Note: Descriptions are shown in the official language in which they were submitted.
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TENSIONING SYSTEM FOR THE FIXING OF A COMPONENT
ON A HANDHELD FIREARM AS WELL AS A
HANDHELD FIREARM EQUIPPED WITH IT
The invention relates to a tensioning system for the fixing of a component in
the region of
the barrel of a handheld firearm as well as a handheld firearm equipped with
such a
tensioning system: a sleeve, in particular a tubular sleeve enclosing the
barrel which is
stationary with regard to the axis of the bore. The component being addressed
here is
preferably a weapon part which can be attached and removed, for example a hand
guard
of the handheld firearm at least partially enclosing the barrel and the
sleeve, which is
supported in a rotationally fixed manner on the housing. The component can
however
also be a weapon in turn, for example a grenade launcher.
Here a position of the handheld firearm is assumed which corresponds to the
normal
firing and shooting position; thus with horizontal barrel and hence horizontal
axis of the
bore (median axis of the barrel) and with grip pointing downward, wherein the
muzzle is
pointing to the front. Specifications such as above, below, right, left as
well as front and
rear are made from the point of view of a marksman holding the weapon in
normal firing
position.
Older target rifles frequently have a separated front shaft. Said front shaft
from time to
time exhibits a holder for the mounting of a hand rest, which however does not
require
any strictly reproducible precision of its location. It is true that the front
shaft as a rule is
fitted on by hand and is seated tightly to the weapon, so that the hand rest
under no
circumstances wobbles. However, this mounting of the front shaft on the weapon
is too
imprecise for one to be able to fasten for example an aiming device to it,
also because the
wood of the front shaft works too much.
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It is also normal to mount bipods or the like on the front shaft. In this case
the barrel does
not regularly contact the shaft, even when the barrel is subject to thermal
expansion. It is
true that in the case of the use of a plastic shaft the problems with the
working with the
wood are omitted. However, one cannot mount an aiming device or the like on
the front
shaft; not even if it should be reproducibly fastened on the weapon. The
plastic shaft
gives, namely, which can lead to unbearable inaccuracies.
In the case of automatic handheld weapons, in particular in the case of
automatic pistols
or submachine guns, there is a quite particular problem in the heating up of
the barrel.
Also tolerances must be taken into consideration for serial production, since
manual
precision production is out of the question, even if the front shaft is
usually constructed
separately. Therefore as a rule it is, i.e. if one assumes a mean value of the
production
tolerances, mounted a bit loose on the weapon. Otherwise a front shaft could
no longer be
mounted to the weapon in the case of the reaching of the maximum production
tolerances.
The front shaft of such weapons is also termed as a "hand guard". It protects
the hand
namely from any contact with the barrel, which in the course of a rapid fire
series
becomes very hot and can add considerable burns in the case of coming into
contact with
it. In the case of gas-operated rifles it moreover protects the marksman's
hand from the
hot combustion gases from the gas piston.
Such a hand guard is as a rule made of metal, or, for the sake of better heat
insulation,
preferably made of plastic or compound materials.
In other respects it is known to fasten mount the barrel removably by means of
a sleeve
nut on the weapon.
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Recently people are equipping such weapons with add-on devices in order to
increase
their operative range, in particular their accuracy of aiming. Since modem
weapons
moreover exhibit a high firing precision, they should basically also be
outfitted with a
device for the holding of such add-on devices. Such holding devices at the
army would
facilitate the equipping of government issue weapons with add-on devices and
in the case
of civil weapons make possible their subsequent equipping.
For example prism rails with relatively great cross sectional area are known
as holding
devices for add-on devices, said prism rails running parallel to the barrel
longitudinal
direction. The great cross sectional area promotes the precisely reproducible
mounting of
an add-on device. Transverse slots secure the positionally accurate attachment
of the
devices and prevent them from shifting in longitudinal direction under firing
stress. The
so-called Picatinny rail is quite widespread in distribution.
Such a rail can now be mounted or constructed on the housing where a firm
connection to
the screwed in barrel exists, in case the housing is rigid enough. However it
is also
common to mount or construct such rails on the hand guard itself; in
particular whenever
devices are to be mounted which require an unhindered "field of vision" to the
front, for
example lights, grenade launchers or the like.
However, sighting devices or the like are not mounted on the hand guard
because said
hand guard necessarily is attached loose on the weapon and as a result the
necessary
reproducibility of the location of the sighting device relative to the barrel
is not available.
For this reason aiming devices, night aiming devices, range finders with
sighting
electronics etc. are still mounted on the weapon housing. This in turn often
requires the
prior removal of existing aiming means, in order to create room for the
desired add-on
device. As a result the weapon is not universal, but rather ultimately only
usable as a
special weapon with limited operative range.
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The invention is intended, among other things, to eliminate this disadvantage
as much as
possible. In particular it is intended to provide a tensioning system by means
of which a
hand guard, an additional weapon, for example a grenade launcher, or another
component
promoting the functionality of the weapon - as independently as possible from
a heating
up or the required tolerance play necessary for its mounting - on the weapon
always
maintains its direction sufficiently precisely reproducible. Preferably this
component
should also be mountable/removable simply and quickly to/from the weapon (e.g.
for
cleaning or for exchange for another such component).
The term "component" is intended here to designate the device which more or
less
encloses the barrel of the weapon in the front shaft region, or aligned in
specified manner
to it, is somewhat parallel. It can be a matter of a hand guard in the actual
sense, but also
can be a pure mounting rail carrier (e.g. carrier of Picatinny rails, STANAG,
PCAPs, etc.)
or combination components, which fulfill both functions, grenade launchers or
the like.
The term also includes other system components more or less embracing the
barrel of the
weapon or aligned to said barrel in predetermined manner, such as interfaces
to a bipod, a
gun carriage or a bayonet, and integrated sighting devices (targeting optics,
lasers, lamps
or the like) as well as associated operational controls, or such components or
assemblies
without interface.
The above task is solved in accordance with the invention by the subject
matter of Claim
1, thus by the fact that the tensioning system of the initially named type
exhibits a device
with which one or more surface region/s facing the sleeve, in the following
called inner
surface region/s, of the component can be brought into contact with one ore
more
opposite outer surface region/s of the sleeve.
While it is true that it is already known to enclose the barrel with a sleeve
(US 1 370
118), however this measure serves the purpose of transferring the recoil to
the butt stock,
not only the hand guard, and therefore requires a physical connection between
the
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transferring sleeve and the barrel causing the recoil. In addition the German
rifle Mod.
1888 is named.
In the following for simplicity's sake only one hand guard is spoken of, since
this is a
preferred embodiment (Claim 4) of the component. The invention however always
comprises another component of the previously named type.
The somewhat sleeve-like hand guard is thus slipped over the sleeve, is
aligned
somewhat parallel to said sleeve and in certain places abuts said sleeve in a
radial
manner. The sleeve for its part encloses the barrel, if necessary with an air
gap, thus
without contact. However it can be constructed as a nut on its rear side, by
means of
which the barrel is removably mounted to the weapon. However the sleeve is
always so
long that the hand guard abuts said sleeve at least in sections when it is
brought into
contact by the device.
Heat occurring in the firing of rounds is conducted away via the air gap
between sleeve
and barrel. It is true that the sleeve also extends in the process, however,
only retarded
and in slight measure. The longitudinal direction of the outer surface of the
sleeve
remains retained or is at best shifted parallel. The tensioning system deforms
the hand
guard in the process at best immaterially.
A thermal expansion of the sleeve also does not jam the hand guard, since the
sleeve only
partially fixes the hand guard in longitudinal direction (Fixed/Floating
Bearings
principle). The hand guard is thus not deformed in the case of heat.
The person skilled in the art only needs to see to it that the Picatinny
rail(s), which are
present if necessary, run on the outer surface of the hand guard parallel to
the lay-on line
- or to the direction of longitudinal extension of the contact surface -
between hand
guard and sleeve; as well as seeing to it that the same lines or surfaces of
hand guard and
sleeve always come into contact with each other, thus become lay-on line or
contact
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surface. The dimensions of the hand guard on the other hand can vary within
the
measurements which are to attribute to tolerance, thermal expansion and/or
wear and tear,
since the tensioning system compensates such dimension changes.
Hence with simple means it is ensured that a hand guard and mounting rail(s)
mounted to
it always maintain their (respective) angular position relative to the axis of
the bore, even
when the hand guard has been removed in the meantime and also when the weapon
has
been fired until the barrel is hot. Thus if the mounting rails have been given
an angular
position parallel to the axis of the bore, they also retain said angular
position. Hence
aiming devices can also be mounted on the hand guard, without a direct
connection
having to exist between the hand guard, which bears the mounting rail for the
aiming
device, and the barrel.
The inner surface of the hand guard is preferably cylindrical or prismatic in
design, since
such a hand guard can be produced cheaply and also easily in mass production.
For this
reason it is expedient to design a straight, continuous longitudinal edge on
the sleeve or to
provide the sleeve with a cylindrical or prismatic outer surface on which the
inner surface
of the hand guard rests.
The tensioning device of the tensioning system is arranged as a clamping
device between
the sleeve and the hand guard. In its clamping position it presses the inner
and outer
surface regions of the hand guard and the sleeve, which are opposite one
another, against
each other, so that the hand guard by and large is fixed to the sleeve (Claim
5).
Preferably, in particular for a realization of the invention in gas-operated
rifles, the
clamping device is arranged between hand guard and sleeve in such a way and
designed
in such a way that it - with regard to the sleeve - is diametrically opposed
to the hand
guard inner surface and sleeve outer surface segments pressed against each
other by said
clamping device and spreads out in its clamping position between hand guard
and sleeve
(Claim 6).
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In the process advantageously a spreader assumes the fixing of the hand guard,
wherein
the spreader is arranged on the clamping device and effects the transmission
of power
between sleeve and hand guard (Claim 7).
Preferably the clamping device exhibits a rotating shaft essentially parallel
to the sleeve
which is arranged between the sleeve and the hand guard and bears a cam. This
cam
constitutes the spreader (Claim 8). In this connection the shaft is arranged
with the cam
on the side of the sleeve which in clamping position is opposite the surface
segment pair
of hand guard and sleeve pressed against each other. The cam makes possible
the smooth
tensioning and relaxing of the clamping device so that the hand guard can be
put on and
taken off practically as often as one likes. In the process the cam can
exhibit a
considerable length in longitudinal direction of the barrel, so that the hand
guard is held
securely without its being locally deformed.
The cam could wedge itself in a clamping position with its excentric part from
inside
between sleeve and hand guard. However, it is preferred that the cam
essentially passes
flush into the shaft on its side radially facing the excentricity. Said shaft
occupies such a
pivoting position in clamping position that the cam supports itself against
the sleeve and
thus elastically bends the shaft. In the process in the clamping position at
least one
tensioning region of the shaft abuts the inside of the hand guard and thus
results in an
areal contact. As a result of this a high tension force can be produced, which
supplies the
corresponding grip of the hand guard, but only a rather slight surface
pressure, because
the force is transferred over a relatively large contact zone between hand
guard interior
and sleeve exterior. In the release position the shaft is distorted opposite
its clamping
position, and the cam either rests loose against the sleeve or releases it
(Claim 9).
In the process it is advantageous if the cam is arranged between the shaft
ends each
forming a tensioning range of the shaft bearing it, so that the shaft in the
clamping
position similar to a leaf spring builds up the clamping force between sleeve
and hand
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guard and correspondingly the magnetic flux runs between sleeve center, cam,
shaft ends
and hand guard. The cam can be mounted on the shaft, is however preferably
connected
to the shaft in one piece. In this way it is guaranteed that the cam never
changes its
angular position with regard to the shaft (Claim 10).
Preferably in the process the sleeve exhibits at least two projections on its
one radial side
which in addition are arranged offset in axial direction (Claim 8). If the
spreader or the
cam is arranged on the radial opposite side and lies axially about between the
two
projections, the hand guard is clamped in such a way that it does not bend
even in the
case of high clamping forces. It supports itself in the process namely on the
one hand in
the region of the sleeve ends, to which on the other hand the two tensioning
ranges
arranged at the shaft ends are diametrically opposed. In addition the mounting
rails
bestow an additional flexural strength to the hand guard. Finally the person
skilled in the
art is familiar with the forces applied by the clamping device and therefore
knows which
measure of clamping in consideration of the production tolerances is still
permissible in
order to hold secure the hand guard and the rails mounted on it in their
desired location.
In the process it is particularly of advantage that the sleeve projections are
designed as
annular rings (Claim 12). Such annular rings, in particular with cylindrical
outer surfaces,
in the case of corresponding inner surface of the hand guard, support said
inner surface
areally, so that it cannot for example be forcefully deformed if the weapon
for example
falls down.
The shaft could exhibit a receiver so that an Allen wrench or the like could
be placed
upon it for its rotation. Preferably however the shaft is connectable or
connected to a
lever for its rotation, whose foot is essentially radially extended from the
shaft to the
outside (Claim 13). The lever can for example be welded on. It remains however
on the
shaft and exhibits with its head end a sufficiently great distance to the
shaft, in order to be
able to adjust said shaft.
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The lever can in the process be preferably formed in such a way that in its
clamping
position it wraps around the sleeve or the hand guard, but with its head
stands away from
said sleeve or hand guard, so that it can also be swiveled to its release
position without a
special tool (Claim 14).
The lever can be seated anywhere on the shaft, for example on its front side
or in the
center. However it is preferred that it is arranged in the region of the rear
shaft end and
behind it, to be more precise on the rear shaft end, a bearing pin is molded
on. The
bearing pin engages in laterally leading recesses of a housing, preferably of
the weapon
housing, and by this means centers the shaft (Claim 15). The rear shaft end is
hence
guided in immediate proximity to the lever in such a way that by means of the
lever great
force can be exercised on the shaft without the shaft subjecting its front
lager bearing to
excessive stress for this reason or going so far from its location that it no
longer runs
parallel to the sleeve.
Advantageously the shaft runs in a recess of the inside of the hand guard.
This recess can
for example be an inside of a Picatinny rail integrated in the hand guard.
Especially in the
case of the shaft with rear bearing pin it is sufficient and preferred that
the front shaft end
supports itself in clamping position of the shaft on the hand guard or a
Picatinny rail
integrated in said hand guard. The walls of such a Picatinny rail in the hand
guard are
namely completely sufficient for fixing of the front shaft end.
Thus the front shaft end does not need to be supported opposite the sleeve.
However, it is
preferred that a slot is built in in the front shaft end in which a spring
clip is seated, said
spring clip extending into a further snap ring groove in the front sleeve end
and by this
means couples the shaft to the sleeve (Claim 16). The spring clip in the
process does not
act as a stationary support, since it can spring out radially from the snap
ring groove or
can be swiveled in circumferential direction to the sleeve. The spring clip
predominantly
serves the purpose of holding the shaft in the case of a removed hand guard.
By this
means the bearing pin constructed on the rear shaft end remains in its
abutment on the
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housing even in the case of a removed hand guard. The shaft thus cannot fall
down, for it
is held in the front by the spring clip and in the rear by the abutment.
It was stated that in principle it is sufficient if the hand guard is only
clamped in radial
direction. In order however to hold the hand guard firm and precisely
positioned on the
weapon even in the case of high, axial acting loading (e.g. recoil),
simultaneously
allowing unhindered thermal expansion, it is preferred that a further cam is
seated near
the rear end of the shaft, said cam engaging in a recess in the hand guard in
the clamping
position of the shaft, preferably engaging radially (Claim 17). In clamping
position the
clamping device hence fastens one end of the hand guard positively to the
weapon, but
allows a free expanding and contracting of the other hand guard end which is
not further
fastened. A removal of the hand guard from the weapon is, however, impossible
as long
as the hand guard is clamped. The above recess in the hand guard is in other
respects
preferably designed to be continuous, so that one can see from the outside
whether the
(further) cam engages into the recess or not. This simplifies the production
and the cam
when locking pushes out any fouling in the recess.
The described holder of the hand guard can be applied in the case of any hand
guard. Due
to the described advantages of the holder however it is preferred if the hand
guard exhibit
on its exterior at least one mounting rail, in particular a Picatinny rail
(Claim 15). Then it
also particularly of advantage that the recess on the inside of the hand guard
constitutes
the inside of a mounting or Picatinny rail, upon which the shaft ends exercise
their
tension force (Claim 19).
The clamping device becomes more secure as a result of the fact that it can be
locked in
its clamping position (Claim 20). A user of the weapon overcomes in the case
of locking
a noticeable latching resistance and recognizes thus solely in the case of
operation -
without a further check being necessary - whether the clamping device is
properly locked
and the hand guard is fixed. This is achieved via a corresponding design of
the active area
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pairings between sleeve and locking element (cam) or between hand guard and
locking
element (tension regions of the shaft) (Claim 21).
The invention also comprises a handheld firearm equipped with the foregoing
described
tensioning system (Claim 22).
The tensioning system according to the invention and the handheld firearm
equipped with
it will now be described in greater detail with the help of exemplary
embodiments and the
enclosed drawings. In the process the figures show the following:
- Figure 1 the lateral view of the front part of an automatic pistol without a
hand guard with a clamping device of the tensioning system
according to the invention,
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- Figure 2 a longitudinal section through a part of the pistol segment shown
in
Figure 1, in the release position of the clamping device, and with
fitted hand guard,
- Figure 3 a longitudinal section as in Figure 2, but in clamping position of
the clamping device,
- Figure 4 a cross-section along Line IV - IV in Figure 2,
- Figure 5 a cross-section along Line V - V in Figure 3,
- Figures 6 and 7 a representation corresponding to Figure 5 with an
alternative
implementation of cam and shaft.
The drawings show a gas-operated weapon which comprises a carrying base block
1,
which represents the housing or is firmly connected to said housing. Therefore
for
simplicity's sake in the following the block is simply termed as "Housing 1".
A barrel 3
with the axis of the bore 4 is inserted into the housing 1 by means of a
spline 7 (Figure 2)
and fastened by means of a slipped over sleeve 5, which like a sleeve nut is
screwed by
means of a thread 9 to the housing 1. On the topside of the housing 1 a
Picatinny rail 23
is constructed.
Further to the front a gas cylinder housing 11 is slipped over the barrel and
fastened with
cross pins 13. The gas cylinder housing 11 is connected to a gas cylinder
running parallel
to the barrel 3 via a gas channel which penetrates the wall of the barrel 3.
Gas channel
and gas cylinder are not shown in the drawing.
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A piston rod 15 parallel to the barrel 3, which is pressed forward by a spring
(not shown)
and moves to the rear in the case of a shot, acts on the breech block carrier
in order to
unlock the mushroom head (Figures 2 and 3) and in order to accelerate it to
the rear
against the force of a breech closing spring (not shown) for opening.
The sleeve 5 surrounds the barrel 3 with clearance and presses said barrel
firmly over a
shoulder and a barrel ring 19 against the housing 1. The thread 9 supplies the
necessary
pressure for this purpose. Thus the sleeve 5 first constitutes a kind of heat
insulation since
over almost its entire length no physical connection to the barrel 3 is made.
Particularly
significant however is the fact that the vibration behavior of the barrel 3
does not change,
regardless of what may be built on the exterior of the sleeve 5.
The inner surface of the sleeve 5 is extensively cylindrical. The outer
surface of the
sleeve 5 can inscribe a circular cylinder, which only touches the front and
rear sleeve end.
Between them the sleeve outer surface is constricted and forms in this way
over the
greatest part of its length a cylinder surface over which the front and rear
sleeve end
project in the manner of a circular ring, to be precise in each case by the
same radial
measure. These two sleeve ends are designed as annular rings 5', 5" with
cylindrical
peripheral area.
The hand guard 21 (Figure 2, 3, 4 and 5) consists of a suitable material, e.g.
plastic,
metal, a plastic with metal inserts or a suitable compound material, and is
formed in one
piece, e.g. as an injection molded part, cast part, extruded profile, milled
part or welded
structure. It exhibits cylindrical inner surface segments 29, 29' (Figures 5,
6 and 7), with
which it radially encompasses the annular rings 5', 5" of the sleeve 5.
The tolerance and heat play opposite the outer surface of the annular rings 5'
5" are such
that the hand guard 21 can be easily slipped onto the weapon without
resistance. In
Figure 4 this is indicated by an annular gap 6 displayed in oversubscribed
manner, which
in the case of locker slipped on hand guard 21 runs between the torus rings
5', 5" and the
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inner surface segments 29, 29'. In the case of hand guard 21 pulled down the
upper inner
surface segment 29 is seated on the torus rings 5' 5" of the sleeve 5 and only
a residual
gap 6' remains between the lower inner surface segment 29' and the torus rings
5', 5"
(Figures 5, 6 and 7).
In the represented exemplary embodiment the topside of the hand guard 21 is
shaped as a
Picatinny rail 25. Said topside connects flush to the Picatinny rail 23 on the
housing 1.
For this purpose, i.e. for alignment of the hand guard 21 (together with
Picatinny rail 25)
in circumferential direction on the sleeve 5, the hand guard exhibits a nose
48 protruding
over its rear frontal area, which engages in a correspondingly designed slot
49 in the
Picatinny rail 23. The region of the hand guard 21 forming the upper Picatinny
rail 25 is
hollowed out from the bottom, which can be necessary for production-technical
reasons,
so that the hand guard 21 exhibits essentially uniform wall thicknesses. The
gas cylinder,
its associate rod assembly and its spring suspension (not shown) proceed in
this upper
hollow space of the hand guard 21.
The seat of the inner surface segments 29, 29' of the hand guard 21 on the
torus rings 5',
5" of the sleeve 5 would be sufficient in and of itself in order to give the
hand guard 21
the necessary grip for its normal usage; not however, in order to achieve its
firm, exactly
reproducible alignment to the axis of the bore 4. In the case of unfavorable
tolerances
between torus rings 5', 5" and the inner surface segments 29, 29' the hand
guard 21 either
cannot be mounted on the weapon, because its interior either has too small of
a diameter,
or it is seated too loosely on the torus rings 5' and 5", because it is
exposed to a powerful
solar irradiation in the case of a cooling barrel 3.
In order to remedy this problem and also give the hand guard 21 a uniquely
reproducible
seat on the weapon, a clamping device 33 is provided which anchors the slipped
on hand
guard 21 exactly on the weapon without however hindering the necessary thermal
expansion in any direction.
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The clamping device 33 exhibits a shaft 35 running essentially parallel to the
barrel 3,
said shaft being seated in the interior of a section of the hand guard 21
designed as the
lower Picatinny rail 27. The named interior lies between the lower inner
surface segment
29'. The shaft 35 is thus housed similar to the throttle linkage 15 in a
hollow space of a
hand guard section constructed as a Picatinny rail. However the bottom of the
interior of
the lower Picatinny rail 27 is, for reasons that will be explained later, not
rounded like it,
but rather flat.
The hand guard 21 also exhibits two lateral Picatinny rails 31 (Figure 5).
The shaft 35 exhibits a swelling 35' and 35" in each of its two end regions.
From its rear
end a bearing pin 39 is coaxial to it, said pin being seated in a receiver
with vertical play
provided in the weapon housing 1. From this bearing pin 39 a lever 37 is
fastened
laterally to the shaft 35. In its clamping position - Figures 5 and 7 - the
lever 37 runs
outside around the sleeve 5 or around the hand guard 21 and contrasts with its
end 38
offset to the outside next to the upper Picatinny rail 25; here, upon the,
viewed from the
rear, left side of the weapon. There this lever end can at any time - even
during the
aiming - be detected with the left eye, so that it is immediately noticed if
the lever 37 is
for example not resting properly on the hand guard (in the closed position)
(Figures 4 and
6). The offset end 38 can in the locking or unlocking of the clamping device
33 also be
actuated with a shoulder strap loop in case greater forces are to be applied
than is possible
in the case of pure manual operation.
The front end region of the shaft 35 ends in a cone-shaped projection which
has a snap
ring groove at its root. This snap ring groove lies radially next to a snap
ring groove
which is built in in the outside of the front annular ring 5' of the sleeve 5.
A spring clip
41, preferably in the form of two, blending circular arcs, of which each is
open at its
topside, is slipped into the snap ring grooves. When the hand guard 21 is
removed, the
spring clip 41 holds the shaft 35 securely, so that it cannot fall off.
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The shaft 35 is constructed as a cam 43 in its center, the side of said cam
opposite the
excentricity exhibiting a broad flattening which blends into the shaft 35. The
cam 43 is
mounted and constructed in such a way that in its clamping position, thus when
the lever
37 is resting on the hand guard 21 (Figure 5), is directed against the sleeve
5 and presses
against said sleeve and by this means bends the shaft 35 a little to the
outside (below).
The flattening of the cam section is designed in such a way that in the case
of a tensioned
shaft 35, that is in its clamping position, said cam section does not exercise
any force on
the hand guard. In the exemplary embodiment a gap remains between the cam
section of
the shaft and the inside of the hand guard 21 opposite said cam section.
The two shaft swellings 35', 35" however are pressed down by the bending
stress of the
shaft 35 to the bottom of the interior of the lower Picatinny rail 27 and pull
the upper
inner surface segment 29 to the cylindrical outer surfaces of the torus rings
5' and 5".
With this the shaft 35 acts over the cam 43 like a leaf spring under tension.
The hand
guard 21 is thus coupled with the sleeve 5 in defined location. For this
purpose the
receiver in the housing 1 centers the bearing pin 39 laterally with sufficient
vertical play
so that the rear shaft swelling 35" can bevel itself in the case of tensioning
onward to the
floor of the interior. The spring clip 41 permits a corresponding vertical
play for the front
shaft swelling 35'. The lateral centering takes place if necessary also
additionally over the
lateral inner surfaces of the interior allocated to the lower Picatinny rail
27, said inner
surfaces being adapted to the diameter of the shaft swelling 35', 35".
The clamping position is shown in Figure 3, from which it can clearly be seen
that the
shaft 35 is slight bent downward and whose swellings 35', 35" press against
the bottom
of the interior allocated to the lower Picatinny rail 27. In the release
position of Figure 2
the cam is laterally distorted and the shaft 35 springs back to its initial
position. The
release and clamping positions are shown in cross-section in Figures 4 and 5.
In clamped state the hand guard 21 is always fixed in the same angular
position relative
to the axis of the bore and retains this angular position even in the case of
thermal
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WO 2006/103062 PCT/EP2006/002866
expansion. While it is true that the front shaft swelling 35' holds the hand
guard, it
however hinders its thermal expansion only immaterially. In the release
position on the
other hand the hand guard 21 can easily be pulled to the front or slipped on
from the
front.
For further securing in axial direction an excentric nose 45 is arranged at
the rear shaft
end between the lever 37 and the Swelling 35" (Figure 3). This nose extends
radially
beyond the swelling 35", to be precise in the direction of the side opposing
the cam 43.
Radially opposite this a collar segment 46 is constructed, which is
accommodated
between the rear frontal area of the sleeve 5 and the housing 1, and with it
fixes the shaft
35 axially. If the lever 37 is locked in place and hence the shaft 35 is
twisted from the
release position to the clamping position, the nose 45 dips down into a (e.g.
radial) recess
47 in the hand guard 21. By the engagement of the nose 45 into the recess 47
the hand
guard 21 is also positively fixed in axial direction.
With this the three above described couplings of the mechanical hand guard 21
to the
weapon are constructively separated from each other:
- The hand guard 21 is radially coupled to the sleeve 5, to be precise via its
radial
supporting surfaces, i.e. its upper inner surface segment 29, said supporting
surfaces radially support themselves on the annular rings 5' and 5" of the
sleeve.
This in turn is achieved with the help of the tensioned shaft 35, whose
central cam
43 presses radially against the sleeve 5 and whose two bulged end regions 35',
35" press radially against the inner surface of the hand guard 21.
- The axial coupling for absorption, in particular recoil forces, takes place
via the
nose 45 in the recess 47 and the collar element 46.
- And the alignment in circumferential direction takes place via the nose 45
and its
holding fixture or slot 49.
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An existing common weapon, which does not have a sleeve in accordance with the
invention for barrel fastening, but rather has only the conventional sleeve
nut for this
purpose, can at any time through the use according to the invention of a
sleeve, a
clamping device and a component, in particular hand guard - in each case of
the
described type - be retrofitted into a weapon in accordance with the invention
(provided
the throttle linkage permits this). Consequently even existing weapons can be
retrofitted
into a universal weapon (automatic pistol, machine gun, light machine gun
etc.), at whose
front shaft aiming devices or the like can be mounted, which must exhibit a
precisely
reproducible angular position relative to the weapon. In the case of aiming
devices the
hand guard with Picatinny rail works to a certain extent as an interface. The
tensioning
system of the invention however also makes possible the mounting and its
precisely
reproducible alignment of other components to the barrel, for example an
additional
weapon, without such an interface.
In the above described embodiment the coupling between the sleeve 5 and the
hand guard
21 takes place via the correspondingly cylindrically constructed inner surface
segment 29
of the hand guard 21 with cylindrically running outer surfaces of the sleeve
annular rings
5', 5". In an embodiment not shown the hand guard can also exhibit even
surfaces inside
which touch the annular rings along axial running contact lines from the
outside roof-like
or which encompass the periphery of the annular rings 5', 5" in tangent-like
manner.
Conversely the outer surfaces of the annular rings can also be constructed
polygonal
(edge progression in axis direction), for example like the outer surfaces of a
screwed nut,
and the inner surfaces of the hand guard can be constructed cylindrical,
wherein in turn
regions of the hand guard inner surface support themselves in line-like manner
on the
edges. Naturally the supporting surfaces of sleeve and hand guard/component
allocated to
each other can also be designed more or less complementary to one another.
The active area of the cam 43 acting on the sleeve 5 is designed in such a way
that the
cam 43 in the case of its pivoting to its clamping position first with a
rounding glides
along the sleeve 5 and then rests in the clamping position with a flattened
region on the
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WO 2006/103062 PCT/EP2006/002866
sleeve 5, so that in the case of jamming a latching resistance in the
transition from
rounded to the flattened region is perceptible. Such a flattening can also
alternatively or
additionally be provided on the bulged shaft ends 35', 35", which then bevel
themselves
in clamping position with the flattened region to the bottom of the lower
Picatinny rail 27
or to the bottom of a recess in the hand guard 21 running there. To this
purpose the
bottom preferably runs even, in order to further amplify the desired snap-in
effect.
Figures 6 and 7 illustrate an embodiment in which the snap-in effect is
obtained by the
fact that the cam 43 in its final clamping position does not point precisely
upward, but
rather so to speak has already exceed its zenith. In the case of locking the
cam 43 shortly
before the final position first passes through the position shown in Figure 6,
in which the
shaft 35 is maximally tensioned and is in the transition to the final clamping
position
(Figure 7) somewhat relaxed again. This tangible relaxing, similar to a toggle
mechanism, causes the desired snap-in effect. The active area of the cam does
not need to
be designed flattened in the process. Here too the residual gap 6' is shown
oversubscribed.
In the case of another (not shown) embodiment the central shaft region
supporting itself
on the sleeve is formed concentrically to the shaft axis and the shaft ends
are provided
with cams which press on the bottom (of the interior above the lower Picatinny
rail) of
the hand guard and thus pull said hand guard down. In the case of a further
embodiment
in the clamping position of the shaft its central region can also rest on the
above named
bottom of the hand guard while the shaft ends support themselves on the sleeve
ends.
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