Note: Descriptions are shown in the official language in which they were submitted.
CA 02306997 2000-04-28
1233-360A
VMD:KGS
LOCKING DEVICE FOR AN ELECTRONIC LOCK-SET
FIELD OF THE INVENTION
The present invention relates generally to electronic
security systems for controlling access through doors and the
like. In particular, the present invention relates to electronic
lock-sets for doors which allow access only to certain
electronically identified individuals.
BACKGROUND OF THE INVENTION
A variety of electronic lock-sets are known. A number of
these known lock-sets are described below for reference.
U.S. Patent No. 5,083,122 (Clark) provides one example of a
known electronic lock-set. Clark shows that an electronic lock-
set can be used to control access through doors by a selectably
variable group of individuals. In brief, Clark employs a motor 8
that is electronically activated to allow or deny access to
certain individuals. Clark includes helical spring 36 that
slidably encloses the motor shaft at one end, and a cross pin 40
passes through the motor shaft and spring. As a result, when the
locking plunger is kept from returning to the locked position by
external means, such as someone keeping the door knob turned
while the motor is programmed to relock it, the motor causes the
spring to compress as the plunger is held at a fixed position by
the external means. Then, when the external force is removed,
the spring will expand and the plunger will move to the unlocked
position.
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CA 02306997 2000-04-28
y i
U.S. Patent No. 5,018,375 (Tully) provides another example
of a known electronic lock-set. The Tully reference shows an
electronic lock-set having a rotary electric motor that is
adapted to disable and enable an outer handle of a door. In this
reference, a locking dog 42a on a dog disk 42 is received in a
slot 46 to couple the handle 18 to allow operation of the handle.
Otherwise, the handle 18 is not coupled and is thus disabled.
Tully includes a motor 60 having a shaft 68 with a transverse pin
72. A spiral spring 74 is secured to the disc 42 in such a
manner that the pin 72 acts as a nut to the pin.
U.S. Patent No. 5,628,216 (Qureshi) provides another example
of a known electronic lock-set. The Qureshi reference shows a
locking device having a locking mechanism with a hollow plunger
engaged with a locking mechanism to move the locking mechanism
into locked and unlocked positions and a motor having a shaft
disposed co-axially with the plunger. In one embodiment, the
locking device has a spring that engages a motor shaft. And, a
pin is fixed to the plunger such that when the shaft rotates the
plunger is moved. In another embodiment (see, e.g., FIGS. 9-10),
the locking device includes a threaded member disposed on the
motor shaft and a threaded surface on the interior of the plunger
such that when the shaft rotates, the plunger is moved.
U.S. Patent No. 5,473,236 (Frolov) provides another example
of a known electronic lock-set. The Frolov reference shows an
electronic lock-set having a motor 72 that is activated to
disengage a locking dog tang 34 to thereby allow rotation of a
latch handle 18. The motor shaft 73 is connected to a drive
screw 30 by a coil spring 26 to permit proper operation if a
jamming condition is present.
U.S. Patent No. 5,421,178 (Hamel) provides another example
of an electronic lock-set, which locks and unlocks rotational
movement of a door handle.
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CA 02306997 2000-04-28
While a variety of electronic lock-sets are known, there are
substantial limitations with existing devices and there remains a
continued need for improved electronic lock-set devices which are
less likely to malfunction or become damaged under certain
conditions, which are relatively inexpensive to manufacture, and
which can operate consistently, economically, reliably and for
long periods of time.
SU1~IARY OF THE INVENTION
The present invention can overcome the above and/or other
problems related to existing lock devices. The present invention
provides improved lock mechanisms to move a locking dog via an
electronic motor within an electronic lock-set so as to, for
example, avoid problems related to binding and the like during
operation of the electric motor.
The lock mechanisms preferably include an electronically
controlled motor that reciprocates the locking dog between door
locking and unlocking positions upon appropriate electronic
access by a user -- such as by inserting an appropriate
electronic key or another electronic access element, etc. The
motor rotates a threaded shaft that, in turn, reciprocates the
locking dog. The motor is electronically controlled to cause
the locking dog to reciprocate along the threaded shaft, while
either: a) at least one spring absorbs energy that may be applied
by external forces that may cause the locking dog to become
locked at a particular position; and/or b) an electronic
detection is made as to whether external binding forces exist and
operation of the motor is controlled based on that detection.
Notable advantages, features and aspects of the present
invention are elaborated upon in the following description of the
preferred embodiments taken together with the accompanying
drawings and claims.
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CA 02306997 2000-04-28
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from
the following detailed description and the accompanying drawings
which are given by way of illustration and are not limitative of
the present invention.
FIG. 1 is a side view of an exemplary electronic lock-set in
which the various embodiments of the of the present invention can
be incorporated;
FIG. 2 is a side view of a locking device according to a
first embodiment of the invention;
FIG. 3(A) is a schematic cross-sectional side view of a
locking device according to a second embodiment of the invention
mounted in an exemplary electronic lock-set;
FIG. 3(B) is a perspective view of a coupling member having
a universal joint for connecting the motor drive shaft to the
screw shaft in embodiments of the present invention;
FIG. 4 is an enlarged cross-sectional side view of the
actuator elements of the locking device shown in FIG. 3.
FIG. 5 is an exploded perspective view of the actuator
elements shown in FIG. 4;
FIGS. 6(A) through 6(D) are partial cross sectional views of
an alternative embodiment of actuator elements as assembled in
preferred embodiments of the present invention;
FIG. 7(A) through FIG. 7(I) are various side views of the
unassembled actuator elements as depicted by FIG. 6(A).
FIG. 8(A) is a schematic cross-sectional side view of a
locking device according to a third embodiment of the invention
mounted in an exemplary electronic lock-set;
FIG. 8(B) is a perspective view of a coupling member having
a radial slot joint for connecting the motor drive shaft to the
screw shaft in embodiments of the present invention;
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FIG. 9 is an enlarged cross-sectional side view of the
actuator elements of the locking device shown in FIG. 8(A).
FIG. 10 is an exploded perspective view of the a first
portion of the actuator elements shown in FIG. 9;
FIG. 11 is an exploded perspective view of the second
portion of the actuator elements shown in FIG. 9;
FIG. 12(A) is a schematic circuit diagram for an electronic
lock-set according to one embodiment of the present invention
utilizing electronic motor control;
FIG. 12(B) is an exemplary circuit diagram of a wake-up
circuit for applying power to an electronic lock-set
microprocessor according to one exemplary embodiment of the
invention wherein electronic motor control (e. g., via software)
is utilized for protection against lock-set binding;
FIG. 13 is a flow chart illustrating preferred steps for
electronic control of motor actuation in a manner to protect
against lock-set binding;
FIG. 14 is an exemplary electrical wiring diagram of the
electronic lock-set motor for use in electronic control of motor
actuation in a manner to protect against lock-set binding.
DETAILED DESCRIPTION OF THE INVENTION
The locking device of the present invention can be
incorporated, as just one of many examples, in an electronic
lock-set like that shown in FIG. 1.
As shown in FIG. 1, an electronic lock-set can be used to
secure a door 10 that separates an unsecure side A (e.g., the
side into which one can freely pass from the opposite side) from
a secure side B (e. g., the side into which one cannot enter from
the opposite side without an appropriate electronic key or the
like), such as, for example, between two separate rooms within a
building. The electronic lock-set can include, for example, an
CA 02306997 2000-04-28
electronic reader 40 and a handle 21 of a lever set 20 on the
unsecure side A of the door. The electronic reader 40 preferably
operates, for example, in conjunction with an electronic key 50
having an electronic credential that resides in, for example, the
key bow of the key. The electronic communication between the key
and the electronic reader can be by any known means. The
electronic lock-set also preferably includes, for example, an
electronic housing 30 and a handle 22 of the lever set 20 on the
secure side of the door. The electronic housing 30 preferably
contains most or all of the electronics required for the system,
including for example, batteries (not shown), a printed circuit
board, an LP chip from Dallas Semiconductor, and/or other
elements, etc. The features of the electronic reader 40 and the
electronic housing 30 can be selected from that already known in
the art. As just one of many examples, the electronic reader 40
and the electronic housing 30 can include features like that of
the front subassembly 40 and the rear subassembly 50,
respectively, described in U.S. Patent No. 5,473,236, the entire
disclosure of which is incorporated herein by reference.
Although an electronic key and an electronic key reader can
be utilized without mechanical lock components, the electronic
key 50 could also include a key blade 51 having key bittings that
operate in conjunction with a lock cylinder within the reader 40
having tumbler pins corresponding to the key bittings (e.g., in
any known manner) to create both a mechanically and
electronically selective access. In other alternative
embodiments, instead of utilizing an electronic key, another
electronic communication device could be employed; for example,
the electronic key 50 and the electronic reader 40 could be
replaced by a card and a card reader, a key pad (e. g., into which
a user enters an entry code), an electronic scanner, or any other
type of reader, such as, for example, any of the readers
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described in the '236 patent. Similarly, the circuitry in the
electronic housing 30 can operate in any known manner, such as
similar to that in the '236 patent, or similar to that in any of
the above-identified patents, the entire disclosures of which
patents are all incorporated herein by reference, or similar to
that of other known electronic lock-sets and the like.
FIG. 2 illustrates a first embodiment of the locking device
according to the present invention. As noted herein-above, the
locking device according to the present invention can be used, as
one illustrative example, in an electronic lock-set like that
shown in FIG. 1. As illustrated in FIG. 2, the first embodiment
of the locking device according to the present invention
preferably includes an electric motor 100 with a motor shaft 110.
The electric motor is preferably a bi-directional motor and can
be similar to motors used in the above-noted patents, which
disclosures are incorporated herein by reference. The motor 100
is preferably connected via wires 101 to an electric power source
-- e.g., to batteries (not shown) contained, for example, within
the electronic housing 30.
In this first embodiment, the motor shaft 110 preferably has
a coil spring 120 having a first end 121 fixed to the motor shaft
100 (e.g., at a retainer ring 115). The coil spring 120
preferably extends coaxially with the axis of the motor shaft
100. A second end 122 of the coil spring is attached to a screw
shaft 130 via a retainer 135. The screw shaft 130 has external
threads 131. An internally threaded disk 140 preferably engages
the threads 131 of the shaft 130. The threaded disk 140 is
preferably provided inside a hollow plunger 150. The hollow
plunger can include, for example, a bottom wall 151, a top wall
7_52, a rear wall, 153 and a front wall 154. The hollow plunger
preferably includes a locking dog 180 fixed thereto. In the
preferred illustrated embodiment, the locking dog 180 is an
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extension of the front wall 154. The screw shaft 130 preferably
extends through the front and rear walls 154 and 153,
respectively, in a manner to be slidably received within holes
154' and 153', respectively. The rear end 132 of the shaft 130
preferably includes a retainer (e. g., a retainer clip) 136 fixed
thereto which retains the plunger 150 thereon. The disk 140
preferably includes a radial pin 141 that is received within a
longitudinal keyway 152 extending parallel to the axis of the
shaft 130 in the upper side of the plunger so that the disk 140
does not rotate relative to the plunger 150. A first spring or
biasing means 160, preferably a coil spring, is located within
the hollow plunger at a first side of the disk 140, and a second
spring or biasing means, preferably a coil spring, 170 is located
at a second side of the disk 140 within the hollow plunger. The
spring 160 extends between a rear surface of the disk 140 and the
inside of the rear wall 153, and the spring 170 extends between a
front surface of the disk 140 and the inside surface of the front
wall 154.
Most preferably, the device is incorporated in a lock-set
having a mechanism similar to that discussed herein-below in
relation to the second and third embodiments (e.g., utilizing a
key tube having a locking dog slot and a handle tube having a
corresponding locking dog slot as described below to engage and
disengage a handle drive mechanism via movement of the locking
dog with the locking device). It is contemplated that the
locking device shown in FIG. 2 can be incorporated into any other
electronic lock-set, where appropriate. As just one example, the
locking device shown in FIG. 2, could replace the motor 60, shaft
68, pin 72, spring 74, dog disk 42 and radial dog 42a of U.S.
Patent No. 5,018,375, incorporated herein by reference.
The plunger 150 should preferably be mounted within the
lock-set in such a manner that the plunger will not rotate around
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the axis of the shaft 130, while being able to reciprocate along
that axis. For example, a radial extension (not shown) and a
keyway (not shown) can be used, or the locking dog 180 can itself
extend within a keyway (not shown) to prevent rotation.
In use, the motor 100 should impart a rotational force via
the spring 120 to the shaft 130. The rotation of the shaft 130
will thus cause the disk 140 to move laterally along the shaft
130 because the pin 141 is retained in the keyway 152 and because
the plunger 150 is similarly prevented from rotating.
If an external force causes the locking dog 180 to bind or
the like at a particular location (e. g., if an individual grasps
a handle in a certain manner) when the motor 100 is activated,
the springs 160, 170 and 120 will function to absorb the
potential energy and allow the motor to rotate without straining
the motor or structure of the locking device. Then, upon
releasing that external force, the springs 160, 170, and 120 will
release the stored energy and cause the plunger 150, and the
locking dog 180, to move to an appropriate position. For
example, even if the plunger 150 binds and remains stationary,
the disk 140 can still move via the motor 100 due to the presence
of the springs. This movement will cause either the spring 160
or 170 to compress
-- depending on the direction of movement of the disk 140 -- and
this potential energy absorbed within the springs) will cause
the plunger to move once the locking dog 180 is later released.
In an alternative version of the first embodiment, one of
the springs 160 or 170 could be omitted. In that case, the
remaining spring could be fixed to both the disk 140 and to an
interior of the plunger so as to impart a tensile force when the
disk is moved relative to the plunger in one direction and a
compressive force when the disk is moved relative to the plunger
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in the opposite direction. Nevertheless, the use of both springs
160 and 170 is preferred.
FIGS. 3-5 show a second embodiment of the invention. In
contrast to the first embodiment, this second embodiment does not
include a coil spring 120. This second embodiment is otherwise
similar to and operates in a similar manner to the first
embodiment. In this second embodiment, as shown schematically in
FIG. 3(A), an inside (e.g., secure side) handle can include an
inside handle tube 22' which houses the motor 100. As also
shown, a motor spacer 22" can also be provided to facilitate
mounting of the motor 100. The motor drive shaft 110 extends
outward and is fixed to a coupling member 120'. The coupling
member 120' is preferably a rigid member (e.g., made of metal or
another appropriate material) that can transmit the drive force
of the motor shaft 110. Preferably, as shown, the shaft 110
extends within a bore 120'-1 in the coupling member 120'. The
shaft 110 is firmly fixed therein so as to rotate the coupling
member 120' upon rotation of the shaft. Preferably, the distal
end 121' of the coupling member 120' includes a universal joint
connection to a drive screw shaft 130 (i.e., a joint, such as
shown by FIG. 3(B), allowing angular movement between the member
120' and the shaft 130 such that the axes a and as can be moved
in relation to and non-parallel to one another) so as to allow a
degree of axial misalignment between motor shaft 110 and screw
shaft 130. The universal joint is preferably included so as to
allow some freedom of movement between the shaft 130 and the
shaft 110. In less preferred embodiments, it can be omitted. In
one exemplary embodiment shown in FIG. 3(B), the universal joint
is provided by forming: a) the coupling member 120' with a hollow
core 120'-2, a longitudinal slot 120-3' in one slide, and a
through hole 120'-4 in an opposite side; and b) the screw shaft
130 with a groove pin 130-1 that extends through the shaft 130
CA 02306997 2000-04-28
with one end being receivable in the hole 120'-4 and the other
end in the slot 120'-3 so as to provide a coupling with a degree
of freedom as described above. It is contemplated that any other
known universal joint can be provided as desired. In addition,
in other constructions, the connection between the shaft 110 and
the coupling member 120' could also include a similar universal
joint or another joint to provide a degree of freedom
therebetween.
As shown in FIG. 4, the coupling device is preferably
provided within an outside handle tube 21' at the outside (e. g.,
the unsecure side A) of the door 10. A key tube 210 is
preferably provided within the handle tube 21'. As best seen in
FIG. 4, the handle tube 21' preferably includes a longitudinal
slot 21'-1 that is alignable with a corresponding longitudinal
slot 211 in the key tube. When the locking dog 180 is positioned
outside of the slot 21'-1 but within the slot 211 as shown in
FIG. 4, the handle tube 21' moves freely around the key tube
without moving the key tube 210 such that the door remains
locked. When the locking dog 180 is moved (e.g., via rotation of
the motor 100 as described herein above) such that it enters the
slot 21'-1 the handle tube 21' is thus locked to the key tube 210
such that movement of the handle 21 can thus impart movement to
the key tube 210 and thus open the door. The door 10 can be
unlocked via rotation of the key tube 210 via a cam 210C at the
inside end thereof which can be used to operate a door bolt
actuator unlatching mechanism in a known manner, such as using
any appropriate mechanism described in the above-noted patents
incorporated herein by reference. Notably, the inside handle
tube 22' also includes a similar cam C which can open the bolt
actuator mechanism in a similar well known manner, without
providing a "locked" state of the inside handle 22.
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As shown inn FIG. 5, the plunger 150 can include a sleeve
150' into which the screw shaft 130, springs 160 and 170,
threaded disk 140, and the front wall 154 are inserted during
assembly (the front wall 154 comprising locking dog 180 being
fixed thereto via appropriate means upon assembly). As shown,
preferably, a distal end of the shaft 130 includes a snap ring
groove 1306 and extends out of a hole in the rear wall 153 (see,
e.g., FIG. 4) so as to receive the retainer ring 136 that helps
retain the plunger 150 thereon.
Accordingly, the second embodiment of the invention can
operate in a similar manner to the first embodiment of the
invention as described above. The first and second embodiments
of the invention can both operate in similar manners and be used
in similar applications and environments. As described above,
preferably, the lock mechanism moves a locking dog 180 to engage
and/or disengage a drive chain of the handle 21 so that movement
of the handle can impart movement to a locking bolt (not shown --
i.e., via the cam 210C -- in a manner as is known in the art)
when engaged (e. g., in an "unlocked" state) or so that movement
of the handle will not impart movement to a locking bolt when the
drive is disengaged (locked state). As described above and shown
by FIG. 4, the device preferably includes an outside handle tube
21' that is fixed to the outside handle 21 and moves therewith,
wherein in the unlocked position, the locking dog is positioned
away from a slot in the handle tube so that the handle tube moves
without driving the locking bolt. In addition, the springs or
other biasing means 160 and 170 preferably remain uncompressed
(e. g., unbiased) in both the locked and unlocked positions unless
the locking dog becomes held or bound in the slot of the handle
tube or the like.
In the embodiments described herein-above, binding of the
locking dog 180 or other mechanical problems which retain or bind
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the plunger 150 in position despite the running or operation of
the motor is dealt with via the use of, e.g., the springs or
biasing members 160 and 170 as described above. As described, in
that manner, for example, the motor 100 can continue to operate
properly without damage thereto, etc. In alternative
embodiments, however, it is contemplated that rather than, or in
addition to -- e.g., in combination with the above first and/or
second embodiments or with other known devices, using such
springs or biasing means, the device can be constructed so as to
control the operation of the motor based on automatic detection
of binding conditions that may occur.
FIGs. 6(A) through 6(D) depict alternative actuator elements
for use with the electronic lock-set according to the second
embodiment of the present invention which is intended to prevent
binding conditions. The alternative embodiment comprises a
plunger 150', threaded disk 140', screw shaft 130', and locking
dog 180'. The plunger 150', as depicted in several side views by
FIGS. 7(A) through 7(C), operates much like the plunger 150
depicted by FIGS. 2 through 4. The substantially cylindrical
plunger 150' has a longitudinal keyway 152' for receiving a pin
or tab 141' extending from the threaded disk 140' (depicted in
several side views by FIGS. 7(E) through 7(G)) which fits within
the plunger 150'. The interaction of the pin or tab 141' and the
keyway 152' prevents rotation of the disk 140' relative to the
plunger 150'.
The disk 140' is a hollow ring shape with internal threads
142' adapted to engage the external threads 131' on the screw
shaft 130'. Thus, rotation of the screw shaft 103' causes the
threaded disk 140' to travel longitudinally along the shaft 103'
since it is fixed from rotation. The screw shaft 130' for this
alternative embodiment of the invention is depicted in a side
view by FIG. 7(D). A locking dog 180', depicted in side views by
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FIGs. 7(H) and 7(I), fits within the end of the plunger 150'
substantially as shown.
As depicted by the figures, the threaded disk 140' in this
alternative embodiment has a pair of pockets 143' on either side
of the internal threads 142' which are adapted to hold a first
spring 160' and a second spring 170' such that the springs 160'
and 170' travel with the threaded disk 140' along the screw shaft
130'. One end of each spring 160' and 170' enters the pockets
143', and the other end of the springs 160' and 170' remain
enclosed in the plunger 150' once the locking dog 180' is
inserted, preferably permanently by staking into the end of the
plunger 150'.
As best seen in FIG. 7(D), the screw shaft 130' has an
externally threaded portion 131' surrounded on either side by two
unthreaded portions 132'(a) and 132'(b). The arrangement of
portions 132'(a) and 132'(b) on either side of threads 131'
allows the threaded disk 140' to engage and disengage from the
threads 131' depending upon the direction of rotation of screw
shaft 130' by motor 100 after each motor cycle to lock or unlock
the lock.
When the threaded disk 140' runs off the threaded portion
131', it has created a preload on one of the springs 160' or
170', as shown in FIGS. 6(B) and 6(A) respectively, that will
ensure engagement between threads 131' and 142' for the next
cycle. (See FIG. 7(A)) This preload has the added benefit of
aiding the motor 100 toward full power during the next cycle
before the plunger 150' and locking dog 180' begin to move. Once
thread engagement has been established, the springs 160' and 170'
transmit the motion from the longitudinally moving threaded disk
140' to the plunger 150'. This motion of the plunger 150' moves
the locking dog 180', during unbinded operation, from a locked
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position I, shown in FIG. 6(A), to an unlocked position II, shown
in FIG 6 (B) .
FIGS. 6(C) and 6(D) illustrate the condition of the lock in
a lock according to this alternative embodiment of the invention
in an impeded unlocked, and impeded lock position, respectively.
It will be appreciated by one skilled in the art that any
impediment to the movement of the plunger 150' or locking dog
180' while the screw shaft 130' is being turned by the motor 100
will still allow the treaded disk to move laterally along the
screw shaft until it reaches either of the unthreaded portions
132'(a) or 132'(b). Thus, a motor cycle attempting to move the
lock from the status depicted in FIG. 6(A) (i.e.,'locked) to the
status depicted in FIG. 6(B) (i.e., unlocked) would cause the
status depicted in FIG. 6(C) (i.e., impeded unlocked) if locking
dog 180' and plunger 150' encountered a binding condition which
somehow prohibited locking dog 180' from moving to position II.
In the impeded unlock position, a larger compression and thus
greater preload is placed on spring 160'. Once the impediment is
removed, the spring 160' will attempt to equalize and the plunger
150' and locking dog 180' will move to position II, as depicted
by FIG. 6(B), without any further motor 100 action.
Similarly, a motor cycle attempting to move the lock from
the unlocked (FIG. 6(B)) position to the locked (FIG. 6(A))
position would cause the status depicted in FIG. 6(D) (i.e.,
impeded locked) if a binding condition was encountered which
prevented locking dog 180' and plunger 150' from moving to
position I. In the impeded lock position, a relatively greater
preload is placed on spring 170'. This preload will tend to
equalize, and the plunger 150' and locking dog 180' will move to
position I (FIG. 6(A)) without any further motor 100 action once
the impediment is removed.
CA 02306997 2000-04-28
FIGS. 8(A), 8(B), and 9-11 illustrate a third embodiment of
the invention which is similar to the second embodiment described
above, but with a modified plunger 150 and related structure
without springs 160 and 170. While the embodiments shown in
these figures could potentially be utilized without electronic
control as described herein-below, it is clearly much more
preferably so controlled.
As best seen in FIG. 8(A) and FIG. 9, the plunger 150 in
this latter embodiment is modified, and simplified, so as to
include an annular shaped member having an upstanding locking dog
180 formed integral to the plunger 150 body that operates in a
similar manner to the locking dog(s)described above with respect
to the first and second described embodiments of the invention.
As shown by FIG. 11, the plunger 150 includes a threaded central
hole through which the threaded shaft 130 is threadingly engaged.
As a result, rotation of the screw shaft 130 directly causes
longitudinal movement of the plunger and, thus, of the integral
locking dog 180.
As in the preceding first and second embodiments, the motor
100 in the third embodiment is preferably mounted upon a motor
mount 22" (e. g., the mount 22" can fix the motor so as to rotate
along with rotation of the tube 22' or so as to remain fixed with
respect to the door 10). FIG. 10 illustrates an exemplary motor
100 and a motor mount 22", shown with screws 128 utilized to fix
the motor to the mount as shown. FIG. 10 also shows an exemplary
manner of fixing the coupling member 121' to the motor shaft 110,
using a set screw 129 to retain the shaft 110 within the hole
121'-1.
FIG. 8(B) depicts a preferred design for a coupling member
120' particularly for use with the embodiment of the present
invention as depicted by FIG. 8(A). The coupling member 120' has
a pair of radial slots 120'-5 disposed on both sides of the
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coupling member 120'. A groove pin 130-1 passes through the
screw shaft 130 and out through either radial slot 120'-5 so as
to connect the coupling member 120' to the screw shaft 130. The
coupling member 120' is attached to the motor shaft 110 (not
shown in FIG. 8(B)) by as set screw 129, and is rotated by the
motor 100. Each time the motor 100 rotates, the coupler is
thereby rotated until the end of both radial slots 120'-5 impact
upon the groove pin 130-1. This impact creates sufficient force
to overcome static friction (or "sticking") of the screw shaft
130 threads at the beginning of each rotation. Such impact could
advantageously be used to eliminate or reduce potential bind
conditions of the electronic locking set. As will be readily
appreciated by one skilled in the art, the above coupling member
design can optionally be used in any of the above embodiments of
the present invention.
While in less preferred embodiments, the device according to
this third embodiment of the present invention could be operated
without any special motor control to accommodate for binding of
the locking dog 180, of the plunger 150 and/or of other elements,
the device according to this third embodiment preferably includes
an operational control that changes operation of the motor upon
the detection of a binding or the like condition.
According to this further aspect of the invention that is
especially applicable with the third embodiment of the invention,
but which can also be applied in the first and second embodiments
(and also, for example, in any other devices including biasing
means), a control is included to change (e. g., modify or alter)
the operation of the motor 100 upon detecting (e.g., sensing or
otherwise determining) the existence of a binding condition or
any other like condition inhibiting the operation of the motor
(e.g., binding the device such that shaft 110 is restrained or
inhibited from rotation even if the motor is continued to be
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operated). Upon determining that a binding or the like
condition exists, the motor can be controlled, for example to:
stop operation, e.g., to stop rotation, of the motor; reverse
operation of the motor; alternate operation (e. g., for short
intervals) of the motor forwards and reverse (e.g., to try and
"free" a binding condition); slow down operation of the motor; or
otherwise control the motor to change its current state of
operation (e.g., whether the motor is currently operating in
forward or reverse).
As shown schematically in FIG. 12(A), in a preferred
embodiment, a binding or the like condition is determined by
monitoring the motor 100 with detector circuitry 300 and
controlling the motor operation with a motor driver 100' via a
processor 400 (e.g., a computer, microprocessor, or any
electronic controller) depending on whether or not a binding or
like condition is detected. As will be readily appreciated by
one skilled in the art, the detector 300 and processor 400 could
be incorporated together into an integral unit, or comprise
separate or multiple elements.
Preferably, the processor 400 (including the detector
circuitry 300) is maintained in an "off" mode with a power switch
600 when the door is not being accessed or under other conditions
in order to avoid wasting energy when the device is not in use.
This is particularly advantageous when the system is battery 500
powered -- which is the preferred. Accordingly, the device
preferably includes a circuit for "turning on" or "waking up" the
processor by transferring the power switch 600 to an "on" mode as
required. Preferably, the turn-on circuit operates to turn on
the system at least one, but preferably all, of the following
ways.
First, the turn-on circuit preferably turns on the device
upon a user attempting to access the door 10 from the unsecure
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side (i.e., attempting to enter the secure side). In that
regard, a key switch 900 is preferably provided that is activated
when the user attempts to activate the lock. In a preferred
embodiment of the invention where the lock is accessed via an
electronic key 50, preferably the key 50 is adapted so as to
complete a circuit upon insertion into the device thus triggering
the key switch 900. For instance, the key blade 51 could be
conductive and used to complete a circuit upon insertion into the
device. It should be understood that a variety of means for
completing a circuit could be employed, such as proximity
switches or sensors or the like which sense the proximity of the
electronic key, card, etc., or the like, or even a separate hand
manipulated switch or button.
Second, the turn-on circuit also preferably can be turned on
via a clock alarm 700, such as timing mechanism or processor,
that can be set so as to activate or deactivate the device based
on predetermined (e.g., pre-programmed) time schedules or
conditions. For instance, access could be allowed as of 8:00
a.m., for example, and could be denied as of 5:00 p.m., for
example.
Third, the turn-on circuit also preferably turns on the
processor via a door switch 800, such as in the form of a
proximity switch mounted between the door and door frame, that
closes a circuit upon opening of the door. In that manner, upon
opening of the door, the processor is preferably activated so
that it may make a determination as to whether the door opened
via proper means (e.g., via a proper access key) or whether it
was opened inappropriately (e.g., via broken or forced entry or
the like).
Preferably, the turn-on circuit will apply power to the
processor in each of the above three ways. FIG. 12(B)
illustrates a preferred embodiment of a turn-on circuit that can
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be used. As noted, normally when not actively engaged in
enabling the door 10 to be opened, the processor U1 will be
turned off. The processor in FIG. 12(B) is turned on by turning
on Q1, which can occur in any of the following three ways: a)
when a key switch, for example, is activated, a ground will be
applied, through a resettable fuse, to R2, which will forward
bias Ql and thus turn it on; b) a processor U2 (e. g., including,
for example, a timer or a real-time clock with alarm features and
an open drain output) can apply a ground to R5, which will turn
Q2 off, which will turn Q3 on, which will apply a ground to R3,
which will thus turn Ql on; and c) a door switch, for example,
can be activated, which will apply a ground to R8, which will
turn Q4 on, which then turns on Q1. When the processor U1 is
turned on, it will turn on Q5, which will apply a ground to R9,
which will turn Ql permanently on, even after the momentary
inputs are gone. The processor U1 will then determine what
turned it on by polling the processor U2 (e. g., timer) and door
switch inputs; if neither of these inputs is active, then the
processor will determine that the key switch turned it on. When
the microprocessor completes its task (e. g., controlling
operation of the motor 100 as described below), it will turn Q5
off, which will turn Ql off, and thus turn U1 off.
As noted, in this latter embodiment, binding or the like can
be sensed by electronic control (e. g., via a software programmed
processor) as opposed to be dealt with by introducing flexure
into the drive mechanism via springs or the like. That is,
rather than providing a mechanism that allows the motor to
continue rotating through a complete cycle during binding, the
device includes electronic control to change motor operation
under such conditions. This latter embodiment has notable
advantages over devices including springs or the like -- such as,
for example, substantially improving actuator performance as well
CA 02306997 2000-04-28
as reliability. For example, performance can be increased by
elimination of "play" in the system (e. g., due to springs, etc.)
and providing "tight" electronic control, and reliability can be
increased by simplifying the structure of the device and quickly
responding to binding and the like conditions via a
microprocessor or the like control.
FIG. 13 shows one preferred manner of using the processor to
control operation of the motor 100. During binding or the like
conditions, the motor 100 will experience a change in condition
that can be detected using, for instance, an arrangement as shown
in FIG. 12. For example, the electrical load upon the motor will
increase upon binding or the like. In this regard, according to
one exemplary method in accordance with the present invention,
the processor can be programmed to perform the steps shown in
FIG. 13 to detect such a condition.
As shown in FIG. 13, at step 1001, the motor 100 is
initially energized in either the forward or reverse direction.
Then, at steps 1002-1003, the processor counts down (i.e.,
delays) for 10 milliseconds. After that, at step 1004, the motor
100 is turned off (e.g., motor driver transistors Ql and Q2 are
turned off). At that point, the motor 100 continues to coast for
a duration. Then, at steps 1005-1006, the processor delays for
50 milliseconds. After that, at step 1007, the motor is
energized again. Then, at steps 1008-1009, the processor delays
for 3 milliseconds. After that, at step 1010, the processor will
perform an A/D conversion, and the result is saved as a reference
value at step 1011. Then, at steps 1012-1013, the processor
delays for another 3 milliseconds. After that, at step 1014, the
processor will perform another A/D conversion, and the result is
saved as a reference value #1 at step 1015. Then, at steps
1016-1017, the processor delays for another 3 milliseconds.
After that, at step 1018, the processor will perform yet another
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A/D conversion, and the result is saved as a reference value #2
at step 1019. Then, at steps 1020-1021, the processor delays
for another 1 millisecond. After that, at step 1022, the
processor de-energizes the motor.
At that point, the processor makes a comparison of the
values obtained to determine if binding or the like has occurred.
In that regard, at step 1023, the value #1 is compared to the
reference value. In the case of binding, the value of the A/D
conversion will increase due to the binding of the motor, and,
thus, if value #1 is larger than the reference value (or larger
by a predetermined amount), then an initial determination of
binding is made. In that case, in order to ensure that binding
has occurred, a second check is (in this preferred embodiment)
conducted between value #2 and the reference at 1024. If the
value #2 is larger than the reference value, then at step 1026
the processor determines that binding or the like is detected.
In that case, the processor can promptly control the motor to
stop, or to otherwise be controlled, such as noted above.
Otherwise, if the value #1 is not larger, the processor can
conclude that no binding has occurred at 1025. Similarly, even
if value #1 is larger, the processor can conclude that no binding
has occurred at 1025 if the value #2 is not larger.
In either case, the processor can, if desired, repeat these
steps as needed until the locking dog 180 has reached a fully
engaged or fully disengaged condition. Notably, this "binding"
detection can also be utilized to determine at what point the
locking dog 180 is in its fully engaged or disengaged conditions
-- for example, upon impinging upon a stop plate (see FIG. 9)
when reaching a fully disengaged (e.g., locked) state, the
processor can detect this condition and can, thus, stop the motor
100, and, similarly, upon impinging upon the rear side of the
slot 211 in the key tube 210 when reaching a fully engaged (e. g.,
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unlocked) state, the processor can detect this condition and thus
stop the motor 100. This can also be used by the processor to
accurately determine the positioning of the locking dog in the
lock assembly. If desired, the processor could also be
programmed so as to monitor the amount of time and/or power,
etc., required to travel between fully engaged and disengaged
positions and to potentially alter operation in the event of
changes in the calibrated times, etc., required, or to provide a
more accurate assessment of whether binding or the like has
occurred, etc.
It is contemplated that in less preferred embodiments, only
one A/D conversion value could be compared with the reference
value. In addition, three or more such values could be used for
comparison in other embodiments. In addition, other embodiments
could utilize different time delays for remaining in energized
and de-energized states. It should be understood that these
method steps are of one preferred embodiment and that a variety
of other embodiments are contemplated.
While detection is preferably via a comparison of such A/D
conversion values, it is contemplated that binding detection
could be achieved in other, although less preferred ways in other
embodiments. For example, in cases where the temperature, noise,
or another factor of the motor may increase upon binding, a
temperature sensor, microphone or another detection means could
be employed, and readings could be obtained and compared in a
similar manner.
According to another aspect of the invention, if desired, a
control could be employed in order to monitor the battery voltage
level. Based on the battery voltage level determined, for
example, the time periods for energizing and/or de-energizing the
motor 100 can be adjusted accordingly based on known operation
conditions of the corresponding motor. Notably, as the battery
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voltage power decreases (e. g., in cases where such voltage
decrease is not prevented by other means), the motor 100 is
affected so as to output a greater amount based on such a
decrease. By pre-conditioning the processor (e. g., pre-
programming) to vary motor "on" and/or "off" times in accordance
with such a voltage decrease, the extent of movement of the
plunger 150 and locking dog 180 can be maintained at a
substantially constant or at a similar enough or desirable enough
level to continue optimal operation of the device.
In this regard, a microprocessor normally requires a
steady, regulated DC power supply for it to function
appropriately. When using a microprocessor that has Analog to
Digital ("A/D") capabilities, a very steady voltage should
preferably be established in order for the circuit to perform
accurate A/D conversions.
Some microprocessors have a range of voltages that they will
operate in, such as from, for example, 5.5 Vdc to 3.0 Vdc, so as
to accommodate various different steady DC operating voltages.
To maintain a steady DC operating voltage, most circuits employ a
voltage regulator of some sort. A common type of regulator is a
switching voltage regulator, such as those referred to as a buck
or boost type of regulator. These can either be step up or step
down types.
Circuits that are primarily battery powered typically have
regulated switching power supplies to maintain a steady voltage
regulation by stepping up or stepping down the battery voltage as
the battery dies down.
According to this additional aspect of the invention, the
circuit can be made so as not to use any kind of voltage
regulation at all. The microprocessor can be powered directly
off of the battery, and even as the battery voltage drops, the
microprocessor will function within a wide voltage range.
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In this regard, preferably, the microprocessor monitors the
DC operating voltage through its internal A/D and makes software
adjustments to allow for a dying battery, such as adjusting the
motor timing routine (e.g., as described above). The A/D has a
very low reference voltage that is well below the microprocessor
cut off voltage. After the battery has died down to a certain
level, the microprocessor can be made to alert the user through
buzzers and LEDs that the battery is getting weak. After a
certain low battery voltage is reached, the microprocessor can
then be made to shut itself off.
This last aspect of the invention provides a number of
substantial benefits, including, for example, a substantial
reduction in monetary costs, a more efficient usage of batteries
and an increased battery life, as well as a variety of other
benefits.
While the present invention has been shown and described
with reference to preferred embodiments presently contemplated as
best modes for carrying out the invention, it is to be understood
that various changes may be made in adapting the invention to
different embodiments without departing from the broader
inventive concepts disclosed herein and comprehended by the
claims which follow.
