U.S. patent application number 10/100227 was filed with the patent office on 2003-09-18 for avionic door lock system.
Invention is credited to Bandy, Paul W., Gaston, Darrell W. JR., Kupfer, Shannon J., Schaeffer, Dwight R., Truong, Binh C..
Application Number | 20030173458 10/100227 |
Document ID | / |
Family ID | 27788330 |
Filed Date | 2003-09-18 |
United States Patent
Application |
20030173458 |
Kind Code |
A1 |
Bandy, Paul W. ; et
al. |
September 18, 2003 |
Avionic door lock system
Abstract
A security system adapted for use on an aircraft to prevent
unauthorized access into a cockpit area of the aircraft via a
cockpit door. The system includes a keypad accessible by
individuals in a cabin area of the aircraft. A logic system is in
communication with the keypad and also with a switch disposed
inside the cockpit. Occupants of the cockpit, via the switch, have
the ability to manually unlock the cockpit door, to deny the
request for entry, or to do nothing, in which case the door will be
automatically unlocked after the expiration of a predetermined time
interval. No amount of tampering with the keypad or destruction of
the keypad can unlock the cockpit door if the cockpit occupants
decide to deny a request for entry via appropriate positioning of
the switch. A pressure sensor in communication with the controller
allows the door to be automatically unlocked in the event of a
decompression condition occurring in the cockpit.
Inventors: |
Bandy, Paul W.; (Kent,
WA) ; Gaston, Darrell W. JR.; (Everett, WA) ;
Truong, Binh C.; (Kirkland, WA) ; Schaeffer, Dwight
R.; (Mercer Island, WA) ; Kupfer, Shannon J.;
(Kirkland, WA) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Family ID: |
27788330 |
Appl. No.: |
10/100227 |
Filed: |
March 18, 2002 |
Current U.S.
Class: |
244/118.5 |
Current CPC
Class: |
B64C 1/1469 20130101;
G07C 9/0069 20130101; G07C 9/33 20200101; B64D 45/0029 20190801;
B64C 2001/009 20130101 |
Class at
Publication: |
244/118.5 |
International
Class: |
B64D 011/00; B64D
013/00 |
Claims
What is claimed is:
1. A security system for preventing unauthorized access to a
control center of a mobile platform, wherein the control center is
separated from a passenger area of said mobile platform by a door;
said system comprising: a lock for locking said door; a user input
device accessible by individuals in said passenger area to input a
predetermined access code to request unlocking of said door; a
controller responsive to said user input device for producing a
signal within said control center when said access code is entered
that entry to said control center has been requested by an
individual within said passenger area; and a control device within
said passenger area in communication with said lock for allowing an
individual in the control center to unlock said door.
2. The system of claim 1, wherein: said control device is in
communication with said controller; wherein said controller is in
communication with said lock; and wherein said control device
commands said controller to unlock said lock.
3. The system of claim 1, wherein said control device comprises a
switch for allowing said lock to be immediately unlocked.
4. The system of claim 2, wherein said control device comprises a
switch having a position signaling said controller to unlock said
lock after a predetermined time delay period has expired.
5. The system of claim 2, wherein said control device comprises a
switch for signaling said controller to ignore said request for
entry and to maintain said lock in a locked position.
6. A security system for preventing unauthorized access to a
cockpit of an aircraft, wherein the cockpit is separated from a
cabin area by a cockpit door, the system comprising: a lock for
locking the door in a closed position; a user input device for
allowing an individual in said cabin area to input a predetermined
access code to request unlocking of the cockpit door; a controller
responsive to said user input device for producing a signal when
said access code is entered that entry to the cockpit has been
requested; and a switch in communication with said lock for
allowing an individual in the cockpit to unlock said door.
7. The security system of claim 6, wherein said lock is responsive
to said controller and said controller is responsive to said
switch; and wherein said controller commands said lock to an
unlocked position a predetermined delay time after said access code
is entered at said user input device.
8. The security system of claim 6, wherein said controller
comprises a chime that produces an audible signal when said access
code is entered at said user input device.
9. The security system of claim 6, wherein said switch comprises a
multi-position switch in communication with said controller for
enabling an individual on said cockpit to deny access to said
cockpit and inhibit operation of said user input device for a
predetermined time period after said access code had been entered
at said user input device.
10. The security system of claim 6, wherein said switch is in
communication with said controller and comprises a multi-position
switch including: a first position in which said switch signals
said controller to unlock said lock when said predetermined delay
time has expired; a second position, in which said switch signals
said controller to immediately unlock said lock; and a third
position in which said switch signals said controller to maintain
said lock in said locked position and to disable said user input
device for said predetermined time period.
11. The security system of claim 10, further comprising: a chime
responsive to said controller for producing an audible signal in
said cockpit when said individual in said cabin area has input said
access code into said user input device.
12. The security system of claim 10, further comprising: an
indicator light responsive to said controller for providing a
visual indication to an individual on said cockpit that an
individual in said cabin area has requested access to said cockpit
via said user input device.
13. The system of claim 6, wherein said user input device comprises
a keypad.
14. The system of claim 13, wherein said keypad comprises: a first
indicator light indicating that said cockpit door is in said locked
position; a second indicator light indicating that said access code
has been received by said controller; and a third indicator light
indicating that said lock has been moved to said unlocked
position.
15. A security system for preventing unauthorized access to a
cockpit of an aircraft, wherein the cockpit is separated from a
cabin area by a cockpit door, the system comprising: a lock for
locking the door in a closed position; a user keypad for allowing
an individual in said cabin area to input a predetermined access
code to request unlocking of the cockpit door; a controller
responsive to said user input device for producing a signal
detectable in said cockpit when said access code is entered that
entry to the cockpit has been requested; a switch in communication
with said controller for allowing an individual in the cockpit to
select an action including: commanding said controller to
immediately unlock said lock; and commanding said controller to
ignore a previous request by said individual, via said keypad, for
access to said cockpit and to maintain said lock in a locked
position.
16. The system of claim 15, wherein said switch includes an
automatic response position which signals said controller to
automatically unlock said lock after a predetermined time delay
period has expired after said access code has been input into said
keypad.
17. The system of claim 15, wherein said predetermined time delay
period includes at least: a first delay interval which commences
when said signal is generated that said access code has been
entered in said keypad; and a second delay interval during which
said controller produces a second signal signaling to said
occupants of said cockpit that said controller will automatically
unlock said lock at an expiration of said first delay interval.
18. The system of claim 15, wherein said predetermined time delay
period includes: a first delay interval which commences when said
signal is generated that said access code has been entered in said
keypad; a second delay interval which commences upon the expiration
of said first delay interval, said controller generating a second
signal at a beginning of said second delay interval reminding
occupants of said cockpit that cockpit door has not been unlocked
or said request for entry denied via said switch; and a third delay
interval during which said controller produces a third signal
signaling to said occupants of said cockpit that said controller
will automatically unlock said lock at an expiration of said third
delay interval.
19. The system of claim 15, wherein said keypad comprises: a first
indicator light for indicating that said lock is in a locked
condition; and a second indicator light for indicating that said
lock has been moved into an unlocked condition.
20. The system of claim 15, wherein said keypad comprises: a first
indicator light for indicating that said lock is in a locked
condition; a second indicator light for indicating that said lock
has been moved into an unlocked condition; and a third indicator
light for indicating that said access code has been received by
said controller and that said occupants in said cockpit have been
apprised of said request for entry to said cockpit.
21. The system of claim 15, wherein said signal comprises an
audible signal generated by a chime, and wherein said chime is in
communication with said controller.
22. The system of claim 15, wherein said controller operates to
inhibit further requests for entry to said cockpit for a
predetermined delay interval if said switch is positioned to
command said controller to ignore said previous request for entry
to said cockpit.
23. A method for securing a control center of a mobile platform
from unauthorized entry, wherein the mobile platform includes a
door separating said control center from a passenger area, the
method comprising: using a lock to lock said door in a closed
position; using a user input device to allow an individual in said
passenger area to input an access code to request entry to said
control center; using a controller to receive said request for
entry and to provide a signal to an occupant in said control center
that a request for entry to said control center has been made;
using a control device for allowing said occupant to perform at
least one action including: immediately unlocking said lock; and
unlocking said lock only after the expiration of a predetermined
time delay interval.
Description
FIELD OF THE INVENTION
[0001] This invention relates to security systems, and more
particularly to a security system adapted for use on a mobile
platform such as an aircraft for preventing unauthorized entry onto
the cockpit of an aircraft.
BACKGROUND OF THE INVENTION
[0002] 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 decompression
event.
[0003] 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.
[0004] 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 either
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 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 both incapacitated.
SUMMARY OF THE INVENTION
[0005] The above and other objects are provided by a security
system in accordance with a preferred embodiment of the present
invention. The security system is particularly well adapted for use
in mobile platforms such as, but not limited to, commercial
aircraft. 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 of the aircraft. 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.
[0006] The security system preferably includes a pressure sensor.
The pressure sensor causes the cockpit door to unlock when a
difference in pressure between the cabin and cockpit is sensed.
[0007] The system generally includes a user input device which is
accessible by individuals in the cabin area. In one preferred form
the input device comprises a keypad. A controller incorporating a
chime 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.
[0008] 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 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.
[0009] 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 control device to either admit or
deny the request for entry, then the chime provides a continuous
audible warning for a 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.
[0010] 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 switch 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. Unlocking can be accomplished only via the
multi position switch.
[0011] 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 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
[0012] The present invention will become more fully understood from
the detailed description and the accompanying drawings,
wherein:
[0013] FIG. 1 is a simplified block diagram of a security system 10
in accordance with a preferred embodiment of the present invention;
and
[0014] FIG. 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.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] The following description of the preferred embodiment(s) is
merely exemplary in nature and is in no way intended to limit the
invention, its application, or uses.
[0016] Referring to FIG. 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 or 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.
[0017] Referring further to FIG. 1, 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.
[0018] 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 momentarily.
[0019] 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
within 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.
[0020] In a preferred embodiment the control device 16 comprises a
multi position rotary switch 28 having a first switch position 30
designated as the "AUTO" position, a second switch position
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 element 36 is released, however, it is biased
back to the AUTO position. An "UNLOCK" indicator light 38 is also
disposed closely adjacent the switch 28, as is a "LOCK FAILED"
indicator light 40. The UNLOCK 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 momentarily.
The LOCK FAILED indicator light 40 indicates that the solenoid 20
has not unlocked the lock 26 of the cockpit door 15.
[0021] 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 door lock
26 is in a locked condition. 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.
[0022] 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 illuminated by the controller 14 to provide an immediate visual
indication of such a condition to the occupants of the cockpit
13b.
[0023] 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.
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 prevent complete
decompression of the cockpit 13b. The pressure sensor 22 is thus
used to detect a drop in pressure within the cockpit 13b and to
immediately signal this event by deenergizing the solenoid 20.
[0024] Referring to FIG. 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. 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 in
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, 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.
[0025] 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 UNLOCKED indicator light 38 to be
continuously illuminated and the chime 24 is caused to output a
continuous audible alert, represented by waveform 56, that the lock
26 of the 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 UNLOCKED indicator light 38, as
well as to command solenoid 20 to unlock the 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 UNLOCKED 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 UNLOCKED 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.
[0026] 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 deenergized. 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.
[0027] In the preferred embodiment described above, the delay
interval between T0 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 75 dB. It
will be appreciated, however, that the duration, frequency and
intensity of these audible signals may be modified to suit user
preferences.
[0028] The UNLOCKED 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.
[0029] When the 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
deenergzied. After this short time interval expires, the controller
14 again automatically energizes the solenoid 20 to cause the lock
26 to lock the door 15.
[0030] The access code is preferably changeable from the controller
14. This is accomplished by engaging a "PROGRAM" key 58 on the
controller 14 as indicated in FIG. 1. Once this key is depressed, a
new access code can be entered at the keypad 12.
[0031] 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 T0 and T3.
In effect, the occupants of the 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.
[0032] 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 such that the cockpit
occupants believe that the cockpit should remain secure from all
individuals in the cabin area.
[0033] 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.
* * * * *