Improvements in the Breech Mechanism of Guns.
Year: 1894

page_text: Date of Application, 11th July, 1894
Complete Specification Left, 26th Mar., 1895-Accepted, 13th Apr.. 1395
PROVISIONAL SPECIFICATION.
Improvements in the Breech Mechanism of Guns.
I, AXEL WELIN, of 9 London Street, in the City of London, Mechanical
Engineer, do hereby declare the nature of this invention to be as follows:
In opening the breech of a gun it requires much more force to start the breech
block than it does to continue to unscrew it and similarly when the block has been
unscrewed it requires more force to begin to draw it rearwards than it does to
continue the motion.
Nevertheless in most existing mechanisms substantially the same leverage is
obtained throughout the motion and it therefore takes an unnecessarily long time to
open the breech.
The primary object of my invention is to remedy this defect.
I turn and unscrew the breech block by a slide or pusher tangential to it the
leverage employed for traversing the slide diminishing when the block has been
started. For this purpose I provide near one end of the slide a roller working in a
suitably formed cam groove in a worn wheel actuated by a worm on the axis of
the haudle; or the groove may be in the slide and the roller on the wheel. The
other end of the slide has a notch in it to receive a projection or tooth on the breech
block.
When the block has been completely unscrewed it is drawn rearwards in its
carrier ring (as hereinafter described) the projection escaping from the notch..
During this time and until the block returns the slide is held stationary although
the worm wheel continues to turn as the portion of the cam now in operation is
circular so that the notch is in the proper position to receive the tooth or projection
when the breech is being closed again.
The shaft of the worm wheel is co-axial with the hinge about which the carrier
ring of the breech block swings, it has fixed to it an arm which during the first
part of the motion travels in a slot in the rear end of the gun. The end of this
arm carries a roller which when the breech block has been unscrewed as above
described, enters a slot in it. This slot is so arranged that at this time it is
tangential or nearly so to the path of the roller, the result beiug that the breech
block is at first very slowly drawn back in its carrier ring. This movement
however makes the slot assume a less and less tangential direction until at last it is
radial or nearly so and therefore the speed of withdrawal continuously increases.
When the breech block has been drawn fully back in its carrier ring the latter is
unlocked (as hereinafter described) and the further rotation of the worm wheel and
arm causes the ring with the block to swing about its axis.
The carrier ring has pivotted to it a lever having a hook at its end which takes
into a notch on the rear end of the gun. The lever carries a roller bearing on a
circular table fixed to the axis of the worm wheel and the hook is thereby kept in
the notch. There is however a depression in the table which comes beneath the
roller just as the breech block has been fully withdrawn and the roller is forced
down into it by the continued motion of the worm wheel the hook and notch being
suitably inclined to produce this result:-the carrier ring is thereby unlocked and
now revolves with the axis of the worm wheel the roller remaining in the depression.
In closing the breech just as the return motion of the carrier ring is completed the .

page_text: roller comes against and rides up a hinged incline so causing the hook to engage
with the notch again locking the carrier ring. The incline being hinged drops
down out of the way when the breech is being opened.
1, AXEL WELIN, of 9 London Street, in the City of London, Mechanical
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 :-
In opening the breech of a gun it requires much more force to start the breech
block than it does to continue to unscrew it and similarly when the block has been
unscrewed it requires more force to begin to draw it rearwards than it does to
continue the motion.
Nevertheless in most existing mechanisms substantially the same leverage is
obtained throughout the motion and it therefore takes an unnecessarily long time to
open the breech.
The primary object of my invention is to remedy this defect.
Figure 1 is a rear elevation of the gun the breech block being unscrewed but not
swung back.
•
Figure 2 is a side elevation and Figure 3 a longitudinal central section of the
same.
In the latter figure the position of the breech block when swung back is also
shown in dotted lines.
Figures and 5 are an elevation and plan (partly in section) of some of the parts
to a larger scale showing the positions when the breech is closed and
Figures 6 and 7 are similar views with the parts in the same positions as in
Figures 1 to 3.
Figure 8 shows some of the parts to a larger scale.
The breech block a is unscrewed by the tangential slide which has a notch b¹
engaging with a single tooth aon the block and the leverage employed for
traversing the slide diminishes when the block has been started. For this purpose
the slide is slotted at 3 to receive a roller cl pivotted on the worm wheel c which is
actuated by the worm d¹ on the axis of the handle.
It will be observed that when the breech is closed as shown in Figure 5 the
slot is almost tangential to the path of the roller c' and therefore in opening the
breech the slide is at first moved very slowly and with great leverage but as
the breech block is turned the leverage decreases and the speed increases until at last
as shown in Figure 7 the slot is almost radial to the path of the rollers c¹. When
the block is fully unscrewed the roller c' escapes from the slot but the slide b is'
prevented from moving back again by the circular surface c on the worm wheel e
which now comes against the circular shoulder * on the slide b. The slide bis
therefore held fast until in closing the gun the surfaces and b³ disengage and the
roller c' again enters the slot b². It will be obvious that the roller might be on the
slide and the slot in the worm wheel.
The shaft of the worm wheel is co-axial with the hinge e¹ about which
the carrier ring e of the breech block a swings, it has fixed to it an arm c
which during the first part of the motion travels in a slot in the rear end of
the gun.
The end of this arm carries a roller cx which when the breech block a
has been unscrewed as above described enters a slot a³ in it as shown in Figures 3.
and 7. This slot is so arranged that at this time it is tangential or nearly so
:

page_text: to the path of the roller, the result being that the breech block is at first very
slowly drawn back in its carrier ring. This movement however makes the slot
assume a less and less tangential direction until at last it is radial or nearly so
and therefore the speed of withdrawal continuously increases. When the breech
and
block a has been drawn fully back in its carrier ring e the latter is unlocked
(as hereinafter described) and the further rotation of the worm wheel
arm c causes the ring with the block to swing about its axis.
The carrier ring e has pivotted to it at en lever e (Figure 2) having a hook e*
at its end which takes into a notch a³ on the rear end of the gun. The lever
carries a roller e bearing on a circular table c³ fixed to the axis of the worm wheel
and the hook is thereby kept in the notch. There is however a depression c* in the
table which comes beneath the roller just as the breech block has been fully
withdrawn and the roller is forced down into it by the continued motion of the
worm wheel the faces of the hook e and notch a being suitably inclined to produce
this result; the carrier ring e is thereby unlocked and now revolves with the axis
of the worm wheel the roller e remaining in the depression c. e is a lever pivotted
at e' in a recess in the carrier ring. When the breech is closed its tail end bears
against a projection a' at the rear of the gun but directly the carrier ring begins
to come away from the breech it drops down into the recess allowing the roller e
to fall into the depression e as above described. In closing the breech the
reverse motions take place; when the carrier ring comes against the gun the
lever is raised lifting the roller e out of the depression c and causing the hook e¹
to engage with the notch a'.
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. Breech mechanism in which greater leverage is obtained both when beginning
to unscrew the breech block and when beginning.to draw the breech block rear-
wards in its carrier ring than subsequently.
2. The combination of the slide b, slot 6, roller and wheel e substantially as
described.
3. The combination of the breech block a slot a² and arm c substantially as
described.
4. Locking the carrier ring to the breech by means of a hooked lever held up by
a rotating table until the breech block has been fully withdrawn substantially as
described.
5. The combination of the lever e and projection a whereby the hooked lever is
raised substantially as described.
6. Breech mechanisms substantially as described and shown in the drawings.
-
Dated this 18th day of March 1895.
VIT
WEI IN
WIN