Improvements in the Firing Mechanism of Automatic Guns.
Year: 1897

page_text: Date of Application, 4th Jan., 1897
Complete Specification Left, 28th Sept, 1897-Accepted, 30th Oct.,
1897
PROVISIONAL SPECIFICATION.
Improvements in the Firing Mechanism of Automatic Guns.
We, HIRAM STEVENS MAXIM, of 18 Queens Gate Place, in the County of
Middlesex, Mechanical Engineer, and LOUIS SILVERMAN, of Crayford Works,
Crayford, in the County of Kent, Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to the firing mechanism of automatic guns and has for
its object to provide such mechanism with improved means whereby the trigger
or similar device can be so controlled that the gun can be caused to fire a single
shot for each pull of the trigger, or to fire a succession of shots automatically as
long as the trigger is held, or can be rendered incapable of firing, these changes
being effected by the adjustment of an external finger piece provided on the gun.
For this purpose we provide the trigger with a sliding piece furnished at its
inner end with a pivoted hook or claw which, when the trigger is in its released
position, is adapted to engage with the ordinary sliding trigger rod or bar
employed in Maxim"
guns for actuating the sear to fire the gun. This hook
or claw is formed with suitably arranged arms or lugs, one of which is acted upon
by a spring that tends to keep the hook in engagement with the said trigger
bar. The other lug is capable of striking against a stop on a rod or spindle
carrying the aforesaid external finger piece when the latter is turned into an
appropriate position. Then, when the trigger is pulled the said hook will be
caused to turn about its pivot as the sliding piece moved rearwardly with it, thus
releasing the trigger bar after firing the gun and allowing it to regain its original
position under the action of its spring. So long as the trigger is held back, the
trigger bar will be out of reach of the hook and cannot therefore be again operated
until the trigger is released and allowed to bring its hook into re-engagement
with the trigger bar. The gun can then be discharged again when the trigger
is next pulled. More than one shot at each pull of the trigger cannot be fired
so long as the finger piece occupies this position.
The aforesaid rod or spindle carrying the external finger piece is also formed
with a radial arm so disposed, that it can, by turning said finger piece into another
position be brought in the rearward path of the trigger bar, such arm then
acting as a stop to prevent the rearward movement of the trigger bar. The pulling
of the trigger will thus be altogether prevented and the gun cannot then be fired
until the finger piece has been re-adjusted.
By turning the said external finger piece into another position both the stop
and the radial arm on the aforesaid spindle can be brought into an inoperative
position and then, when the trigger is pulled, and held the gun will continue
firing a rapid succession of shots automatically.
29 66
The above specified three positions of the finger plate or piece may be indicated
on the side plate of the gun by any suitable words such as single safe" and
"automatic to indicate the various positions into which the finger piece is to

page_text: be turned according as the gun is to fire single shots, or to be thrown out of
action, or to fire automatically:>
Dated this 4th day of January 1897.
Improvements in the Firing Mechanism of Automatic Guns.
We, HIRAM STEVENS MAXIM, of 18 Queens Gate Place, in the County of
Middlesex, Chevalier of the Legion of Honour, Civil and Mechanical Engineer,
and LOUIS SILVERMAN, of Crayford Works, Crayford, in the County of Kent,
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:
-
66
This invention relates to the firing mechanism of automatic guns and has for
its object to provide such mechanism with a device which we term a trigger
regulator" whereby the trigger, or its equivalent, can be so controlled or regulated
that the gun can either be caused to fire a single shot for each pull of the trigger,
or to fire a succession of shots automatically as long as the trigger is held, or
can be rendered temporarily incapable of firing; these changes being effected
by the adjustment of an external finger-piece on the gun.
For this purpose we provide the trigger with a pivoted hook or claw which,
when the trigger is in its released position, is adapted to engage with the ordinary
sliding trigger-bar employed in "Maxim" guns for actuating the scar to fire the
gun. This hook or claw is formed with suitably arranged arms or lugs, on one
of which a spring plunger acts to press the hook into engagement with the said
trigger bar. The other lug is capable of striking a stop on a rod or spindle
carrying the aforesaid external finger-piece when the latter is turned into an
appropriate position. When the finger-piece is in this position only a single
shot can be fired at each pull of the trigger, but by varying the position of the
said finger picce so as to shift the afore-ard stop into a position where it will
not be struck by the lug on the hook or claw, a succession of shots can be fired
automatically as long as the trigger is held; or by still further varying the
position of the said finger piece to bring a radial arm or stop thereon into
proximity to the trigger bar, the trigger will be prevented from being pulled,
with the result that the gun cannot be fired until the finger piece is re-adjusted.
In order that our said invention may be clearly understood and readily carried
into effect we will proceed to describe the same more fully with reference to the
accompanying drawings, in which:-
Figure 1 is a side elevation of the rear portion of an automatic gun of which
only so much is shewn as will suffice to explain our present improvements.
Figure 2 is a vertical section of part of the preceding figure.
Figures 3 and 4 are horizontal sections taken approximately on the line 1. 1.
of Figure 1, shewing respectively the position of the pivoted hook or claw before
and after the pulling back of the trigger to fire a single shot.
Figure 5 is a side elevation of the said pivoted hook or claw shewn detached.
Figures 6, 7 and 8 are detail views of the regulator and its stops.
Figure 9 is a horizontal section shewing a modification of the hook or claw
for the purpose hereinafter stated, the trigger being pulled back.
A is the framing or casing of the gun; B the handle which is grasped by the

page_text: gunner in firing the gun; C the trigger; D the pivoted hook or claw; E the
usual trigger bar; and F the external finger-piece.
According to the construction illustrated, the upper end of the trigger C is
pivotally mounted at b within the hollow handle B and is connected by a pin c
to a sliding piece C'. The inner end of this sliding piece is forked to receive the
hook or claw 1 which is held in position by a vertical pivot pin d about which
it is capable of turning in a horizontal-plane. This hook or claw has arms or
lugs d d formed thereon, one of which (d) is acted upon by the spring plunger d
located in a cavity formed in the rear plate A' of the gun casing, whereby the
said hook or claw is normally kept in the position represented in Figure 3. The
said hook or claw is also provided with a shoulder which by coming against
the end of the sliding piece C₁ limits the extent to which the hook or claw can
be displaced by the said spring plunger.
The
The said external finger piece F is mounted on the spindle f and is furnished
on its inner side with a projection f¹ that is adapted to enter one or other of the
notches or holes a formed in the framing or casing A of the gun, so as to keep
the finger-piece in any of the three positions into which it is to be set.
inner end of the said spindle is formed with the stops f2 and f³, the former con-
sisting of a projection extending longitudinally from the spindle and the latter
consisting of an arm or projection extending radially or laterally from the said
spindle. When the said finger-piece is shifted into the position represented in
Figures 3 and 4 the stop f2 occupies a position just in rear of the longer lug d
of the hook or claw, so that if the trigger be pulled, the sliding piece C¹ will be
drawn outwardly, and in such movement will cause the said claw to shift the
trigger bar E rearwardly a sufficient distance to fire the gun. But during this
rearward movement of the sliding piece C¹ the aforesaid longer lug will have
been restrained in its rearward movement by coming against the said stop fon
the spindle f, whereby the hook or claw will have been caused to turn about its
pivot, against the resistance of the spring plunger d, into the position represented
in Figure 4. In this manner the trigger bar is released by the said hook or claw
after the firing of a single shot, and resumes its forward position again as is
well understood. So long as the trigger is held back the trigger-bar will lie out
of reach of the hook or claw (see Figure 4) and, unless the trigger be released to
permit the sliding piece C and the hook or claw to resume their original positions,
the trigger-bar cannot again be operated by pulling the trigger. On the release
of the trigger, the said hook or claw, by the action of the spring plunger d*,
re-engages with the trigger bar as represented in Figure 3, and the gun can then
be once more discharged when the trigger is next pulled. More than one shot
at each pull of the trigger cannot however be fired so long as the finger piece F
occupies this position.
By turning the said finger-piece towards the right into a position to remove
the stop from behind the lug and bring the radial arm or stop f³ into the
rearward path of the trigger bar E, such arm or stop will prevent the rearward
movement of the trigger bar. The gun cannot then be fired until the finger-piece
has been re-adjusted.
By still further turning the finger-piece towards the right, into a position to
carry the arm or stop as well as the stop out of reach of the claw and the
trigger bar respectively, then, when the trigger is pulled and held, it will not be
<lisengaged from the trigger bar and consequently the gun will continue firing a
rapid succession of shots automatically.
68
The above specified three positions of the finger-piece are indicated on the side
plate of the gun by any suitable signs or words, such as single," "safe," and
automatic," as shewn in Figure 1, to indicate the various positions into which
the said finger-piece has to be turned, according as the gun is to fire single shots,
or to be thrown out of action, or to fire automatically.
In the modification illustrated by Figure we have shewn the hook or claw
provided with a tail piece d¹ and we have so arranged the stops f³ ³ on the

page_text: spindle that when the finger piece is set into the "automatic" position as shewn
in this figure, the aforesaid tail will (when the trigger is pulled) arrive above the
said stop whereby liability of the hook's becoming unintentionally disengaged
from the trigger bar E by the vibration due to the firing of the gun will be
avoided.
:
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
'
1. An automatic gun provided with a trigger-regulator by the adjustment of
which the firing of the gun can be varied as above set forth.
'
2. The combination with the trigger, of a pivoted hook or claw for engaging
with the trigger-bar, and adjustable stops whose position relatively to the said
hook and the trigger-bar can be varied by an external finger-piece for the purposes
specified!
3. The trigger-regulator constructed and arranged substantially as described
with reference to Figures 1 to 8 of Figure 9 of the accompanying drawings and
for the purposes specified.
Data is 50th dive of Cantomban 1907
174
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicants.