U.S. patent number 3,889,501 [Application Number 05/388,094] was granted by the patent office on 1975-06-17 for combination electrical and mechanical lock system.
Invention is credited to Charles P. Fort.
United States Patent |
3,889,501 |
Fort |
June 17, 1975 |
**Please see images for:
( Certificate of Correction ) ** |
Combination electrical and mechanical lock system
Abstract
The specification discloses a combination electrical and
mechanical lock system which includes a lock having a fixed lock
cylinder and a rotatable key slug having a key aperture
therethrough. A first solenoid is mounted in the lock cylinder and
includes a lock pin which is normally extended to prevent rotation
of the key slug. A pair of light sources and a pair of light
detectors are mounted in the lock for generating electrical signals
when a key having coded apertures therethrough is inserted into the
key slug. Circuitry is responsive to predetermined characteristics
of the electrical signals for operating the first solenoid to
retract the lock pin to allow rotation of the key slug. A second
solenoid is mounted in the lock cylinder and includes a latch pin
operable to be extended in response to an electrical power failure
in the system. When the latch pin is extended and a proper
mechanical key is inserted and rotated, extension of the lock pin
is prevented. A plurality of spring loaded pin tumblers are mounted
in the lock cylinder and are operable to be moved away from the key
slug upon insertion of a proper mechanical key to enable rotation
of the key slug during an electrical power failure.
Inventors: |
Fort; Charles P. (Dallas,
TX) |
Family
ID: |
23532661 |
Appl.
No.: |
05/388,094 |
Filed: |
August 14, 1973 |
Current U.S.
Class: |
70/283;
70/DIG.51; 70/337; 70/405; 361/172 |
Current CPC
Class: |
E05B
47/063 (20130101); E05B 49/006 (20130101); G07C
9/00904 (20130101); E05B 47/0004 (20130101); Y10T
70/7446 (20150401); Y10T 70/7859 (20150401); Y10T
70/713 (20150401); E05B 2047/0008 (20130101); Y10S
70/51 (20130101) |
Current International
Class: |
E05B
47/06 (20060101); E05B 49/00 (20060101); G07C
9/00 (20060101); E05b 047/06 () |
Field of
Search: |
;70/262,263,264,277,279,282,283,DIG.51 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Craig, Jr.; Albert G.
Attorney, Agent or Firm: Richards, Harris & Medlock
Claims
What is claimed is:
1. A lock system comprising:
a lock having a lock cylinder and a key slug rotatable within said
cylinder,
a pin contacting a surface on said key slug for normally preventing
said lock from being opened,
electrical means adapted for movement of said pin,
a key having first and second series of discrete coded portions
formed therein, said first series being laterally offset relative
to said second series,
means in said lock, for detecting the passage of said coded
portions upon insertion of said key and for generating first and
second electrical signals in response thereto,
said first electrical signals comprising a series of data pulses
spaced apart according to a predetermined configuration and said
second electrical signals comprising a series of clock pulses
spaced apart by a common interval, one edge of said clock pulses
occurring concurrently with ones of said data pulses,
means for sampling said data pulses in response to said one edge of
said clock pulses, and
means responsive to a predetermined sampled sequence of said data
pulses for activating said electrical means for movement of said
pin to permit opening said lock.
2. The lock system of claim 1 wherein said coded portions comprise
series of apertures formed through said key, said apertures in said
first series being spaced apart in a predetermined coded
configuration relative to said apertures in said second series,
means for transmitting light through said apertures, and
means for detecting light passed through said apertures.
3. The lock system of claim 1 and further comprising:
a second key having coded lands and grooves and operable to open
said lock only when the electrical power supply for said lock is
inoperative.
4. The lock system of claim 1 and further comprising:
means within said lock for permitting insertion of said key when
said lock is in the locking position, and
means for preventing removal of said key from said lock when said
lock is not in the locking position.
5. A lock system comprising:
a lock having a lock cylinder and a key slug rotatable within said
cylinder either in a first or second direction wherein the lock
system may be opened by rotation said key slug in said first
direction,
a pin contacting a surface on said key slug for normally preventing
rotation of said key slug in said first direction,
a key for being received by said key slug and having s first series
of apertures along the length thereof and further including a
second series of apertures located below said first series,
light source means mounted in said lock for transmitting light
through said apertures as said key is inserted into said key
slug,
first light sensitive means for generating an electrical data
signal representative of light transmitted through one of said
series of apertures,
second light sensitive means for generating an electrical clock
signal representative of light transmitted through the other of
said series of apertures,
circuitry for sampling said data signal in response to said clock
signal and for generating an enable signal upon detection of a
predetermined sampled signal sequence, and
means for moving said pin in response to said enable signal to
allow said key to rotate said key slug in said first direction to
open the lock system.
6. The lock system of claim 5 and further comprising:
a first set of tumbler pins in said lock cylinder,
a second set of tumbler pins in said key slug alignable with said
first set of tumbler pins upon rotation of said key slug in said
lock cylinder,
a second key having coded lands and grooves thereon for positioning
said second set of tumbler pins in said key slug at the interface
between said key slug and said lock cylinder thereby maintaining
said second set of tumbler pins at said interface during rotation
of said key slug within said lock cylinder so that said key slug
may be rotated in said second direction,
a cam surface on said key slug for camming said pin away from said
surface on said key slug when said key slug is rotated in said
second direction, and
means for maintaining said pin away from said surface on said key
slug to allow rotation of said key slug in said first direction
thereby opening the locking system.
7. The lock system of claim 5 wherein said moving means comprises a
solenoid for moving said pin in response to said enable signal.
8. A lock system comprising:
a first key having coded discrete portions therein and a second key
having a coded series of lands and grooves along one edge,
a lock having a rotatable key slug with a key aperture for
receiving either of said first or second keys,
electrical circuitry responsive to said coded discrete portions
when said first key is inserted into said lock for enabling said
key slug to be rotated to an unlocked position,
mechanical means operable only when said electrical circuitry is
deenergized for enabling said second key to be inserted into said
key slug and said key slug to be rotated to an unlocked position,
and
means for preventing said key slug from being rotated to an
unlocked position by said second key when electrical power is
available to said lock system.
9. The lock system of claim 8 wherein said discrete portions
comprise apertures formed through said key and further
comprising:
means for transmitting light through said coded apertures,
means for generating electrical signals in response to light
transmitted through said apertures, said electrical circuitry
responsive to said electrical signals for enabling said key
slug.
10. A combination electrical and mechanical lock system
comprising:
a lock having a fixed lock cylinder and a rotatable key slug having
a key aperture therethrough,
a first solenoid mounted in said lock cylinder and having a lock
pin engaged to normally prevent rotation of said key slug to an
unlocked position,
a first key having coded apertures therethrough,
a light source and a light detector mounted in said lock for
generating electrical signals when said first key having coded
apertures is inserted into said key slug,
circuitry responsive to predetermined characteristics of said
electrical signals for operating said first solenoid to disengage
said lock pin to allow rotation of said key slug to an unlocked
position,
means actuated by rotation of said key slug to withdraw said lock
pin from its normally locking position,
a plurality of spring loaded pin tumblers mounted in said lock
cylinder at an angle to vertical,
a second key for insertion into said key aperture and having coded
lands and grooves adapted to position said pin tumblers to allow
rotation of said key slug to actuate said means for withdrawing
said lock pin, and
a second solenoid mounted in said lock cylinder and having a latch
pin operable to be extended in response to an electrical power
failure to prevent the return of said lock pin to its normally
locking position thereby allowing rotation of said key slug to an
unlocked position during an electrical power failure.
11. A lock system comprising:
a lock having a lock cylinder and a key slug rotatable within said
cylinder in either a first or second direction wherein the lock
system may be opened by rotating said key slug in said first
direction,
a first set of tumbler pin holes in said lock cylinder at an angle
to vertical,
first tumbler pins carried in said first set of pin holes,
a second set of vertical tumbler pin holes in said key slug, said
second pin holes being alignable with said first pin holes,
second tumbler pins carried in said second set of pin holes,
means for normally preventing rotation of said key slug in said
first direction,
a first key for being received by said key slug and having a series
of apertures disposed along the length thereof,
a light source mounted in said lock for transmitting light through
said apertures as said key is inserted into said key slug,
light sensitive means for generating electrical data signals
representative of the light transmitted through said series of
apertures,
circuitry for detecting said data signals and for generating an
enable signal upon detection of a predetermined sample signal
sequence,
means for withdrawing said rotation preventing means in response to
said enable signal to allow said key to rotate said key slug in
said first direction to open said lock system,
a second key having coded lands and grooves thereon for positioning
said second set of tumbler pins in said key slug at the interface
between said key slug and said lock cylinder thereby maintaining
said second set of tumbler pins at said interface during rotation
of said key slug within said lock cylinder so that said key slug
may be rotated in said second direction,
means associated with said key slug for withdrawing said rotation
preventing means as said key slug is rotated in said second
direction,
means actuated by an electrical power failure to the system for
securing said rotation prevention means in the withdrawn position
to allow rotation of said key slug in the first direction to unlock
the locking system.
Description
FIELD OF THE INVENTION
This invenetion relates to security systems, and more particularly
relates to a lock system which is normally operated by an
electrical circuit which senses a key having discrete coded
portions therein, but which may be alternatively operated by a
conventional mechanical key upon electrical failure.
THE PRIOR ART
A wide number of different types of security systems have been
heretofore developed for use when security must be provided for a
large number of doors and when large numbers of people are
involved. For example, hotels and motels have a large number of
different rooms, each of which is assigned to a different key to
allow access to a particular room only by a designated guest.
Substantial problems occur with the use of ordinary mechanical
keys, not the least of which is the ease with which such mechanical
keys may be duplicated or stolen. When such mechanical keys are
lost, the entire lock must generally be replaced in order to
maintain security. Due to the expense and complexity of changing
locks, it is difficult to maintain security in such a system over a
long period of time. A need has thus arisen for a security system
in which security may be continuously provided to a large number of
areas, such that access is available only when a person has a
specific key, the system yet having the capability to enable
selective changing of the key which opens a designated room in
order to maintain the security of the entire system over a long
period of time. Such a security system must be easy to operate and
to change the keys which operate the system, and yet must be able
to be operated continuously even during the event of electrical
power failures.
SUMMARY OF THE INVENTION
In accordance with the present invention, a lock is provided which
includes a key having coded areas therein. A lock receives the key
and includes structure for sensing the positions of the coded areas
and for generating electrical signals in response thereto.
Circuitry is responsive to a predetermined electrical signal for
enabling the lock to be opened by rotation of the key.
In accordance with another aspect of the invention, a lock system
includes a key having first and second series of apertures formed
therethrough. A lock has a device for transmitting light through
the series of apertures and further includes devices for generating
first and second electrical signals in response to light received
through the series of apertures. Circuitry samples the first
electrical signals in response to portions of the second electrical
signals. Circuitry is responsive to a predetermined sampled
sequence of the first electrical signals for enabling the lock to
be opened by manual rotation of the key.
In accordance with another aspect of the invention, a lock system
is provided which includes a lock cylinder and a key slug rotatable
within the cylinder. A device is provided for normally preventing
rotation of the key slug. A key is dimensioned to be received
within the key slug and includes a first series of apertures along
the length thereof and further includes a second series of
apertures located below the first series. A light source is mounted
in the lock for transmitting light through the apertures as the key
is inserted into the key slug. A first light sensitive device
generates electrical data signals representative of light
transmitted through the series of apertures. A second light
sensitive device generates an electrical clock signal
representative of light transmitted through the other of the series
of apertures. Circuitry samples the data signal in response to the
clock signal and generates an enable signal upon detection of a
predetermined sampled data signal sequence. Structure is provided
to unlock the rotation preventing means in response to the enable
signal to allow the key to rotate the key slug.
In accordance with another aspect of the invention, a lock system
includes a first key havng coded apertures therethrough and a
second key having a coded series of lands and grooves along one
edge. A lock includes a rotatable key slug with a key aperture for
receiving either of the first or second keys. Electrical circuitry
is responsive to the coded apertures when the first key is inserted
into the lock for enabling the key slug to be rotated to an
unlocked position. A mechanical device is operable only when the
electrical circuitry is deenergized for enabling the second key to
be inserted in the end of the key slug and the key slug to be
rotated to the unlocked position.
In accordance with yet another specific aspect of the invention, a
combination electrical and mechanical lock system includes a lock
having a fixed lock cylinder and a rotatable key slug having a key
aperture therethrough. A first solenoid is mounted in the lock
cylinder and includes a lock pin engaged to normally prevent
rotation of the key slug. A light source and a light detector are
mounted in the lock for generating electrical signals when a key
having coded apertures is inserted into the key slug. Circuitry is
responsive to predetermined characteristics of the electrical
signals for operating the first solenoid to disengage the lock pin
to allow rotation of the key slug. A second solenoid is mounted in
the lock cylinder and has a latch pin operable to be extended in
response to an electrical power failure. The latch pin, when
extended, prevents engagement of the lock pin with the key slug. A
plurality of spring-loaded pin tumblers are mounted in the lock
cylinder and are operable to be moved away from the key slug upon
insertion of a key having coded grooves and lands to enable
rotation of the key slug during an electrical power failure.
DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and for
further objects and advantages thereof, reference is now made to
the following description taken in conjunction with the
accompanying drawings, in which:
FIG. 1 is a diagrammatic block diagram of a portion of the present
lock system;
FIG. 2 is a front view of a lock used in the present system;
FIG. 3 is a perspective view of a key having coded apertures
according to the invention;
FIG. 4 is a section view taken generally along the section lines
4--4 shown in FIG. 2;
FIG. 5 illustrates a side view, partially sectioned, of the key
shown in FIG. 3 when inserted into the present lock;
FIG. 6 is a section view taken generally along the section lines
6--6 in FIG. 2;
FIGS. 7a-b illustrates the data and clock waveforms generated by
the present lock;
FIG. 8 is a sectional view of the present lock when the lock pin
prevents clockwise rotation of the key slug;
FIG. 9 is a sectional view corresponding with FIG. 9 illustrating
how the lock pin is cammed upwardly by counter clockwise rotation
of the key slug by the mechanical key;
FIG. 10 is a sectional view of the lock illustrating operation of
the spring loaded pin tumblers when the lock is in the mechanical
mode of operation;
FIG. 11 illustrates a side view of the mechanical key inserted into
the lock sectioned generally along the section line 11--11 in FIG.
10;
FIG. 12 illustrates the line termination logic circuitry logic of
the invention;
FIG. 13 illustrates the line termination unit selection logic;
FIG. 14 illustrates the memory accessing and test data compare
logic; and
FIG. 15 illustrates the key assignment console interface
circuitry.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a block diagram of the present security system
which includes a desk console 10 having a keyboard array 12 which
may comprise for example a standard ASCII typewriter keyboard. The
console 10 includes a key slot 14 for insertion of electronic keys
according to the invention. The console further includes a display
16 whereby information input into the system by operation of the
keyboard 12 may be displayed. The console 10 is connected through
interface logic 18 to a central processor 20 which may include a
memory 22. The interface logic 18 is connected through an
electrical conductor 24 to the region of a door 26. The conductor
24 is connected to a circuit box 27 which is connected via an
electrical lead 28 to a lock 30 constructed in accordance with the
present invention. A plurality of similar locks installed in
additional doors in the area are connected to the interface logic
18 in a similar manner.
In operation of the present system, a plurality of coded keys are
normally maintained under the control of the operator of the
console 10. Assuming that the present security system is utilized
in a hotel, when a guest checks in, one of the coded keys is
inserted into the key slot 14 entering the key number into the
console, and the guest's name and the assigned room number are
entered into the keyboard 12 and all are displayed on the display
16. The information thus entered is also applied through the
interface logic 18 to the central processor 20 for storage therein.
This assigns the inserted key to the assigned room number.
Thereafter, the lock 30 may be actuated only by the particular
coded key assigned to the guest's room. A plurality of conventional
mechanical keys are also provided for use in case of a power
failure which renders the electronic system shown in FIg. 1
inoperative. Upon the occurrence of a power failure, one of the
mechanical keys may be utilized to operate the lock 30. When the
power to the system is restored, the lock 30 automatically reverts
to the electronic mode and cannot be operated by the mechanical
key. When the guest checks out, the assigned coded key is released
from assignment by operation of the keyboard 12 and thereafter the
coded key will not open the lock 30.
An important aspect of the present security system is that any one
of the plurality of coded keys may be assigned to operate any of
the locks in the system by proper insertion of the key in the key
slot 14 and by operation of the keyboard 12. If one of the coded
keys is thus stolen or duplicated, the single coded key could not
be utilized to operate any of the door locks, as the coded key
assigned to a particular lock will be periodically changed each
time a guest departs from the room.
Maids and other members of the hotel staff whose duties require
guestroom entry may be issued a coded key which is assigned to a
group of rooms by proper operation of the keyboard 12. If desired,
the system may be operated so that a maid's coded key may be used
only once per door lock and may be used only during a specified
period of the day. In order to increase the security provided by
the present system, a much larger number of coded keys may be
provided than the number of door locks in the hotel, thereby
allowing assignment of a large number of different keys to the
various door locks. If desired, the system may be operated to sound
an alarm in case a particular coded key which has been stolen is
inserted into any of the door locks in the system.
FIG. 2 illustrates a front view of the door lock 30 shown in FIG.
1. The lock includes a lock cylinder 32 which is rigidly mounted
within the door 26 in the conventional manner. A rotatable key slug
34 is mounted within the lock cylinder 32 and includes a key
aperture 36. Rotation of the key slug 34 in the clockwise direction
causes operation of a door bolt in the well known manner. The key
aperture 36 is dimensioned to receive either the coded key shown in
FIG. 3 or the conventional mechanical key shown in FIG. 11. When
the lock is in the electronic mode, only the coded key may be
rotated to operate the lock, while when electrical power is
disabled, only the mechanical key may be operated to operate the
lock.
A first solenoid 38 is mounted within the lock cylinder and
includes a movable lock pin 40. The second solenoid 42 is mounted
within the lock cylinder at a right angle to the solenoid 38 and
also includes a movable latch pin 44 which places the system in the
mechanical mode upon a power failure, as will subsequently be
described.
A pair of light emitting diodes 46 and 48 are laterally and
vertically offset from one another on one side of the lock cylinder
32 and emit rays of light which pass through apertures in the coded
key. the light transmitted through the key is detected by a pair of
phototransistors 50 and 52 which are likewise laterally and
vertically offset from one another. A first set of tumbler pins,
not shown in FIG. 2, are mounted in front of and behind the locking
pin 40 of the solenoid 38. A second set of spring biased tumbler
pins 54 are mounted at a 45.degree. angle from the first set and
are utilized in the mechanical mode of operation of the system as
will be subsequently described.
FIG. 3 illustrates a perspective view of the preferred coded key 60
of the invention. The key includes a conventional handle 62 and an
elongated key portion 64. An upwardly extending projection 66 is
formed on the forward end of the key to prevent the key from being
withdrawn from the lock once inserted and rotated. A first series
of apertures 68 are spaced along the upper portion of the key
according to a predetermined binary coded configuration. A second
series of spaced apart apertures 70 are spaced apart below the
first series of apertures. The series of apertures 68 is formed by
rectangular vertical slots in one side of the key in order to
define apertures 72 which extend completely through the width of
the key. The second series of apertures 70 is formed by vertical
slots made in the opposite side of the key in order to form the
apertures 74 which extend completely through the side of the
key.
The apertures 72 are spaced apart according to a predetermined
binary coded configuration. Each of the keys utilized with the
system have a different binary coded configuration of apertures.
The array of apertures 70 comprises a series of apertures 74 which
are evenly apart in order to generate clock pulses to enable
sampling of the signals generated by the coded series.
As previously noted, light from diodes 46 and 48 is transmitted
through the series of apertures 68 and 70 and is detected by
phototransistors 50 and 52 to generate data and clock signals.
While the preferred embodiment of the coded key uses coded
apertures, it will be understood that other discrete coded areas
could be formed on the key and detected. For example, magnetic
particles could be spaced along the length of the key to form a
coded data array and a clock array, and magnetic sensors could
detect the passage of the magnetic particles to generate electrical
data and clock signals. Similarly, the coded apertures in the key
as shown in FIG. 3 could alternatively be sensed by metal fingers
which complete an electrical circuit upon the occurrence of an
aperture. Other techniques for sensing coded apertures or other
types of discrete coded areas on the key are intended to be
encompassed by the present invention.
FIG. 4 is a section view taken along the section lines 4--4 in FIG.
2. The solenoid 38 includes a solenoid winding 80 which may be
energized by electrical signals to move the solenoid pin 82 and
lock pin 40 upwardly. A spring 84 normally biases the lock pin 40
in the illustrated downward position when solenoid 38 is
deenergized in order to lock the key slug 34 to prevent clockwise
rotation. The key slug 34 must be rotated in the clockwise method
in order to open the locked door. An aperture 86 is formed through
the side walls of the key slot 36 to emit light from the light
emitting diode 46, while an aperture 88 is formed to emit light
from the light emitting diode 48.
A plurality of vertical pin apertures 90a-e are formed in the lock
cylinder 32 and are adapted to mate with corresponding apertures
formed in the key slug 34 as illustrated in FIG. 11. Tumbler pins
92a-e are adapted to slidably move vertically within the apertures
in the key slug and in apertures 90a-e. If a mechanical key having
a wrong shape is inserted into the key slot 36, the pins 92a-e will
be raised into apertures 90a-e in order to prevent the rotation of
the key slug 34.
FIG. 5 illustrates the insertion of the coded key 60 into the key
slot 36. Upon insertion, the projection 66 causes each of the
tumbler pins 92a-e to be initially moved upwardly into apertures
90a-e and then the tumbler pins 92a-e fall downwardly behind the
projection 66. When the key slug 34 is rotated by the key 60, the
tumbler pin 92e prevents withdrawal of the key 60, as pin 92e is no
longer aligned under apertures 90e. When the key slug 34 is again
vertically aligned with the openings 90a-e, key 60 may be removed
from the lock.
FIG. 6 illustrates a sectional view taken generally along the
section line 6--6 of FIG. 2 and illustrates the second set of
tumbler pins 54a-e which are spring loaded within apertures set in
the lock cylinder at 45.degree. from the vertical. When the key
slug 34 is in the vertical position, as shown in FIG. 6, the
tumbler pins 54a-e bear against the outer edge of the key slug 34
and are maintained in the illustrated upward position. When the key
slug 34 is rotated by the proper mechanical key, the pins 54a-e
rest on top of the pins 92a-e to enable proper operation of the
lock in the manner to be subsequently described. If an improper
mechanical key is inserted into the key slug 34 and rotated, one or
more of the pins 54a-e will move into the apertures in the key slug
and will prevent further rotation of the key slug.
Operation of the lock when in the electronic mode will now be
described with reference to FIGS. 7 and 8. When the electrical
power is on, the solenoid 38 is normally deenergized and the
solenoid pin 82 is forced downwardly by spring 84 into a cammed
recess formed within the lock slug 34 as illustrated in FIG. 8. The
cam recess includes an abutment wall 96 and a cam surface 98.
As the coded key shown in FIG. 3 is inserted into the key slot 36,
light rays are transmitted from the light emitting diodes 46 and 48
through the series of apertures 68 and 70 and are detected by the
phototransistors 50 and 52. The outputs of the phototransistors
comprise squarewave signals representative of the light received
due to the passage of the key into the key slot 36. Typical output
signals from the phototransistors 50 and 52 are illustrated in
FIGS. 7a-b. The output of the phototransistor 52 comprises a
periodic wavetrain shown in FIG. 7a which serves as the clock
signal of the ivention. The output of the phototransistor 50
comprises a plurality of square pulses such as shown in FIG. 7b
which are apaced apart relative to FIG. 7a by varying amounts in
accordance with the coded spacing of the apertures 72.
Electronic circuitry, to be subsequently described, receives the
waveforms shown in FIGs. 7a-b and samples the transmitted
identification data signals shown in FIG. 7b upon each positive
going transition of the clock pulse shown in FIG. 7a. Thus, the
waveform of FIG. 7b is sampled at time t.sub.1 as a logic "1", and
is sampled at time t.sub.2 as a logic "0". The resulting binary
code output detected by the comparator circuitry of the invention
is then compared against the stored binary code input into the
central processor 20 as the correct code for that particular lock.
If the detected code matches the stored code, an energizing signal
is applied to the solenoid 38 and the solenoid pin 82 is moved
upwardly in order to remove the lock pin 40 from contract with the
abutment wall 96. The lock slug 34 may then be rotated clockwsie by
the key 60 in order to operate the door bolt in the conventional
manner.
While the present invention could be operated using only a single
set of key apertures in a spaced apart coded configuration and a
plurality of light sources and light detectors each corresponding
to a different key aperture, the use of the clock signal enables
the code to be detected with only two light sources and two
detectors irrespective of the speed in which the key is inserted
into the key slot. In normal operation of the system in the
electronic mode, the solenoid 42 is maintained in the energized
position and thus the latch pin 44 is withdrawn from engagement
with the lock pin 40.
However, in case of a power failure, the electronic mode of
operation of the system is not possible. Thus, when the electrical
power fails, the solenoid 42 is deenergized and the latch pin 44 is
moved outwardly from the solenoid 42 by operation of a spring 100.
A mechanical key which includes coded lands and grooves may then be
inserted into the key slot 36 and the key slug 34 rotated
counterclockwise. The mechanicl key must include coded lands and
gooves which interfit with the tumbler pins 92a-e in such manner as
shown in FIG. 11 in order to enable counterclockwise rotation of
the key slug 34 and to establish the mechanical mode.
Rotation of the key slug 34 in the counterclockwise manner causes
the lock pin 40 to be moved upwardly due to the cam surface 98.
When the key slug 34 reaches the position shown in FIG. 9, the lock
pin 40 reaches an upper position such the the latch pin 44 abuts
with the annular surface 104 of the lock pin 40 and prevents the
lock pin 40 from being moved downwardly. The system is now in the
mechanical mode and cannot be operated by any of the coded keys
60.
Once the lock pin 40 is latched as shown in FIG. 9, the key is then
rotated clockwise in order to operate the door bolt. FIg. 10
illustrates the proper alignment of pin 92a with the pin tumbler
54a in order to allow rotation of the key slug. The lands and
grooves of the mechanical key are such that the pins 92a-e mate
with the tumbler pins 54a-e at the periphery of the key slug 34 to
enable clockwise movement of the key slug 34 to enable operation of
the door bolt in the conventional manner. If the proper machanical
key has not been inserted, the tumbler pins 54a-e will project
downwardly into the key slug 34 and prevent further rotation.
FIG. 11 illustrates a sectional view taken generally along section
lines 11--11 in FIG. 10 illustrating the proper operation of the
mechanical key 110. As illustrated, the mechanical key 110 includes
lands and grooves such that the tumbler pins 92a-e contact the
tumbler pins 54a-e at the outer periphery of the key slug 34.
When the electrical power again comes on, the solenoid 42 is
re-energized and the latch pin 44 is withdrawn, thereby allowing
the lock pin 40 to be pushed downwardly by operation of the spring
84. The key slug 34 is then again locked against clockwise rotation
by the lock pin 40 and the mechanical key 110 will not work to
rotate the key slug 34 in the clockwise position beyond the
vertical position. The coded key 60 must then be used to open the
lock in the manner previously described.
FIGS. 12-15 illustrate the circuitry for determining the validity
of a particular coded key and for assigning coded keys to various
rooms as desired. The transmitted clock (TC) signal shown in FIG.
7a and the transmitted key ID signal shown in FIG. 7a are
transmitted to the circuitry shown in FIG. 12. The ID line
terminates in a line receiver 101 which outputs to the data input
of serial in/parallel out shift register 104. The TC line
terminates in line receiver 102 which outputs to the clock input of
shift register 104 and to the reset input of flipflop 106. As the
coded key is inserted into the key slot of FIG. 4, the light beam
through aperture 88 is interrupted by slots 74 of FIg. 3, producing
the TC signal. The light beam through aperture 86 is interrupted by
slots 72 of FIG. 3, producing the signal pattern of FIG. 7b. The
slots 72 of FIG. 3 represent a binary code and are unique to each
key of the system.
At the time t.sub.1 of FIG. 7, the clock signal causes the binary
data then present on the ID signal, a logical "1," to be shifted
into the shift register 104 of FIg. 12. At time t.sub., a lgical
"0" is shifted into the shift register 104. The clocking continues
as the key progresses into the key slot, until 16 data bits have
been loaded into the shift register 104. This condition is signaled
by the DATA READY output of shift register 104 going to a logical
"1," causing a service request to be made to selection logic 201
shown in FIG. 13. Logic 201 comprises logic to generate a memory
address corresponding to the particular data ready signal line or
lines requesting service and logic to queue and select one of a
plurality of lines requesting service for servicing. The memory
address lines are gated by gates 205 in response to the address
enable strobe from the memory timing and control logic. The address
of the selected line termination unit is also routed to the data
enable selector 202, the unlock strobe selector 203, and to the
reset strobe selector 204.
Following receipt of the memory service request signal from 201,
memory timing and control 301 (MTC), shown in FIG. 14, activates
ADDRESS ENABLE which causes gates 205 to apply the state of the
memory address lines from logic 201 to the address bus and to
generate the read request signal received by control 301. Control
301 then causes the memory 302 to begin a read access of the
location specified by the address appearing on the address bus.
Concurrent with the address enable strobe, control 301 activates
the data enable strobe to data enable selector 202 (FIG. 13). If
line termination logic LTL No. 1, corresponding to a particular
lock, is selected for service, for example, selector 202 issues a
data enable to gates 105, thereby applying the contents of shift
register 104 to the memory test data compare bus received by
comparator 303.
Following receipt of cycle complete from the memory 302, control
301 issues a start compare strobe to comparator 303. If the data on
the memory read data bus is logically equal to the data on the test
data compare bus, the comparator 303 activates the equal compare
strobe received by unlock strobe selector 203 and the OR gate 304.
Since the address input to selector 203 corresponds to LTL No. 1,
an unlock strobe is issued to flipflop 106, clocking it to the set
condition. The output Q of flipflop 106 received by line driver 103
causes an ulock pulse to be transmitted to the unlock solenod 80 of
FIG. 4, causing the lock pin 82 to be withdrawn. The key slug 36 is
thus enabled to be rotated clockwise by the key operator,
unlatching the lock mechanism.
If the data on the memory read data bus received by comparator 303
is logically unequal to the data on the test data compare bus,
comparator 303 activates the unequal compare strobe received by
reset strobe selector 204, through OR gate 304. Since LTL No. 1 is
selected by the memory address received by 204, the reset line
toshift register 104 is activated, clearing the register 104.
Clearing register 104 removes its DATA READY singnal from logic
201. Logic 201 then services the next queued LTL requesting service
and repeats the key validation cycle.
The assignment of persons to keys and keys to rooms is accomplished
using console 10 of FIG. 1. Referring to FIG. 15, the console
consists of an alpha/numeric keyboard 401 for entering information
manually into refresh memory 403 and a key reader similar to FIG. 2
for entering the key ID into memory 403. The contents of memory 403
are stored in memory 302 of FIG. 14 by operation of an ENTER BUTTON
on keyboard 401. Terminal interface logic 406 operates to transfer
the contents of memory 403 to memory 302, beginning at a location
corresponding to the room ID. The key ID is stored in this first
location, the keyholder's name and other information in following
location. Writing to memory is accomplished in a manner similar to
reading, but in a different mode.
Whereas the present invention has been described with respect to
specific embodiments thereof, it will be understood that various
changes and modifications will be suggested to one skilled in the
art, and it is intened to encompass such changes and modifications
as fall within the scope of the appended claims.
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