U.S. patent number 3,748,956 [Application Number 05/259,616] was granted by the patent office on 1973-07-31 for silencer for fire arms.
This patent grant is currently assigned to Carl Walther Sportwaffenfabrik. Invention is credited to Siegfried Hubner.
United States Patent |
3,748,956 |
Hubner |
July 31, 1973 |
SILENCER FOR FIRE ARMS
Abstract
A silencer comprises a hollow cylindrical casing closed by front
and rear end walls having aligned openings to define a passage
therethrough for a bullet and propellant gases emerging from the
muzzle opening of a firearm. A plurality of partitions within the
casing define chambers with at least one chamber being constructed
as a return-flow chamber. The partitions have openings therein for
the passage of the bullet with the edges of the openings being
serrated and bent toward the rear end wall of the casing. A tubular
element with openings therein defines a passage through the
return-flow chamber for the bullet and gases.
Inventors: |
Hubner; Siegfried
(Stuttgart-Heumaden, DT) |
Assignee: |
Carl Walther Sportwaffenfabrik
(Ulm/Donau, DT)
|
Family
ID: |
5809884 |
Appl.
No.: |
05/259,616 |
Filed: |
June 5, 1972 |
Foreign Application Priority Data
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|
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|
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Jun 4, 1971 [DT] |
|
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P 21 27 877.3 |
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Current U.S.
Class: |
89/14.4 |
Current CPC
Class: |
F41A
21/30 (20130101) |
Current International
Class: |
F41A
21/00 (20060101); F41A 21/30 (20060101); F41c
021/18 () |
Field of
Search: |
;89/14R,14L,14D |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Bentley; Stephen C.
Claims
What is claimed is:
1. A silencer for a firearm comprising a hollow cylindrical casing
having a front end wall and a rear end wall, said rear end wall
having an entrance opening through which a bullet and discharge
gases pass from the muzzle opening of a firearm said front end wall
having an exit opening aligned with said entrance opening to define
a passage for a bullet and gases through the casing, a plurality of
partitions each having a passage opening therein within said casing
to define a plurality of chambers, means within one of said
chambers for defining a return-flow chamber having conical front
end and rear end walls, a tubular element between the end walls of
said return-flow chamber aligned with said passage, there being
openings in the wall of said tubular element, the edges of the
partition passage openings forwardly of said return-flow chamber
being serrated and bent toward the casing rear end wall.
2. A silencer as claimed in claim 1 and comprising a coarse wire
screen within said return-flow chamber.
3. A silencer as claimed in claim 2 wherein the wires of said
screen have a thickness of at least 0.5 to 1.0 mm.
4. A silencer as claimed in claim 3 wherein said wires have a
rectangular cross section.
5. A silencer as claimed in claim 1 wherein the bent serrated edges
of said partition openings are funnel-shaped and the lengths of the
serrations increase from the front end wall toward the rear end
wall.
6. A silencer as claimed in claim 1 wherein at least one partition
adjacent said front end wall has additional openings therein.
7. A silencer as claimed in claim 1 wherein the conical end walls
of said return-flow chamber taper toward the casing rear end wall.
Description
The present invention relates to silencers for hand firearms, more
particularly, to the structure of a plurality of partitions within
the silencer forwardly of a return-flow chamber.
Up to the present time, known silencers for hand firearms can be
generally classified into two groups. In one group, the discharge
and propellant gases that follow the bullet into the silencer are
stored for a short period of time in a plurality of successive
chambers which are closed to the outside. This produces a throttle
expansion of the propellant gases through the bullet exit opening
in the front end wall of the silencer. In a second group, at least
a portion of the propellant gases are diverted to the exterior
through a plurality of lateral openings in the silencer. The
silencers of the first group have gained particularly wide
acceptance because of better efficiency. The silencers of the
second group have been employed, as a practical matter, only in
those cases where it is desired to avoid the propagation of
propellant gases at supersonic velocities and the velocities of the
gases are to be lowered into the subsonic range prior to discharge
of the bullet from the barrel.
Silencers have also been proposed in which there is provided a
return-flow chamber positioned immediately adjacent to the silencer
rear wall opening through which the bullet and gases enter the
silencer. Such a chamber is provided with a central tubular element
to define a passage for the bullet and gases and is capable of
receiving a large portion of the propellant gases following the
projectile. Such silencers equipped with return-flow chambers have
been found to be quite effective.
In order to achieve a more effective storage of a large portion of
the propellant gases in a return-flow chamber silencer as well as
in other chambers formed by successive partitions, it has been
proposed to provide funnel-shaped structures axially pOsitioned on
the partitions so as to force the propellant gases following the
projectile to expand and thus remove a large portion of such gases
from moving along the direction of the bullet. It has also been
proposed to provide lateral interruptions in such funnel-shaped
walls in order to improve the flow of the propellant gases to these
walls. It has further been proposed to establish a turbulence in
the propellant gases by various arrangements of guiding fins.
Inducing these turbulent movements in the gases results in an
effective filling of the various chambers of the silencer.
However, it is a general rule that the silencing effect achieved in
such silencers becomes greater as the manufacturing cost of the
silencer increases. In addition, the return-flow chamber type of
silencer does not permit any further reduction of the noise of
discharge below a certain sound level. This results from the fact
that the forcing of the propellant gases to the desired degree of
expansion and, accordingly, the possibility of a short period
storage in the chambers cannot be effectively obtained with known
silencers.
It is therefore the principal object of the present invention to
provide a novel and improved silencer for firearms.
It is another object of the present invention to provide a more
efficient silencer of the type having a return-flow chamber and a
plurality of successive chambers formed by a series of
partitions.
It is a further object of the present invention to provide a
silencer having structural features therein which effectively
divert a large portion of the discharge gases following closely
upon and in close contact with the projectile.
It is still another object of the present invention to provide a
silencer having effective structural elements for diverting gas
flow adjacent and following a projectile which is effective in
operation and inexpensive to manufacture.
The objects of the present invention are achieved and the
disadvantages of the prior art as described above are eliminated by
the silencer of the present invention which essentially comprises a
hollow cylindrical casing having front and rear end walls with
aligned openings therein to define a passage for the bullet and
discharge gases. A return-flow chamber is provided in the rearward
portion of the silencer and has conical-shaped forward and rear
walls. A tubular element extends between the end walls of the
return-flow chamber and is aligned with the passage for the bullet.
A plurality of partitions are positioned forwardly of the
return-flow chamber with the partitions having passage openings
therein. Each passage opening has a serrated edge with the
serrations being bent rearwardly to define a funnel which diverts
effectively the gases flowing directly in front of, beside and
behind the bullet. The conical end walls of the return-flow chamber
prevent an excessively uniform or smooth gas thrust and facilitate
the flow of discharge gases through openings provided in the rear
wall of the return-flow chamber. Gases entering the tubular element
of the return-flow chamber behind the projectile are drawn off into
the return-flow chamber through a plurality of lateral openings in
the tubular element. The pressure waves thus formed by the
discharge gases are partially extinguished by striking pressure
waves reflected in the return-flow chamber.
On the basis of tests and measurements conducted on a silencer
constructed in accordance with the present invention, there was
obtained a much more effective silencing effect of the noise
produced by the discharge of a firearm than of other known
silencers.
Other objects and advantages of the present invention will be
apparent from the accompanying description when taken in
conjunction with the following drawings, which are exemplary,
wherein;
FIG. 1 is a longitudinal sectional view through a silencer of the
present invention;
FIG. 2 is a front elevational view of one of the rear partitions in
the silencer of FIG. 1; and
FIG. 3 is a front elevational view of one of the forward partitions
of the silencer of FIG. 1.
Proceeding next to the drawings wherein like reference symbols
indicate the same parts throughout the various views a specific
embodiment of the present invention will be described in
detail.
As may be seen in FIG. 1, the silencer comprises a hollow
cylindrical casing 10 closed by a rear end wall 11 and a front end
wall 12. The rear end wall 11 is provided with an entrance bore 13
through which projects a muzzle 14 of a hand firearm. The muzzle 14
projects into the silencer and the silencer is attached to the
muzzle by a threaded connection.
The front end wall 12 is provided with a bullet exit opening 15.
The exit opening 15 is the only opening in the silencer through
which discharge gases can escape.
The interior of the silencer is divided into a plurality of
individual chambers by means of a plurality of partitions.
Immediately subsequent to the entrance opening 13 of the silencer
there is provided a return-flow chamber 16 formed by a conical
front end wall 17 and a conical rear end wall 18. A tubular element
19 passes through the chamber 16 between the end walls 17 and 18
and forms a passage for a bullet and discharge gases. The outer
face of the return-flow chamber 16 is formed by the silencer casing
10. A plurality of openings 20 are provided in the conical end wall
18 and openings 21 are provided in the tubular element 19 to
provide passages for lateral flow of the discharge gases into the
chamber 16. The rear wall openings 20 are conical in shape which
provides a throttling of the gases flowing outwardly from the
return-flow chamber 16.
The two end walls 17 and 18 of the return-flow chamber are conical
and taper toward the rear end wall 11 of the silencer. The conical
shape of rear end wall 18 avoids an excessive initial thrust
exerted by the gases as they enter the silencer through opening 13.
In addition, the gases expanding in the chamber defined by the rear
end wall 11 and the conical wall 18 of the chamber flow through
openings 20 into the interior of the return-flow chamber 16.
The conical shape of the front end wall 17 forces an expansion of
the propellant gases discharged from the tubular element 19 in a
forward direction.
The gases immediately following the bullet passing through the
tubular element 19 are drawn through the lateral openings 21 into
the interior of the return-flow chamber. This will continue until
the pressure is equalized between the interior of the tube 19 and
the interior of the return-flow chamber 16. In addition, the air
displaced by the bullet passing through the tube 19 is drawn
through openings 21 into the return-flow chamber. In order not to
decrease the effectiveness of the subsequent chambers, provisions
are made to avoid or at least diminish the effect of the pressure
wave pushed in front of the bullet. This is achieved by positioning
a very coarse wire screen 22 in the interior of the return-flow
chamber 16. The wires of the screen have a diameter or thickness of
at least 0.5 to 1.0 mm. and preferably the wires have a rectangular
cross-section. The pressure waves expanding within the return-flow
chamber 16 and basically originating from the propellant gases
flowing in through openings 20 of the rear wall 18 of the return
flow chamber and partially overtaking the movement of the bullet
are broken up and partially reflected by the wire screen 22. The
pressure waves reflected by the wire screen 22 and the front end
wall 17 of the return-flow chamber thus partially extinguish
subsequent pressure waves and, in effect, bring about a phase shift
of 180.degree. in the pressure waves. The wire screen is thus not
employed for the purpose of absorbing the energy of propellant
gases as in the case of known wire screens but for bringing about a
maximum reflection of the pressure waves within the return flow
chamber.
Additional chambers are formed subsequently to the return-flow
chamber 16 by a plurality of partitions 23, 24, 25 and the inner
face of the cylindrical casing 10. These partitions are provided
with passage openings 26 arranged concentrically with respect to
the casing 10 and are aligned with the tubular element 19 so as to
define a passage through the silencer for the bullet and discharge
gases.
The partitions 23, 24 and 25 are in the form of discs. The edges of
the passage openings 26 are notched or serrated with these
serrations being bent rearwardly toward the casing rear end wall
11. The rearward partitions 23 or those furthest away from the
front wall of the silencer have prongs or serrations 27 which are
larger than the prongs or serrations 28 of the forward partitions
24 and 25. As can be seen in FIG. 1, the passage openings 26 as
defined by the prongs 27 and 28 are funnel-shaped which divert or
expand the propellant gases passing through the passages 26 as
known in the art.
In addition to the passage openings 26, the foremost partitions 25
are provided with additional openings 29 that facilitate the
equalization of the overpressure prevailing in the silencer after a
shot to the atmosphere pressure outside of the silencer.
The rearwardly bent serrations or prongs 27 and 28 in the
partitions subsequent to the return-flow chamber 16 function to
break up the waves produced by the bullet passing through the
silencer. They produce an effective turbulence in the cylindrical
column of discharge gases following the bullet and also in the
gases flowing directly beside the bullet or drawn along by the
bullet. Thus, the gases are progressively diverted into the
chambers formed by the partitions 23, 24 and 25. It is preferable
that the extent of bending of the prongs or serrations, and thus
their lengths, increases from the front toward the rear of the
silencer. This structure enables the funnel-shaped bent edges of
the passages 26 to bring about an expansion of the discharge gases
that are rendered turbulent.
The partitions 23, 24 and 25 having the prongs 27 and 28 can be
manufactured and mounted in the cylindrical casing 10 in a simple
operation. The partitions can be formed of duraluminum discs and
the passages 26 formed by punching cross slots at the centers of
the discs and by bending the resulting prongs or serrations by a
suitable punch. In the front partitions 24 and 25 the hole 26 is
bored initially so that the lengths of the prongs 28 are relatively
small. Tubular sleeves 30 are positioned within the casing 10
between discs 23, 24, 25, end walls 17 and 18 of the return-flow
chamber 16 and outer end walls 11 and 12 of the silencer for
axially spacing the components within the silencer and for
positioning the components therein.
Thus it can be seen that the present invention has disclosed an
improved silencer comprising a return-flow chamber and a plurality
of partitions defining successive chambers therein. The edges of
the passages in the partitions are funnel-shaped and notched to
improve the diversion and expansion of the gases and to enhance the
turbulence of the gases diverted into the individual chambers. The
components of the silencer are simple in structure and can be
assembled with a minimum of labor so that the result is a simple
but effective silencer which is relatively inexpensive in cost.
It will be understood that this invention is susceptible to
modification in order to adapt it to different usages and
conditions, and accordingly, it is desired to comprehend such
modifications within this invention as may fall within the scope of
the appended claims.
* * * * *