Note: Descriptions are shown in the official language in which they were submitted.
ELECTRIC STRIKE INCLUDING A BIASING
MECHANISM FOR A KEEPER SUPPORT BRACKET
TECHNICAL FIELD
The present invention relates to strike mechanisms for electrically locking or
unlocking a door in a frame; more particularly, to such strike mechanisms
wherein a
keeper support bracket is moveable between blocking and unblocking positions
to
selectively allow a keeper to be placed from a locked position and an unlocked
position
to allow a latch to be released from the strike; and most particularly, to a
biasing
mechanism including dual opposing springs that impose approximately a zero net
force
on the keeper support bracket when in the locked position.
BACKGROUND OF THE INVENTION
As is known in the art of door latching, typically an electrically-controlled
strike is
mounted in a frame portion of a door and engages a lockset disposed on or in
an edge
portion of the door. Typically, the lockset includes a latch, and possibly a
dead latch. In
the case of a mortise-type lockset, the dead latch is linearly spaced-apart
from the latch
along the edge portion of the door. In either lockset type, the latch is
reciprocally
moveable between an engaged position so that it can engage an entry chamber in
the
strike, thereby to secure the door in a closed state, and a released position,
wherein the
latch is permitted to exit the entry chamber and to release the door from the
closed state
and is free to open. Similarly, if included, the dead latch is reciprocally
moveable
between an enabling position (extended) that permits movement of the latch
from its
engaged position to the released position and a disabling position (depressed)
that
prohibits movement of the latch from its engaged position to its release
position.
Typically, the latch is resiliently biased into the engaged position and the
dead latch is
resiliently biased into the enabled position.
U.S. Patent No. 6,581,991 B2, the relevant disclosure of which is incorporated
herein by reference, discloses an electrically-controlled strike comprising a
housing
adapted to be mounted in a frame portion of a door and having a cavity with a
forwardly
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disposed opening that is sized and adapted to receive a spring latch and a
dead latch
when the door is in the closed state. The invention provides a single
electrically
actuated door latch structure that can be customized to a variety of spring
latch and
dead latch arrangements.
U.S. Patent No. 9,183,976, assigned to Hanchett Entry Systems, Inc., discloses
a springless electromagnet actuator having a mode selectable magnetic armature
that
may be used in door latching applications. A standard solenoid body and coils
are
combined with a non-magnetic armature tube containing a permanent magnet,
preferably neodymium. The magnet is located in one of three positions within
the
armature. When biased toward the stop end of the solenoid, it may be
configured to act
as a push solenoid. When biased toward the collar end of the solenoid, it may
be
configured to act as a pull solenoid. In either case, no spring is required to
return the
armature to its de-energized position. Positioning the magnet in the middle of
the
armature defines a dual-latching solenoid requiring no power to hold it in a
given state.
In one aspect, positive coil pulse may move the armature toward a stop end,
whereas a
negative coil pulse moves the armature toward a collar end. The armature will
remain at
the end to which it was directed until another pulse of opposite polarity is
supplied to the
actuator.
International Patent Publication No. WO 2014/152187, the relevant disclosure
of
which is incorporated herein by reference, discloses a circuit, apparatus and
method for
improving energy efficiency, reducing cost and/or improving quality of
electronic locks.
The electronic lock controller circuit includes an input for receiving a
legacy pulse, a
power circuit for extracting power from the legacy pulse to power the
electronic lock
controller circuit, a detector circuit for detecting a polarity of the legacy
pulse and a
microcontroller having an output for connection to a lock actuator. The
microcontroller
sends an output pulse via the output to control the lock actuator and the
output pulse
having reduced power as compared to the legacy pulse at the input. The power
may be
reduced by reducing voltage and/or reducing the duration of the voltage pulse.
What is needed in the art is an interchangeable actuator module wherein each
module may include a user-selected and/or condition-dependent actuator, such
as, for
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example, a standard solenoid, a low power springless solenoid or a motor such
as a low
power stepper motor actuator. Such modules may further be configured to reside
within
strike housings having different depths depending upon the size/type of latch
assembly
being used.
It is an aspect of the present invention to reduce the cost and complexity of
an
electrically-controlled strike for a door with a mortise lockset and to
improve reliability of
operation. Another aspect of the present invention is to decrease the time in
which a
stepper motor-controlled electric strike is moved from a locked state to an
unlocked
state to allow a door to be moved to an opened state in a timely manner.
SUMMARY OF THE INVENTION
Briefly described, one aspect of the present invention is directed to an
interchangeable, unitized actuator module for an actuator-controlled electric
strike, for
operating in conjunction with a latch of a mortise-type or cylindrical-type
lockset,
wherein the latch has an engaged position so as to selectively secure a door
in a closed
state. The electric strike may comprise a housing including a back wall and
opposing
side walls defining an entry chamber therein. A keeper is rotatably disposed
in the entry
chamber about an axis for rotation between a locked position and an unlocked
position.
The interchangeable actuator module may include a body, at least one keeper
release
and an actuator selectively movable between a first actuator position and a
second
actuator position. The actuator is unitized in that the actuator is contained
within the
body and at least a portion of the keeper release is contained within the
body. The
actuator may in turn include an actuating device, which may be a solenoid or a
motor,
and a keeper support bracket and a keeper support. The keeper release engages
the
keeper support which extends downwardly from the keeper support bracket. The
support bracket may include an actuator extension that is configured to mount
onto or
otherwise engage a plunger of the activating device. In the case of a pull
type solenoid
operating in a fail secure mode, actuation of the solenoid upon receiving
power via
leads extending out of the module causes the plunger to be pulled into the
body of the
solenoid. As the keeper support bracket is engageable with the plunger via an
actuator
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extension, the inward travel of the plunger pulls with it the keeper support
bracket. The
keeper support is likewise displaced by travel of the keeper support bracket
such that
the keeper support is no longer operatively coupled to the keeper release.
Thus, with
the solenoid plunger retracted, any load on the keeper (such as an authorized
attempt
to withdraw a latch from the entry chamber of the housing) pivots the keeper
so that the
keeper drives the keeper release toward a back wall of the housing against a
biasing
member. Once any load on the keeper is removed, the keeper is returned to its
locked
position by its own biasing member while the keeper release is returned to the
extended
position via its biasing member. In this manner, once power to the solenoid
has been
cut off, the plunger returns to its original extended position, such as via a
plunger return
spring. In turn, the keeper support bracket and keeper support return to their
original
positions so as to lock the keeper.
In accordance with another aspect of the invention, a unitized,
interchangeable
actuator module is provided as described above, so that an existing electric
strike may
be readily retrofitted with a replacement actuator module.
In accordance with a further aspect of the invention, the unitized actuator
module
is configured to interchangeably reside within housings having entry chambers
of
differing depth.
In accordance with another aspect of the present invention, the keeper release
and the keeper support are configured such that a load placed on the keeper
when the
latch is in the engaged position and the keeper is in the locked position is
transferred
from the keeper through the keeper release and keeper support to the back wall
of the
housing.
In accordance with a further aspect of the present invention, the actuating
device
may comprise a spring return solenoid and a plunger, wherein the keeper
release is
operatively coupled to the plunger and configured for sliding movement when
the
actuating device moves between a first and second actuator positions.
In accordance with yet another aspect of the invention, the actuating device
may
comprise a stepper motor including a shaft. The keeper release is coupled to
the shaft
and configured for sliding movement when the stepper motor moves between a
first and
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second actuator positions. The actuator module may also include a
microcontroller
configured to sense a voltage having a first polarity supplied to the stepper
motor
wherein, upon sensing the voltage having the first polarity the
microcontroller drives the
stepper motor from the first to the second actuator position. The actuator
module may
further include a constant-current, constant-voltage (CCCV) charger and a
super
capacitor, the microcontroller controlling the CCCV charger to charge the
super
capacitor after the stepper motor has been driven to the second actuator
position, the
super capacitor being used to provide a second voltage having a polarity
opposite the
first polarity to selectively drive the stepper motor from the second actuator
position to
the first actuator position.
In accordance with another aspect of the invention, the actuating device may
comprise a springless electromagnet actuator, wherein the keeper release is
coupled to
the plunger and configured for sliding movement when the actuating device
moves
between the first and second actuator positions. The actuator module may also
include
a microcontroller configured to sense a voltage having a first polarity
supplied to the
actuating device wherein, upon sensing the voltage having the first polarity
the
microcontroller drives the springless electromagnet actuator from the first to
the second
actuator position. The actuator module may further include a constant-current,
constant-voltage (CCCV) charger and a super capacitor, the microcontroller
controlling
.. the CCCV charger to charge the super capacitor after the springless
electromagnet
actuator has been driven to the second actuator position, the super capacitor
being
used to provide a second voltage having a polarity opposite the first polarity
to
selectively drive the springless electromagnet actuator from the second
actuator
position to the first actuator position.
In accordance with another aspect of the present invention, the housing is
configured to receive one of a plurality of strike plates, wherein each of the
plurality of
strike plates are configured to accommodate different types of locksets.
In accordance with another aspect of the present invention, the keeper
includes
an extendable face portion in communication with the entry chamber, the
extendable
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face portion being adjustable to define a width of the entry chamber. The
extendable
face portion may be adjusted to an infinite number of positions using a set
screw.
In accordance with a further aspect and non-limiting exemplary embodiment of
the present invention, an actuator-controlled electric strike may be provided
for
.. operating in conjunction with a latch and deadbolt of a lockset, wherein
the latch has an
engaged position so as to secure a door in a closed state and a released
position. The
strike may comprise a housing including a longitudinal length, a back wall
extending
along the housing longitudinal length, and upstanding side walls defining an
entry
chamber therein. The strike may further comprise a keeper disposed in the
entry
chamber about an axis of rotation parallel with the back wall, wherein the
keeper is
rotatable about the axis of rotation between a locked position and an unlocked
position.
The back wall is disposed opposite the keeper when the keeper is in the locked
position. The strike may further comprise a deadbolt bracket adjustably
positioned in
the entry chamber along the housing longitudinal length. The deadbolt bracket
includes
a first wall, a second wall, and a bracket side wall connecting the first wall
and the
second wall, wherein the deadbolt bracket defines at least a portion of a
deadbolt
receiving chamber for the deadbolt.
In another exemplary, non-limiting embodiment, the first wall includes a first
distal
end, and the second wall includes a second distal end, and the first and
second distal
ends are disposed against one of the side walls of the housing, and wherein
the
deadbolt bracket and the one of the side walls define the deadbolt receiving
chamber
for the deadbolt. Further, the deadbolt bracket may include a tab extending
from at
least one of the first and second distal ends, and one of the side walls of
the housing
has a slot defined therein configured to receive the tab.
In yet another exemplary, non-limiting embodiment, the first wall includes a
first
distal end, the second wall includes a second distal end, and the first and
second distal
ends are disposed against the back wall of the housing, wherein the deadbolt
bracket
and the back wall define the deadbolt receiving chamber for the deadbolt.
Further, the
deadbolt bracket may include a tab extending from at least one of the first
and second
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distal ends, wherein the back wall of the housing has a slot defined therein
configured to
receive the tab.
In accordance with yet a further aspect of the present invention, the housing
is
configured to receive a latch bolt monitor, wherein the housing is configured
to receive
the latch bolt monitor in the entry chamber. The housing may include a back
wall,
wherein the latch bolt monitor is mounted to the back wall.
In accordance with another aspect of the invention, the strike may further
include
a trim plate disposed around the keeper, wherein the trim plate is mounted to
one of the
housing of the strike or a door frame.
In accordance with yet another aspect of the invention, a lip extension may be
fitted to the electric strike in order to for the electric strike to be used
with a wider, non-
standard door frame. The lip extension may include a bottom panel, a first
side wing,
and a second side wing, wherein the first side wing extends from a first end
of the
bottom panel, wherein the second side wing extends from a second end of the
bottom
.. panel, and wherein the lip extension is mounted to the housing. The lip
extension may
include a rib disposed on the bottom panel that extends between the first side
wing and
the second side wing, wherein the rib is disposed adjacent to a notch formed
in the
housing. At least one of the first side wing and the second side wing may
include a
notch defined in a distal end that is configured for being disposed adjacent
to a strike
plate mounted to the housing. The bottom panel of the lip extension may be
positioned
adjacent to a bottom panel of the housing. Further, the lip extension may be U-
shaped.
In accordance with another aspect of the invention, the housing may include a
back panel, a bottom panel and opposing side walls to define the entry
chamber, and at
least one of the sidewalls includes an edge. The keeper may include a keeper
base
and a ramp element, wherein the ramp element includes a surface that is
contactable
by the latch, and wherein the surface of the ramp element extends beyond the
edge of
the at least one of the side walls when the keeper is in the locked position
to prevent the
latch from contacting the edge of the at least one of the side walls. A
profile of the
surface of the ramp element may be configured to match a profile of the edge
of the at
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least one of the side walls. For example, the surface of the ramp element
includes a
rounded profile.
In another aspect, the surface of the ramp element may include an extension
flange that covers the edge of the at least one of the side walls when the
keeper is in
the locked position.
In another aspect of the invention, the ramp element may include a surface
contactable by the latch wherein the surface extends beyond a front profile of
the
housing to prevent the latch from contacting an edge of a side wall of the
housing.
In another aspect, the housing may include a front profile, and the keeper may
include a keeper base and a ramp element. The ramp element includes a surface
that
is contactable by the latch, and the surface of the ramp element extends
beyond the
front profile of the housing when the keeper is in the locked position to
prevent the latch
from contacting the edge of the at least one of the side walls. In still a
further aspect of
the present invention, a method is provided for locking or unlocking a door
having an
actuator-controlled electric strike for operating in conjunction with a latch
of a lockset is
included, wherein the latch has an engaged position so as to secure a door in
a closed
state and a released position, and wherein the strike includes a housing
including a
back wall and opposing side walls and defining an entry chamber therein; a
keeper
rotatably disposed in the entry chamber about an axis for rotation between a
locked
position and a unlocked position; and an actuator module including a keeper
release
configured to engage the keeper and an actuator selectively movable between a
first
actuator position and a second actuator position, wherein when the actuator is
in one of
the first or second actuator positions the keeper release is coupled to the
keeper to
secure the keeper in the locked position, and wherein when the actuator is
selectively
moved to the other of the first or second actuator positions the keeper
release is
decoupled from the keeper and the keeper is rotatable to the unlocked
position, the
method for unlatching comprising the steps of: providing an input voltage to
drive the
actuator from the first actuator position to the second actuator position;
after driving the
actuator to the second actuator position, using the input voltage to charge a
capacitor;
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removing the input voltage; and providing a return voltage via the capacitor
to drive the
actuator from the second actuator position to the first actuator position.
In yet a further aspect of the invention, a method for changing a unitized
actuator
module of a strike assembly is provided wherein the actuator module is a first
actuating
module including a body, an actuator and a keeper release, the method
comprising the
steps of:
a) providing the strike assembly having a housing, wherein the first
actuator
module is disposed in the housing, and a keeper movably disposed in the
housing. The
first actuator module includes a first body, a first actuating device
comprising one of a
solenoid or a motor, and a first keeper release operatively engageable with
said
movable keeper to selectively release said keeper from a locked position to a
released
position;
b) allowing for the removal of the first actuator module from the housing;
and
c) allowing for the installation of a second actuator module in place of
the
first removable actuator module wherein the second actuator module includes a
second
actuating device comprising one of a solenoid or a motor, and further
comprising a
second keeper release operatively engageable with the movable keeper to
selectively
release the keeper from the locked position to the released position.
In a further aspect of the present invention, a method may include having the
actuator module include a microcontroller, wherein the microcontroller senses
an input
polarity of the input voltage and drives the actuator from the first actuator
position to the
second actuator position. Further, the capacitor may be a super capacitor, and
the
actuator module may further include a constant-current, constant-voltage
(CCCV)
charger. The microcontroller controls the CCCV charger to charge the super
capacitor
after the actuator has been driven to the second actuator position, wherein
the super
capacitor provides a second voltage having a polarity opposite the input
polarity to drive
the actuator from the second actuator position to the first actuator position.
In a further aspect of the present invention, an actuator-controlled electric
strike
for operating in conjunction with a latch of a lockset is provided. The latch
has an
engaged position so as to secure a door in a closed state and a released
position. The
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strike comprises a housing defining an entry chamber therein, a keeper
disposed in the
entry chamber about an axis of rotation wherein the keeper is rotatable
between a
locked position and an unlocked position, and a keeper support bracket movable
between a blocking position and an unblocking position. When the keeper
support
bracket is in the blocking position, the keeper is held in the locked
position, and wherein
when the keeper support bracket is in the unblocking position the keeper is
able to be
moved to the unlocked position. The strike further comprises a motor
operatively
connected to the keeper support bracket and actionable in a first direction to
move the
keeper support bracket toward the blocking position, and actionable in a
second
.. direction to move the keeper support bracket toward the unblocking
position, wherein
the second direction is opposite of the first direction. The strike further
includes a
biasing member applying a net force to the keeper support bracket, wherein the
biasing
member comprises a first spring and a second spring. A first spring constant
of the first
spring is different than a second spring constant of the second spring. The
first spring
applies a first force to the keeper support bracket in the first direction,
and the second
spring applies a second force to the keeper support bracket in the second
direction,
wherein when the keeper support bracket is in the blocking position, the net
force of the
biasing member applied to the keeper support bracket is approximately zero.
In a further aspect, the keeper support bracket may include an actuator
extension
that is operatively coupled to the motor, wherein the keeper support bracket
is
selectively moveable by the motor between the blocking position and the
unblocking
position. The motor may be a stepper motor, and a keeper release may be
operatively
coupled between the keeper support bracket and the keeper. The strike may
further
include a motor carrier operatively connected between the motor and the keeper
.. support bracket, wherein the motor carrier may be formed of a polyether
ether ketone
polymer. Furthermore, the stepper motor may include a lead screw having a
screw
thread, and the motor carrier may include a carrier thread mateable with the
screw
thread, wherein when the stepper motor is actionable in either the first
direction or the
second direction, the motor carrier acts upon the keeper support bracket to
move the
keeper support bracket between the blocking position and the unblocking
position.
Date Recue/Date Received 2021-04-12
In another aspect, the present invention includes a method of improving the
performance of an electric strike. The electric strike includes a keeper
movable
between a locked position and an unlocked position, and a support bracket
movable by
a stepper motor actuator between a blocking position and an unblocking
position.
When the support bracket is in the blocking position the keeper is in the
locked position,
and wherein when the support bracket is in the unblocking position the keeper
is in the
unlocked position. The method comprises the steps of: a) providing a first
spring
operatively coupled to the support bracket to apply a first force in a first
direction to
move the support bracket toward the blocking position, wherein the first
spring includes
a first spring constant; b) providing a second spring operatively coupled to
the support
bracket to apply a second force in a second direction opposite the first
direction to move
the support bracket toward the unblocking position, wherein the second spring
includes
a second spring constant that is different than the first spring constant; and
c) selecting
the first and second spring constants so that a net force exerted on the
support bracket
by the first and second springs is approximately zero when the support bracket
is in the
blocking position, whereby the performance of the electric strike is improved
by
increasing an acceleration of the support bracket upon an initial movement of
the
support bracket toward the unblocking position by the stepper motor actuator.
The method may further comprise the step of selecting the first and second
spring constants so that a net force exerted on the support bracket by the
first and
second springs is positive in the first direction applied in the unblocking
direction when
the support bracket is in the unblocking position.
Numerous applications, some of which are exemplarily described below, may be
implemented using the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will now be described, by way of example, with reference
to the accompanying drawings, in which:
FIG. 1 is a perspective view of an actuator-controlled electric strike in
accordance
with the present invention;
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FIG. 2 is an exploded view of the actuator-controlled electric strike shown in
FIG.
1;
FIG. 3 is a side view of the actuator-controlled electric strike shown in FIG.
1 with
the housing shown in phantom view including a strike plate, and the keeper in
the
locked position;
FIG. 4 is a side perspective view of the actuator-controlled electric strike
taken
along line 4-4 in FIG. 1;
FIG. 5 is a top perspective view of an embodiment of an actuator module used
with the actuator-controlled electric strike shown in FIG. 1 wherein the
module housing
is shown in phantom;
FIG. 6 is a side view of the actuator-controlled electric strike shown in FIG.
1 with
the housing shown in phantom view including the strike plate, and the keeper
in the
unlocked position;
FIG. 7 is a side perspective view of the actuator-controlled electric strike
shown
in FIG. 6 along the same line as 4-4 in FIG. 1;
FIG. 8 is a partial exploded bottom perspective view of an embodiment of an
actuator module used with the actuator-controlled electric strike shown in
FIG. 1;
FIG. 9 is a schematic view of actuator circuit for use with an actuator-
controlled
electric strike in accordance with the present invention;
FIG. 10 is a representative current diagram using the circuit shown in FIG. 9;
FIG. 11 is a cross sectional perspective view of an actuator-controlled
electric
strike having an adjustable strike shim in accordance with the present
invention with the
adjustable strike flush with the keeper;
FIG. 12 is a cross sectional perspective view of an actuator-controlled
electric
strike similar to FIG. 11 having the adjustable strike shim extending inwardly
from with
the keeper;
FIG. 13 is a perspective view of an actuator-controlled electric strike
including
latch bolt monitors in accordance with the present invention;
FIG. 14 is a perspective view of an actuator-controlled electric strike
including a
trim plate in accordance with the present invention;
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FIG. 15 shows various strike plates that may be used an actuator-controlled
electric strike in accordance with the present invention;
FIG. 16 is an exploded view of an actuator-controlled electric strike
including a
deadbolt bracket in accordance with the present invention;
FIG. 17 is a perspective view of the actuator-controlled electric strike
including a
deadbolt bracket shown in FIG. 16;
FIG. 18 is a perspective view of a prior art electric strike;
FIG. 19 is a perspective view of a prior art mortise lock set;
FIG. 20A is a perspective view of the actuator controlled electric strike in
accordance with the invention and installed in a standard door frame;
FIG. 20B is a perspective view of the actuator controlled electric strike in
accordance with the invention and installed in a door frame that is wider than
the door
frame shown in FIG. 20A;
FIG. 21 is a perspective, exploded view of a lip extension and electric strike
as
shown in FIG. 20B, in accordance with the invention;
FIG. 22 is a cross-section of a stepper motor driven actuator taken along line
22-
22 in FIG. 23B;
FIG. 23A is a perspective view of the actuator shown in FIG. 23B with a
support
bracket shown in the unlocked position;
FIG. 23B is a perspective view of the actuator with the support bracket shown
in
the locked position;
FIG. 24 is a cross-sectional view of the actuator taken along line 24-24 in
FIG.
23B; and
FIG. 25 is a chart showing the forces exerted on the support bracket between
the
locked position and unlocked position.
Corresponding reference characters indicate corresponding parts throughout the
several views. The exemplifications set out herein illustrate currently
preferred
embodiments of the present invention, and such exemplifications are not to be
construed as limiting the scope of the invention in any manner.
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DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 2, an embodiment of an actuator-controlled
electric
strike having an interchangeable, unitized actuator module 26, in accordance
with the
present invention, is generally indicated by reference numeral 20. Strike 20
generally
comprises a housing 22 and a keeper 24 rotatably mounted thereto. Unitized
actuator
module 26 (comprising a body 61 and an actuator 69 and a keeper release 62,
wherein
actuator 69 is contained within body 61 and at least a portion of keeper
release 62 is
contained within body 61 ¨ see FIG. 5), when inserted into housing 22 as a
unit, is
configured to cooperate with keeper 24 so as to control locking and unlocking
of keeper
24 as will be discussed in greater detail below with specific reference to
FIGS. 3-7.
Turning again to FIGS. 1 and 2, housing 22 includes an upstanding back wall 28
disposed opposite keeper 24 when keeper is in a closed position, bottom panel
30 and
opposing upstanding side walls 32, 34 thereby defining an entry chamber 36
having a
depth (D). See FIG. 3. Side walls 32, 34 may include flanges 32A, 34A for
receiving a
strike plate 38. See FIGS. 1, 2, 13-17. Side walls 32, 34 may also include
apertures
40, 42 configured to receive pivot pin portions 44, 46, respectively.
Apertures 40, 42
are positioned so as to coincide with a corresponding through bore 48 passing
along a
length of keeper 24 such that, upon insertion of pivot pin portions 44, 46,
along with
spring pin portion 50, keeper 24 is pivotally mounted onto housing 22 and
rotatable
about an axis X parallel with back wall (see FIG. 4). Spring pin portion 50 is
configured
to mount a biasing member such as coil spring 52 whereby the coil spring
operates to
bias keeper 24 toward the closed position, such as that shown in FIGS. 1, 3
and 4.
Keeper 24 may further include an extendable face portion 54, integrated with
keeper 24,
which will be discussed in more detail below with regard to FIGS. 11 and 12.
Leads 56
are connected at one end to an actuating device resident within actuator
module 26 and
extend outwardly from housing 22 wherein a second end 58 is connected to a
power
supply (not shown) so as to power the actuating device on demand.
FIGS. 3 and 4 show various views of strike 20 with keeper 24 in the closed
position and FIG. 5 shows the internal components of an exemplary embodiment
26' of
an actuator module that may reside within housing 22. Generally, keeper 24 may
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Date Recue/Date Received 2021-04-12
include a notched portion 60 at the keeper end proximate through bore 48, the
notched
portion 60 is configured to engage a keeper release 62 slidably mounted within
body 61
of actuator module 26. Keeper release 62, in turn, engages a keeper support 64
of
actuator 69 also resident within actuator module 26. In this manner, the
keeper is in the
locked position such that any load placed on keeper 24 (such as an
unauthorized
attempt to open a door whose latch is secured within entry chamber 36 in the
direction
generally indicated by arrow 66 ¨ FIG. 4) is transferred from the keeper
through the
release 62 to the keeper support 64 and ultimately to the back wall 28 of
housing 22. A
biasing member, such as a coil spring 67, operates to bias keeper release 62
into the
extended, locked position shown in FIGS. 3-5.
Referring now to FIG. 5, actuator module 26' includes keeper release 62 and
actuator 69'. Actuator 69', in turn, includes an actuating device 74', shown
here as a
solenoid, and an associated keeper support bracket 68 and keeper support 64.
Keeper
release 62 engages keeper support 64 which extends downwardly from keeper
support
bracket 68. Keeper support bracket 68 includes an actuator extension 70' that
is
configured to mount onto or otherwise engage plunger 72' of solenoid 74'. In
the case
of a pull type solenoid operating in fail secure mode, actuation of solenoid
74' upon
receiving power via leads 56 causes plunger 72' to be pulled into the body of
solenoid
74' in the direction generally indicated by arrow 76. As keeper support
bracket 68 is
engageable with plunger 72' via actuator extension 70', the inward travel of
plunger 72'
results in a sliding travel of keeper support bracket 68 in direction 76,
wherein keeper
support bracket 68 may be slidably coupled with a guide 77 that is fixedly
positioned
relative to body 61. Keeper support 64 is likewise displaced by travel of
keeper support
bracket 68 such that keeper support 64 is no longer aligned with and
operatively
coupled to keeper release 62. With additional reference to FIGS. 6 and 7, at
this point,
any load on keeper 24 (such as an authorized attempt to withdraw a latch from
entry
chamber 36) operates to pivot keeper 24 about pin portions 44, 46, 50 so that
keeper 24
drives keeper release 62 linearly, perpendicular to the axis X and/or toward
back wall 28
of housing 22 against biasing member 67. Once any load on keeper 24 is removed
(such as after the removal of the door latch), keeper 24 is returned to its
locked position
Date Recue/Date Received 2021-04-12
by biasing member 52 while keeper release 62 is returned to the extended
position via
biasing member 67. In this manner, once power to actuating device 74' has been
withdrawn, plunger 72' may return to its original position, such as via a
plunger return
spring 78', to thereby return keeper support bracket 68 and keeper support 64
to their
original positions whereby keeper support 64 is again aligned with and
operatively
coupled to keeper release 62 so as to lock keeper 24.
As further shown in FIG. 5, actuator module 26' may include second keeper
release 62a disposed at the opposite end of the module. Second keeper release
62a
cooperates with second keeper support 64a of support bracket 68. In accordance
with
.. this aspect of the invention, the opposing forces imparted on the keeper
when an
unauthorized attempt is made to withdraw the latch from the entry chamber are
balanced across the length of the keeper and translated evenly through first
and second
keeper releases 62,62a to the back wall of the housing.
FIG. 8 shows an alternative actuator module 26", including actuator 69" and
keeper release 62". Actuator 69" includes actuating device 74" such as a
stepper
motor, and keeper support bracket/support, 68", 64", respectively. As shown,
keeper
support 64" has been disengaged from keeper release 62" so as to allow
pivoting of
keeper 24 (not shown) to drive keeper release 62" rearwardly (keeper
unlocked). To
facilitate the sliding translation of keeper support 64", keeper support
bracket 68"
includes an actuator extension 70" configured to engage with rod 72" on
stepper motor
74". Actuation of stepper motor 74" by a voltage having a first polarity
causes rotation
of shaft 80" so as to advance actuator extension 70" (and keeper support
bracket 68"
and keeper support 64") in one direction (such as the direction indicated by
arrow 76) so
as to cause disengagement of keeper support 64" from a rear surface of keeper
release
62", such as, for example, shouldered notch 71" of keeper release 62".
Supplying a
voltage having the opposite polarity then reverses rotation of shaft 80" to
advance
actuator extension 70" in the opposite direction so as to cause engagement of
keeper
support 64" with shouldered notch 71". A biasing member, such as spring 78",
may
assist in driving actuator extension 70" in direction 76 toward stepper motor
74".
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Date Recue/Date Received 2021-04-12
As further shown in FIG.8, actuator module 26" may include second keeper
release 62a" disposed at the opposite end of the module. Second keeper release
62a"
cooperates with second keeper support 64a" of keeper support bracket 68". In
accordance with this aspect of the invention, the opposing forces imparted on
the
keeper when an unauthorized attempt is made to withdraw the latch from the
entry
chamber are balanced across the length on the keeper and translated evenly
through
first and second keeper releases 62",62a" to the back wall of the housing.
An alternate embodiment of the actuator is shown in FIGS. 22-24 as actuator
269. Actuator 269 may include stepper motor 274, lead screw 280 of stepper
motor
274, motor carrier 275, support bracket 268, including keeper support 264 and
actuator
extension 270, and a pair of opposing springs 277, 279 acting on support
bracket 268.
As seen in FIG. 23B, spring 277 may be disposed between a side wall 261a of
body
261 and an outer surface of keeper support 264. Further, spring 279 may be
disposed
between an opposing side wall 261b of body 261 and an outer surface of keeper
support 264'. Springs 277 and 279 exert a combined force on support bracket
268 and
collectively form biasing member 278. External threads 281 of lead screw 280
matingly
engage internal threads 283 of motor carrier 275.
Actuation of stepper motor 274 by supplying a voltage having a first polarity
causes rotation of lead screw 280 so as to advance motor carrier 275 (and
actuator
extension 270 of keeper support bracket 268 that is in touching contact with
motor
carrier 275) in a first, keeper unlocking direction shown as arrow 276 in FIG.
23A.
Stepper motor 274 may continue to drive towards the unlocked state (FIG. 23A)
until a
lock state switch 292 is depressed by, for example, an inner surface 294 of
keeper
support 264'. Note that, in the keeper unlocked state, keeper support 264 is
no longer
.. aligned with and operatively coupled to keeper release 262. At this point,
the keeper
(not shown) is allowed to pivot and to release the latch as described above.
Supplying stepper motor 274 a voltage having the opposite polarity reverses
rotation of lead screw 280 to move motor carrier 275 in a second keeper
locking
direction opposite the first keeper unlocking direction. Upon movement of
motor carrier
275 in the second keeper locking direction shown as arrow 282 in FIG. 23B,
spring 277
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Date Recue/Date Received 2021-04-12
biases actuator extension 270 against motor carrier 275 so as to move support
bracket
268 in the second locking direction 282 as well. As shown in FIG. 23B, support
bracket
268 has moved to the right (locking direction) so that keeper support 264 is
aligned with
and operatively coupled to keeper release 262, so as to prevent pivoting of
the keeper
(not shown) and to prevent release of the latch as described above. At this
point, lock
state switch 292 is released to indicate that the actuator 269 is in the
locked state. If
actuator 269 is unable to detect that the lock state switch 292 has been
released and
has failed to relock, stepper motor 274 may be configured to retry locking at
a user
configurable rate and/or duration. Further, a notification signal may be
communicated,
for example, wirelessly, to indicate to an access control system that actuator
269 is
unsecure and failed to relock.
As best shown in FIG 23A, actuator 269 may include second keeper release 262'
disposed at the opposite end of actuator 269. Second keeper release 262' may
cooperate with second keeper support 264' of keeper support bracket 268.
In the presently described embodiment, the spring constants of springs 277 and
279 are different and configured with respect to keeper support bracket 268 to
provide
equal but opposing forces on support bracket 268 so that when keeper support
bracket
268 is in the position shown in FIG. 23B (keeper locked), the forces exerted
by the two
springs on keeper support bracket 269 are equal but opposing. At this point,
since the
forces are equal but opposing, the net lateral force on keeper support bracket
268 to
oppose its movement in a direction to unlock the keeper is approximately zero.
As best shown in FIG. 25, the lateral forces exerted on keeper support bracket
268 by springs 277 (line 286) and 279 (line 288) are indicated. In the example
shown,
when actuator 269 is in its locked state at point L (FIG. 23B), spring 277 is
exerting a
positive 14.0g force in direction 282 to hold keeper support 264 in alignment
with keeper
release 262, At the same time, spring 279 is exerting a 14.0g force in the
opposite
direction (direction 276 shown in FIG. 23A). This is represented as a negative
14.0g
force at point L (line 288 in FIG. 25). At point U in FIG. 25, actuator 269
has reached its
unlocked state (FIG. 23A) wherein keeper support 264 is not aligned with and
not
operatively coupled to keeper release 262. In the example shown, spring 277 is
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Date Recue/Date Received 2021-04-12
exerting a positive 46.0g force on keeper support 264 in direction 282 when
keeper
support 264 is in its unlocked state. At the same time, spring 279 is exerting
a 9.0g
force on keeper support 264' in the opposite direction to hold actuator 269 in
its
unlocked state. This is represented as a negative 9.0g at point U in FIG. 25.
Line 290
represents the net lateral force imposed on keeper support bracket 268 by
biasing
member 278 (composite of springs 277 and 279) as support bracket 268 travels
between its keeper locked position L and its keeper unlocked position U. As
can be
seen in FIG. 25, a 37.0g force in direction 276 to be imposed by motor carrier
275 on
actuator extension 270 in keeper unlocked position U.
Importantly, the net lateral force exerted on support bracket 268 by biasing
member 278 is zero in keeper locked position L. This provides for an increase
in
acceleration of support bracket 268 when actuator 274 is commanded to move the
support bracket 268 in the unlocking direction to quickly release the latch
from the
keeper.
Over time, it is further noted that the internal threads 283 of motor carrier
275
may wear causing the force needed by stepper motor 274 to rotate lead screw
280 and
to move support bracket 268 away from position L to increase. The resulting
sluggishness of movement of support bracket 268 to in the unlocking direction
would
counter the advantages bestowed by the embodiment including the dual springs
277,
279 discussed above. To reduce wear of the internal threads, motor carrier 285
may be
molded of a wear resistant, high performance engineering plastic such as a
polyether
ether ketone polymer (PEEK).
In accordance with the embodiment shown in FIGS. 22-25, a method of
improving the performance of a strike actuator of an electric strike whereby
the
acceleration of the support bracket may be increased to quickly unlock the
keeper is
provided. The electric strike includes a stepper motor actuator, a keeper
movable
between a locked position and an unlocked position, and a support bracket
movable by
the stepper motor between a blocking position and an unblocking position. When
the
support bracket is in the blocking position the keeper is in the locked
position, and when
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Date Recue/Date Received 2021-04-12
the support bracket is in the unblocking position the keeper is in the
unlocked position.
The method comprises the steps of:
1. providing a first spring operatively coupled to the support bracket to
apply a
first force in a first direction to move the support bracket toward the
blocking
position;
2. providing a second spring operative coupled to the support bracket to apply
a
second force in a second direction to move the support bracket toward the
unblocking position, wherein a spring constant of the second spring is
different than a spring constant of the first spring;
3. selecting the spring constants so that a net force exerted on the support
bracket by the first and second springs is approximately zero when the
support bracket is in the blocking position,
whereby an acceleration of the support bracket is increased upon an initial
movement of the support bracket toward the unblocking position.
A further step may include further selecting said spring constants so that a
net force
exerted on said support bracket by said first and second springs is
approximately is
positive in a direction to move said support bracket in its unblocking
direction when said
support bracket is in its unblocking position.
In accordance with an aspect of the present invention, actuator module 26" may
be configured to operate stepper motor 74" as a low power actuator. To that
end, and
with additional reference to FIGS. 9 and 10, actuator module 26" may further
include a
switching regulator 82", microcontroller 84", a constant-current constant-
voltage
(CCCV) regulator 86" and one or more super capacitors 88", such as model no.
JUMT1474MED,supplied by Nichicon Corporation of Karasumadori Oike-agaru,
Nakagyo-ku, Kyoto, 604-0845 Japan. When external power 90", such as a voltage
ranging from about 10VDC to about 30VDC, is supplied to actuator module 26",
on-
board microcontroller 84" senses that power has been supplied (at time 92,
FIG. 10)
and drives the actuating device, such as stepper motor 74", from a first
position to a
second position using an actuator motor driver integrated circuit 94" (during
time period
96, FIG. 10). After the actuator drive operation has completed,
microcontroller
Date Recue/Date Received 2021-04-12
84"enables an onboard CCCV regulator 86" to charge on-board super capacitor(s)
88"
(during time period 98, FIG. 10). After a fixed period of time microcontroller
84"
disables CCCV regulator 86" (at time 100, FIG. 10). Once external power 90" is
removed, microcontroller 84" may power the actuating device 74" using energy
stored
in super capacitor(s) 88". Actuating device 74" is then driven to return to
the first
position. In this manner, after charging of super capacitor(s) 88" has been
completed,
the power consumption of actuator module 22" is reduced. As a further benefit,
the
use of the controllable CCCV regulator allows for the peak current seen at an
external
supply output to be limited.
As can be noted from the above, actuator module 26" may be selected to
operate in either a fail safe mode or a fail secure mode depending on whether
the first
position has keeper support 64, 64" coupled to keeper release 62, 62" (fail
secure) or
whether the first position has members 62/64, 62"/64" decoupled from one
another (fail
safe). To ensure that the actuator drive operation completes when a pre-load
condition
is present, a position sensor 95" may be used to supply the microcontroller
with
actuator position data. In one embodiment, position sensor 95" may be a
contactless
linear position Hall sensor in conjunction with a magnet. It should be
understood that
the position sensor may incorporate any suitable sensor system capable of
sensing the
actuator drive position, such as, but not limited to, a photo sensor, a
pressure sensor, a
micro switch, a passive infrared sensor, a radio frequency (RF) sensor, a reed
switch, or
the like. If microcontroller 84" determines the actuator drive was not
successfully
completed after receiving actuator position data from position sensor,
microcontroller
84" will continue to drive the actuator until the desired position is
successfully reached.
To conserve power, position sensor 95" may be switched to a power down state
when it
is not being used.
In accordance with a further aspect of the present invention, the actuating
device
may be a springless electromagnet actuator having a non-magnetic armature
containing
a permanent magnet combined with a solenoid body and coils similar to that
disclosed
within US Patent Application, Serial No. 13/833,671. When using such a
springless
electromagnet actuator, microcontroller 84" can use input power 90" to provide
a first
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Date Recue/Date Received 2021-04-12
pulse having a first polarity to drive the armature to the second position.
Input voltage
90" may then charge super capacitor(s) 88" through CCCV regulator 86" under
microcontroller 84" control as described above. Once input power is removed,
super
capacitor(s) 88" may then provide the power needed for a second pulse having a
.. second polarity to return the armature to the first position.
While the actuating device has been described as either a solenoid, a stepping
motor or a springless electromagnet actuator, it is understood the actuating
device in
accordance with the invention may include other types of motors, including a
DC motor,
or other types of powered actuating devices, including piezo electric and
shape memory
devices.
Turning now to FIGS. 11 and 12, in accordance with an aspect of the present
invention, keeper 24 may be configured to include an extendable face portion
54. Face
portion 54 may be positionally adjusted to define the width of entry chamber
36 as
measured between the outer face of face portion 54 and the inner surface of
back wall
.. 28 of housing 22 (such as from width Wi shown in FIG. 11 to width W2 shown
in FIG.
12), thereby minimizing the gapped clearance between an extended latch and the
width
of the entry chamber.
In accordance with this aspect, keeper 24 may include a groove 102 adapted to
received face portion 54. One or more set screws 104 may be threadably
inserted
within corresponding threaded apertures 106 within face portion 54. Set screws
104
may be selectively advanced until the desire width is created, i.e., width W2.
Groove 102
may include respective recesses 108 configured to receive a respective set
screw 104.
A fastener, such as hex screw 110 is then threaded through face portion 54 and
into
keeper 24 to secure face portion 54 to the keeper. Width W2 may be selected
such
there is little movement of the door latch, and subsequently the door, when
the latch is
locked within strike 20. Reduced movement minimizes unnecessary wear and tear
on
the latch and the strike, as well as reduces door movement and subsequent
noise. In
addition, when used in conjunction with a cylindrical-type lockset, and when
extendable
face portion 54 is adjusted outward and keeper 24 is in its locked position as
shown in
FIG. 12, surface 111 of extendable face portion 54 may serve as a resting
platform for
22
Date Recue/Date Received 2021-04-12
the dead latch of the lockset when the associated latch is received by entry
chamber 36.
Thus, extendable face portion 54 provides additional assurance that the dead
latch
remains retracted when the cylindrical lockset is in a locked position,
thereby preventing
an unauthorized forced retraction of the associated latch to unlock the door.
Provision
of set screws 104 enables fine incremental control of the placement of face
portion 54
over a wide range of entry chamber widths without requiring multiple shim
members
which are presently employed within the art. Further, in the prior art, a shim
pack was
provided with the strike product so that, at the time of installation, the
width of the entry
chamber could be varied as needed, by the selection and installation of the
appropriate
sized shim to the face of the keeper. However, overtime, through usage of the
door,
the width of the entry chamber can be expected to change, requiring a
different sized
shim to take up the gapped clearance. Often, the shim pack would be discarded
after
original strike installation so that a later re-adjustment of the gapped
clearance could not
be made. In accordance with the invention, the means for re-adjusting the
gapped
clearance remains with the strike so that re-adjustments can be conveniently
made at
any time after original installation.
FIGS. 13-15 show additional features that may be included with strike 20. For
instance, as shown in FIG. 13, strike 20 may be configured to house one or
more latch
bolt monitors (LBM) 112, which may also be interchangeable across a multitude
of
electric strike models. LBM 112 may be secured to housing 22 of strike 20 by
way of
screws or other fasteners inserted through holes 114 defined within back wall
28 of
housing 22 (see FIG. 2). Back wall 28 may also include apertures 116 through
which
wires associated with LBM 112 may be passed for proper operation of LBM 112.
FIG. 14 shows an optional trim plate 118 that may be placed around keeper 24
when strike 20 is mounted to the door frame. Trim plate 118 may be mounted
directly
to frame 120 or to housing 22. Trim plate 118 may be used to improve
aesthetics or
may be used to cover any small gaps or cracks between strike 20 and the
underlying
frame 120.
As seen in both FIGS. 13 and 14, strike 20 may include a strike plate 38
configured to rest against flanges 32A and 34A of respective side walls 32, 34
of
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Date Recue/Date Received 2021-04-12
housing 22. Strike plate 38 may be mounted to frame 120 via screws 122. As
shown in
FIG. 15, strike 20 may be configured to receive one of any number of various
strike
plates, such as anyone of strike plates 38A-38E, depending on the type of
latch system
mounted onto the door, including a cylindrical-type lockset (see FIG. 38C, for
example).
As shown in FIGS. 16 and 17, strike 20 may further include an open-sided
deadbolt bracket 124 comprising, for example, a rear wall 128, a bracket side
wall 131,
and a front wall 134, which is proportioned to receive a deadbolt (not shown),
wherein a
distal ends 133, 135 of bracket 124 may abut side wall 34 of housing 22, and
bracket
124 and side wall 34 conjunctively define a walled deadbolt receiving chamber
123
having a vertical length 129. In the prior art, the end of the deadbolt
bracket is not open
but, instead, includes an end wall that is generally the thickness 125 of the
bracket and
abuts with side wall 34 of housing 22 when the deadbolt bracket is assembled
into
housing 22. Thus, in the prior art, the vertical length the deadbolt receiving
chamber is
reduced by the added thickness 125 of the bracket abutting side wall 34. In
some
cases, the reduced vertical length of the receiving chamber of a prior art
deadbolt
bracket interferes with an extended deadbolt, thereby preventing full
engagement of the
deadbolt in the strike, or preventing compatibility of the strike with some
dead bolts.
Deadbolt bracket 124 in accordance with the invention may be mounted within
housing 22 by a pair of screws 126 passing through holes 114 define within
back wall
28 of the housing and threaded into corresponding holes 127 defined in rear
wall 128 of
deadbolt bracket 124. Side wall 34 may include a slot 130 configured to
receive a tab
132 extending from an end 135 of front wall 134 of deadbolt bracket 124. In
this
manner, deadbolt bracket 124 is rigidly secured along two faces of housing 22
such that
any load placed on the deadbolt latch (not shown) impacts the deadbolt bracket
and
housing 22 and not keeper 24.
Thus, the deadbolt receiving chamber 123 of open-sided deadbolt bracket 124
provides more room and greater vertical clearance for the associated deadbolt
and, if
keeper 24 were to be compromised or otherwise fail, the door would remain
secure due
to the deadbolt securely residing within receiving chamber 123 of deadbolt
bracket 124.
In addition, deadbolt bracket 124 may also be made to be interchangeable
across a
24
Date Recue/Date Received 2021-04-12
multitude of electric strike models. While deadbolt bracket is shown as being
U-shaped
in FIGS. 16 and 17, it should be understood that deadbolt bracket is not
necessarily
limited to this specific shape. Further, in another aspect, the open ended
portion of
deadbolt bracket 124 could also be oriented so that it abuts back wall 28 of
housing 22
instead of side wall 34 of housing 22.
FIGS. 18 and 19 show a typical mortise lockset 140 (FIG. 19) and a typical
electric strike 160 (FIG. 18) in the prior art. Mortise lockset 140 includes
latch 142 and
dead latch 144 linearly spaced-apart from latch 142. Latch 142 may be a spring
latch
having tapered contact face for making initial contact with the keeper when
the door is
moved to its closed position. Dead latch 144 is reciprocally moveable between
an
enabling position (extended, as shown) that permits movement of the latch from
its
extended engaged position (as shown) to a released position, and a disabling
position
that prohibits movement of the latch from its engaged position to its released
position. It
is well known in the art that, as a door is moved to a closed position and
dead latch 144
begins initial contact with an associated strike plate, latch 142 (FIG. 18)
must begin to
move from its extended position and toward its release position before dead
latch 144
moves away from its enabling (extended) position. If the dead latch is caused
to move
away from its extended position first, it will prohibit movement of the latch
toward its
released position, thereby blocking the latch from properly entering strike
cavity 168
(and preventing the door from latching).
Referring to FIG. 18, prior art electric strike 160 includes a housing 162
having
side walls 32', 34', a prior art deadbolt receiving chamber 123' for receiving
an
extendable dead bolt (not shown), and a longitudinal length 161. Side walls
32', 34'
include edge 170 comprising front edge 172, top edge 174 and front profile 176
joining
front edge 172 and top edge 174 to form continuous edge 170. Prior art
electric strike
160 also includes a pivotable keeper 164 (shown in a locked position), having
a
contoured surface 166 running the longitudinal length 178 of the keeper,
wherein the
entire length of contoured surface 166 resides between side walls 32', 34'.
Keeper 164
pivots about pivot pin 44 about axis of rotation X (FIG. 3). Also included in
electric strike
160 is receiving cavity 168 for receiving latch 142 when the door is closed.
As can be
Date Recue/Date Received 2021-04-12
seen, with a proper door to door frame alignment, and therefore a proper
vertical
alignment of the latch and dead latch relative to cavity 168, both the latch
and dead
latch will make contact with contoured surface 166 and will cause a proper
sequencing
of the retraction of the latch followed by the retraction of the dead latch.
However, with
an improper alignment, such as might be caused by a sagging door, the dead
latch 144
may not make contact with contoured surface 166 and may instead contact edges
172
or 174, or front profile 176 of edges 170 before latch 142 makes contact with
contoured
surface 166. As a result, latch 142 is prohibited from moving toward its
released
position, thereby blocking the latch from entering cavity 168 and preventing
the door
from latching.
Referring now again to FIGS. 13, 16 and 17, in another aspect of the
invention,
keeper 24' may include a ramp element 23' and a keeper base 27', wherein ramp
element 23' may include a contoured surface 33' that is contactable by a
spring latch
and/or dead latch of a lockset as the door is moved to a closed position. In
this aspect,
with additional reference to FIG. 3, contact surface 33' may extend a distance
(A)
beyond a front profile 41' of housing 22 when keeper 24' is in the locked
position to
prevent the spring latch and/or dead latch from contacting housing 22 or frame
120 as
the door is moved to the closed position. For example, contact surface 33' may
extend
distance (A) beyond a front edge 43' of at least one of side walls 32, 34 when
keeper
24' is in the locked position to prevent the spring latch and/or dead latch
from contacting
housing 22 or frame 120 as the door is moved to the closed position. Further,
at least a
portion of a profile 45' of contact surface 33' may be configured to match at
least a
portion of front profile 41' of housing 22, for example, the profile of front
edge 43' of at
least one of side walls 32, 34. While profile 45' of contact surface 33' is
shown as being
rounded, it should be understood that other profiles are also contemplated
herein.
In yet another aspect of the invention, keeper 24' may optionally include at
least
one extension flange 29' that projects from an end of ramp element 23' that
extend
beyond at least one of side edges 25' of keeper base 27'. When keeper 24' is
in a
locked position ((FIG. 13), extension flange 29' covers front edge 43' of a
respective
side wall 32, 34 so that a misaligned spring latch or dead latch will contact
ramp
26
Date Recue/Date Received 2021-04-12
element 23' instead of front edge 43', such as, for example, a corner of
housing 22. To
that extent, front edge 43' of side walls 32, 34 may be contoured to accept
the
underside of extension flange 29' of ramp element 23' so that a top portion
37' of
contact surface 33' of keeper 24' may be essentially flush with a top surface
39 of strike
.. plate 38 mounted to strike (FIG. 3).
Several aspects of this invention have been disclosed as being desirably
interchangeable across a multiple of electric strike models, thereby
demonstrating the
versatility of the disclosed electric strike and its ability to meet various
strike needs. In
another aspect of the invention, a strike lip extension can be used with the
disclosed
electric strike in order to make the electric strike adaptable to fit a
variety of door frames
that might exist in the field. Referring to FIGS. 20A, 20B and 21, U-shaped
lip extension
180 may be used in conjunction with actuator controlled electric strike 20,
shown in FIG.
1, when an existing door frame cut-out is wider than the a standard cut-out
width.
Referring to FIG. 20A, electric strike 20 and strike plate 38A are shown
mounted
.. in cut out 119 of a standard width door frame 120 designed to receive a
standard 1 %
inch thick door. As can be seen in this figure, keeper 24 is in its locked
position and
rounded edge 166 of keeper 24 is in close alignment with edge 121 of the door
frame.
Referring now to FIG. 20B, the same electric strike 20 and strike plate 38A
are mounted
in cut out 119' of a door frame 120' having surface 182' of door frame 120'
wider that the
width of surface 182 shown in FIG. 20A. In conjunction with the wider door
frame and
wider cut out shown in FIG. 20B, edge 184 of strike plate 38A is disposed a
greater
distance 186' from surface 121' of the door frame than the edge 184 of strike
plate 38A
is disposed from surface 121 in FIG. 20A (see dimension 186). To close out the
gap
190' between electric strike 20 and frame surface 121' caused by the larger
cut out 119',
.. lip extension 180 is provided.
Referring now to FIG. 21, housing 20 of strike 22 includes a notch 192 that
may
run the entire length of housing 20. U-shaped lip extension 180 includes
bottom panel
181 and side wings 183 extending from opposite ends of bottom panel 181 and
formed
at right angles to bottom panel 181 to form the U-shape. Rib 193, which may
have a
square or rectangular cross-section, is disposed on the bottom panel 181 and
extends
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Date Recue/Date Received 2021-04-12
between side wings 183. Notches 185 are formed on the leading corners of side
wings
183. The notches 185, rib 193 and length of side wings 183 are configured so
that,
when lip extension 180 is fitted and mounted to strike 22, the inside surface
of bottom
panel 181 fits closely and is adjacent to the bottom surface 21 of housing 22,
notches
185 fit closely and are adjacent to strike plate 38A and housing flanges 32A,
34A, and
rib 193 fits closely and adjacent to notch 192 of housing 20. Alignment holes
187 (2 of
3 shown), formed within notch 192, receive mating pegs (not shown) formed in a
leading edge of bottom panel 181 to aid in further alignment of the lip
extension to the
strike housing. Fasteners 191, such as screws, are used to secure the lip
extension to
.. the housing. As can be seen in FIG. 20B, when electric strike 20 is then
secured to
door frame 120', a neat package is created whereby gap 190' is entirely
concealed by
U-shaped extension 180.
In accordance with a further aspect of the present invention, a method for
locking
or unlocking a door having an actuator-controlled electric strike for
operating in
conjunction with a latch of a lockset is included, wherein the latch has an
engaged
position so as to secure a door in a closed state and a released position, and
wherein
the strike includes a housing including a back wall and opposing side walls
and defining
an entry chamber therein; a keeper rotatably disposed in the entry chamber
about an
axis for rotation between a locked position and a unlocked position; and an
actuator
.. module, including a keeper release configured to engage the keeper, and an
actuator
selectively movable between a first actuator position and a second actuator
position,
wherein when the actuator is in one of the first or second actuator positions
the keeper
release is coupled to the keeper and the keeper is secured in the locked
position, and
wherein when the actuator is selectively moved to the other of the first or
second
actuator positions the keeper release is decoupled from the keeper and the
keeper is
rotatable to the unlocked position, the method for unlatching comprising the
steps of
providing an input voltage to drive the actuator from a first position to a
second position;
after driving the actuator, using the input voltage to charge a capacitor;
removing the
input voltage; and providing a return voltage via the capacitor to drive the
actuator from
.. the second position to the first position.
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Date Recue/Date Received 2021-04-12
The method may further include the actuator module having a microcontroller
wherein the microcontroller senses an input polarity of the input voltage and
drives the
actuator from the first actuator position to the second actuator position.
Further, the
capacitor may be a super capacitor wherein the actuator module further
includes a
constant-current, constant-voltage (CCCV) charger, the microcontroller
controlling the
CCCV charger to charge the super capacitor after the actuator has been driven
to the
second actuator position, the super capacitor then providing a second voltage
having a
polarity opposite the input polarity to drive the actuator from the second
actuator
position to the first actuator position.
A method for changing an actuator module of a strike assembly is provided
wherein said actuator module is a first actuating module including an actuator
and a
keeper release, comprising the steps of:
1) providing said strike assembly having said first actuator module disposed
in a
strike assembly housing wherein said housing includes a movable keeper,
wherein the
first actuator module includes a first actuating device comprising one of a
solenoid or a
motor, and further comprising a first keeper release operatively engageable
with said
movable keeper to selectively release said keeper from a locked position to a
released
position;
2) allowing for the removal of said first removable actuator module from said
housing; and
3) allowing for the installation of a second removable actuator module in
place of
said first removable actuator module wherein the second actuator module
includes a
second actuating device comprising one of a solenoid or a motor, and further
comprising a second keeper release operatively engageable with said movable
keeper
to selectively release said keeper from a locked position to a released
position.
While the invention has been described by reference to various specific
embodiments, it should be understood that numerous changes may be made within
the
spirit and scope of the inventive concepts described. Accordingly, it is
intended that the
invention not be limited to the described embodiments, but will have full
scope defined
by the language of the following claims.
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