Improvements in Single Trigger Mechanism for Double-barrelled Fire-arms.
Year: 1897

page_text: Improvements in Single Trigger Mechanism for Double-barrelled
Fire-arms.
We, AUGUSTE FRANCOTTE AND COMPANY, of 53 Mont Saint Martin, Liège in the
Kingdom of Belgium, Gun Manufacturers, 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 which enables both barrels of a double barrelled
gun to be fired with a single trigger without the possibility of the second discharge
taking place accidentally, as it is only after the first discharge, and after the single
trigger has returned to its normal position that the second sear can be released by a
fresh pressure exerted on the trigger. This mechanism consists of a slide guided on
the trigger and operated by the locking lever, or by the bolt of the gun with the aid
of a rod, stem, or shank acted on by a spring.
Figure 1 of the accompanying drawings shows a side view and a section, taken on
the line A-B, of the single trigger.
Figure 2 shows six views of the slide.
Figure 3 two views of the lever operated by the bolt of the barrels, and Figure 4
two views of a second lever operated by the first and which second lever operates the
rod actuating the slide.
Figure 5 shows three views of the rod.
Figure 6 is a side view of the mechanism of the gun uncocked.
Figure 7 a similar view with the mechanism cocked.
Figure 8 is a section taken on the line C-D of Figure 6 showing in plan the sear
levers and the mechanism of the trigger uncocked.
Figure 9 is a similar section taken on the line C-D of Figure
showing the same
parts at the moment of cocking, that is to say when the locking lever bis pushed to
the right.
Figure 10 is a side view of the mechanism of the trigger at the moment of firing
the first (right hand) barrel.
Figure 11 is a side view of the mechanisın shown in Figure 10, after the discharge
of the right hand barrel and release of the trigger.
The slide a, Figures 2 and 6 to 11, is located on the trigger d, and is free to slide
thereon, being guided by its grooves a¹ a¹; it is held on the trigger partly by means
Price &11

page_text: of a small button a² projecting laterally into the groove a¹ and which engages in a
groove d¹ of the trigger d (see Figure 1), and partly by the hook cl of the rod c.
Figure 5, which actuates it by reason of its engagement in the hook a³, Figure 2.
The rod c is placed and guided in the stay f of the plate of the trigger guard, and is
surrounded by a helical spring n which tends constantly to force it back towards the
rear end of the gun. This rod c is operated by the backward movement of the bolt v
of the barrels (see Figure 9), by means of the levers i (Figure 3) and o (Figure 4)
placed at the front part of the stay.f, and which levers pivot on their respective
axes and o' (Figure 10). The lever i (Figure 3) is provided at its side with an arm
having an hook 2 which engages in the hook 02 of the lever o (Figure 4) as shown
by dotted lines in Figure 10; the upper end of the lever o takes into a slot c³ in the
rod c. r and 8 are the sear levers, and 8 the heels of these levers. In the uncocked
position of the mechanism the sear lever r stands at a higher level than the lever 8,
in order that the projection at of the slide a may pass under the heel ¹ of the said
lever r.
The part as of the slide (see Figure 2) is sufficiently low to pass under the
heel 8 of the left hand sear lever s.·
v
-
The action is as follows:-When the locking lever b is moved from left to right the
bolt of the barrels (Figure 9) moves backwards, and the barrels can be tilted, which
latter action cocks the hammers. In its backward movement the bolt v comes against
the lever i and causes it to pivot backwards; the hook 2 of the lever i moves forward
and downwards and pushes the hook o² of the lever o also downwards, this causes the
upper end of the lever o to move forward, and as it is engaged in the slot c² of the
rod c the latter is moved forward also and the spring n is compressed (Figure 9).
Then under the pressure of the main spring (transmitted from the hammer to the
right hand sear) the sear lever r descends, its heel 1 takes into the notch a behind
the shoulder at of the slide a, Figures 2 and 9, and holds the said slide in the
position it occupies in Figures 7 and 9. In this position the heels 8¹ of the left hand
sear lever a does not come over the slide a, but over a notch or recess a' of this slide
(Figures 2 and 9); so that the trigger can act without coming in contact with this
heel s¹. Then, if the trigger d is pulled the slide is raised (Figure 10) and as the
bottom of its notch a is in contact with the heel r¹ of the right hand sear lever r
the corresponding hammer falls and fires the right hand barrel. Neither the recoil
nor the prolonged pressure of the finger on the trigger can at that moment cause the
second discharge or firing of the left hand barrel. In fact when the slide a has reached
the end of its forward movement (Figure 7) that is to say when the locking lever b
has been turned into position for opening the gun, the hook a³ of the slide a (which
hook is wider than the hook cl of the rod c, Figure 5, and consequently projects laterally
on both sides of the hook c¹) takes into a transverse notch of the stay f exactly under a
hook of that stay (Figures 6, 7, 10, 11). Now when the trigger d is pulled to fire
the first shot, the hook a³ of the slide is raised so that the hook c¹ of the rod c takes
more deeply into the opening of the hook a³, and the latter comes to bear against
the front of the hook t of the stay f (Figure 10). Therefore at the moment of firing
the first shot the slide is booked into the stay f and cannot move back so long as
the finger bears against the trigger; besides this the heel of the right hand sear
lever always occupies its position behind the projection at of the slide, so that it is
absolutely impossible for the slide a to move backwards whatever may be the action
of the recoil, and consequently the two shots cannot be fired simultaneously.
At the moment of firing the first shot the trigger mechanism occupies the position
shown in Figure 10, and the spring u of the trigger tends to push it downwards.
When the finger leaves the trigger d the latter with the slide descends, the hook a³
leaves the hook t of the stay f and the lower edge of the bevil as of the slide a comes
to the level of a stop d², shaped as a double inclined plane, arranged on the plate g of
the trigger guard. By the action of the spring n (the slide a being liberated from the
heel and from the hook t) the side a is moved back and the edge of the bevil a8
comes against the stop d² (Figures 9 and 11). In this position the heel s¹ of the left
hand sear lever s still stands over the notch a of the slide (Figure 9). When the
trigger is again pulled the bevil as is pressed by the spring n of the rod c and slides

page_text: backwards over the stop d², and the slide a takes the position shown in Figures 6 and 8
at the end of the slot-guide d³ of the trigger. Then the surface a³ of the slide a
stands immediately below the heel s¹ of the left hand sear lever 8. Therefore, if the
pressure on the trigger continues the left hand barrel is fired and the slide a, which
has reached the end of its backward movement remains in place until a fresh
movement of the locking lever b to the right returns it into the forward position
(Figure 7).
The trigger mechanism above described can be applied either to guns with
hammers or to hammerless guns, or to rifles whatever breech action they may be
fitted with. Small modifications necessary for the adaptation of the mechanism to
various circumstances will be familiar to gun makers and consequently need not be
described here.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
First. A single trigger mechanism for double barrelled guns, which consists of a
slide a guided on the trigger and actuated by a rod c. provided with a helical spring n
and placed in the stay f on the plate of the trigger guard, and by two two-armed
levers o and the lower arms of which engage with one another whilst the other
arm of the lever o takes into a slot in the rod c, and the other arm of the lever i
stands in the path traversed by the bolt v of the barrels when the locking lever b
is a operated, so that the said bolt by its backward movement causes the
levers i and o to turn on their fulcra and draw the rod c forward, compressing
the spring n and causing the slide a to advance partially under the heel of one of the
sear levers, the heel of the other sear lever standing over a notch a7 in the said
slide a, substantially as described.
Second. The sear lever r so arranged that when the gun is uncocked the said
lever allows the slide a to advance under its heel r¹, whilst the pressure of the
corresponding main spring causes this lever to descend so that its heel 1 comes
behind a projection at of the slide in order to hold the sa d slide in place until
after the discharge of the first barrel and the complete libeiration of the trigger,
substantially as described.
Third. In the mechanism forming the subject of the first caiming clause hereof,
the arrangement of a hook 3 in front of the slide a which, when the first shot is
fired, engages in front of a hook t of the stay f of the plate of the trigger guard and
remains engaged therewith until the trigger is entirely freed from the pressure
exerted upon it, substantially as described.
Fourth. In the mechanisin forming the subject of the first claiming cause hereof
the stop d² so placed and arranged on the plate g of the trigger guard that it
stops the backward movement of the slide a after the firing of the first shot and the
liberation of the sear, and holds the said slide in a position such that the heel s'
of the second sear lever still stands over the notch a of the slide, whilst on a fresh
pressure being applied to the trigger the slide moves over the said stop, and by the
action of the spring n is immediately pushed to the end of its backward movements
whereby the surface as of the slide a is brought under the said heel s¹ of the second
sear lever 8 and allows the second shot to be fired, substantially as described,
Dated this 20th day of April 1897