Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Two-way Trigger
The invention relates to a trigger device for a firearm, in particular a self-
loading military
rifle, especially an attack rifle, having
- a trigger piece,
- a sear release part connected to the trigger piece and
- at least one trigger spring which acts on the sear release part (generic
part of Claim 1).
In this documentation we assume a firearm which is held in the normal
horizontal firing
position when being horizontally fired. "To the front" accordingly means "to
the
muzzle", the grip is seated "below" etc.
More than 100 years ago the so-called "double pull trigger" was introduced in
the
German army. In the case of other armies it was normal to place the finger on
the trigger
while shooting and continuously increase the pressure until - after traveling
a rather
small trigger path - the shot went off. In the case of the double pull trigger
on the other
hand a defined, additional trigger path with a defined trigger resistance was
present; once
this trigger path had been traveled then the trigger resistance increased, and
after the
traveling of a further, rather small trigger path the shot went off. The
advantage of this
device was that one could place the finger upon the trigger without having to
risk the shot
going off upon the slightest movement. Thus one could also place the finger
upon the
trigger with cold hands or while shaking from nervousness and "take the
pressure point ",
according to which the shot could be discharged more precisely or could be
avoided
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than would have otherwise been the case (in the case of a so-called "flint
trigger").
However, the disadvantage was that the triggering of the shot was in principle
slowed
down and a greater trigger path was required. For this reason this "double
pull trigger"
was introduced, even if only in a few armies, because many armies were already
equipped with a rifle which had been designed prior to the invention of the
"double pull
trigger".
In the case of automatic firearms the double pull trigger was in principle
excluded, since
there was simply no room for it in the complicated mechanism, and since in
other
respects it would have been necessary at least prior to each first shot or
burst of fire to
move the trigger over the long path to the pressure point. Instead of this one
devised a
device for the adjustment of the trigger spring with whose help it was
possible if
necessary to switch between winter operation (hard trigger) and summer
operation (soft
trigger).
Nevertheless, it would be preferable if the trigger had a short path that
could be adjusted
by force and if necessary also by distance to be covered before it reached the
pressure
point", that is the place at which the discharging of the shot takes place in
the case of a
hardening trigger. In the process this device, if at all, should only take up
such slight
additional space, that the accommodation in an existing automatic firearm is
possible, to
be precise, also if in the case of said existing automatic firearm the
original sear release
part was designed as the trigger itself. This latter named task appears upon
first glance to
be completely impossible, but is however, as we shall see, realizable by means
of the
invention. In the process however the trigger path which is traveled before
the pressure
point is reached has to be rather short in order to still be able to
accommodate the trigger
in an existing trigger guard, and in order to likewise facilitate the emission
of rapidly
succeeding single shots or bursts of fire,
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as was the case with the previous trigger, wherein the function, as always
intended,
should be improved.
This problem is solved in accordance with the invention by the features of
Claim 1.
It is true that bisecting the trigger for the production of a double pull
trigger and placing a
lost-motion spring between the two parts is already known (FR 2 619 440 A).
Arranging a spring between the trigger and the disconnector in order to
improve the
function is also known (US 6 772 5481B1). However, arranging the latter named
spring
between the sear release part and the disconnector and not, as would be
obvious, between
the trigger piece and the sear release part, is not obvious. In the case of
the invention the
force of the lost-motion spring can therewith be practically freely selected.
The excessive movement of the trigger piece (of the actual trigger) forwards
is prevented
by the first of the stops, while the second of the stops establishes the firm
connection
between the trigger piece and the sear release part when pulled over a lost-
motion
distance. The two stops hence define a lost-motion distance of the trigger.
The distance of
these stops, that is the lost-motion distance, can constructively be freely
selected, so that
the additional trigger path is selected in such a way that it is compatible
with the present
conditions (trigger guard, other operating elements).
However, the requirement is a lost-motion spring which presses the trigger
forwards over
the lost-motion distance - the force of this spring must, in proportion to the
trigger
spring, which loads the sear release part, be significantly lower, so that a
well perceivable
pressure point remains when the lost motion of the trigger piece has been
traveled and the
trigger piece is at the pressure point.
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Now if the automatic firearm or the weapon was originally equipped with a
trigger piece
which is connected in a single piece to the sear release part, so that the
flint trigger is
indispensable/unalterable, then it is sufficient to separate the trigger piece
structurally
from the sear release part and provide the stops as well as the lost-motion
spring in order
to provide a weapon which constructively actually cannot have one with a
double pull
trigger. This is the special accomplishment of the invention, because any
person skilled in
the art would have scrapped the present basic construction/framework and
redesigned it
from the ground up if they wanted a double pull trigger.
The trigger piece could for example be relocatably mounted in the direction of
fire in the
sear release part between the two stops. This however carries the risk that
the lost motion
of the trigger piece over the course of time will become stiff. While it is
true that the
weapon will then function as always, however; this will only be possible with
a flint
trigger. For this reason in accordance with the invention it is preferred that
the trigger
piece is pivoted around a transverse axis on the sear release part (Claim 2).
However, a
soiling of the pivot bearing can be practically ruled out. Moreover, another
advantage is
present in that the trigger piece only exhibits an extremely slight lost
motion where it
emerges from the housing, said lost motion lying within the tolerances of the
corresponding slot/slit in the housing. Hence, if a weapon is intended to be
retrofitted to
the inventive trigger no modification is to be performed on the housing.
Another embodiment of the invention consists in the fact that at least one of
the stops is
constructed as a horizontal area on the trigger piece and/or on the sear
release part (Claim
3). In the simplest case an upper area is constructed on the trigger piece and
a lower area
is constructed on the sear release part, said area extending over the entire
corresponding
part. Both areas extend slightly angled to each another, so that
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in the case of an unpulled trigger the front parts, in the case of a pulled
trigger the rear
parts of the areas are seated upon each other.
A preferred embodiment of the invention lies in the fact that the lost-motion
spring
between the two areas is active and preferably is arranged behind the pivot
bearing
between said areas (Claim 4). Thus the lost-motion spring is practically
arranged within
the trigger and requires no external space whatsoever. In the preferred case
the lost-
motion spring is moreover constructed as a pressure spring, so that its
arrangement is
easily possible by placement in on or two boreholes which are constructed in
the trigger
piece and/or in the sear release part. For retrofitting in an automatic weapon
another, two-
way trigger is simply to be installed.
In accordance with a further embodiment of the invention it is especially
preferred that an
adjusting screw for the pressure point path is arranged in front of the pivot
bearing and
across the area (Claim 5). With this adjusting screw the location of the front
stop, which
becomes active in the resting position of the trigger, can be modified, so
that the trigger
within the given boundaries can either be set so that a maximum lost-motion
(pressure
point path) is achieved, or so that in each case an equal lost motion is
achieved.
Moreover, if necessary a setting which accommodates the properties of the
marksman
can be performed.
In accordance with a further embodiment of the invention an additional
advantage lies in
the fact that the lost-motion spring can be adjusted or replaced. Thus not
only can a
rusted or worn out spring be replaced with a new one, but rather also the
prevailing force
during the lost-motion path is adjustable, so that either the pressure point
can be custom
set, or can be adapted to the properties of the respective trigger,
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for example, in the case of a very light "summer trigger" is still clearly
perceptible, on the
other hand in the case of the "winter trigger" is still distinctly perceptible
through the
glove.
Overall it has been managed with only three additional parts (trigger piece,
transverse
axis and lost-motion spring) and within the confines of a conventional trigger
device to
drastically change its properties.
The subject matter of the invention will be explained more closely with the
help of the
exemplary embodiments with the attached drawing. The figures show the
following:
Figure 1 shows the longitudinal section through an inventive trigger device
with the
safety catch on.
Figure 2 shows the longitudinal section through an inventive, two-way trigger.
Figure 3 shows the top view of the trigger with trigger spring.
Figure 4 shows a representation similar to Figure 1, however in with the
safety catch off.
Figure 5 shows a representation similar to Figure 4, however right before the
discharge,
and
Figure 6 shows the trigger of a modified design.
With the help of Figure 1 first a conventional trigger device not shown in all
details will
be explained.
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A hammer 1 is provided, which is cocked by a mainspring (not shown) around a
transverse axis 3 and which exhibits two catches: one trigger catch 5, into
which the sear
arm 7 of a single part trigger 9, 11 engages, and a disconnector catch 13,
into which the
disconnector nose 17 of a disconnector 15 can engage, said disconnector 15
being pivoted
in a longitudinal slot 19 of the trigger 9, 11 around an axis 21 and being
elastically
pressed upwards by a disconnector spring 23. A safety roller 25 holds the rear
part of the
trigger 9, 11 tight, so that it is fixed around the axis 21.
Parts 9 and 11 however form a single component in the case of the known
trigger device,
different than shown in Figure 1, where the inventive two-way trigger is
shown.
If the safety roller 25 is turned, as is shown for example in Figures 4 and 5,
then the
trigger 9, 11 in the case of actuation can carry out a counterclockwise rotary
movement
until the trigger piece 7 releases the trigger catch 5. This rotary movement
is however in
the case of the known single piece trigger 9, 11 quite short. At the same time
the
disconnector nose 17 lies on the hammer I and is pushed back against the
spring 23. Now
the hammer 1 can move counterclockwise and releases. In the process, the
trigger 9, 11
remains in its position.
The release of the hammer 1 discharges a shot, on the basis of which the
breech (not
shown) is pushed back and the hammer I is cocked again clockwise. In the
process the
disconnector nose 17 is first pressed against the spring 23 into the
longitudinal groove 19
and then engages in the hammer via the disconnector catch 13, said hammer
being held
by the catch 13 and nose 17.
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If the trigger 9, 11 is now released, then the trigger piece 7 presses against
the hammer 1
before the disconnector catch 17 is pulled back so far that it releases the
disconnector
catch 13. The hammer 1 engages a little bit (counterclockwise) forwards and
engages
with its trigger catch 5 back in the trigger sear 7.
In accordance with the invention, however, as shown the trigger 9, 11 is
broken down
into two parts, namely a sear release part 9 and a trigger piece 11, which are
flexibly
connected to each other by a transverse axis 27. A lost-motion spring 33 in
the process
loads the trigger piece 11 clockwise around the transverse axis 27 until the
trigger piece
is seated in a front catch 35 against the sear release part 9.
If the trigger piece 11 is now actuated, that is, moved counterclockwise, then
first the
front stop 35 is vacated and the lost-motion spring 33 is compressed, while
the trigger
spring 29 holds the sear release part 9 in its location until the rear stop 37
is reached.
Now the trigger piece 11 moves together with the sear release part 9 like the
known,
single piece trigger 9, 11 and disengages the trigger catch 5 from the trigger
sear 7. In the
process the disconnector 15 behaves precisely as in the above described case,
because the
trigger spring 29 loads only the sear release part 11, just as in the
described case of the
single piece trigger 9, 11.
This trigger spring 29 can be seen more closely from Figures 2 and 3, where
its formation
as a wire spring can be seen, which acts on both sides of the sear release
part 11.
Further the attachment of the transverse axis 27 by means of an overall
vertical pin 31
can be seen from Figure 2, under which in the trigger piece part 11 a borehole
41 is
formed,
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in order to give the pin 31 room for disassembly. The lower area of the sear
release part
and the upper area of the trigger piece are a bit inclined to each other, so
that in the case
of the sear release part 11 the front stop 35 goes into action when the sear
release part is
at rest, and the rear stop 37 goes into action when the trigger piece 11 is
pulled.
Figure 4 illustrates the function of the mechanism in the case of a disengaged
safety
roller, and Figure 5 shows the trigger device directly after firing, while the
hammer I is
just accelerating.
The lost-motion spring 33 can also be mounted accessibly to the extent that it
can be
effortlessly replaced when for example a softer or harder trigger spring is
selected.
The possibility also exists of adjusting the spring action via a screw similar
to the lost-
motion setting (not shown).
Figure 6 shows a further development of the invention, wherein an adjusting
screw
spindle 43 is inserted into the trigger piece 11. This screw spindle 43 can be
adjusted
from below by means of a screw driver and serves the purpose of shortening or
lengthening the lost-motion path which the trigger piece part 11 travels
relative to the
sear release part 9.
