U.S. patent application number 11/699453 was filed with the patent office on 2010-09-23 for percussion device for a medium or large calibre weapon.
This patent application is currently assigned to CTA International. Invention is credited to Michel Baubois, Michel Lenoble.
Application Number | 20100236392 11/699453 |
Document ID | / |
Family ID | 37024998 |
Filed Date | 2010-09-23 |
United States Patent
Application |
20100236392 |
Kind Code |
A1 |
Lenoble; Michel ; et
al. |
September 23, 2010 |
PERCUSSION DEVICE FOR A MEDIUM OR LARGE CALIBRE WEAPON
Abstract
A percussion device for a medium or large caliber weapon
incorporating a firing pin, spring means and a drive cam for the
firing pin enabling its displacement in translation up to an
"armed" position and the compression of the spring means, such
device wherein it incorporates means to immobilize the firing in
the "armed" position, these means being supported by the weapon
breech and able to take up a position in which they immobilize the
firing pin and another in which they release the firing pin.
Inventors: |
Lenoble; Michel; (Bourges,
FR) ; Baubois; Michel; (Bourges, FR) |
Correspondence
Address: |
STEPTOE & JOHNSON LLP
1330 CONNECTICUT AVENUE, N.W.
WASHINGTON
DC
20036
US
|
Assignee: |
CTA International
Bourges Cedex
FR
|
Family ID: |
37024998 |
Appl. No.: |
11/699453 |
Filed: |
January 30, 2007 |
Current U.S.
Class: |
89/27.12 |
Current CPC
Class: |
F41A 19/37 20130101 |
Class at
Publication: |
89/27.12 |
International
Class: |
F41A 17/56 20060101
F41A017/56 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 30, 2006 |
FR |
06.00824 |
Claims
1.-3. (canceled)
4. A percussion device according to claim 12, wherein said sear
means comprises an immobilizing a face substantially orthogonal to
the axis of displacement of said firing pin for ensuring
immobilization of said firing pin in the armed position, and a
bearing face for said actuator, substantially orthogonal to said
immobilizing face of said firing pin and to the axis of
displacement of said actuator, said bearing face for being
subjected to the action of said actuator.
5. A percussion device according to claim 4, wherein said sear
means is L-shaped, a first branch of which, positioned orthogonally
to said firing pin, is for ensuring immobilization of said firing
pin in the armed position, and a second branch, substantially
perpendicular to the first branch and to said actuator, is for
being subjected to the action of said actuator.
6. A percussion device according to claim 4, wherein said sear
means is supported by a pivot having a hinge pin orthogonal to said
immobilizing face of said firing pin.
7. A percussion device according to claim 6, wherein said sear
means comprises a beveled face onto which said firing pin presses
when being moved into its armed position thereby pivoting said sear
means around said pivot.
8. A percussion device according to claim 5, wherein said sear
means is supported by a pivot having a hinge pin orthogonal to said
immobilizing face of said firing pin.
9. A firing process for a piece of ammunition that includes a
percussion device according to claim 12, comprising: triggering
rotation of the drive cam by a first firing cycle command to drive
said firing pin in translation to its armed position and to
compress the spring means; immobilizing the firing pin by said sear
means and by a second percussion command; the triggering
displacement of the sear means to release the firing pin which,
under the action of the spring means, is displaced in translation
and strikes an ammunition thereby firing it.
10. The firing process for a piece of ammunition according to claim
9, wherein said percussion device includes position sensors for the
drive cam and the percussion command is delivered only when said
drive cam is in a percussion zone.
11. The firing process for a piece of ammunition according to claim
10, wherein movement of the firing pin into the armed position and
compression of the spring means are performed simultaneously when
said ammunition is pushed into position.
12. A percussion device for a medium or large caliber weapon, and
for support by the breech of such a weapon, said device comprising:
a firing pin body housing a firing pin and spring means for driving
said firing pin in firing axial translation; a drive cam for
displacing said firing pin in the opposite axial translation
direction and loading said spring means thereby placing said firing
pin in an armed position; sear means for immobilizing the firing
pin in an armed position, said sear means being movable from a
safety position wherein the sear means immobilizes the firing pin
in its armed position, to a firing position wherein the sear means
can release the firing pin for firing translation. an
electromagnetic actuator for displacing the sear thereby releasing
the firing pin for firing translation; a spring-loaded tappet for
exerting force on the sear means in a direction opposite to that of
the actuator; an arming lever, one end of which is mounted for
rotation about an arming axis spaced from and orthogonal to the
axis of firing translation of the firing pin; a cam follower
mounted for rotation about the arming axis and connected to the
arming lever; the drive cam mounted for rotation about a third axis
parallel to the arming axis and spaced therefrom so that the cam
follower abuts the drive cam, whereby rotation of the drive cam
will cause rotation of the cam follower and the arming lever; a
second end of said arming lever contacting a drive finger on the
firing pin body for moving the firing pin in axial translation
thereby loading the firing pin spring and placing the firing pin in
armed position.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The technical scope of the present invention is that of
medium and large caliber weapons, and more particularly ammunition
percussion devices positioned in such weapons.
[0003] 2. Description of the Related Art
[0004] The equipment of military vehicles necessitating the use of
weapons integrated into a turret increasingly requires the use of a
fire control able to ensure, at all times, the control in space of
the position of the gun barrel, be the carrier at rest or in
movement.
[0005] This constraint of having to ensuring the firing of a
turreted weapon with a carrier in movement, whilst retaining a high
probability of reaching the target, obliges both the position of
the barrel in space as a function of time and also the projectile
launching time to be controlled.
[0006] Present-day weapon mechanisms generally carry out firing in
two phases; a first phase in which the ammunition is pushed into
position and triggered by pressing on the fire control and a second
percussion phase of the ammunition triggered by a computer
verifying that the gun barrel is aligned with the objective when
the projectile exits the barrel.
[0007] The percussion of the ammunition implements a cam whose
geometry firstly enables the compression of spring means and
secondly the release of the firing pin.
[0008] A major drawback to these devices lies in the fact that the
reaction time between the compression of the spring means and the
exiting of the projectile from the barrel muzzle necessarily
exceeds a few tenths of a second. This cycle time is not compatible
with firing in movement which necessitates a time of a few
hundredths of a second between the validation by the computer and
the actual percussion of the ammunition.
SUMMARY OF THE INVENTION
[0009] The aim of the present invention is to supply an
electromagnetic device aiming to overcome these problems.
[0010] The device thus relates to a percussion device for a medium
or large caliber weapon incorporating a firing pin, spring means
and a drive cam for the firing pin enabling the displacement in
translation of the firing pin up to an "armed" position and the
compression of the spring means, such device wherein it
incorporates means to immobilize the firing in the "armed"
position, these means being supported by the weapon breech and able
to take up a position in which they immobilize the firing pin and
another in which they release the firing pin.
[0011] According to one characteristic of the invention, the means
to immobilize the firing pin in the "armed" position is a sear
displaced by an actuator so as to release the firing pin.
[0012] According to another characteristic of the invention, the
percussion device incorporates a tappet exerting a stress on the
sear in a direction substantially opposing that of the
actuator.
[0013] According to yet another characteristic of the invention,
the sear incorporates a face to immobilize the firing pin,
substantially orthogonal to the axis of displacement of the firing
pin, to ensure the immobilization of the firing pin in the "armed"
position, and a bearing face for the actuator, substantially
orthogonal to the immobilizing face of the firing pin and to the
axis of displacement of the actuator, the bearing face being
subjected to the action of the actuator.
[0014] According to another characteristic of the invention, the
sear is "L" shaped, a first branch of which, positioned
orthogonally to the firing pin, ensures the immobilization of the
firing pin in the "armed" position and a second branch,
substantially perpendicular to the first one and to the actuator,
is subjected to the action of the actuator.
[0015] According to another characteristic of the invention, the
sear is supported by a pivot with a hinge pin orthogonal to the
immobilizing face of the firing pin.
[0016] According to another characteristic of the invention, the
sear incorporates a beveled face onto which the firing pin presses
when being moved into its "armed" position enabling the bearing
stress of the firing pin on the beveled face to be transformed into
a pivoting of the sear around its pivot.
[0017] Lastly, the invention also relates to a firing process for a
piece of ammunition implementing a percussion device according to
the invention, wherein the rotation of the cam is triggered, by
means of a first "firing cycle" command, so as to drive the firing
pin in translation up to its "armed" position and compress spring
means, and by means of a second "percussion" command, the
displacement of the immobilizing means is triggered so as to
release the firing pin which, under the action of the spring means,
is displaced in translation and strikes the ammunition, thereby
firing it.
[0018] According to one characteristic of the process, the
percussion device incorporates cam position sensors and the
"percussion" command is only delivered when the cam is in a
percussion zone.
[0019] According to one characteristic of the process, the movement
of the firing pin into the "armed" position and the compression of
the spring means are performed simultaneously when the ammunition
is pushed into position.
[0020] A first advantage of the device according to the invention
lies in the reduction in time between the firing command and the
firing of the ammunition.
[0021] Another advantage lies in the possibility of adapting the
device to all types of medium or large caliber weapon.
[0022] Another advantage lies in the fact that the elements
composing the device according to the invention may be controlled
manually, thereby enabling the device to function even in the event
of the failure or destruction of the vehicle's power source.
[0023] Another advantage lies in the fact that the device according
to the invention integrated into a weapon with an advanced firing
control prevents any firing "out-of-zone" since only the appearance
of the percussion command linked to the coincidence between the
laying of the gun and the line of sight authorizes the ammunition
to be fired.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Other characteristics, particulars and advantages of the
invention will become apparent from the following description given
by way of illustration and in reference to the appended drawings,
in which:
[0025] FIGS. 1 and 2 show a percussion device according to the
invention, when being placed in its "armed" position,
[0026] FIG. 3 shows an embodiment of the sear,
[0027] FIG. 4 shows an embodiment of the cam,
[0028] FIG. 5 shows a variant embodiment of the sear, and
[0029] FIG. 6 shows the immobilizing of the firing pin in its
"armed" position.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0030] FIGS. 1 and 2 are respectively front and rear perspective
views showing an example embodiment of the percussion device
according to the invention, being placed in its "armed" position.
For the sake of clarity, only those elements required for the
comprehension of the invention have been shown. Certain elements,
such as the drive means for the cam, the ammunition or the gun
breech, are not shown but are already well known to someone skilled
in the art and thus do not require any further description or
specific representation.
[0031] The percussion device thus shown is a percussion device for
a medium or large caliber weapon incorporating a cam 1, an arming
lever 2, a firing pin 4, spring means 5, a sear 8, an actuator 6
and a tappet 10. This device is arranged in a classical manner in
the breech of the weapon it equips.
[0032] The cam 1 is made in a known manner. It has a rotational
movement around rotational axis Z and incorporates a lateral
rolling surface 12 (which will not be further described)
cooperating with the arming lever 2 so as to drive it in
rotation.
[0033] The arming lever 2 incorporates a rotation shaft 33 whose
ends 23 and 24 are supported by bore holes in the breech so as to
form a pivot link with the breech. The arming lever 2 also
incorporates a pin 22, that is off-centre with respect to the shaft
33, around which a roller 11 pivots that is intended to cooperate
with the lateral rolling surface 12 of the cam 1. The arming lever
lastly incorporates a groove 21 (FIG. 2) intended to cooperate with
the firing pin 4.
[0034] The firing pin 4 is substantially cylindrical in shape, with
axis X. It incorporates a percussion rod 14 at one end intended to
ensure the percussion of the ammunition, and a limit stop 18 at the
other end enabling the compression of the spring 5 during the
displacement of the firing pin. It also incorporates a drive finger
3 cooperating with the groove 21 in the arming lever 2 and an
immobilizing finger 13 intended to cooperate with the sear 8. The
firing pin 4 is arranged in a sleeve (not shown) which holds it in
place and enables it to translate along axis X. Thus, when the
arming lever 2 is in rotation, the drive finger 3 is displaced
along the groove 21 and only transmits to the firing pin 4 the
component along axis X of the displacement of the arming lever 2,
thereby transforming the rotation of the lever 2 into the
translation of the firing pin 4.
[0035] The spring 5 is positioned along axis X of the firing pin 4
between the firing pin limit stop 18 and a support (not shown) for
the spring integral with the breech.
[0036] The sear 8 (more particularly illustrated in FIG. 3) is
substantially in the form of a polyhedron. It incorporates a face
15 to immobilize the firing pin (shown in FIG. 2), substantially
orthogonal to the axis of displacement X of the firing pin 4, and a
bearing face 17 for the actuator, substantially orthogonal to the
face 15 to immobilize the firing pin. The sear 8 is linked to the
breech by means of a pin 32 making a pivot link between the sear 8
and the breech. The pin 32 is substantially parallel to the axis of
displacement X of the firing pin 4.
[0037] The sear 8 also incorporates a beveled face 30, arranged
such that it forms an angle of approximately 45.degree. with the
axis of displacement X of the firing pin 4, enabling a stress along
axis X to be transformed into an orthogonal stress and thereby
making the sear 8 revolve around its pin 32.
[0038] The actuator 6 is classically in the form of a motor body
(for example, and electric or pneumatic jack) fitted with a rod 7
able to translate and transmit a stress to the sear 8. The rod 7
presses on bearing face 17 of the sear enabling a stress to be
applied to the sear 8 so as to make it pivot around its pin 32. For
example, an electromagnet will be used by way of an actuator 6, the
coil of this electromagnet enabling a hub to be displaced onto
which the rod 7 of the actuator will be joined.
[0039] The tappet 10 is arranged in opposition to the actuator 6.
It is subjected to the action of a spring 9 and provides a constant
stress on the sear 8 in an opposing direction to that of the rod
7.
[0040] FIG. 4 shows the cam 1 making a rotational movement around
rotational axis Z in direction F thanks to motor means (not shown).
The cam 1 is already known and its geometry is defined by the
weapon into which the invention is integrated. In this embodiment,
the cam 1 incorporates a lateral rolling surface 1 for the roller
11 on which different zones are organized: a so-called "low dead
centre" zone 25 with constant radius R1; a so-called "spring
compression" zone 26 whose distance from axis Z increases following
F; a so-called "high dead centre" 27 with constant radius R2
greater than R1; a "dog-tooth" zone followed by a so-called
"percussion" zone 28 and a "firing pin withdrawal" zone 29. The cam
1 is integrated in the kinematics of the weapon system and makes
one revolution per weapon cycle.
[0041] FIG. 3 shows an embodiment of the sear 8. In this
illustration, the sear 8 can be seen to incorporate a bore hole 31
providing a passage for pin 32.
[0042] FIG. 5 illustrates a variant embodiment of the sear 8. In
this variant, the sear 8 is L-shaped, a first branch 19 of the L,
arranged orthogonally to the firing pin 4, incorporates a face 15
to immobilize the firing pin and ensures that the firing pin 4 is
immobilized in its "armed" position, and a second branch 20,
substantially perpendicular to the first one and to the actuator 6,
incorporates a bearing face 17 subjected to the action of the
actuator 6. A bore hole 31 with an axis orthogonal to the face 15
provides a passage for a pivot.
[0043] The device according to the invention functions as
follows:
[0044] The firing cycle is initiated by means of a first "firing
cycle" command (for example, when the firer presses on a firing
button). As soon as the firing cycle is engaged, the cam 1 is made
to revolve following arrow F. The profile of the lateral rolling
surface 12 of the cam 1 is defined so as to ensure the rotation of
the arming lever 2 by means of the roller 11 when the weapon's
firing cycle is engaged. Thus, the circular movement of the cam 1
is transformed into a rotational movement of the arming lever 2.
The law of movement of the arming lever thus depends on the
manufacturing profile of the cam 1 which in turn depends on the
kinematics of the weapon concept intended to receive the invention.
Someone skilled in the art can define this profile in a known
manner for the weapon in question.
[0045] While the cam 1 is revolving, the roller 11 rolls on the
lateral rolling surface 12. When the roller rolls on the low dead
centre 25, the raceway is circular, there is thus no movement of
the arming lever 2.
[0046] When the roller 11 reaches the spring 5 compression zone 26,
the geometry of the raceway tends to distance the roller 11 from
the rotational axis X of the cam, thereby driving the arming lever
2 in rotation. The groove 21 in the arming lever 2 acts as a
bearing point for the drive finger 3 of the firing pin. Thus, the
movement of the arming lever 2 is transformed into a rectilinear
translational movement of the firing pin 4. The translation of the
firing pin 4 causes the compression of the percussion spring 5. The
finger 13 of the firing pin 4 then presses against the beveled face
30, thereby causing the sear 8 to revolve around its axis 3 and to
retract, allowing the firing pin 4 to pass.
[0047] At the end of the displacement of the firing pin, the finger
13 of the firing pin 4 is no longer pressing on the beveled face 30
of the sear 8 which, under the action of the tappet 10 and its
spring 9, is returned to the locked position. The roller 11 then
reaches the "high dead centre" zone 27 at which the raceway is
circular. There is thus no movement of the arming lever 2 and no
further translation of the fining pin 4. The firing pin 4 is locked
in position. The cam continues to revolve until it reaches its
starting position. When the roller 11 has passed through the "high
dead centre" zone 27, it finds itself in the "percussion" zone 28,
the percussion of the ammunition is thus now possible and firing
may be triggered by means of a second "percussion" command (this
command being able to be supplied automatically, for example, after
a time which allows for the dissipation of any vibration generated
by loading the ammunition, or by a calculator verifying the
coincidence between laying the weapon and the line of sight). The
ammunition is pushed into position at the same time as the firing
pin 4 is moved into its "armed" position by the compression of the
spring means 5.
[0048] Firing is triggered by means of the "percussion" command;
the roller 11 then rolls on the "percussion" zone 28 enabling the
reversal of the firing pin. Simultaneously, the coil of the
electromagnet 6 is activated and the rod 7 of the hub of the
electromagnet 6 acts on the sear 8 thereby unlocking the firing pin
4 held by its finger 3. The firing pin 4 is thereafter only
subjected to the action of the spring 5 which expands to propel the
firing pin 4 towards the ammunition. The percussion of the primer
is effective.
[0049] As soon as the electromagnet's coil is deactivated, the
tappet spring 9 pushes the tappet 10 and causes the sear 8 to
revolve. At the same time, it also pushes the hub of the of the
actuator's 6 electromagnet by acting, via the sear 8, on the rod
7.
[0050] The roller 11 thereafter reaches the "firing pin withdrawal"
zone 29 and the device is effectively returned to its starting
position and a second firing cycle may commence.
[0051] FIG. 6 illustrates the immobilization of the firing pin in
its "armed" position. In this Figure, the immobilizing finger 13
can be seen to be pressing on the immobilizing face 15 of the sear
8. This immobilizing face of the firing pin is substantially
orthogonal to the axis of displacement of the firing pin 4 (and
thus to the stress due to the compression of the spring 5) which
enables the stresses of the spring 5 to be withstood and the firing
pin 4 to be immobilized.
[0052] In a specific embodiment, the invention incorporates
position sensors so that the position of the cam can be known.
Thus, the computer can deliver the "percussion" command only when
the "percussion" command is delivered when the cam is in the
percussion zone, which is to say when the roller 11 has passed
through the "high dead centre" zone 27.
[0053] Preferentially, elements will be used which are able to be
activated manually in the event of a failure or the destruction of
the vehicle's power source.
[0054] Thus, the device according to the invention enables two
modes of operation: a "classical" mode of operation, and an
"optimized" mode of operation. The "optimized" mode of operation is
that which has been described previously, and consists in
performing the percussion in two stages: a first stage in which the
ammunition is pushed into position and the spring is compressed,
and a second stage in which the firing pin is release following a
"percussion" command. This mode of operation advantageously enables
precision fire which will not be disturbed by the vibrations due to
the positioning of the ammunition, or distorted by an overlong wait
between the validation of the fire and the actual percussion. The
"classical" mode of operation is that which is currently used by
weapons which are not equipped with a device according to the
invention, in which the firing pin is never immobilized (for
example, the electromagnet 6 is constantly activated) and the
percussion is triggered by the passage of the roller through the
"high dead centre" zone 27. This mode of operation is less precise
but enables a high rate of fire and is adapted to close-range
firing. The gunner may thus choose the mode of operation which is
best suited to the target to be reached.
[0055] We note that the law of movement of the cam 1 is specific to
the kinematics of the weapon in which the invention is integrated
but respects certain general principles such as the withdrawal of
the firing pin (zone 29) after the firing phase (zone 28), the
absence of stressing on the spring for the majority of the firing
cycle, then the compression of the spring when the chamber (zone
26) is being closed and the release of the firing pin enabled as
soon as the chamber is closed (end of zone 27).
* * * * *