U.S. patent application number 11/534967 was filed with the patent office on 2008-03-27 for system and method for safing and arming a bore-launched projectile.
This patent application is currently assigned to Chang Industry, Inc.. Invention is credited to John Philip Mandich, John William Sigler.
Application Number | 20080072781 11/534967 |
Document ID | / |
Family ID | 39223538 |
Filed Date | 2008-03-27 |
United States Patent
Application |
20080072781 |
Kind Code |
A1 |
Sigler; John William ; et
al. |
March 27, 2008 |
SYSTEM AND METHOD FOR SAFING AND ARMING A BORE-LAUNCHED
PROJECTILE
Abstract
A safing and arming (SA) system and method for a bore-launched
projectile is provided. The SA system includes an arming switch,
including a detonator, movable from a first position to a second
position. When the arming switch is in the first position, the
detonator is separated from an explosive train of the projectile.
When the arming switch is in the second position, the detonator is
substantially aligned with the explosive train, allowing the
projectile to be armed. Safing systems are provided for retaining
the arming switch in the first (safe) position. Various embodiments
also allow for release of the arming switch so as to allow the
arming switch to be moved to the second (armed) position, wherein
the release may be triggered by a selected acceleration force
exerted on the projectile and/or a determination that the
projectile has been launched from the launch bore.
Inventors: |
Sigler; John William; (La
Mirada, CA) ; Mandich; John Philip; (Anaheim,
CA) |
Correspondence
Address: |
ALSTON & BIRD LLP
BANK OF AMERICA PLAZA, 101 SOUTH TRYON STREET, SUITE 4000
CHARLOTTE
NC
28280-4000
US
|
Assignee: |
Chang Industry, Inc.
|
Family ID: |
39223538 |
Appl. No.: |
11/534967 |
Filed: |
September 25, 2006 |
Current U.S.
Class: |
102/251 |
Current CPC
Class: |
F42C 15/24 20130101;
F42C 15/192 20130101 |
Class at
Publication: |
102/251 |
International
Class: |
F42C 15/24 20060101
F42C015/24 |
Claims
1. A safing and arming system adapted to be operably engaged with a
projectile including an explosive train, the projectile being
adapted to be launched from a launch bore, the system comprising:
an arming switch configured to be movable from a first position to
a second position, the arming switch being further configured to
operably engage a detonator such that, when the arming switch is in
the first position, the detonator operably engaged therewith is
substantially out of alignment with the explosive train and such
that, when the arming switch is in the second position, the
detonator operably engaged therewith is substantially aligned with
the explosive train such that the explosive train is capable of
being armed; a first acceleration safety device configured to be
capable of operably engaging the arming switch so as to normally
retain the arming switch in the first position, the first
acceleration safety device being further configured to disengage
the arming switch so as to allow the arming switch to be moved to
the second position, in response to an acceleration force having a
selected magnitude and a selected duration, the acceleration force
being imparted on the first acceleration safety device by an
acceleration of the projectile with respect to the launch bore
during a launch of the projectile; and a proximity safety device
configured to be capable of operably engaging the arming switch so
as to normally retain the arming switch in the first position, the
proximity safety device being further configured to sense an inner
wall defining the launch bore so as to allow the arming switch to
be moved to the second position, such that the explosive train is
capable of being armed, when the projectile is launched from the
launch bore.
2. A safing and arming system according to claim 1, wherein the
proximity safety device comprises: a first pin slidably disposed in
a first pin, the first pin including a first end configured to
contact the inner wall of the launch bore and a second end
configured to engage the arming switch so as to normally retain the
arming switch in the first position when the projectile is disposed
within the launch bore; and a biasing element operably engaged with
the first pin, and configured to bias the first pin towards the
inner wall of the launch bore such that, when the projectile is
launched from the launch bore, the first end of the first pin
becomes unconstrained, and the second end of the first pin
disengages the arming switch such that the arming switch is capable
of being moved to the second position so that the explosive train
is capable of being armed.
3. A safing and arming system according to claim 1, further
comprising an actuator device operably engaged with the arming
switch and configured to be capable of moving the arming switch
from the first position to the second position in response to a
signal.
4. A safing and arming system according to claim 3, wherein the
proximity safety device further comprises a tab configured to
normally cover an optical sensor in communication with the
detonator, the tab being configured to uncover the optical sensor
when the projectile is launched from the launch bore such that the
optical sensor is capable of transmitting the signal to the
actuator device so that the actuator device is capable of moving
the arming switch from the first position to the second position at
a selected time after the projectile is launched from the launch
bore.
5. A safing and arming system according to claim 3, further
comprising: a wiring assembly configured to short circuit the
signal to prevent the signal from being transmitted to the actuator
device; and a second acceleration safety device configured to be
capable of disabling the wiring assembly in response to the
acceleration force such that the signal is capable of being
transmitted to the actuator device.
6. A safing and arming system according to claim 1, wherein the
arming switch comprises a rotatable cylinder having a central axis
and defining an arming channel extending radially outward from the
central axis, the arming channel being configured to receive the
detonator such that, as the rotatable cylinder is rotated from the
first position to the second position, the detonator becomes
substantially aligned with the explosive train so that the
explosive train is capable of being armed.
7. A safing and arming system according to claim 1, wherein the
first acceleration safety device comprises: a first setback weight
slidably disposed in a first setback weight chamber; a second pin
configured to be capable of operably engaging the arming switch so
as to normally retain the arming switch in the first position; and
a first linkage arm operably engaged between the first setback
weight and the second pin such that, as the first setback weight
slides within the first setback weight chamber in response to the
acceleration force, the first linkage arm is configured to
disengage the second pin from the arming switch so as to allow the
arming switch to be moved to the second position.
8. A safing and arming device according to claim 7, wherein the
first setback weight is configured to slide within the first
setback weight chamber in response to the acceleration force having
the selected magnitude and the selected duration.
9. A safing and arming system according to claim 5, wherein the
second acceleration safety device comprises: a second setback
weight slidably disposed in a second setback weight chamber; a
cutting device slidably disposed in a cutting channel; and a second
linkage arm operably engaged between the second setback weight and
the cutting device such that, as the second setback weight slides
within the second setback weight chamber in response to the
acceleration force, the second linkage arm is configured to move
the cutting device within the cutting channel such that the cutting
device cuts at least one wire within the wiring assembly so that
the signal is capable of being transmitted to the actuator
device.
10. A safing and arming device according to claim 9, wherein the
second setback weight is configured to slide within the second
setback weight chamber in response to the acceleration force having
the selected magnitude and the selected duration.
11. A safing and arming system according to claim 5, wherein the
wiring assembly comprises electrical connections selected from the
group consisting of: a short circuit connection to ground for the
signal; a short circuit connection to ground for a detonator arming
signal; a short circuit connection to ground for an electronic
controller configured to control the detonator; and combinations
thereof.
12. A safing and arming system adapted to be operably engaged with
a projectile including an explosive train, the projectile being
adapted to be launched from a launch bore, the system comprising:
an arming switch configured to be movable from a first position to
a second position, the arming switch being further configured to
operably engage a detonator such that, when the arming switch is in
the first position, the detonator operably engaged therewith is
substantially out of alignment with the explosive train and such
that, when the arming switch is in the second position, the
detonator operably engaged therewith is substantially aligned with
the explosive train such that the explosive train is capable of
being armed; an actuator device operably engaged with the arming
switch and configured to move the arming switch from the first
position to the second position in response to a signal; and a
proximity safety device configured to be capable of operably
engaging the arming switch so as to normally retain the arming
switch in the first position, the proximity safety device being
further configured to sense an inner wall defining the launch bore
so as to allow the arming switch to be moved to the second position
when the projectile is launched from the launch bore, such that the
arming switch is capable of being moved to the second position so
that the explosive train is capable of being armed, the proximity
safety device further comprising a tab configured to normally cover
an optical sensor in communication with the detonator, the tab
being configured to uncover the optical sensor when the projectile
is launched from the launch bore such that the optical sensor is
capable of transmitting the signal to the actuator device so that
the actuator device is capable of moving the arming switch from the
first position to the second position at a selected time after the
projectile is launched from the launch bore.
13. A safing and arming system according to claim 12, wherein the
proximity safety device further comprises: a first pin slidably
disposed in a first pin channel, the first pin including a first
end configured to contact the inner wall of the launch bore, the
first pin also including a second end configured to engage the
arming switch so as to normally retain the arming switch in the
first position, the tab being configured to extend from the first
pin so as to normally cover the optical sensor in communication
with the detonator when the projectile is disposed within the
launch bore; and a biasing element operably engaged with the first
pin, and configured to bias the first pin towards the inner wall of
the launch bore such that, when the projectile is launched from the
launch bore, the first end of the first pin becomes unconstrained,
and the second end of the first pin disengages the arming switch so
that the actuator device is capable of moving the arming switch to
the second position, such that the explosive train in capable of
being armed and such that the tab uncovers the optical sensor so
that the optical sensor is capable of transmitting the signal to
the actuator device to move the arming switch from the first
position to the second position at a selected time after the
projectile is launched from the launch bore.
14. A safing and arming system according to claim 12, further
comprising a first acceleration safety device configured to be
capable of operably engaging the arming switch so as to normally
retain the arming switch in the first position, the first
acceleration safety device being further configured to disengage
the arming switch in response to an acceleration force having a
selected magnitude and a selected duration, the acceleration force
being imparted on the first acceleration safety device by an
acceleration of the projectile with respect to the launch bore
during a launch of the projectile.
15. A safing and arming system according to claim 12, further
comprising: a wiring assembly configured to short circuit the
signal to prevent the signal from being transmitted to the actuator
device; and a second acceleration safety device configured to be
capable of disabling the wiring assembly in response to a force
having a selected magnitude and a selected duration, imparted on
the second acceleration safety device by an acceleration of the
projectile with respect to the launch bore during a launch of the
projectile such that the signal is capable of being transmitted to
the actuator device.
16. A safing and arming system according to claim 12, wherein the
arming switch comprises a rotatable cylinder having a central axis
and defining an arming channel extending radially outward from the
central axis, the arming channel being configured to receive the
detonator such that, as the rotatable cylinder is rotated from the
first position to the second position, the detonator becomes
substantially aligned with the explosive train so that the
explosive train is capable of being armed.
17. A safing and arming system according to claim 14, wherein the
first acceleration safety device comprises: a first setback weight
slidably disposed in a first setback weight chamber; a second pin
configured to be capable of operably engaging the arming switch so
as to normally retain the arming switch in the first position; and
a first linkage arm operably engaged between the first setback
weight and the second pin such that, as the first setback weight
slides within the first setback weight chamber in response to the
acceleration force, the first linkage arm is configured to
disengage the second pin from the arming switch so as to allow the
arming switch to be moved to the second position.
18. A safing and arming device according to claim 17, wherein the
first setback weight is configured to slide within the first
setback weight chamber in response to the acceleration force having
the selected magnitude and the selected duration.
19. A safing and arming system according to claim 15, wherein the
second acceleration safety device comprises: a second setback
weight slidably disposed in a second setback weight chamber; a
cutting device slidably disposed in a cutting channel; and a second
linkage arm operably engaged between the second setback weight and
the cutting device such that, as the second setback weight slides
within the second setback weight chamber in response to the
acceleration force, the second linkage arm is configured to move
the cutting device within the cutting channel such that the cutting
device cuts at least one wire within the wiring assembly so that
the signal is capable of being transmitted to the actuator
device.
20. A safing and arming device according to claim 19, wherein the
second setback weight is configured to slide within the second
setback weight chamber in response to the acceleration force having
the selected magnitude and the selected duration.
21. A safing and arming system according to claim 15, wherein the
wiring assembly comprises electrical connections selected from the
group consisting of: a short circuit connection to ground for the
signal; a short circuit connection to ground for a detonator arming
signal; a short circuit connection to ground for an electronic
controller configured to control the detonator; and combinations
thereof.
22. A method for safing and arming a projectile including an
explosive train, using a safing and arming system, the projectile
being adapted to be launched from a launch bore, the method
comprising: securing an arming switch in a first position so as to
normally retain the arming switch in the first position, the arming
switch being configured to be movable from the first position to a
second position, and to operably engage a detonator such that, when
the arming switch is in the first position, the detonator operably
engaged therewith is substantially out of alignment with the
explosive train and such that, when the arming switch is in the
second position, the detonator operably engaged therewith is
substantially aligned with the explosive train such that the
explosive train is capable of being armed; releasing the arming
switch so as to allow the arming switch to be moved to the second
position, the arming switch being released in response to: an
acceleration force having a selected magnitude and a selected
duration, the acceleration force being imparted on the projectile
by an acceleration of the projectile with respect to the launch
bore during a launch of the projectile; and a determination that
the projectile has been launched from the launch bore.
23. A method according to claim 22, wherein the securing step
further comprises: securing the arming switch in the first position
with a first acceleration safety device configured to be capable of
operably engaging the arming switch so as to normally retain the
arming switch in the first position; and securing the arming switch
in the first position with a proximity safety device configured to
be capable of operably engaging the arming switch so as to normally
retain the arming switch in the first position, the proximity
safety device being further configured to sense an inner wall
defining the launch bore.
24. A method according to claim 22, wherein the releasing step
further comprises: disengaging a first acceleration safety device
from the arming switch so as to allow the arming switch to be moved
to the second position, in response to an acceleration force having
a selected magnitude and a selected duration, the acceleration
force being imparted on the first acceleration safety device by an
acceleration of the projectile with respect to the launch bore
during a launch of the projectile; sensing the inner wall of the
launch bore with a proximity safety device; determining when the
inner wall is no longer sensed by the proximity safety device,
after disengaging the first acceleration safety device from the
arming switch; and disengaging the proximity safety device from the
arming switch after the determining step so as to allow the arming
switch to be moved to the second position such that the explosive
train is capable of being armed when the projectile is launched
from the launch bore.
25. A method according to claim 24, wherein the proximity safety
device comprises a first pin slidably disposed in a first pin
channel, and the method further comprises: contacting an inner wall
of the launch bore with a first end of the first pin when the
projectile is disposed within the bore; engaging a second end of
the first pin with the arming switch so as to normally retain the
arming switch in the first position when the projectile is disposed
within the bore; and biasing the first pin towards the inner wall
of the launch bore, with a biasing element operably engaged
therewith, such that, when the projectile is launched from the
launch bore, the first end of the first pin becomes unconstrained,
and the second end of the first pin disengages the arming switch
such that the arming switch is capable of being moved to the second
position so that the explosive train is capable of being armed.
26. A method according to claim 24, further comprising moving the
arming switch from the first position to the second position, with
an actuator device operably engaged therewith, in response to a
signal received by the actuator device.
27. A method according to claim 26, wherein the proximity safety
device comprises a tab configured to normally cover an optical
sensor in communication with the detonator and the actuator device,
and the method further comprises: moving the tab so as to uncover
the optical sensor when the projectile is launched from the launch
bore such that the optical sensor is capable of transmitting the
signal to the actuator device; and transmitting the signal from the
optical sensor to the actuator device such that the actuator device
is capable of moving the arming switch from the first position to
the second position at a selected time after the projectile is
launched from the launch bore.
28. A method according to claim 26, further comprising: Normally
short-circuiting the signal with a wiring assembly to prevent the
signal from being transmitted to the actuator device; disabling the
wiring assembly in response to the acceleration force with a second
acceleration safety device such that the signal is capable of being
transmitted to the actuator device; and transmitting the signal to
the actuator device such that the actuator device is capable of
moving the arming switch from the first position to the second
position.
29. A method for safing and arming a projectile including an
explosive train, using a safing and arming system, the projectile
being adapted to be launched from a launch bore, the method
comprising: securing an arming switch in a first position so as to
normally retain the arming switch in the first position, the arming
switch being configured to be movable from the first position to a
second position, and to operably engage a detonator such that, when
the arming switch is in the first position, the detonator operably
engaged therewith is substantially out of alignment with the
explosive train and such that, when the arming switch is in the
second position, the detonator operably engaged therewith is
substantially aligned with the explosive train such that the
explosive train is capable of being armed; determining when the
projectile has exited the launch bore; releasing the arming switch
so as to allow the arming switch to be moved to the second position
after a selected time period following the determining step;
uncovering an optical sensor configured to transmit a signal;
transmitting the signal to an actuator device operably engaged with
the arming switch; and moving the arming switch from the first
position to the second position with the actuator device, in
response to the transmitted signal, at a selected time after the
transmitting step.
30. A method according to claim 29, wherein the securing step
further comprises securing the arming switch in the first position
with a proximity safety device configured to be capable of operably
engaging the arming switch so as to normally retain the arming
switch in the first position, the proximity safety device further
comprising a tab configured to normally cover an optical sensor in
communication with the detonator, the proximity safety device being
further configured to sense an inner wall of the launch bore.
31. A method according to claim 30, further comprising: determining
when the inner wall of the launch bore is no longer sensed by the
proximity safety device; disengaging the proximity safety device
from the arming switch after the determining step so as to allow
the arming switch to be moved to the second position such that the
explosive train is capable of being armed when the projectile is
launched from the launch bore; and moving the tab so as to uncover
the optical sensor such that the optical sensor is capable of
transmitting the signal.
32. A method according to claim 30, further comprising: contacting
the inner wall of the launch bore with a first end of a first pin
when the projectile is disposed within the launch bore, the first
pin being slidably disposed in a first pin channel defined by the
system and having the tab operably engaged therewith; engaging a
second end of the first pin with the arming switch so as to
normally retain the arming switch in the first position when the
projectile is disposed within the launch bore; and biasing the
first pin towards the inner wall of the launch bore, with a biasing
element operably engaged with the first pin such that, when the
projectile is launched from the launch bore, the first end of the
first pin becomes unconstrained, and the second end of the first
pin disengages the arming switch such that the arming switch is
capable of being moved to the second position so that the explosive
train is capable of being armed.
33. A method according to claim 29, further comprising: securing
the arming switch in the first position with a first acceleration
safety device; and disengaging the first acceleration safety device
from the arming switch so as to allow the arming switch to be moved
to the second position, in response to an acceleration force having
a selected magnitude and a selected duration, the acceleration
force being imparted on the first acceleration safety device by an
acceleration of the projectile with respect to the launch bore
during a launch of the projectile.
34. A method according to claim 29, further comprising: Normally
short-circuiting the signal with a wiring assembly to prevent the
signal from being transmitted to the actuator device; disabling the
wiring assembly in response to the acceleration force with a second
acceleration safety device such that the signal is capable of being
transmitted to the actuator device; and transmitting the signal to
the actuator device such that the actuator device is capable of
moving the arming switch from the first position to the second
position.
35. A method according to claim 34, wherein the disabling step
comprises cutting at least one wire within the wiring assembly such
that the signal is capable of being transmitted to the actuator
device.
Description
FIELD OF THE INVENTION
[0001] Various embodiments of the present invention relate
generally to a system and method for safing and arming a
bore-launched projectile so as to prevent unintended arming of the
projectile.
BACKGROUND OF THE INVENTION
[0002] Munitions (such as explosive projectiles) are often provided
with a safing and arming ("SA") device that is designed to allow
the projectile to arm its explosive train (and consequently, in
some cases, the warhead carried by the projectile) only after the
projectile has undergone an intentional launch event. For example,
all munitions qualified by the United States government must comply
with the requirements of U.S. Department of Defense ("DOD")
MIL-STD-1316, entitled "Safety Criteria for Fuze Design," which
sets forth specific guidelines and requirements for the design of
an acceptable SA device. For example, MIL-STD-1316 specifies that
an acceptable SA device must sense two independent arming
environments prior to arming.
[0003] Conventional SA devices carried by bore-launched explosive
projectiles utilize simultaneous acceleration and spin imparted by
a gun launch as the two independent arming environments to indicate
an intentional launch event. However, there exists a growing class
of munitions that do not produce spin upon gun launch and that
experience relatively low acceleration forces (i.e. low-g
acceleration) during launch. Such no-spin, low-g munitions present
problems for conventional SA devices since the magnitude of a
launch acceleration force is typically lower than that resulting
from an accidental drop of the projectile (i.e. when loading and/or
handling the projectile prior to launch). Furthermore, conventional
SA devices do not utilize electronic safety back-up systems that
are capable of reliably identifying an intentional launch event
and/or positively preventing the arming of an explosive projectile
(via hard-wired and/or switched short circuits) during non-launch
events (such as an accidental drop). Therefore, conventional SA
devices may have some shortcomings, especially when applied to
newer no-spin and/or low-g bore-launched munitions.
[0004] Thus, there exists a need for SA devices capable of
distinguishing between an intentional launch and an accidental drop
of a projectile equipped with such an SA device. Furthermore, there
exists a need for SA devices capable of sensing arming environments
other than projectile spin, so as to be compatible with no-spin
bore-launched projectiles, while still providing an independent
safeguard against an accidental arming and/or detonation. There
also exists a need for SA devices that provide parallel electronic
safeguards against accidental and/or unintentional arming of an
explosive projectile that may be coupled to one or more of the
arming environments sensed by the SA device.
BRIEF SUMMARY OF THE INVENTION
[0005] Various embodiments presented herein provide technical
solutions to many of the problems inherent in conventional SA
devices while providing robust and, in some cases, multiple
independent safeguards against accidental arming of a projectile.
According to various embodiments of the present invention, a safing
and arming system is provided to be operably engaged with a
projectile adapted to be launched from a launch bore.
[0006] In one embodiment, the system comprises an arming switch
configured to be movable from a first position to a second
position. The arming switch is further configured to operably
engage a detonator, such that when the arming switch is in the
first position, the detonator is substantially out of alignment
with the explosive train. Furthermore, the arming switch is further
configured such that when the arming switch is in the second
position, the detonator is substantially aligned with the explosive
train such that the explosive train is capable of being armed. In
some embodiments, the arming switch comprises a rotatable cylinder
having a central axis and defining an arming channel extending
radially outward from the central axis. Furthermore, in such
embodiments, the arming channel is configured to receive the
detonator such that as the rotatable cylinder is rotated from the
first position to the second position, the detonator is
substantially aligned with the explosive train such that the
explosive train is capable of being armed. In some embodiments, the
system further comprises an actuator device operably engaged with
the arming switch. In such embodiments, the actuator device is
configured to be capable of moving the arming switch from the first
position to the second position in response to a signal.
[0007] According to some system embodiments, the system further
comprises a first acceleration safety device configured to be
capable of operably engaging the arming switch so as to normally
retain the arming switch in the first position. Furthermore, the
first acceleration safety device is configured to disengage the
arming switch so as to allow the arming switch to be moved to the
second position, in response to an acceleration force having a
selected magnitude and a selected duration. For example, the
acceleration force may be imparted on the first acceleration safety
device by an acceleration of the projectile with respect to the
launch bore during a launch of the projectile.
[0008] In some system embodiments, the first acceleration safety
device comprises: a first setback weight slidably disposed in a
first setback weight chamber; a second pin configured to be capable
of operably engaging the arming switch so as to normally retain the
arming switch in the first position; and a first linkage arm
operably engaged between the first setback weight and the second
pin. Thus, in such embodiments, in response to the acceleration
force, the first setback weight slides within the first setback
weight chamber and the first linkage arm is configured to disengage
the pin from the arming switch so as to allow the arming switch to
be moved to the second position. In some embodiments, the first
setback weight is configured to slide within the first setback
weight chamber in response to the acceleration force having the
selected magnitude and the selected duration.
[0009] The system may also further comprise a proximity safety
device configured to operably engage the arming switch so as to
normally retain the arming switch in the first position. The
proximity safety device is further configured to sense an inner
wall of the launch bore. The proximity safety device is further
configured to allow the arming switch to be moved to the second
position such that the explosive train is capable of being armed
when the projectile is launched from the launch bore. In some
embodiments, the proximity safety device comprises a first pin
slidably disposed in a first pin channel, wherein the first pin
includes a first end configured to contact an inner wall of the
launch bore, and a second end configured to engage the arming
switch so as to normally retain the arming switch in the first
position when the projectile is disposed within the launch bore. In
such embodiments, the proximity safety device further comprises a
biasing element operably engaged with the first pin for biasing the
first pin towards the inner wall of the launch bore such that when
the projectile is launched from the launch bore, the first end of
the first pin becomes unconstrained, and the second end of the
first pin disengages the arming switch such that the arming switch
is capable of being moved to the second position so that the
explosive train is capable of being armed.
[0010] According to some system embodiments, the proximity safety
device further comprises a tab configured to normally cover an
optical sensor in communication with the detonator. In such
embodiments, the optical sensor is configured to be capable of
transmitting the signal to the actuator device when the tab is
moved to uncover the optical sensor. The tab of the proximity
safety device is further configured to uncover the optical sensor
when the projectile is launched from the launch bore such that the
optical sensor is capable of transmitting the signal to the
actuator device. Thus, in such embodiments, the actuator device may
be rendered capable of moving the arming switch from the first
position to the second position at a selected time after the
projectile is launched from the launch bore.
[0011] Some system embodiments of the present invention further
comprise a wiring assembly configured to short circuit the signal
to prevent the signal from being transmitted to the actuator
device. In some such system embodiments, the wiring assembly may
comprise electrical connections including, but not limited to: a
short circuit connection to a ground for the signal; a short
circuit connection to a ground for a detonator arming signal; a
short circuit connection to a ground for an electronic controller
configured to control the detonator; and combinations of such
electrical connections. In some embodiments, the system further
comprises a second acceleration safety device configured to be
capable of disabling the wiring assembly in response to the
acceleration force such that the signal is capable of being
transmitted to the actuator device. The second acceleration safety
device may comprise: a second setback weight slidably disposed in a
second setback weight chamber; a cutting device slidably disposed
in a cutting channel; and a second linkage arm operably engaged
between the second setback weight and the cutting device such that
as the second setback weight slides within the second setback
weight chamber in response to the acceleration force, the second
linkage arm is configured to move the cutting device within the
cutting channel such that the cutting device cuts at least one wire
within the wiring assembly such that the signal is capable of being
transmitted to the actuator device. As described herein with
respect to the first acceleration safety device, the second setback
weight provided in some system embodiments may also be configured
to slide within the second setback weight chamber in response to
the acceleration force having the selected magnitude and the
selected duration.
[0012] Various embodiments of the present invention also provide a
method for safing and arming a projectile including an explosive
train, using a safing and arming system. As described herein, the
projectile is adapted to be launched from a launch bore. In some
embodiments, the method first comprises securing an arming switch
in a first position so as to normally retain the arming switch in
the first position wherein the arming switch is configured to be
movable from the first position to a second position. The arming
switch is further configured to operably engage a detonator, such
that when the arming switch is in the first position, the detonator
is substantially out of alignment with the explosive train and such
that when the arming switch is in the second position, the
detonator is substantially aligned with the explosive train such
that the explosive train is capable of being armed. The method
further comprises a step for releasing the arming switch so as to
allow the arming switch to be moved to the second position.
According to some method embodiments, the arming switch may be
released by: an acceleration force having a selected magnitude and
a selected duration, the acceleration force being imparted on the
first acceleration safety device by an acceleration of the
projectile with respect to the launch bore during a launch of the
projectile; and a determination that the projectile has been
launched from the launch bore.
[0013] According to some method embodiments, the securing step
described herein further comprises securing the arming switch in
the first position with a first acceleration safety device
configured to be capable of operably engaging the arming switch so
as to normally retain the arming switch in the first position.
Furthermore, the securing step may also further comprise securing
the arming switch in the first position with a proximity safety
device configured to be capable of operably engaging the arming
switch so as to normally retain the arming switch in the first
position, wherein the proximity safety device is further configured
to sense an inner wall defining the launch bore.
[0014] Furthermore, the releasing step may further comprise
disengaging a first acceleration safety device from the arming
switch so as to allow the arming switch to be moved to the second
position, in response to an acceleration force having a selected
magnitude and a selected duration. As described herein, the
acceleration force may be imparted on the first acceleration safety
device by an acceleration of the projectile with respect to the
launch bore during a launch of the projectile. Furthermore, the
releasing step may also further comprise steps including, but not
limited to: sensing the inner wall of the launch bore with a
proximity safety device; determining when the inner wall is no
longer sensed by the proximity safety device, after disengaging the
first acceleration safety device from the arming switch; and
disengaging the proximity safety device from the arming switch
after the determining step so as to allow the arming switch to be
moved to the second position such that the explosive train is
capable of being armed when the projectile is launched from the
launch bore. According to some such method embodiments, the
proximity safety device comprises a first pin slidably disposed in
a first pin channel. In such embodiments, the method may further
comprise steps including, but not limited to: contacting an inner
wall of the launch bore with a first end of the first pin when the
projectile is disposed within the bore; engaging a second end of
the first pin with the arming switch so as to normally retain the
arming switch in the first position when the projectile is disposed
within the bore; and biasing the first pin towards the inner wall
of the launch bore. The biasing step may be accomplished in some
embodiments with a biasing element operably engaged with the first
pin. Thus, when the projectile is launched from the launch bore,
the first end of the first pin becomes unconstrained, and the
second end of the first pin disengages the arming switch such that
the arming switch is capable of being moved to the second position
so that the explosive train is capable of being armed.
[0015] Additional method embodiments of the present invention may
further comprise steps for moving the arming switch from the first
position to the second position with an actuator device operably
engaged therewith, in response to a signal received by the actuator
device. In such embodiments, the method may comprise normally
short-circuiting the signal with a wiring assembly to prevent the
signal from being transmitted to the actuator device. The method
may also further comprise disabling the wiring assembly in response
to the acceleration force with a second acceleration safety device
such that the signal is capable of being transmitted to the
actuator device. The method may also further comprise transmitting
the signal to the actuator device such that the actuator device is
capable of moving the arming switch from the first position to the
second position. Furthermore, in some method embodiments, the
proximity safety device comprises a tab configured to normally
cover an optical sensor in communication with the detonator. Such
method embodiments may further comprise steps for: moving the tab
so as to uncover the optical sensor when the projectile is launched
from the launch bore such that the optical sensor is capable of
transmitting the signal to the actuator device; and transmitting a
signal from the optical sensor to the actuator device such that the
actuator device is capable of moving the arming switch from the
first position to the second position at a selected time after the
projectile is launched from the launch bore.
[0016] Thus, various embodiments of a safing and arming system and
associated method according to the present invention may provide
one or more advantages that may include, for example: providing a
robust mechanical safing system that allows a projectile to arm
only after an intentional launch event; providing a safing system
that is capable of discerning between acceleration loads resulting
from a launch event and a shock load resulting from rough handling
and/or an accidental drop; providing a parallel optical and/or
electronic safing system that is capable of activating an
electronic arming system; providing a safing and arming system that
is compatible with "no-spin" bore-launched projectiles having
relatively low launch acceleration rates; and providing a
readily-adjustable mechanical safing mechanism that may be adjusted
to function under a wide range of launch acceleration
conditions.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0017] Having thus described various embodiments in general terms,
reference will now be made to the accompanying drawings, which are
not necessarily drawn to scale, and wherein:
[0018] FIG. 1 shows an exemplary exploded schematic depiction of a
safing and arming system according to one embodiment of the present
invention;
[0019] FIG. 2 shows an exemplary cross-sectional schematic view of
a safing and arming system installed in a bore-launched projectile
according to one embodiment of the present invention;
[0020] FIG. 3 shows an exemplary schematic of a safing and arming
system according to one embodiment of the present invention,
including a first acceleration safety device and a proximity safety
device operably engaged with a rotatable arming switch;
[0021] FIG. 4A shows a schematic view of a first side of a
rotatable arming switch defining a bearing surface configured to be
operably engaged with a piston actuator for operating a safing and
arming system according to one embodiment of the present
invention;
[0022] FIG. 4B shows a schematic view of a second side of a
rotatable arming switch defining a shear pin channel configured to
be operably engaged with a shear pin for operating a safing and
arming system according to one embodiment of the present
invention;
[0023] FIG. 4C shows a schematic cut-away view of a rotatable
arming switch defining a detonator channel configured to carry a
detonator as part of a safing and arming system according to one
embodiment of the present invention;
[0024] FIG. 4D shows a schematic end view of a rotatable arming
switch including a bearing surface operably engaged with a piston
actuator for operating a safing and arming system according to one
embodiment of the present invention;
[0025] FIG. 5 shows a schematic view of a first acceleration safety
device forming a part of a safing and arming system according to
one embodiment of the present invention;
[0026] FIG. 6 shows a schematic view of a proximity safety device
forming a part of a safing and arming system according to one
embodiment of the present invention;
[0027] FIG. 7 shows a schematic view of a second acceleration
safety device forming a part of a safing and arming system
according to one embodiment of the present invention;
[0028] FIG. 8 shows a cross-sectional schematic of a safing and
arming system according to one embodiment of the present invention,
wherein the arming switch is in a safe position and a first
acceleration safety device and a proximity safety device are
engaged with the arming switch to retain the arming switch in the
safe position;
[0029] FIG. 9 shows a cross-sectional schematic of a safing and
arming system according to one embodiment of the present invention,
wherein the arming switch is in a safe position and a first
acceleration safety device is disengaged from the arming switch in
response to an acceleration force;
[0030] FIG. 10 shows a cross-sectional schematic of a safing and
arming system according to one embodiment of the present invention,
wherein the arming switch is in a safe position, a first
acceleration safety device is disengaged from the arming switch in
response to an acceleration force, and a proximity safety device is
disengaged from the arming switch;
[0031] FIG. 11 shows a cross-sectional schematic of a safing and
arming system according to one embodiment of the present invention,
wherein the arming switch is in an armed position;
[0032] FIG. 12 shows a cross-sectional schematic of a safing and
arming system according to one embodiment of the present invention,
including a second acceleration safety device, wherein the second
acceleration safety device is positioned so as to complete a short
circuit; and
[0033] FIG. 13 shows a cross-sectional schematic of a safing and
arming system according to one embodiment of the present invention,
including a second acceleration safety device, wherein the second
acceleration safety device is positioned so as to disable a wiring
assembly.
DETAILED DESCRIPTION OF THE INVENTION
[0034] Various embodiments of a system and associated method for
safing and arming a bore-launched projectile now will be described
more fully hereinafter with reference to the accompanying drawings,
in which some, but not all embodiments are shown. Indeed, system
and method may be embodied in many different forms and should not
be construed as limited to the embodiments set forth herein;
rather, these embodiments are provided so that this disclosure will
satisfy applicable legal requirements. Like numbers refer to like
elements throughout.
[0035] While the various system 1 and method embodiments of the
present invention are described in the context of a safing and
arming system 1 having a rotatable arming switch 10 (see FIGS.
4A-4D, for example), it should be understood that the various SA
system 1 and method embodiments described herein may also be
applied to a linearly slidable arming switch (not shown) wherein at
least one of the first acceleration safety device 30, the second
acceleration safety device 60, and the proximity safety device 40,
otherwise described herein, may be configured to retain the
linearly slidable arming switch (and a detonator 11 carried
thereby) normally out of alignment with an explosive train.
Furthermore, while various safing and arming systems 1 and methods
are described herein in the context of a "no-spin" bore-launched
projectile (adapted to be launched from a smooth bore tube, for
example), it should be understood that the various embodiments
described herein may also be used in conjunction with projectiles
imparted with a spin upon launch (such as explosive projectiles
launched from a barrel or launch tube having a rifled bore, for
example). In addition, it should be understood that the various
system and method embodiments disclosed herein may be used in
conjunction with any number of projectile types having an explosive
train configured to detonate an explosive warhead (such as a high
explosive anti-tank (HEAT) round, for example) and/or configured to
initiate the launch of a kinetic energy penetrator device from a
sabot, for example.
[0036] Embodiments of the present invention include a safing and
arming (SA) system 1 (see FIG. 1, for example) adapted to be
operably engaged with a projectile 100 including an explosive train
(such as a series of explosive charges carried by the projectile
100 for exploding a warhead 101, for example, as shown in FIG. 2).
As shown generally in FIG. 2, the SA system 1 may be disposed
substantially adjacent to the explosive train as part of a
projectile 100 that is adapted to be launched from a launcher 200
defining a launch bore 202.
[0037] In some embodiments, such as that shown generally in FIG. 1,
the SA system 1 comprises an arming switch 10 that may be carried
by a system housing 20. As shown generally in the cross-sectional
schematics of FIGS. 10 and 11, the arming switch 10 may be
configured to be movable from a first position (see FIG. 10, for
example) to a second position (see FIG. 11, for example).
Furthermore, as shown generally in FIG. 4C, the arming switch 10
may be further configured to operably engage a detonator 11 (such
as an M55 detonator device, for example), such that when the arming
switch 10 is in the first position, the detonator 11 is
substantially out of alignment with the explosive train (see FIG.
10, for example), and such that, when the arming switch 10 is in
the second position, the detonator 11 is substantially aligned with
the explosive train such that the explosive train is capable of
being armed (see FIG. 11, for example).
[0038] According to some embodiments, as shown generally in FIGS.
4A-4D, the arming switch 10 may comprise a rotatable cylinder
having a central axis and defining an arming channel 10F extending
radially outward from the central axis. As shown in FIG. 4C, the
arming channel 10F defined by the arming switch 10 may be
configured to receive the detonator 11 such that, as the rotatable
cylinder is rotated from the first position to the second position,
the detonator 11 is substantially aligned with the explosive train
of the projectile 100 such that the explosive train is capable of
being armed. According to some such embodiments, the arming channel
10F defined by the arming switch 10 may be further configured to
receive an explosive lead element 13 such that the explosive lead
element 13 is disposed substantially between the detonator 11 and a
primary explosive charge (and/or warhead) carried by the projectile
100. Thus, when the arming switch 10 is in the second (armed)
position (see FIG. 11), the explosive lead element 13 may, in some
embodiments, act as a transfer charge between the detonator 11 and
the primary explosive charge (and/or warhead) carried by the
projectile 100. For example, in some embodiments, the detonator 11
may comprise an M55 "stab" detonator configured to initiate the
explosive lead element 13 which, in turn, may be configured to
produce a sufficient explosive output to initiate the detonation of
the primary explosive charge (and/or warhead) carried by the
projectile 100. Thus, the explosive lead element 13 may increase
the reliability of the arming and detonation mechanism of the
projectile 100.
[0039] Furthermore, the arming switch 10 may comprise, for example,
a metal and/or metallic alloy exhibiting relatively robust
dimensional stability and corrosion resistance so as to further
improve the reliability of the arming switch 10. For example, in
some embodiments, the arming switch 10 may comprise a stainless
steel material (such as 303 stainless steel) machined as shown
generally in FIGS. 4A-4C and as described further herein so as to
be compatible with various types of acceleration safety devices
(see generally, element 30, FIG. 3) and proximity safety devices
(see generally, element 40, FIG. 3). According to some SA system 1
embodiments (as shown in FIG. 8, for example), the arming switch 10
may define a locking channel 10C configured to be capable of
receiving a pin 33 of a first acceleration safety device 30 (FIG.
5) and/or a second end 45 of a bore rider pin 44 (FIG. 6) included
as part of a proximity safety device 40.
[0040] As shown in FIG. 3, the SA system 1 may further comprise a
first acceleration safety device 30 carried by the system housing
20 (see FIG. 1, showing an exploded view of the SA device 1
including the system housing 20 depicted relative to the arming
switch 10). The first acceleration safety device 30 is configured
to be capable of operably engaging the arming switch 10 (via a pin
33, for example, as shown in FIG. 3) so as to normally retain the
arming switch 10 in the first position (see FIG. 10, showing the
arming switch 10 substantially out of alignment with an explosive
train of a projectile). The first acceleration safety device 30 may
be further configured to disengage the arming switch 10 (as shown
in FIG. 9, for example) so as to allow the arming switch 10 to be
moved to the second position in response to an acceleration force
having a selected magnitude and a selected duration. As shown in
FIG. 2, the acceleration force may be imparted on the first
acceleration safety device 30 (carried by the system housing 20 of
the SA system 1) by an acceleration of the projectile 100 with
respect to the launcher 200 during a launch of the projectile in
the launch direction 300.
[0041] For example, in some embodiments, as shown in FIG. 5, the
first acceleration safety device 30 comprises a first setback
weight 31 slidably disposed in a first setback weight chamber 22
defined by the system housing 20 (see FIG. 1). In addition, the
first acceleration safety device 30 comprises a pin 33 configured
to be capable of operably engaging the arming switch 10 (by
extending into the locking channel 10C defined by the arming switch
10, for example) so as to normally retain the arming switch 10 in
the first position (see FIG. 8, elements 33 and 10C). In order to
link the release of the pin 33 from the locking channel 10C with
the movement of the first setback weight 31 within the first
setback weight chamber 22, the first acceleration safety device 30
further comprises a first linkage arm 32 operably engaged between
the first setback weight 31 and the pin 33 such that, as the first
setback weight 31 slides within the first setback weight chamber 22
(in response to the acceleration force, for example), the first
linkage arm 32 is configured to disengage the pin 33 from the
arming switch 10 (or, more particularly, the locking channel 10C
that may be defined thereby) so as to allow the arming switch 10 to
be moved to the second position (see, for example, FIG. 11, showing
the first acceleration device 30 and the proximity device 40
(described further herein) disengaged from the arming switch 10
such that the arming switch 10 is movable to the second "armed"
position). As will be appreciated by one skilled in the art, in
some embodiments, various characteristics of the first setback
weight 31 (and other components of the first acceleration safety
device 30) may be selected such that the first setback weight 31 is
configured to slide within the first setback weight chamber 22,
defined by the system housing 20, in response to an acceleration
force having a selected magnitude and a selected duration.
Furthermore, as shown generally in FIG. 5, the first acceleration
device 30 may further comprise a cantilever spring 34 operably
engaged between the first setback weight 31 and the system housing
20 so as to provide a selected amount of resistance to sliding
movement of the first setback weight 31 within the first setback
weight chamber 22 defined by the system housing 20. Thus, in such
embodiments, the characteristics (such as, for example, spring
rate, stiffness, and/or other mechanical properties) of the
cantilever spring 34 may be selected such that the cantilever
spring 34, in conjunction with the mechanical properties of the
first setback weight 31, allows the first setback weight 31 to
slide within the first setback weight chamber 22 only in response
to an acceleration force having a selected magnitude and a selected
duration. Thus, the first acceleration safety device 30 may be
configured only to allow arming of the explosive train (by
disengaging the arming switch 10, for example, as shown generally
in FIG. 9) in response to acceleration force intensity and/or
duration that is indicative of an intentional launch of the
projectile 100 (as opposed to relatively short-duration
acceleration forces resulting from accidental drops and/or rough
handling of the projectile 100). Furthermore, in order to increase
the likelihood that the first acceleration safety device 30 remains
operable and robust for the projected storage life of the
projectile 100, the components thereof may be comprised of
particularly selected materials for corrosion resistance and
enhanced mechanical properties. For example, in some embodiments,
the first setback weight 31 and the pin 33 may be formed of 303
stainless steel. Furthermore, in some embodiments, the first
linkage arm 32 may be formed of aluminum or an aluminum alloy (such
as, for example, 6061-T651 aluminum). By selecting the particular
characteristics of the first setback weight 31, cantilever spring
34, the pin 33, and/or the first linkage arm 32, the embodiments of
the SA system 1 may be configured such that projectiles having
relatively low-g loads during launch may still be reliably armed
without compromising the safing capabilities of an SA system 1
according to embodiments of the present invention. In other
embodiments, the mass, weight, and or geometry of the first setback
weight 31 may be customized for the specific launch conditions of
the particular projectile 100 that is configured to carry the SA
system 1 such that the first setback weight 31 is configured to
initiate the disengagement of the pin 33 from the arming switch 10
(see FIG. 9, for example) only in response to acceleration
conditions that are indicative of an intentional launch of the
projectile 100.
[0042] As shown in FIG. 3, the SA system 1 may further comprise a
proximity safety device 40 carried by the system housing 20 (see
FIG. 1, showing an exploded view of the components of the proximity
safety device 40 relative to the system housing 20). As shown in
FIG. 3, the proximity safety device 40 (and/or a bore rider pin 44
thereof) is configured to be capable of operably engaging the
arming switch 10 so as to normally retain the arming switch 10 in
the first position. Furthermore, as shown generally in FIG. 2, the
proximity safety device 40 (and/or a bore rider pin 44 thereof) is
further configured to sense an inner wall 201 of the launch bore
202 so as to allow the arming switch 10 to be moved to the second
position (see FIG. 11, for example) such that the explosive train
is capable of being armed when the projectile 100 is launched from
the launch bore 202. The proximity safety device 40 may comprise,
in some embodiments, a bore rider pin 44 biased radially outward
from the system housing 20 so as to contact and therefore sense or
detect the inner wall 201 defining the launch bore 202 when the
projectile 100 is positioned within the launch bore 202.
[0043] For example, as shown in FIGS. 3 and 5, the proximity safety
device 40 may comprise a bore rider pin 44 slidably disposed in a
pin channel 20A defined by the system housing 20 (see also, the
cross-sectional schematics of the SA system 1 shown in FIGS. 8-11).
The bore rider pin 44 includes a first end 44A configured to
contact the inner wall 201 of the launch bore 202 and a second end
45 configured to engage the arming switch 10 (i.e. to extend into a
locking channel 10C defined therein) so as to normally retain the
arming switch 10 in the first position (see FIG. 9, for example)
when the projectile 100 is disposed within the bore 202. As shown
in FIGS. 1 and 3, the proximity safety device 40 may comprise a
biasing element 41 (such as a coil spring, for example) operably
engaged between the system housing 20 and the bore rider pin 44
(and/or a spring tab 46 extending outward from the bore rider pin
44) so as to bias the bore rider pin 44 towards the inner wall 201
of the launch bore 202 such that, when the projectile 100 is
launched from the launch bore 202, the first (wall-sensing) end 44A
of the bore-rider pin 44 becomes unconstrained, and the second end
45 of the bore rider pin 44 disengages the arming switch 10 (as
shown generally in FIG. 10, for example) and such that the arming
switch 10 is capable of being moved to the second position (as
shown, for example, in FIG. 11). According to some SA system 1
embodiments, the bore rider pin 44 (and the tab 42 and spring tab
46 extending therefrom) may be formed of corrosion-resistant and
reliably-machined material so as to increase the reliability of the
proximity safety device 40. For example, in some embodiments, the
bore rider pin 44 may be formed of 6061-T651 aluminum.
[0044] In other embodiments, the proximity safety device 40 may
comprise one or more non-contact sensors configured to be capable
of sensing the inner wall 201 of the launch bore 202. For example,
the proximity safety device 40 may comprise one or more optical
sensors, magnetic sensors, piezoelectric elements, and/or other
sensors or transducer devices configured to sense the inner wall
201 defining the launch bore 202. Furthermore, the proximity safety
device 40 (and/or one or more sensors thereof) may be in
communication with an actuator device 50 configured to disengage
the pin 44 from the locking channel 10C defined by the arming
switch 10 so as to allow the arming switch 10 to be moved to the
second position when the proximity safety device 40 has determined
that the projectile 100 has exited the launch bore 202. As
described further herein, various control elements may be in
communication with an actuator device 50 in some embodiments of the
SA system 1 to ensure that the arming switch 10 is not moved to the
second (armed) position (see FIG. 11, for example) until a selected
time after the proximity safety device 40 has determined that the
projectile 100 has exited the launch bore 202 (so as to ensure that
the projectile 100 and/or an explosive train carried thereby will
not be armed until the projectile 100 has reached a pre-determined
"safe" distance from the launch bore 202).
[0045] Thus, once the first acceleration safety device 30 and the
proximity safety device 40 have been disengaged from the arming
switch 10 (see FIGS. 9 and 10, respectively); the arming switch 10
may be capable of being moved to the second position (as shown, for
example, in FIG. 11). In order to facilitate the movement of the
arming switch 10 to the second (armed) position, the SA system 1,
as shown in FIGS. 1 and 3, may further comprise an actuator device
50 operably engaged between the system housing 20 and the arming
switch 10 and configured to be capable of moving the arming switch
10 from the first position to the second position in response to a
signal, wherein the signal may be, for example, an electrical or
other suitable signal. For example, as shown in FIG. 4D, in some
embodiments, the actuator device 50 may comprise one or more
electromechanical piston actuators capable of extending a piston 51
to engage a bearing surface 10A defined by a rotatable cylindrical
arming switch 10 such that as the piston 51 extends, the arming
switch 10 is moved from the first (safe) position (see FIG. 10, for
example) to the second (armed) position (see FIG. 11, for example).
In case of an accidental extension of the piston 51 while the first
acceleration safety device 30 and the proximity safety device 40
are still engaged with the locking channel 10C of the arming switch
10 (as shown, for example, in FIG. 8), some embodiments of the SA
system 1 may comprise an arming switch 10 defining a cutaway
section 10E behind the bearing surface 10A such that the piston 51
may shear and/or penetrate the bearing surface 10A if the actuator
device 50 is initiated when at least one of the first acceleration
safety device 30 and the proximity safety device 40 are still
engaged with the locking channel 10C of the arming switch 10.
[0046] According to some additional embodiments, the arming switch
10 may be provided with additional safety features to reduce the
risk of unintentional and/or accidental movement and/or rotation of
the arming switch 10 from the first (safe) position to the second
(armed) position. For example, cylindrical embodiments of the
arming switch 10 (see FIGS. 4A-4D, for example) may define a shear
pin slot 10D (defined off-center from the axis of the cylindrical
arming switch 10) for receiving a shear pin 14 (see FIGS. 1 and 3).
According to some SA system 1 embodiments, the shear pin 14 may
extend through one or more apertures defined by the system housing
20 (and through the shear pin slot 10D) for preventing the rotation
of cylindrical arming switch 10 embodiments relative to the system
housing 20 of the SA system 1. Furthermore, the shear pin 14 may be
configured to predictably fail in response to a torque generated by
the action of the piston 51 (and/or other actuator device 50
component) on a bearing surface 10A defined by the arming switch
10.
[0047] According to various embodiments, the actuator device 50,
which is configured to move the arming switch 10 from the first
position to the second (armed) position as shown in the sequential
views of FIGS. 10 and 11, may be in communication with one or more
control devices configured to generate a signal that may be
required to initiate movement of the actuator device 50. The
control devices may be disposed on a circuit board 80 that is
operably engaged with the system housing 20 of the SA system 1 (see
FIG. 1). In addition (and as described further herein), the
actuator 50 may comprise, for example, an electromechanical device
or other suitable device configured to be in communication with one
or more of the control devices via a wiring assembly 62 (see FIG.
7, for example) configured to maintain a short circuit around the
actuator device 50 so as to reduce the risk of the actuator device
50 unintentionally initiating the movement of the arming switch 10
to the second (armed) position. In other embodiments, as described
herein, the actuator device 50 may be in communication with an
optical sensor 43 (see FIGS. 1 and 3) configured to be capable of
generating the initiating signal in response to a change in
detected ambient optical conditions. As described further herein,
the optical sensor 43 may be included as part of and/or be coupled
with the proximity safety device 40 such that the optical sensor 43
generates the initiating signal for the actuator device 50 only
after a selected time has elapsed since the proximity safety device
40 no longer senses the inner wall 201 defining the launch bore
202. Thus, the combination of the optical sensor 43 (and/or other
control devices and/or wiring assemblies 62, as described further
herein), may provide secondary safeguards (to supplement, for
example, the first acceleration safety device 30 and proximity
safety device 40 described herein) against the accidental,
premature, and/or unintentional arming of the explosive train
carried by the projectile 100. In addition, some SA system 1
embodiments, may further comprise one or more logic circuits
carried by the circuit board 80 and configured to be in
communication with the actuator device 50 and/or one or more of the
first acceleration safety device 30 and the proximity safety device
40 to ensure that the mechanical disengagement of these devices
from the arming switch 10 occurs according to a timing schedule and
in an order that is indicative of an intentional launch event.
[0048] As shown, in FIGS. 3 and 6, the proximity safety device 40
(and/or the bore rider pin 44 that may be included as part of the
proximity safety device 40) may further comprise a tab 42
configured to normally cover an optical sensor 43 in communication
with the actuator device 50. As described generally herein, and as
shown, for example in FIGS. 8-11, the optical sensor 43 may be
operably engaged with the system housing 20 (and/or a circuit board
80 operably engaged therewith). Further, the tab 42 may be
configured to uncover the optical sensor 43 when the projectile 100
is launched from the launch bore 202 such that the optical sensor
43 becomes capable of transmitting the signal to the actuator
device 50 so that the actuator device 50 is capable of moving the
arming switch 10 from the first position (see FIG. 10, for example)
to the second (armed) position (see FIG. 11, for example) at a
selected time after the projectile 100 is launched from the launch
bore 202. For example, as shown generally in FIGS. 8-11, the tab 42
may be operably engaged with and/or integrated with the bore rider
pin 44 of the proximity safety device 40. Therefore, according to
such embodiments, when the bore rider pin 44 loses contact with the
inner wall 201 defining the launch bore 202, the biasing element 41
urges the bore rider pin 44 outward from the system housing 20 (see
FIG. 10, for example) such that the tab 42 uncovers and/or removes
a substantially opaque barrier between a light source (not shown)
and a light detection device (not shown) that may be included as
part of the optical sensor 43. In response to the removal of the
tab 42, one skilled in the art will appreciate that the optical
sensor 43 may transmit the signal to the actuator device 50 so as
to initiate the movement of the arming switch 10 to the second
(armed) position (as shown generally in FIG. 11).
[0049] According to some additional embodiments, as shown generally
in FIGS. 7, 12 and 13, the SA system 1 may further comprise a
wiring assembly 62 disposed between the optical sensor 43 (and/or
one or more of the control devices carried by the circuit board 80
of the SA system 1) and the actuator device 50. Furthermore, in
some embodiments, the wiring assembly 62 may be disposed between an
energy source (carried, for example, by the circuit board 80) and a
device configured to be capable of initiating the detonation of the
explosive train (such as, for example, the detonator 11 carried by
the arming switch 10, as shown in FIGS. 4A-4C). Thus, the wiring
assembly 62 may be configured to normally provide and maintain a
short circuit around the actuator device 50 so as to reduce the
risk of the actuator device 50 unintentionally initiating movement
of the arming switch 10 to the second (armed) position. In some
embodiments, the wiring assembly 62 may be configured to normally
provide and maintain a short circuit around the detonator 11 (or
other explosive component of an explosive train carried by the
projectile 100) so as to reduce the risk of unintentionally
actuating the explosive train (even if the arming switch 10 (and
the detonator 11, carried thereby) are substantially aligned with
the explosive train of the projectile 100). The wiring assembly 62
may comprise, in various SA system 1 embodiments, a normally closed
switch (as shown, for example in FIG. 12, showing a slider switch
66 normally in electrical contact with one or more contacts carried
by the wiring assembly 62). According to other SA system 1
embodiments, the wiring assembly 62 may comprise a substantially
continuous set of electrical connections (established by wires, for
example, as shown in FIG. 7). According to various SA system 1
embodiments, the electrical connections (established by wires (see
element 66A) and/or contacts 66B disposed on the slider switch 66)
may include, but are not limited to: a short circuit connection to
ground for the signal transmitted between the optical sensor 43 and
the actuator device 50; a short circuit connection to ground for a
detonator 11 arming signal; a short circuit connection to ground
for a controller device (such as a chip and/or other controller
carried by the circuit board 80) configured to control the
detonator 11; and combinations of such electrical connections.
[0050] The wiring assembly 62 may thus serve as at least one
component of a second acceleration safety device 60 (see exploded
components of a second acceleration safety device 60 as shown, for
example, in FIG. 7). The various components of the second
acceleration safety device 60 (including, for example, a second
setback weight 61 and a second linkage arm 63) may thus be
configured to be capable disabling the wiring assembly 62 in
response to the acceleration force of the projectile 100 such that
a signal is capable of being transmitted to the actuator device 50
and/or detonator 11 in order to align the explosive train and/or
actuate the explosive train only after the projectile 100 has
experienced an acceleration force having a selected magnitude and
duration. As described above with respect to the first acceleration
safety device 30, the second setback weight 61 of the second
acceleration safety device 60 may comprise materials having a
selected mass and/or density such that the second acceleration
safety device 60 only disables the short circuit of the explosive
train and/or actuator device 50 in response to acceleration force
(produced by movement of the SA system 1 in the launch direction
300, for example) having an intensity and/or duration that is
indicative of an intentional launch of the projectile 100 (as
opposed to relatively short-duration acceleration forces resulting
from accidental drops and/or rough handling of the projectile
100).
[0051] In some embodiments, as shown in FIG. 7 for example, the
second acceleration safety device 60 may comprise a second setback
weight 61 slidably disposed in a second setback weight chamber 27
defined by the system housing 20. The second acceleration safety
device 60 may, in some embodiments, further comprise a cutting
device 65 configured to be capable of cutting one or more wires 66A
in the wiring assembly 62. Furthermore, the cutting device 65 may
be slidably disposed in a cutting channel (not shown) defined by
the system housing 20 (and/or a cutting channel defined between two
halves 62A, 62B of the wiring assembly 62). In addition, the second
acceleration safety device 60 may further comprise a second linkage
arm 63 operably engaged between the second setback weight 61 and
the cutting device 65 such that, as the second setback weight 61
slides within the second setback weight chamber 27 in response to
the acceleration force, the second linkage arm 63 is configured to
move the cutting device 65 within the cutting channel (via the
interaction of a second linkage arm slot 63B and a cutting device
bearing element 65B, for example) such that the cutting device 65
(and/or a cutting edge 65A defined thereby) cuts at least one wire
66A within the wiring assembly 62 so that a signal is capable of
being transmitted to the actuator device 50 and/or the detonator
11. As described herein with respect to the first setback weight 31
(provided as a component in some embodiments including a first
acceleration safety device 30), the second setback weight 61 may be
configured to slide within the second setback weight chamber 27 in
response to the acceleration force having a selected magnitude and
a selected duration.
[0052] According to some additional embodiments, as shown in FIGS.
12-13, the second setback weight 61 of the second acceleration
safety device 60 may be configured to slide within the second
setback weight chamber 27 in response to an acceleration force
imparted on the SA system 1 such that the second setback weight 61
initiates the disconnection of a contact between a slider switch 66
and the wiring assembly 62, via the second linkage arm 63.
[0053] A method for safing and arming a projectile 100 including an
explosive train, using an SA system 1 that may be disposed
substantially adjacent to the explosive train, is further provided
in additional embodiments described herein. As described herein
with respect to FIG. 2, the projectile 100 may be adapted to be
launched from a launch bore 202. According to one embodiment, the
method comprises providing an arming switch 10 carried by a system
housing 20, wherein the arming switch 10 is configured to be
capable of moving from a first position to a second position. The
arming switch 10 is further configured to operably engage a
detonator 11 (and/or carry a detonator 11, as shown generally in
FIG. 4C, for example). Thus, when the arming switch 10 is in the
first position (see FIG. 10), the detonator 11 is substantially out
of alignment with the explosive train, and when the arming switch
10 is in the second (armed) position (see FIG. 11, for example),
the detonator 11 is substantially aligned with the explosive train
such that the explosive train is capable of being armed.
[0054] Such a method may further comprise securing the arming
switch 10 in the first position so as to normally retain the arming
switch 10 in the first position (see, for example, FIG. 8), and
then selectively releasing the arming switch 10 (see, for example,
FIG. 10) so as to allow the arming switch 10 to be moved to the
second position (see, for example FIG. 11). As described herein
with respect to the various SA system 1 embodiments, the releasing
step may be triggered by various intentional launch indicators that
may include, but are not limited to: an acceleration force having a
selected magnitude and a selected duration, the acceleration force
being imparted on the projectile 100 by an acceleration of the
projectile 100 with respect to the launch bore 202 during a launch
of the projectile 100; and a determination that the projectile 100
has been launched from the launch bore 202 (see FIG. 2, for
example).
[0055] As described herein with respect to the SA system 1
embodiments, the securing step described herein may be accomplished
by two or more safety devices (which may be, in some embodiments,
mechanically independent). For example, in some method embodiments,
the securing step may comprise securing the arming switch 10 in the
first position using a first acceleration safety device 30 carried
by the system housing 20 and configured to be capable of operably
engaging the arming switch 10 (and/or a locking channel 10C defined
therein, as shown in FIGS. 8-11) so as to normally retain the
arming switch 10 in the first (safe) position. The securing step
may also further comprise securing the arming switch 10 in the
first position using a proximity safety device 40 (which may
comprise a bore rider pin 44, as described in the SA system 1
embodiments) configured to be capable of operably engaging the
arming switch 10 (and/or a locking channel 10C defined therein, as
shown in FIGS. 8-11) so as to normally retain the arming switch 10
in the first (safe) position. As described further herein, the
proximity safety device 40 may be configured to sense the inner
wall 201 of the launch bore 202 such that the proximity safety
device 40 disengages the arming switch 10 only at some selected
time after the projectile 100 has exited the launch bore 202.
[0056] As shown generally in FIG. 9, the releasing step may further
comprise disengaging a first acceleration safety device 30 from the
arming switch 10 so as to allow the arming switch 10 to be moved to
the second position, in response to an acceleration force having a
selected magnitude and a selected duration, with the acceleration
force being imparted on the first acceleration safety device 30
(and/or the first setback weight 31 thereof) by an acceleration of
the projectile 100 with respect to the launch bore 202 during a
launch of the projectile 100. In addition, the releasing step may
also comprise, as shown in FIG. 9, sensing the inner wall 201 of
the launch bore 202 with a proximity safety device 40 (and/or the
bore rider pin 44 included as part of the proximity safety device
40, in some embodiments). According to such method embodiments, the
releasing step may further comprise determining that the inner wall
201 is no longer sensed by the proximity safety device 40, after
disengaging the first acceleration device 30 from the arming switch
10 (see FIG. 9); and disengaging the proximity safety device 40 (as
shown in FIG. 10, for example) from the arming switch 10 after the
determining step so as to allow the arming switch 10 to be moved to
the second position such that the explosive train is capable of
being armed when the projectile 100 is launched from the launch
bore 202. As described herein with respect to some SA system 1
embodiments of the present invention, the proximity safety device
40 may comprise a bore rider pin 44 slidably disposed in a first
pin channel 20A defined by the system housing 20. According to such
embodiments, the method may further comprise (as shown in FIG. 9):
contacting the inner wall 201 of the launch bore 202 with a first
end 44A of the bore rider pin 44 when the projectile 100 is
disposed within the launch bore 202; and engaging a second end 45
of the bore rider pin 44 with the arming switch 10 (and/or a
locking channel 10C defined therein) so as to normally retain the
arming switch 10 in the first position, when the projectile 100 is
disposed within the launch bore 202. In such method embodiments,
the method may further comprise biasing the bore rider pin 44
towards the inner wall 201 of the launch bore 202 using a biasing
element 41 (such as a coil spring, for example) operably engaged
between the system housing 20 and the bore rider pin 44 (and/or a
spring tab 46 extending outward from the bore rider pin 44), such
that when the projectile 100 is launched from the launch bore 202
(see FIG. 2, for example), the first end 44A of the bore rider pin
44 (see FIG. 10, for example) becomes unconstrained, such that the
second end 45 of the bore rider pin 44 disengages the arming switch
10 (and/or a locking channel 10C defined therein) such that the
arming switch 10 is capable of being moved to the second position
and consequently such that the explosive train is capable of being
armed.
[0057] As described herein with respect to some SA system 1
embodiments of the present invention, the proximity safety device
40 and the operation thereof may be coupled with an optical sensor
43 configured to be capable of transmitting a signal to initiate an
arming sequence of the projectile 100 (i.e. by initiating the
movement of an actuator device 50 to actuate the arming switch 10
(see FIG. 4D, for example), and/or by initiating the generation of
arming signals that may be transmitted to the detonator 11 carried
by the arming switch 10). According to such embodiments, as shown
generally in FIG. 3, the proximity safety device 40 (and/or a bore
rider pin 44 included as a component of the proximity safety device
40) may comprise a tab 42 configured to normally cover an optical
sensor 43 in communication with the detonator 11 and/or the
actuator device 50 (as described further herein). The optical
sensor 43 may be operably engaged with the system housing 20
(and/or a circuit board 80 disposed therein). Thus, in such
embodiments, the method may further comprise steps for moving the
tab 42 so as to uncover the optical sensor 43 (and/or remove a
substantially opaque barrier between a light source and a light
detection device that may be included as part of the optical sensor
43) when the projectile 100 is launched from the launch bore 202
(see FIGS. 9 and 10, sequentially showing the movement of the tab
42 relative to the optical sensor 43 as the projectile 100 exits
the launch bore 202). Thus, once the tab 42 is removed, the optical
sensor 43 is capable of transmitting the signal to the actuator
device 50 and/or the detonator 11 for initiating the arming and/or
actuation of the explosive train carried by the projectile 100.
Furthermore, the method may further comprise transmitting the
signal from the optical sensor 43 to the actuator device 50 and/or
detonator 11 such that the actuator device 50 is capable of moving
the arming switch 10 from the first position (see, for example,
FIG. 10) to the second (armed) position (see FIG. 11) at a selected
time after the projectile 100 is launched from the launch bore 202.
Furthermore, the method embodiments of the present invention may
also comprise, moving the arming switch 10 from the first (safe)
position to the second (armed) position using an actuator device 50
operably engaged between the system housing 20 and the arming
switch 10 (see, for example, FIG. 4D (showing the contact between a
piston 51 of the actuator device 50 and a bearing surface 10B
defined by a cutaway of the arming switch 10) in response to a
signal received by the actuator device 50.
[0058] As described herein with respect to SA system 1 embodiments
including a second acceleration safety device 60 (configured to be
capable of disabling a normally short-circuited electrical pathway
between a control device and a portion of the explosive train
(and/or the actuator device 50), for example), the providing step
may further comprise providing a wiring assembly 62 (see, for
example, FIGS. 7, 12 and 13) operably engaged with the system
housing 20 and configured to be capable of short circuiting a
signal suitable for actuating the explosive train and/or initiating
movement of the actuator device 50. According to such embodiments,
the method may further comprise disabling the wiring assembly 62
(i.e. by cutting one or more wires, as shown in FIG. 7 and/or by
disengaging a slider switch 66B from the contacts on the wiring
assembly 62 (as shown in FIGS. 12 and 13)), in response to the
acceleration force, using a second acceleration safety device 60
operably engaged with the system housing 20, such that the signal
is capable of being transmitted to the actuator device 50 and/or
some portion of the explosive train carried by the projectile 100.
Following the disabling step, such method embodiments may further
comprise a step for transmitting the signal to the actuator device
50 such that the actuator device 50 is capable of moving the arming
switch 10 from the first (safe) position (see FIG. 10) to the
second (armed) position (see FIG. 11. In some embodiments, the
transmitting step may further comprise transmitting a signal from a
control device carried by the system housing 20 (and/or a circuit
board 80 disposed therein), wherein the signal is configured to be
capable of actuating at least a portion of the explosive train
(such as the detonator 11 carried by the arming switch 10).
[0059] Many modifications and other embodiments of the system and
method set forth herein will come to mind to one skilled in the art
having the benefit of the teachings presented in the foregoing
descriptions and the associated drawings. Therefore, it is to be
understood that the inventions are not to be limited to the
specific embodiments disclosed and that modifications and other
embodiments are intended to be included within the scope of the
appended claims. Although specific terms are employed herein, they
are used in a generic and descriptive sense only and not for
purposes of limitation.
* * * * *