Improvements in the Firing Mechanism of Automatic and similar Fire-arms.
Year: 1896

page_text: Date of Application, 11th Aug., 1896
Complete Specification Left, 11th May, 1897-Accepted, 11th Nov., 1897
PROVISIONAL SPECIFICATION,
Improvements in the Firing Mechanism of Automatic and similar
Fire-arms.
I, HUGH WILLIAM GABBETT-FAIRFAX, of 107 Lambeth Palace Road, London,
S.E., Civil Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to the firing mechanism of automatic and similar fire-
arms and has chiefly for its object to so construct such mechanism that the continuous
discharge of the weapon will not take place by merely pulling the trigger and
keeping it in its pulled back position. In other words the mechanism can be so
adjusted to regulate the firing that the trigger must be pulled in the usual manner
for every discharge of the fire-arm.
According to my invention I provide a sear which is preferably in the form
of a pivoted lever engaging at one end with a notch or bent in the hammer or
tumbler and provided at the opposite end with a projection which is more or
less of triangular or wedge shape. The trigger has an arm to the end of which
is pivoted or hinged a contact piece having a projection thereon which is also
of triangular or wedge shape. When the hammer is cocked these two triangular
or wedge shaped projections lie with their apices in contiguity to each other.
On pulling the trigger to discharge the weapon the sear is released from the
hammer by the action of the projection on the trigger arm which projection at
the same time assumes a position in front of the projection on the sear-lever.
Therefore when the hammer again assumes its cocked position and the sear again
engages therewith, the projection on the trigger arm will not act upon the sear
notwithstanding that the trigger be still kept in its pulled position. By releasing
the trigger the contact-piece, by reason of its pivotal connection to the trigger-
arm, can regain its normal position and bring the apex of the projection thereon
in contiguity to the apex of the projection on the sear-lever. Then when the
trigger is next pulled the sear-lever is operated to release the hammer.
It will be obvious that I may locate the pivoted or hinged contact piece on
the sear-lever instead of on the trigger-arm as above stated.
Instead of forming the sear arm and the trigger arm with triangular projections
as above stated I may provide them with small abutting rollers or other curved
surfaces.
According to a modification of my invention I provide the trigger with two
pivotal arms controlled by springs. The free end of one of these arms which
I may term the trigger arm lies in proximity to the free end of the sear-lever
and the free end of the other arm which I may term a locking arm lies in proximity
to an adjustable stop carried by the frame of the weapon. The locking arm has
a tooth which engages with a notch or bent in a circular portion of the trigger
arm and retains the latter in a position to actuate the sear-lever when the trigger
is pulled. The aforesaid adjustable stop is so situated relatively to the locking
arm that, as the trigger is pulled, and immediately the trigger arm has actuated

page_text: the sear lever the said locking arm is released from engagement with the notch
or bent in the trigger arm, whereby the latter is forced by its spring into a
position to be out of reach of the sear-lever and rests upon a suitable stop. By
releasing the trigger the aforesaid locking arm is again brought into engage-
ment with the notch or bent in the trigger-arm so that the sear-lever will be
actuated when the trigger is next pulled. When the aforesaid adjustable stop
is turned into a position to be out of the path of the locking arm the trigger-arm
remains locked to the trigger and consequently as long as the trigger is pulled
the weapon continues to fire automatically until the cartridges are all spent. This
modification of the firing mechanism therefore enables me to effect the firing
of the weapon either automatically or non-automatically.
Dated this 11th day of August 1896.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in the Firing Mechanism of Automatic and similar
Fire-arms.
I, HUGH WILLIAM GABBETT-FAIRFAX, of 107 Lambeth Palace Road, London,
S.E., Civil 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:-
This invention relates to the firing mechanism of automatic and similar fire-
arms and has chiefly for its object to so construct such mechanism that a single
pull of the trigger will cause only one discharge instead of a continuous or
repeated discharge of the weapon. In other words the mechanism is so constructed
that the trigger must be pulled like that of an ordinary fire arm for every discharge.
According to my invention I provide the trigger with two spring-controlled
pivotal arms which are so arranged relatively to each other and to a stop that
the pulling of the trigger first causes one of the pivotal arms to act on the sear
and release the hammer and then causes the other of the pivotal arms to come
against the said stop, thereby disengaging the aforesaid arms so that the sear
cannot be acted upon by them until the trigger has been released and again pulled.
The aforesaid stop is in some instances made adjustable for the purpose of
enabling it to be thrown out of action when it is desired to render the firing of
the weapon continuously automatic.
In order that the invention may be clearly understood and readily carried into
effect I will proceed to describe the same more fully with reference to the accom-
panying drawings, in which
Figure 1 is a side view of an automatic fire-arm provided with one construc-
tion of my improved firing mechanism, a part of the casing being removed to
allow the construction of the said mechanism to be clearly seen.
Figure 2 is a similar view with the parts in the position they occupy when
the trigger is pulled and the weapon fired.
Figure 3 is a detail view of a convenient form of adjustable stop for the purpose
referred to.
Figure 4 is a side view of an automatic fire-arm similar to that shown in
Figure 1 but having a modified construction of my improved firing mechanism
applied thereto.
Figure 5 is a similar view but with the parts in the position they occupy when
the trigger is pulled and the weapon fired.

page_text: Referring more particularly to Figures 12 and 3, a is the trigger which is
pivoted at a and is acted upon by a spring a². The said trigger is provided with
two arms b and c the former of which I term the trigger arm while the latter I
term the locking arm. The said trigger arm has a circular portion or boss b
whereby it is mounted on the pivot pin of the trigger. The locking arm is
pivoted at e to the trigger and has a tooth which engages with a notch or
hent & in the circular portion of the trigger arm b. The said arms b and e
are acted on by a spring d which tends to turn them in opposite directions and
to thus maintain the tooth in engagement in the bent b
e is a sear-lever which in the example shown is arranged horizontally and is
pivoted at el. e is the sear proper which forms a downward continuation of the
said lever. f is the firing hammer which is pivoted at f¹ and, in the example
of fire-arm illustrated, is adapted to be cocked by the recoil movement of the breech
block in the manner set forth in the Specification of my prior Patent No. 18686
of the year 1895. The hammer has a recess or notch fa in which the sear e is
caused to engage by a spring acting on the sear-lever.
y is the adjustable stop by which the firing of the weapon can be rendered
continuously automatic when desired. This stop is arranged transversely in the
path of movement of the free end of the locking arm e and consists of a cylindrical
block or rod, as seen more clearly in Figure 3, having a notch g' therein, and
also provided with a button g2 by which it can be turned on its axis. The arrange-
ment is such that when the flat face of the notch is horizontal as in Figure 1,
the end of the locking arm c will strike against it when the trigger is pulled
(see Figure 2) so disengaging the tooth from the notch 2. When however the
stop g is given a quarter turn in the direction of the arrow (Figure 1) so that
the flat face of the notch is vertical, (as shown in dotted lines) then the end of
the locking arm will pass through the notch without touching the flat face thereof
and the aforesaid disengagement of the two arms be will not take place. The
fire-arm will then continue firing so long as the trigger is pulled and ammunition
supplied thereto.
The operation of the mechanism above described is as follows:-
Supposing the parts to be in the position shown in full lines Figure 1 that is
to say with the hammer cocked ready for firing, then when the trigger is pulled
the locking arme will be moved downward for a certain distance without turn-
ing on its pivot, and the movement of the trigger will be imparted to the trigger-
arm owing to the engagement of the tooth in the notch be. This movement
will cause the trigger arm b to raise the sear-lever e and disengage the sear e
from the notch f so releasing the hammer and permitting the firing to take place.
The parts are so adjusted that this happens before the trigger has been drawn
completely back, and at the moment when the end of the arm c is on the point of
coming in contact with the adjustable stop y. Immediately therefore that the
firing has taken place the continued movement of the trigger brings the end of
the arme against the said stop, so depressing the tooth and causing it to clear
the notch of the trigger armi b as already stated. The trigger arm & will there-
fore turn about its axis a under the influence of the spring d and assume the
position represented in Figure 2, its end thus lying out of contact with and
resting against a stop 63.
It will thus be seen that when the breech block recoils after the discharge of
the gun and encks the hammer, the sear will, under the influence of the
spring e, engage in the notch f of the hammer and thereby keep it cocked, so
that no further discharge can take place until the trigger arm and locking arm
are allowed to engage again by releasing the trigger and subsequently pulling
the trigger.
In the modified construction of the firing mechanism shown in Figures 4 and 5
the same letters of reference are employed to designate similar parts to those
already described, and as the operation of the mechanism is substantially the
same as that already set forth above no special description thereof is necessary.

page_text: The stop g shewn in Figures 4 and 5 differs from that shown in Figures 1 to 3
in that it is not adjustable. A somewhat different arrangement of springs is
also employed, the tail of the trigger arm being acted upon by an independent
spring d, and the locking arm c and sear lever e have a common spring d³.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:
1. An automatic or similar fire-arm in which the trigger is provided with two
spring-controlled pivoted arms which are arranged to operate in conjunction with
a stop and a sear substantially as described and for the purpose specified.
2. The adjustable stop for use with the aforesaid pivoted arms on the trigger
substantially as described and for the purpose specified.
3. The improved firing mechanism constructed and operating substantially as
hereinbefore described with reference to either of the arrangements illustrated in
the accompanying drawings.
HUGH W. GABBETT-FAIRFAX.
Haseltine, Lake & Co.,
45 Southampton Buildings, W.C., Agents for the Applicant.