Note: Descriptions are shown in the official language in which they were submitted.
CA 02545107 2006-04-27
AVIONIC DOOR LOCK SYSTEM
FIELD OF THE INVENTION
This invention relates to security systems, and more particularly to a
security system adapted for use on a mobile platform for preventing
unauthorized entry into the cockpit of an aircraft.
BACKGROUND OF THE INVENTION
At the present time there is an increasing need for controlling access to
particular areas of mobile platforms. More specifically, there is an
increasing
need to control access to a cockpit of a commercial aircraft. Present day
security systems often involve a simple lock or other system requiring the use
of a key to unlock a door leading to a cockpit. However, such systems can be
inconvenient for flight attendants who may need to periodically enter the
cockpit area of an aircraft, such systems require a low force to open the door
in case of a decompression event.
Present day systems for preventing unauthorized access to the cockpit
of a commercial aircraft through the use of a key can be forced open, and also
can be foiled by an intruder if the intruder should gain access to the key.
Accordingly, there is a strong need for a security system for preventing
unauthorized access into a cockpit of a commercial aircraft which does not
suffer from the above-described limitations.
More specifically, there is a need for a security system for use on a
commercial aircraft which provides the pilot, co-pilot or other occupants of
the
cockpit a signal that entry into the cockpit is being requested. Such a system
would ideally give the individuals in the cockpit an opportunity to make an
assessment as to whether or not entry into the cockpit will be permitted
immediately, or whether entry should be denied. There is further a need for
such a system which allows the pilot, co-pilot or other cockpit occupant to
unlock the door separating the cockpit from the cabin area of the aircraft
from
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a convenient location within the cockpit. Also required is the ability for the
flight attendant to unlock the door after alerting the pilot and co-pilot for
a pre-
set time, in case the pilot and co-pilot are unable to perform the needed
operation to unlock the door.
SUMMARY OF THE INVENTION
The above and other objects are provided by a security system in
accordance with preferred embodiments of the present invention. The
security system is particularly well adapted for use in mobile platforms such
as, but not limited to, commercial aircraft. In one embodiment, the security
system operates to lock a door which separates a cockpit from a passenger
cabin area, and to allow occupants of the cockpit to receive signals
indicating
that a request for entry into the cockpit has been made by an individual in
the
passenger cabin area. The system further enables an occupant of the cockpit
to provide a signal to the system allowing immediate unlocking of the cockpit
door, or to deny the request to unlock the door.
The system in one preferred form includes a user input device which is
accessible by individuals in the cabin area. The input device may comprise a
keypad. A controller incorporating an audible component is disposed in the
cockpit. The logic system communicates with a control device positioned for
convenient use by persons in the cockpit, as well as with a lock operably
associated with the cockpit door. In one preferred form the control device
comprises a multi-position rotary switch.
In a preferred embodiment the multi position rotary switch provides
three switch positions: an "AUTO" position, an "UNLOCK" position and a
"DENY" position. An individual in the cabin area makes a request to gain
entry to the cockpit by entering a predetermined access code into the keypad.
It will be appreciated that the access code is a pre-programmed, restricted
code that only individuals, such as flight attendants, would be apprised of in
advance of entering the aircraft. When a correct access code is input to the
keypad, the logic system generates an aural and visual annunciation within
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the cockpit apprising individuals in the cockpit that a request to enter the
cockpit has been made.
If the switch is in the AUTO position, the occupants of the cockpit have
a predetermined time period in which to decide either to unlock the cockpit
door or to deny the request to enter. If a decision is made to allow entry,
the
occupants may leave the switch in the AUTO position, in which case the logic
system will automatically unlock the lock associated with the cockpit door at
the expiration of the predetermined time interval. If the occupants decide
that
entry should not be permitted, then the switch can be moved to the DENY
position. This signals the logic system that the request to enter is being
denied. The logic system will immediately disable the keypad and prevent
further entry signals from being generated within the cockpit for a
predetermined time thereafter.
If the occupants decide to grant immediate entry, then moving the
switch to the UNLOCKED position sends a signal to the logic system that the
lock to the cockpit door should be immediately unlocked. The logic system
then sends a signal to a suitable device, such as a solenoid, that immediately
unlocks the cockpit door. The UNLOCK position unlocks the door at any time
and stops all ongoing visual and aural annunciations.
In one preferred embodiment the signal provided by the logic system is
provided by a chime associated with a controller. The logic system also
implements an intelligent series of time delays after a request for entry has
been made at the keypad. When such a request has been made, the
controller causes the chime to emit an audible signal to the occupants of the
cockpit. The controller also simultaneously begins a first predetermined delay
interval. If no action has been taken at the control device by any occupant of
the cockpit at the expiration of the first predetermined delay interval, a
second
audible warning is provided by the chime and a second predetermined delay
interval is commenced.
At the end of the second predetermined delay interval, if still no action
has been taken by any occupant via the switch to either admit or deny the
request for entry, then the chime provides a continuous audible warning for a
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third predetermined time delay interval. At the end of the third delay
interval
the controller automatically sends a signal to the solenoid to unlock the lock
to
the cockpit door. A visual indicator also preferably flashes intermittently
during the third delay interval further signaling that the cockpit door will
be
unlocked within a very short time if no action is taken.
This operating scheme thus provides a short time period for the
occupants of the cockpit to make an assessment as to whether the request for
entry to the cockpit should be granted or denied. Conveniently, the door lock
is automatically unlocked without intervention by the occupants of the cockpit
provided the control device is in the AUTO position. The provision of both
audible and visual signals virtually eliminates the possibility that the
occupants
of the cockpit will not realize that a request for entry has been made. It
further
allows automatic unlocking of the cockpit door unless an occupant of the
cockpit intervenes through appropriate control of the switch. The switch also
provides a cut-off feature to remove power to the lock, if necessary.
It will be appreciated that the keypad described above does not have
the capability under any circumstances to unlock the door lock of the cockpit
door. The lock is controlled strictly by signals received from the controller
and
a pressure sensor provided in the cockpit. Accordingly, no amount of
tampering with the keypad, or even the destruction of the keypad, can result
in unlocking of the cockpit door once it is locked.
Further, the present invention could also include a display system in
communication with the controller to display at least one of a visual
indicator
or message announcing that entry to the cockpit has been requested.
Generally, the display system may include left, right and central multi-
function
displays which are capable of displaying at least one of a message or visual
indicator to the occupants of the cockpit. Thus, the display system may
provide an additional or alternative method for notifying the occupants in the
cockpit that entry into the cockpit has been requested.
Further areas of applicability of the present invention will become
apparent from the detailed description provided hereinafter. It should be
understood that the detailed description and specific examples, while
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indicating the preferred embodiment of the invention, are intended for
purposes of illustration only and are not intended to limit the scope of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed
description and the accompanying drawings, wherein:
Figure 1 is a detailed schematic of a security system 10 in accordance
with a preferred embodiment of the present invention;
Figure 1 a is a simplified schematic of the security system of Figure 1;
Figure 2 is a timeline of the three time delay intervals implemented by the
controller of the system after a request to unlock the cockpit
door is received; and
Figure 3 is an environmental view of an alternate embodiment of the
present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description of the preferred embodiments) is merely
exemplary in nature and is in no way intended to limit the invention, its
application, or uses.
Referring to Figure 1, there is shown a security system 10 for
controlling access into a control center of a mobile platform. In the
following
description, the mobile platform will be referred to as a commercial aircraft
and the control center will be referred to as the cockpit of the aircraft. It
will be
appreciated, however, that the system 10 of the present invention is equally
applicable to non-moving structures where it is desired to closely control
access to a sensitive area of the structure. It is anticipated that the
invention
may also find applications on other mobile platforms such as ships, trains or
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even buses. The system 10 advantageously includes only a limited number
of independent component parts making it easily retrofitable to existing
commercial or other types of aircraft.
Referring further to Figures 1 and 1 a, the system 10 generally includes
a user input device in the form of a keypad 12 which is disposed in the
passenger cabin area 13a of an aircraft 13, and in one preferred location on a
door post assembly 15a adjacent a door 15 of the aircraft 13 facing the
passenger cabin area. However, the keypad 12 may be placed in virtually
any location where it can be conveniently accessed by flight crew members
who may need to gain periodic access to the cockpit 13b of the aircraft 13.
The keypad 12 is in communication with a logic system 14. The logic
system 14, in turn, is in communication with a control device 16, a circuit
breaker 18 and a door lock solenoid 20. An ambient air pressure sensor 22
disposed in a cockpit 13b of the aircraft 13 communicates with the door lock
solenoid 20 and the logic system 14. The door lock solenoid 20 is operably
associated with a door lock 26 for the cockpit door 15, as will be described
in
greater detail below.
The logic system 14 comprises a suitable controller, and more
preferably an 8-bit controller. Advantageously, the controller 14 includes a
chime 24 which is used to generate an audible signal which is emitted through
speakers 25 disposed in the cockpit 13b of the aircraft 13. The control device
16 is also disposed in the cockpit 13b and may be mounted on an overhead
panel, in an aisle stand panel or at any other conveniently accessible
location
in the cockpit 13b.
With continuing reference to Figures 1 and 1 a, and additional reference
to Figure 2, the control device 16 includes a multi position rotary switch 28
having a first switch position 30 designated as the "AUTO" position, a second
switch position 32 designated the "UNLOCK" position and a third switch
position 34 designated as the "DENY" position. The switch 28 comprises a
manually engageable switch element 36 which is spring biased normally into
the AUTO position. The switch element 36 can be moved momentarily into
either the UNLOCK position or the DENY position. As soon as the switch
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element 36 is released, however, it is biased back to the AUTO position. An
"AUTO UNLK" indicator light 38 is also disposed closely adjacent the switch
28, as is a "LOCK FAILED" indicator light 40. The "AUTO UNLK" indicator
light 38 is illuminated when a predetermined access code has been correctly
entered into the keypad 12, as will be described in greater detail below. The
LOCK FAILED indicator light 40 indicates that the solenoid 20 has received a
signal from the logic system 14 to lock the door lock 26 of the cockpit door
15,
but the door lock 26 is not in the locked position.
In addition, the controller 14 may also include a cut-off switch 60. The
cut-off switch 60 is in communication with the circuit breaker 18 and the
logic
system 14. In particular, the cut-off switch 60 is in communication with the
chime 24 of the logic system 14 to enable the occupants of the cockpit 13b to
interrupt the flow of current from the circuit breaker 18 to the chime 24 in
the
case of a failure of the chime 24. Thus, in a case where the chime 24
malfunctions, the occupants of the cockpit 13b can toggle the cut-off switch
60
into the "OFF" position, and the chime 24 will be de-energized and power will
be removed from the solenoid 20. When the chime 24 is operational, the cut-
off switch 60 will be toggled into an "ON" position.
The keypad 12 comprises a plurality of numeric keys 42 and an
"ENTER" key 42a, a first indicator light 44, a second indicator light 46 and a
third indicator light 48. The first indicator light 44 preferably comprises a
red
LED for indicating that the system 10 has power for operation. A second
indicator light 46 preferably comprises an amber LED which is illuminated
when a user inputs the predetermined access code correctly via the keys 42
and 42a. Third indicator light 48 preferably comprises a green LED which
signals that the solenoid 20 has unlocked the door lock 26.
The solenoid 20 includes a microswitch 50 for sensing the position of a
plunger 20a of the solenoid 20. Accordingly, the controller 14 can verify that
the plunger 20a has been moved into the locked position when the solenoid
20 is energized. This provides an additional degree of security in the event
the solenoid 20 fails and the plunger 20a is not moved into the "LOCKED"
position. In such instance, the LOCK FAILED indicator light 40 will be
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illuminated by the controller 14 to provide an immediate visual indication of
such a condition to the occupants of the cockpit 13b.
With continuing reference to Figures 1, 1 a and 2, the ambient air
pressure sensor 22 is used to detect a drop in pressure in the cockpit 13b
when the cockpit door 15 is closed. The ambient air pressure sensor 22 may
include dual sensing elements (not shown) for increased reliability. The
ambient air pressure sensor 22 is in further communication with the control
device 16. Generally, based upon the pressure reading taken by the ambient
air pressure sensor 22, the control device 16 may signal the solenoid 20 to
unlock the cockpit door 15. Such a condition might occur, for example, if the
windshield of the aircraft 13 was broken. In such a situation, it would be
necessary to immediately unlock the cockpit door 15 to allow passenger cabin
air pressure to vent through the open cockpit door 15. The ambient air
pressure sensor 22 is thus used to detect a drop in pressure within the
cockpit
13b and to immediately signal this event by de-energizing the solenoid 20.
Referring to Figure 2, a description will now be provided of the
predetermined time delay sequence that is implemented by the controller 14.
"TO" represents the instant that a user correctly enters the predetermined
access code via the keypad 12. This code preferably comprises a three to
eight digit numeric code. It is provided to flight attendants or other
individuals,
prior to entering the aircraft, who may have a need to periodically enter the
cockpit 13b while the aircraft 13 is in operation. Immediately after receiving
the correct access code, the controller 14 causes the chime 24 to generate an
audible signal represented by pulses 52 and the "AUTO UNLK" indicator light
38 is continuously illuminated. Pulses 52 represent two "beeps" or other short
duration audible signals which immediately apprises the individuals in the
cockpit 13b that a request for access to the cockpit has just been made. At
T0, a first predetermined delay interval is commenced which extends in to
"T1". At T1, if the controller 14 has not received either an UNLOCK or a
DENY command via the switch 28 (i.e., the switch 28 has not been moved to
either of these positions), then the controller causes the chime 24 to again
provide audible signals, while the "AUTO UNLK" indicator light 38 remains
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continuously illuminated, represented by pulses 54, to remind the occupants
of the cockpit 13b that someone is requesting access to the cockpit. T1
represents the expiration of the first delay interval and the beginning of a
second delay interval.
At "T2", if the switch 28 still has not been moved out of the AUTO
position during the second delay interval, then the controller 14 causes a
third
delay interval to be commenced. At T2 the controller 14 causes the "AUTO
UNLK" indicator light 38 to flash continuously and the chime 24 is caused to
output a continuous audible alert, represented by waveform 56, that the door
lock 26 of the cockpit door 15 will be unlocked within a very short time
period
if no operator action is taken via the switch 28. At any time, an occupant in
the cockpit 13b may move the switch element 36 of the switch 28 to the
UNLOCK position 32, which signals the controller 14 to turn off the chime 24
and the "AUTO UNLK" indicator light 38, as well as to command solenoid 20
to unlock the door lock 26. Also at any time during the first delay interval,
the
second delay interval or the third delay interval, an occupant in the cockpit
13b may move the switch element 36 to the DENY position 34. This signals
the controller 14 to turn off the chime 24 and the "AUTO UNLK" indicator light
38, and further inhibits operation of the keypad 12 for a predetermined time
thereafter. This predetermined time may vary but is preferably for a time
interval of between five minutes to thirty minutes. During this time, if an
individual should again correctly enter the access code into the keypad 12, no
audible or visual signals would be provided by the chime 24 or "AUTO UNLK"
indicator light 38. After the expiration of this time period, then the user
may
again input the access code into the keypad 12 and make another request to
access the cockpit 13b.
At T3, as long as no operator selection has been made via the switch
28 (i.e., meaning that the switch element 36 has remained in the AUTO
position 30), the controller 14 causes the solenoid 20 to be de-energized.
This causes the door lock 26 to be unlocked. Thereafter, manual actuation of
the door handle of the cockpit door 15 will allow the door to be opened.
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In the preferred embodiment described above, the delay interval
between TO and T3 is user programmable from about 15 seconds to about
120 seconds in 15 second increments. Preferably, the delay interval between
T2 and T3 has a minimum duration of at least 10 seconds. The audible
signals represented by pulses 52 and 54 preferably comprise 0.5 second
duration audible signals having a frequency of preferably around 500 Hz at
approximately 85 to 93 dB. It will be appreciated, however, that the duration,
frequency and intensity of these audible signals may be modified to suit user
preferences.
The "AUTO UNLK" indicator light 38, when flashing during the third
delay interval, preferably flashes at a 50% to 60% duty cycle, with 60% being
the more preferred duty cycle. Again, however, the frequency at which this
light flashes may be tailored to suit user preferences.
When the door lock 26 of the cockpit door 15 is unlocked at point T3,
the door is preferably maintained in the unlocked position for a predetermined
time interval, and more preferably for at least about five seconds. Again,
this
delay interval could also be modified. During this time period the solenoid 20
remains de-energized. After this short time interval expires, the controller
14
again automatically energizes the solenoid 20 to cause the door lock 26 to
lock the cockpit door 15.
The access code and time delay settings are preferably changeable
from the controller 14. The access code can be changed by engaging a
"PROGRAM" key 58 on the controller 14 as indicated in Figure 1. Once key
58 is depressed, a new access code can be entered at the keypad 12. The
time delay settings may be modified by engaging a "PROGRAM" key 59 on
the controller 14, as shown in Figure 1. Similarly, once key 59 is depressed,
new time settings may be entered via the keypad 12.
Another optional feature which may be implemented is a "door bell"
mode. This mode may be implemented by selecting a particular key, such as
the "1" key on the keypad 12, followed by the "ENTER" key 42a. This causes
the chime 24 to generate an audible signal but does not begin the time delay
period represented between TO and T3. In effect, the occupants of the
CA 02545107 2006-04-27
cockpit 13b are simply apprised that an individual in the cabin area 13a of
the
aircraft 13 is requesting access to the cockpit. The audible signal may
comprise one or more short duration signals by the chime 24.
Alternatively, as shown in Figure 3, the controller 14 may be in
communication with a visual display system 62 in the cockpit 13b to indicate
the status of the door lock 26. More specifically, the visual display system
62
aircraft may include three multifunction displays, a left display 64, a center
display 66, and a right display 68. Of the three multifunction displays, the
left
display 64 is generally dedicated exclusively to the occupant seated in a left
seat (not shown), the right display 68 is generally dedicated exclusively to
the
occupant seated in a right seat (not shown), and the center display 66 is
typically shared by the both occupants. The controller 14 may send a signal
to the visual display system 62 which provides a pop-up window 70 (shown in
phantom) on the visual display system 62 to indicate that the door lock 26 is
unlocked or that the door lock 26 has failed to unlock the cockpit door 15.
The pop-up window 70 may be displayed on either the left display 64, right
display 68 or center display 66, or on an any combination of displays, such
as,
for example, the left display 64 and right display 68. The pop-up window 70
may also be scrolled across each of the displays 64-68. The pop-up window
70 may further include any appropriate message, such as "Access is
Requested" or the like. Thus, the pop-up window 70 provides immediate
visual notification of the condition of the door lock 26 to the occupants of
the
cockpit 13b seated in front of the visual display system 62.
The system 10 of the present invention thus provides a means by
which individuals in the cabin area of the aircraft can request access to the
cockpit, and can further initiate a process by which a locked cockpit door
will
be automatically unlocked if no intervention is taken by occupants of the
cockpit. The inclusion of the pressure sensor also ensures that in the event
of
a decompression condition occurring in the cockpit, the cockpit door will be
automatically and immediately unlocked so that the door can be quickly
opened. Importantly, the system 10 provides the occupants of the cockpit
with the ultimate authority to deny the requested access if circumstances are
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such that the cockpit occupants believe that the cockpit should remain secure
from all individuals in the cabin area.
Those skilled in the art can now appreciate from the foregoing
description that the broad teachings of the present invention can be
implemented in a variety of forms. Therefore, while this invention has been
described in connection with particular examples thereof, the true scope of
the
invention should not be so limited since other modifications will become
apparent to the skilled practitioner upon a study of the drawings,
specification
and following claims.
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