Improvements in and relating to Breech mechanism for Ordnance.
Year: 1897

page_text: Date of Application, 29th Nev., 1897
Complete Specification Left, 29th Aug., 1898 -Accepted, 29th Oct.. 1898
PROVISIONAL SPECIFICATION.
Improvements in and relating to Breech mechanism for Ordnance.
I, ROBERT MATTHEWS, Engineer, of Sir W. G. Armstrong Whitworth & Co.,
Ltd., of Openshaw, Manchester, in the County of Lancaster, do hereby declare the
nature of this invention to be as follows:-
This invention relates to mechanism for opening and closing the breech of a gun
provided with a swinging breech-block and has special reference to guns in which
the breech-block is a conical or taper plug with continuous or uninterrupted screw-
threads. The chief object of my invention is to so construct the mechanism that
the opening and closing of the breech-block can be effected with great rapidity
and with a very advantageous manner of applying the power for operating the
mechanism.
I hinge to a ring mounted on the breech end of the gun, a swinging carrier which
according to my invention is provided with an inwardly projecting support for the
breech-block, such support being co-axial with the breech-block so that the latter
can rotate and slide thereon. The breech block is of conical formation and has
suitably shaped external screw threads to engage with the screw threads in the
breech of the gun. It is likewise formed with internal screw threads to engage
with corresponding threads on the aforesaid support. The said external threads
may be of buttress or other formation with clearance at the bottom so that with
a few turns of the block they become clear of the breech threads and permit the
block, by a continued rotary movement, to be withdrawn from the breech by the
action of its internal threads on the threads of the block support. If preferred, I
may employ instead of the threads on the said block support, small rollers working
in spiral grooves having an increasing pitch so as to cause a rapid withdrawal of
the block during the last part of its rotary movement; or the threads on the said
support may be of a quicker pitch than that of the external threads of the block,
the threads on the block being so formed and arranged that the holding faces are
always in contact until the threads clear.
The breech block has on its outer end a neck or shank provided with elongated
gear teeth which engage with a series of pinions arranged circularly around the
said neck with their axles mounted in a rotative ring or rings. Arranged con-
centrically around and external to the said ring or rings is another rotative ring
having internal teeth which gear with the aforesaid series of piuions.
These two rings are connected by pivoted rods or links to a double crank or
eccentric in such a manner that when the breech is closed the aforesaid rods or
links are at the dead centres and thereby effectually resist any tendency of the
block to unscrew and open when the gun is fired. The aforesaid double crank or
eccentric is mounted on an axle adapted to be operated by a hand wheel or lever
and bevel or other gearing. The said double crank or eccentric and the rods or
links are so disposed that the toothed ring will be caused to turn in an opposite
lirection to that of the ring carrying the series of pinions, during the opening or
closing movement of the breech block, so that the said series of pinions will receive

page_text: a rapid and very powerful rotary movement about their axes in actuating the
breech block.
The aforesaid pivoted levers may be connected to the rings at points situated
diametrically opposite to each other when the breech is closed, and the position of
the links is then such that they form the sides of a triangle whose apex is at the
centre or axis of the double crank. It will be obvious that if necessary extra power
for actuating the breech block by these links can be obtained by setting one link
a little out of centre on the principle of the Napier brake, but with the links
arranged as herein before stated, that is to say on the principle of the Stanhope
levers sufficient power will be available for easily operating the block at the point
of opening or closing the breech.
When the said links are connected to the two rings at points diametrically
opposite as above stated, they are both in tension when opening the breech block.
They may however be connected to the said rings at points adjacent to each other
with the opposite ends of said links connected to crank arins projecting from
opposite sides of the axle. In this case as one link will be in tension and the other
in compression, less power will be lost in friction than in the first described arrange-
ment, owing to the balancing tendency of the stresses.
When my improved mechanism is applied to small guns I may dispense with
worm gearing for working the double crank or eccentric and operate the axle by
means of a suitable lever on a vertical shaft.
I do not confine myself to the use of the means above stated for manually actuat-
ing my improved mechanism as any appropriate means may be employed, and if
necessary, hydraulic, electric or other power may be employed for actuating the
breech mechanism.
The outer periphery of the aforesaid internally toothed ring may be adapted
to turn upon an interior circular surface on the carrier. Or the said ring may be
provided with rollers or ball bearings.
Suitable locking bolts are provided to prevent the carrier from being swung
open before the breech-block has been fully withdrawn and to prevent the rotation
of the breech-block until the said carrier has been brought completely home against
the gun in closing the breech.
Safety arrangements are also provided to prevent firing until the breech is
securely closed.
Auxiliary hand levers may be provided for use in assisting in starting the move-
ment of the block in the event of any fouling of the obturator or of the block-
ihreads.
T71 9041. ....
1007
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
COMPLETE DIECIFICATION.
Improvements in and relating to Breech-mechanism for Ordnance.
I, ROBERT MATTHEWS, Engineer, of Sir W. G. Armstrong Whitworth & Co.,
Ltd., of Openshaw, Manchester, in the County of Lancaster, 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 to mechanism for opening and closing the breech of a
gun provided with a swinging breech-block and has special reference to guns in
which the breech-block is a conical or taper plug with continuous or uninterrupted

page_text: screw-threads. The chief object of my invention is to so construct the mechanisın
that the opening and closing of the breech can be performed with great rapidity
and with a very advantageous manner of applying the power for effecting such
operation.
According to my invention hinge to the breech-end of the gun a swinging
carrier in which the screw-threaded conical breech-block is so mounted on a screw
threaded or similarly constructed support forming part of the carrier, that when
the said block is rotated it slides longitudinally thereon in opening or closing the
breech. The rotary movement is imparted to the breech-block by toothed gearing
comprising a circular series of pinions carried by a pair of rings serving as a
rotary frame therefor, the said pinions engaging with elongated teeth on a neck
or shank formed on the breech-block and likewise engaging with an internally
toothed ring circumferentially arranged with respect to the pair of other rings
carrying the pinions. The aforesaid rings are connected by pivoted rods or links
to a double crank in such a manner that when the breech is closed, the aforesaid rods or
links are at the dead centre of the crank's movement and thereby effectually resist
any tendency of the block to unscrew and open when the gun is fired. The afore-
said double crank is mounted on an axle adapted to be operated by a hand wheel or
lever and bevel or other gearing which is so arranged that in opening the breech
after the withdrawal of the breech block, the continued movement of the said hand
wheel will cause the carrier to be swung open, and the closing of the breech will
be effected by the continuous movement of the handle in the reverse direction.
The said double crank and the rods or links are furthermore so disposed that the
circumferential toothed ring will be caused to turn in an opposite direction to that
of the rings carrying the pinions, during the opening or closing movement of the
breech block, so that the said pinions will receive a rapid and very powerful rotary
movement about their axes in actuating the breech block.
In order that my said invention may be clearly understood and readily carried
into effect I will proceed to describe the same more fully with reference to the
accompanying drawings in which:-
Figure 1 is an end elevation of the breech end of a gun provided with my
improved breech mechanism.
Figure 2 is a vertical transverse section of the same shewing the internal parts
of the mechanism in the position they occupy when the breech is closed.
Figure 3 is a horizontal section taken approximately on the line 1, 1, of Figure 2.
Figures 4 and 5 are similar views to Figures 2 and 3 but shew a slight modifica-
tion.
Figure 6 is a view similar to Figure 4, but shews a further modification.
In all of the figures like reference letters indicate similar parts.
A is the breech-block; B the swinging carrier; B¹ the support thereon for the
breech-block CC the circular series of pinions; D D the pair of rings carrying
such pinions E the internally toothed ring; and D' E' are the links connecting
the said rings with the double crank F.
The breech-block A is, as already stated. of conical formation with suitably
shaped external screw threads A' to engage with the screw threads in the breech
of the gun. It is likewise formed with internal screw threads a to engage with
corresponding threads on the support B¹. In the drawings I have shewn the
external threads A' of buttress formation, so that with a few turns of the block they
become clear of the breech threads and permit the block by its continued rotary
movement to be withdrawn from the breech by the action of the internal threads a
on the threads of the support B¹.
If preferred, I may employ instead of the threads 6 on the said support B', small
rollers working in spiral grooves having an increasing pitch so as to cause a rapid
withdrawal of the block during the last part of its rotary movement. Preferably
the threads b on the support 13 are of a coarser or quicker pitch than the external
threads of the block and are so arranged that the holding faces of the external
threads remain in contact with the threads in the gun until the threads are clear

page_text: of each other; the holding faces of the threads are thus subjected to a rubbing
action during both the opening and the closing of the breech which effectually
keeps them clean.
The aforesaid support B' projects from a disc B2 which is bolted or otherwise con-
nected to the swinging carrier in a position co-axial with the bore of the gun. The
carrier is also formed with a socket piece B³ between which and the support B an
annular space is left for the reception of the neck or shank A of the breech block.
This neck or shank is provided with elongated teeth a¹ for gearing with the
circular series of pinions CC which in turn gear with the internally toothed ring E
circumferentially arranged with respect to the said rings D and pinions C.
The said pinions are held in place between the pair of rings D D by short
axles ee which enter corresponding holes in the pair of rings.
The swinging carrier is constructed in the form of a casing so as to almost com-
pletely enclose the mechanism and is hinged to a ring B on the breech end of the
gun by a pin or axle G. This pin or axle is provided with a bevel pinion gear-
ing with another bevel pinion mounted on a short shaft G₁ arranged at right
angles to the axle G. The shaft G is also provided with a spur pinion g³ which
gears with a toothed segment f forming part of the double crank F, such segment
being furnished with an axle f¹ by which it is supported in bearings on the
carrier B.
The outer ends of the links D¹ and E' are connected to the double crank F at
points on opposite sides of the axle f¹, by means of pins d and e, while the inner
ends of the said links are connected by pins and el to the rings D and E respec-
tively. The relative position of the said pins and e¹, when the breech is
closed, is such that the revolution of the shaft G, by the hand wheel G2 and worm
gearing G, in a direction to open the breech, will cause the toothed segment f,
through the medium of the toothed gearing g¹², to partially rotate in the
direction of its arrow and the links D₁ and E¹ to be shifted in opposite directions,
whereby a pull will be exerted on the links D¹ and a push on the links E' as
indicated by the arrows thereon. By this operation the said links will be caused
to occupy the position represented by the dotted centre lines in Figure 2, the
bosses on the toothed segment being cut away at f³ to permit the links to assume
such position.
The aforesaid movement of the links will turn the rings D and E in opposite
directions and, through the intervention of the interposed pinions C that gear
with the elongated teeth of the breech block, the latter will receive a powerful and
rapid rotary movement which will cause it at the same time to slide on the sup-
port B until it is stopped by the portion coming against the inner end of the
said support B. Further rotary movement of the toothed segment and the
pinions will therefore be prevented and the continued revolution of the hand
wheel G will then cause the carrier to move with the axle G and swing open into
the position represented by the dotted lines in Figure 3.
A suitable locking bolt is provided to prevent the carrier from being swung open
before the breech-block has been fully withdrawn and to prevent the rotation of
the breech-block until the said carrier has been brought completely home against
the gun in closing the breech. I have shown a bolt for this purpose in the form
of a rotative piece having three arms 3 h3, the latter of which, viz., is adapted
to engage with a cavity or recess formed in a lug b¹ on the ring B. The other two
arms h¹³, are acted upon by a projection a³ on the breech-block to partially
rotate the bolt and cause it to assume its locked and unlocked positions. This
projection is so situated that when the breech-block has almost completed its
revolutions in being withdrawn from the breech, it arrives above the said arm h¹,
and as the block terminates its final revolution, acts upon and depresses the arm h¹.
The rotative bolt is thus turned about its pivot pin h a sufficient distance to bring
the arm into a position above the said projection and also to bring the arm h³
out of engagement with the recess in the lug b. The carrier is thus released and
allowed to swing open. On the carrier is a pin h which acts in conjunction with

page_text: the locking bolt. Such pin is provided with a spring h³ and a pin ho which latter
when the carrier is closed as represented in Figure 3 comes against the lug bland
keeps the said pin out of the path of the arm h³. When however the arin h³ is
disengaged and the carrier swings open, as aforesaid, the pin h is caused by its
spring to advance and bring its inner end beneath the said arm 3 so as to lock
the latter in its disengaged position. Any rotation of the breech block in either
direction so long as the carrier is open, is therefore prevented, by reason of the
projection a³ at such time lying between the two arms h³. When however the
said carrier is swung back again to close the breech, the pin his retracted by
its fin hcoming against the lug b Then the breech block in commencing to
rotate in the reverse direction to that which it performs in opening the breech,
brings its projection against the arm and by raising it causes the rotary bolt
to resume its original position with its arm in engagement with the said recess
in the lug b. The carrier is thus locked in its closed position until again released
by the projection a³ on the breech block as above explained.
Safety arrangements are also provided to prevent firing until the breech is
securely closed.
In Figures 4 and 5 I have shown the toothed segment of the double crank
provided with bevel teeth instead of ordinary spur teeth, the said segment gearing
directly with the bevel pinion y on the axle G. I thus dispense with the shaft Gi
and pinions illustrated in Figures 1 to 3 and thereby simplify this part of the
mechanism. I prefer however to employ the spur gearing shown in the preceding
figures as it enables a carrier of smaller radius to be employed.
In the construction of the mechanism hereinbefore described the links D' and E'
are shown connected to the said rings D and E at points d' and which are adjacent
to each other, while the outer ends of the said links are connected to the double
crank at points d and e on opposite sides of the axle f. This construction I prefer,
but if desired the links may be arranged in the manner indicated in Figure 6
wherein they are shown with their inner ends de' connected to the rings D and E
at points situated diametrically opposite to each other when the breech is closed,
while the outer ends d and e of the said links are both connected to the double
crank on the same side of the axle f' and adjacent to each other. The position of
the links is then such that they form the sides of a triangle whose apex is at the
centre of the double crank. When the said links are connected to the two rings
in this manner, they are both in tension when opening the breech block. It will
be obvious that if necessary extra power for actuating the breech block by these
links can be obtained by setting one link slightly out of the centre line between
the pin cor and the shaft on the principle of the Napier brake; but with
the links arranged as herein before stated, that is to say on the principle of the
Stanhope lever, sufficient power will be available for easily operating the block at
the point of opening or closing the breech.
When my improved mechanism is applied to small guns I may dispense with
worm gearing G for working the double crank and operate the mechanism by
means of a suitable lever on a vertical shaft.
I do not confine myself to the use of the means above stated for manually
actuating my improved mechanism as any appropriate means may be employed,
and if necessary, hydraulic, electric or other power may be utilized for the purpose.
The outer periphery of the aforesaid internally toothed ring E may be adapted
to turn upon a circular surface on the carrier as shown at 135 in Figure 6. Or the
ring may be furnished with ball bearings as shown at in Figures 3 and 5,
Auxiliary hand levers may be provided for use in assisting in starting the move-
ment of the block in the event of any fouling of the obturator or of the block-
threads taking place.
Having now particularly described and ascertained the nature of my said
invention. and in what manner the same is to be performed, I declare that what
I claim is:
1. A screw-threaded conical breech-block to which motion is imparted by a series

page_text: of pinions each of which is caused to revolve about its own axis simultaneously
with the concentric angular movement of the entire series about the axis of the
breech-block, for the purpose specified.
2. The combination with a screw-threaded conical breech-block of a series of
pinions carried by a pair of rotative rings and geared with teeth on the breech
block and with teeth on a circumferential ring, the said rotative rings and the
said circumferential ring being adapted to be moved angularly and simultaneously
in opposite directions for operating the breech block substantially as described.
3. The combination of the rods or links with the crank and rings for transmitting
motion in opposite directions to the latter substantially as and for the purpose
specified.
4. The combination with the conical breech block, of a screw threaded or spirally
grooved support whereby the said block is caused to slide longitudinally during its
revolution substantially as described and for the purpose specified.
The combination with the aforesaid breech block and the swinging carrier
of a locking bolt arranged substantially as described to operate as and for the
purposes specified.
6. Breech mechanism constructed and adapted to operate substantially as
described with reference to Figures 1 to 3, or Figures 4 and 5, or Figure 6 of the
accompanying drawings for the purposes specified.
1 1
L 1000
HASELTINE, LAKE & Co..
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.