2 will operate to close the breech as above
described.
The controlling channel T7 affords a comparatively large opening for the escape
of the liquid at the commencement of the running out and so avoids unnecessary
shock. The gradual contraction of the channel towards the middle affords an
increasing resistance sufficient to control the opening of the breech as above
described and these variations of cross sectional area serve to regulate the speed at
which the breech will close under the influence of the spring T
To limit the opening movement of the breech-block provide a pair of hinged
or pivoted links W, WI connecting the carrier-bracket to the breech. The block
can swing back until these links are fully extended as shown by the dotted lines in
Figure 12 and by full lines in Figure 16. The end of the link W is slotted at W
as shown, and the end of the link. W is furnished with a heel piece Ws to engage
with the end of the gun and prevent the link W₁ from swinging outward too
far. By this construction I ensure that the links will not lock the breech-block
when the latter is required to close and will always fold in the proper direction.
In Figures 15 and 16 I have shown a construction by which the breech can be
opened by hand as well as automatically. The mechanism for opening it auto-
matically is similar to that shown in Figures 10 to 12. In this case however the
rack S is not fixed to the piston rod T, the latter being made hollow and screw
threaded internally, and the rack having a screw threaded extension S² which
screws into the rod. Upon the rear end of the hollow rod I loosely mount a
handle S3 which is furnished with a catch or pawl of any suitable construction and
adapted to engage with teeth formed on the rod in such a manner that by working
the handle backwards and forwards by hand the rod T can be rotated in either
direction and the screwed part S2 of the rack S¹ moved in or out. By these means
the breech can be opened by hand.
I sometimes make the large part A' of the block somewhat longer than the small
part A, and I then cut away the corners of the screw threads of the large part A¹
as shown at a, and also the corresponding corners of the screw threads of the breech
so that the block may swing clear of the breech when it has been withdrawn a
distance equal to the length of the small part A'. By this means I reduce slightly
the axial movement of the block.

page_text: 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. A breech-block baving two or more cylindrical parts of different diameters,
and furnished, on each cylindrical part, with interrupted screw-threads arranged in
spiral sections, substantially as, and for the purpose specified.
2. Such a breech-block having grooves F in the plain spiral parts of the block,
and teeth H in the rear part of the block, substantially as, and for the purpose,
specified.
3. The combination with such a breech-block of a segment wheel secured thereto
and gearing with another wheel carried by a part which is connected with the block
and slides longitudinally in a slot in the carrier-bracket as the breech-block moves
in and out of the breech, substantially as described with reference to Figures 8 and 9
and for the purpose, specified.
4. The apparatus described with reference to Figure 10 for opening the breech
automatically during the running out of the gun after recoil.
5. The combination with the said hydraulic apparatus of the means for
keeping the breech open until it is required to be closed, substantially as
described.
6. The combination with the carrier bracket of the hinged or pivoted
links W, W constructed and operating substantially as described and for the
purpose specified.
7. A gun provided with breech-mechanism constructed substantially as described
with reference to Figures 2 and 3, or to Figures 4 and 5, or to Figures 6 and 7,
or to Figures 8 and 9, or to Figures 10 to 16, and operating as, and for the purposes,
specified.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.