Information
-
Patent Grant
-
6565130
-
Patent Number
6,565,130
-
Date Filed
Wednesday, December 5, 200122 years ago
-
Date Issued
Tuesday, May 20, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Michael Best & Friedrich LLP
-
CPC
-
US Classifications
Field of Search
US
- 292 92
- 292 93
- 292 144
- 292 201
- 070 2791
- 070 282
-
International Classifications
-
Abstract
An exit bar employs a dual action latch retractor comprising a slotted link which connects manual and electrically actuated latch retraction means. The slot permits the latch to be retracted by a solenoid latch retractor regardless of the position of the push bar or other manual latch retraction means. A buffer spring transmits energy from the solenoid latch retractor to the push pad so that under normal circumstances actuation of the solenoid latch retractor retracts both the latch and push pad. However, if the push pad is jammed in the projected position, the buffer spring is compressed to permit relative movement between the solenoid latch retractor and the manual latch retraction mechanism. As soon as the force holding the push pad in an extended position is removed, the energy stored in the buffer spring is applied to the push pad through the mechanical linkage to retract the push pad.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of door security systems. More specifically, this invention relates to the use of a push or exit bar for securing a doorway.
2. Description of the Related Art
Exit bars, also known as push bars or panic bars, that allow egress through a doorway while limiting ingress are well-known components of door security and emergency systems. The conventional exit bar is mounted on the interior side of the door to be secured and is oriented generally horizontally across the face of the door. A housing or frame supports a push pad or bar for receiving a push force. The push force applied to the movable push pad operates a door latch through a linkage to permit opening of the door. Conventional exit bars typically employ a mechanical linkage between the movable push pad and the latch to actuate the latch mechanism for unlatching the door.
To avoid excessive wear to the exit bar components during periods of high traffic through a doorway, it is known to fix or “dog” the exit bar in an unlocked condition. Typically, the push pad is locked in its depressed or actuated position to avoid unnecessary wear to the associated linkage. It is also known to equip an exit bar with an electromagnetic latch retractor as described in U.S. Pat. No. 6,104,594, assigned to the assignee of the present invention. By integrating a building security system with exit bars including electromagnetic latch retractors, it is possible to effectuate the latching and unlatching of exit bars remotely and/or automatically.
U.S. Pat. No. 6,104,594 describes the use of an electric circuit to generate a high energy pulse through the electromagnet to generate a retraction force sufficient to retract the push pad and with it the mechanical linkage and latch to unlock the door. A possible deficiency of this approach is that, if the push pad is held or jammed in an extended position, the latch cannot be retracted by the electromagnet (even at high power). An alternative arrangement is to apply the electromagnetic retraction force only to the latch, without also retracting the push pad as described in U.S. patent application Ser. No. 09/414,202, filed Oct. 7, 1999 and also assigned to the assignee of the present invention. This permits latch retraction regardless of the position of the push pad. However, in high traffic situations, the push pad and its associated linkages are free to move as people push to open the door and are exposed to the resulting high rates of wear.
There is a need in the art for an exit bar equipped with remotely actuateable means for retracting the latch as well as the push pad which will reliably retract the latch even if the push pad is jammed in an extended position.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a new and improved dual action latch retractor for retracting the push pad and latch of an exit bar that will reliably retract the latch regardless of the position of the push pad.
Another object of the present invention is to provide a new and improved dual action latch retractor for remotely retracting the push pad and latch of an exit bar.
These and other objects are achieved in an exit bar in which a slotted link is used to connect a solenoid latch retractor to the push pad and the associated manual latch retraction mechanism. The slot permits the latch to be retracted by the solenoid latch retractor regardless of the position of the push bar. A buffer spring transmits energy from the solenoid latch retractor to the push pad so that under normal circumstances actuation of the solenoid latch retractor retracts both the latch and push pad. However, if the push pad is jammed in the projected position, the buffer spring is compressed to permit relative movement between the solenoid latch retractor and the manual latch retraction mechanism. Compression of the buffer spring permits the latch to be retracted while the push pad remains in the extended position. As soon as the force holding the push pad in an extended position is removed, the energy stored in the buffer spring is applied to the push pad through the mechanical linkage to retract the push pad.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will be evident to one of ordinary skill in the art from the following detailed description, made with reference to the accompanying drawings, in which:
FIG. 1
is a schematic view of an exit bar equipped with a dual action latch retractor in accordance with the present invention mounted to a door and illustrating various auxiliary features thereof;
FIG. 1A
is a partial enlarged front view of the exit bar of
FIG. 1
, with the push pad removed;
FIG. 2
is a sectional view through the exit bar of
FIG. 1A
, taken along line
2
—
2
thereof and including the push pad;
FIG. 3
is the sectional view of
FIG. 2
with the solenoid energized and the push pad in an extended position;
FIG. 4
is the sectional view of
FIG. 2
with the solenoid energized and the push pad in a retracted position;
FIG. 5
is a perspective exterior view of the exit bar of
FIG. 1A
with portions of the push pad and housing removed; and
FIG. 6
is a perspective view of the latch mechanism, mechanical linkage and solenoid latch retractor of the exit bar shown in
FIGS. 1A through 5
with the push pad, latch mechanism cover and housing removed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawings, wherein like numerals represent like components or structures throughout the several Figures, a preferred embodiment of an exit bar equipped with a dual action latch retractor in accordance with the present invention is generally designated by the numeral
10
. The exit bar
10
is mounted in a horizontal position across the interior side of a door
12
to be secured (FIG.
1
). The exit bar
10
latches against a strike
14
mounted to the door frame from which the door
12
is supported. A push force applied at the front of the exit bar
10
retracts the latch bolt
42
from the strike
14
and releases the door
12
to open for egress. Power is supplied to the exit bar
10
from a remote power source
22
over lines
24
in a conventional manner.
Exit bars in accordance with the present invention are readily adaptable for communication with a remote control or security system
26
. The remote security system
26
can be used to issue commands to the exit bar
10
to remotely unlatch the door and also to maintain the door in an unlatched state.
With reference to
FIGS. 1A through 6
, the exit bar
10
has an elongated main housing
32
which mounts to the door face to support and surround the exit bar internal components. The length of the housing
32
is preferably sufficiently long to substantially span the width of the door
12
. The main housing
32
is mounted to the door by means of screws or other fasteners (not shown) which secure the back panel
34
of the housing
32
in surface to surface disposition to the interior (secured) face of the door
12
. The main housing
32
is preferably a channel shaped extrusion defining an elongated opening spaced away from the face of the door
12
. A transversely displaceable push pad
36
defines a push face for receiving a push force exerted toward the door
12
by a person attempting egress through the door. The push pad
36
preferably spans a substantial longitudinal portion of the housing
32
adjacent that end of the housing closest the latch assembly
18
.
Fixed inside the main housing
32
is a frame
40
. The generally channel shaped frame
40
is secured to the back panel
34
of the main housing
32
by screws or other fasteners (not shown). For purposes of describing the invention as viewed in
FIGS. 1A through 6
, the main housing
32
defines a central longitudinal axis which extends parallel to the back panel
34
and a transverse axis which extends perpendicularly from the back panel
34
.
The exit bar secures the door by use of a latch assembly
18
that may encompass a variety of forms. The latch assembly includes a retractable or releasable latch bolt
42
which is pivotally mounted to a latch frame
20
. The latch bolt
42
is biased toward an extended or latched position by a latch pre load spring
23
that acts on a latch link
21
. A latch cover
19
surrounds the latch housing
20
to keep contaminants from the latch assembly
18
. When push pad
36
is pushed into the housing
32
by a person attempting egress, a pair of parallel push pad rails
44
mounted to the push pad
36
are moved toward the rear panel
34
of the exit bar
10
.
With reference to
FIGS. 2 through 4
, the push pad
36
is mounted to longitudinally extending rails
44
which are pivotally linked to the frame
40
by a master main link
50
and a slave main link
52
. The master main link
50
and slave main link
52
are pivotally connected to the rails
44
by pins
54
,
56
respectively. As best seen in
FIG. 6
, a master main link pin
58
extends through the master main link
50
and slidably engages in master main link slots
60
defined by the frame
40
. In a similar construction, a slave main link pin
62
extends through the slave main link
52
and slidably engages in slave main link pin slots
64
defined by the frame
40
.
As viewed in
FIGS. 2 through 4
, the master and slave main links
50
,
52
extend from the rails
44
to almost the bottom of the channel defined by the frame
40
. A second master main link pin
66
extends through the master main link
50
and slidably engages in master main link lower slots
68
(hidden by auxiliary rail
80
in
FIGS. 2-4
) defined by frame
40
. A second slave main link pin
70
extends through the slave main link
52
and slidably engages in slave main link lower slots
72
defined by frame
40
. The master and slave lower guide slots
68
,
72
are oriented generally parallel to the back panel
34
of the housing
32
in the longitudinal direction. A main spring guide
76
is engaged by the second slave link pin
70
. A main spring
78
is compressively engaged between the main spring guide
76
and a flange formed by the frame
40
to bias the push pad
36
and associated master and slave main links
50
,
52
toward a projected position (best seen in FIGS.
2
and
3
).
Opposed auxiliary rails
80
connect the master and slave main links
50
,
52
at their second master and slave main link pins
66
,
70
. The construction of the master and slave main links
50
,
52
and the associated pins and slots define a transverse path of motion, e.g., toward the door, for the push pad
36
and rails
44
. Upon application of a push force, the transverse motion of the rails
44
and push pad
36
toward the door is translated into a generally longitudinal motion away from the latch
42
at second master main link pin
66
and second slave main link pin
70
. The provision of auxiliary rails
80
linking second master and slave main link pins
66
,
70
ensures that a push force applied to either end of the push bar
36
will result in a substantially equivalent longitudinal motion at the bottom of the master main link
50
.
The master and slave main links
50
,
52
, master and slave link slots
60
,
64
, lower guide slots
68
,
72
, rails
44
, push pad
36
and auxiliary rails
80
act in concert to form a manual latch retraction mechanism which translates a push force applied to the push pad into a longitudinal latch retraction force at the second master main link pin
66
located at the bottom of the master main link
50
. As best seen in
FIGS. 2-4
, the second master main link pin
66
passes through a slot
67
defined by a solenoid link
90
. The solenoid link is operatively connected between a solenoid plunger
94
and latch link
21
for transmitting a retraction force generated by the solenoid
92
to the latch assembly
18
. An adjuster
96
(best seen in
FIG. 6
) fixes one end of the solenoid link to the solenoid plunger
94
. The adjuster permits fine tuning of the position of the solenoid link relative to the solenoid plunger
94
and solenoid
92
. The adjuster
96
has a shaft that penetrates an axial bore in the solenoid plunger
94
. The shaft is fixed in a selected position relative to the plunger
94
by set screws (not shown) in bores that intersect the axial bore.
As best seen in
FIGS. 1A
,
5
and
6
, the solenoid link defines a yoke comprising two transversely spaced arms which extend longitudinally toward the latch assembly before bending toward each other to define a parallel, closely spaced connection on either side of the latch link
21
. Solenoid link
90
and latch link
21
are connected by a pin
17
which is slidably engaged in longitudinal slots
15
defined by the frame
40
(see FIG.
6
).
A coiled buffer spring
100
surrounds a buffer spring guide
98
disposed between the arms of the solenoid link
90
. Pin
66
passes through one end of the buffer spring guide to fix the guide relative to the lower end of the master main link
50
. The closely spaced arms of the solenoid link
90
define a solenoid link slot
67
. Second master main link pin
66
extends transversely through the outer auxiliary rails
80
, lower guide slots
68
defined by the frame, master main link
50
, solenoid link slot
67
and the buffer spring guide
98
. Thus, the second master main link pin
66
is movable in a longitudinal direction relative to the frame
40
in longitudinal slots
68
and also in solenoid link slot
67
relative to the solenoid link.
The function of an exit bar
10
equipped with a dual-action latch retractor in accordance with the present invention will now be described with reference to
FIGS. 1A through 6
.
FIGS. 1A
,
2
,
5
and
6
illustrate the relative positions of the components of the exit bar
10
in a stable, latched condition. Latch
42
is biased toward its extended latched position by latch preload spring
23
, which is compressively engaged between a flange of the frame
40
and connecting pin
17
which joins the arms of the solenoid link
90
to the latch link
21
. Push pad
36
and the associated parts of the manual latch retraction mechanism are biased toward an outwardly projected position by main spring
78
. Main spring
78
is compressively engaged between the main spring guide
76
and a flange projecting from the frame
40
. It should be noted that latch preload spring
23
biases the latch
42
toward its projected latched position and also biases the solenoid link
90
and attached solenoid plunger
94
toward the position illustrated in FIG.
2
.
A push force applied to the push pad is coupled by rails
44
to the upper end of the master and slave main links
50
,
52
through pins
54
,
56
. The master and slave main links
50
,
52
move inwardly relative to the exit bar housing
32
and frame
40
with master main link pin
58
and slave main link pin
62
guided in master and slave main link pin slots
60
,
64
. It should be noted that the master and slave main link slots
60
,
64
are angled such that movement of the push pad
36
relative to the exit bar housing
32
and latch cover
19
is substantially perpendicular, e.g., toward the face of the door
12
. The inward and pivoting movement of master and slave main links
50
,
52
in response to a push force causes master and slave second main link pins
66
,
70
to move longitudinally away from the latch assembly
18
in slots
68
,
72
. When the push bar has been fully compressed into the exit bar housing
32
by a push force, second main link pin
66
has reached the end of solenoid link slot
67
and exerted a retraction force on the latch
42
via the latch link
21
(see FIG.
4
). In this position, the main spring
78
is compressed between the main spring guide and the frame
40
. Buffer spring
100
is not compressed because the relative positions of the solenoid link
90
and the master main link
50
lower end have not changed. In other words, second main link pin
66
is still at the right hand end of solenoid link slot
67
. Release of the push force against the push pad
36
will permit the main spring
78
and latch pre load spring
23
to return the components of the exit bar to their extended latched positions as illustrated in FIG.
2
.
An exit bar
10
equipped with a dual-action latch retractor in accordance with the present invention may also be unlocked, e.g., latch
42
retracted, by actuation of solenoid
92
. The exit bar
10
is equipped with control electronics
110
for generating current in solenoid
92
to produce a magnetic field which in turn creates a retraction force on solenoid plunger
94
. Solenoid, link
90
and connected latch link
21
apply the retraction force generated by the solenoid to the latch
42
. The dual-action latch retractor in accordance with the present invention is configured to retract both the latch
42
and the push bar
36
with its associated linkages. Retracting the latch
42
releases the door
12
for egress while retracting the push pad
36
and its associated manual latch retraction mechanism avoids excessive wear on the mechanism during periods of high traffic through the door.
Since the latch retraction force generated by the solenoid must also retract the push pad
36
and its associated manual latch-retraction mechanism, the initial force generated by the solenoid
92
must be substantial. Therefore, the control electronics
110
are capable of generating an initial high-current pulse to overcome the inertia of the push pad
36
and its associated manual latch retraction mechanism as well as overcoming the force exerted on the latch by the latch preload spring
23
. Maintaining the components of the exit bar in the positions illustrated in
FIG. 4
requires less current than the initial movement thereto, so the control electronics also provide a lower current retaining power to the solenoid
92
following the initial retraction pulse.
In accordance with a particular aspect of the present invention, the dual-action latch retractor is provided with means for permitting relative movement between the solenoid link
90
and the lower end of the master main link
50
(second master main link pin
66
). This allows the retraction force generated by the solenoid
92
to retract the latch
42
regardless of the position of the push pad
36
and its associated manual latch-retraction mechanism. It is advantageous for the door to be capable of remote automated release even when the push pad
36
and/or the manual latch retraction mechanism are jammed in their extended latched positions. Further, it is advantageous that when the jamming force is released, the dual-action latch retractor then retract the push pad
36
and its associated manual latch-retraction mechanism to avoid wear commonly associated with high traffic situations.
These objects are achieved in the illustrated preferred embodiment by applying the retraction force generated by the solenoid
92
to the master main link
50
through a buffer spring
100
. When the push bar is free to move and the solenoid is actuated, the buffer spring
100
efficiently transmits the retraction force to the lower end of the master main link
50
to retract the push pad and the manual latch-retraction mechanism. If the push pad is jammed, as illustrated in
FIG. 3
, the solenoid
92
is still capable of retracting the latch
42
via the solenoid link
90
and the latch link
21
. The buffer spring
100
is compressed by the altered relative positions of the master main link second pin
66
and the solenoid link
90
. As can be seen in
FIG. 3
, pin
66
has moved to the left end of solenoid link slot
66
thereby compressing the buffer spring
100
which is engaged between the buffer spring guide
98
and the solenoid link
90
. When the jamming force is removed, energy stored in the compressed buffer spring
100
is sufficient to retract the push pad and the associated manual latch-retraction mechanism.
Thus, the dual-action latch retractor in accordance with the present invention is capable of retracting both the latch and the manual latch-retraction mechanism of an exit bar regardless of the position of the push pad relative to the exit bar housing
32
. The exit bar
10
is fully integratable with building security and alarm systems, permitting remote automatic release and dogging of the latch and manual latch-retraction mechanisms, respectively.
While a preferred embodiment of the foregoing invention has been set forth for purposes of illustration, the foregoing description should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit and the scope of the present invention.
Claims
- 1. A dual action latch retractor comprising:an actuator electrically actuatable to generate a first latch retraction force; a solenoid link extending from a first end fixed to said actuator to a second end operatively connected to retract a latch and comprising means for permitting relative movement between said solenoid link and a manual latch retraction mechanism operatively connected to said solenoid link; said manual latch retraction mechanism configured to translate a manual force applied to an operator into a second latch retraction force and apply said second latch retraction force to said solenoid link to retract said latch, said manual latch retraction mechanism biased toward a first position and movable to a second position to retract said latch in response to application of said manual force to said operator; and bias means for biasing, said manual latch retraction mechanism relative to said solenoid link so that said first retraction force is applied through said bias means and said manual latch retraction mechanism to move said operator from said first position to said second position, wherein said means for permitting relative movement permits retraction of said latch by said first latch retraction force regardless of the position of said manual latch retraction mechanism.
- 2. The dual action latch retractor of claim 1, wherein said actuator comprises a solenoid including an electromagnet and a plunger attracted by a magnetic field generated by said electromagnet to generate said first latch retraction force, said solenoid link first end being fixed to said plunger.
- 3. The dual action latch retractor of claim 1, wherein said bias means comprises a buffer spring and when said first latch retraction force is applied to said solenoid link with said manual latch retraction mechanism held in said first position, said buffer spring compresses to store a portion of said first latch retraction force and when said manual latch retraction mechanism is released, said buffer spring applies said stored force through said manual latch retraction mechanism to move said operator from said first position to said second position.
- 4. The dual action latch retractor of claim 1, wherein said means for permitting relative movement comprises a slot in said solenoid link and said manual latch retraction mechanism is operatively connected to said solenoid link by a pin movable in said slot.
- 5. The dual action latch retractor of claim 1, wherein said means for permitting relative movement comprises a slot in said solenoid link and said manual latch retraction mechanism is operatively connected to said solenoid link by a pin movable in said slot, said dual action latch retractor further comprising a buffer spring guide connected to said manual latch retraction mechanism by said pin and including protrusions,wherein said buffer spring surrounds said buffer spring guide and is compressibly engaged between said solenoid link and said protrusions such that movement of said pin in said slot caused by said manual latch retraction mechanism being held in said first position during application of said first latch retraction force to said solenoid link compresses said buffer spring and when said manual latch retraction mechanism is released, said buffer spring expands to move said manual latch retraction mechanism from said first position to said second position.
- 6. The dual action latch retractor of claim 3, wherein said operator and manual latch retraction mechanism are biased toward said first position by a main spring having an axis, said buffer spring having an axis parallel to said main spring axis.
- 7. The dual action latch retractor of claim 2, wherein said solenoid plunger includes an adjuster for fixing said solenoid link first end in a selected position relative to said plunger and electromagnet.
- 8. An exit bar comprising:a retractable latch biased toward a projected latched position; a manual latch operator operatively connected to a manual latch retraction mechanism, a force applied to said operator being translated by said manual latch retraction mechanism into a first latch retraction force, said operator and manual latch retraction mechanism movable between a first latched position and a second latch retraction position; a solenoid comprising a coil and a plunger, an electrical current applied to said coil generating a second latch retraction force; a mechanical connection between said latch, said manual latch retraction mechanism and said solenoid plunger comprising a solenoid link; and means for selectively permitting relative movement between said manual latch retraction mechanism and said solenoid link, said means for selectively permitting relative movement including a slot in said solenoid link, a pin slidable in said slot and engaged with said manual latch retraction mechanism, a buffer spring operatively connected so that said second latch retraction force is transmitted to said manual latch retraction mechanism through said buffer spring, wherein if said operator is held in said first latched position during application of said second latch retraction force, said buffer spring is compressed and when said operator is released, said compressed buffer spring releases energy to move said operator and manual latch retraction mechanism to said second retraction position, said relative movement occurring when said manual latch operator fails to move in response to said second latch retraction force, wherein said first latch retraction force moves said solenoid link to retract said latch and said second latch retraction force moves said solenoid link to retract said latch regardless of the position of said operator and manual latch retraction mechanism.
- 9. An exit bar comprising:a retractable latch biased toward a projected latched position; a solenoid comprising a coil and a plunger, an electrical current applied to said coil generating a first retraction force; a mechanical connection between said latch and said solenoid plunger comprising a solenoid link, said solenoid link defining a slot; a manual latch retraction mechanism including an operator for receiving a manual latch retraction force which, when applied to said operator is translated by said manual latch retraction mechanism into a second retraction force, said operator and manual latch retraction mechanism movable between a first latched position and a second latch retraction position; a buffer spring arranged such that said first retraction force is applied to said manual latch retraction mechanism through said buffer spring; and a buffer spring guide fixed relative to said pin, wherein said buffer spring surrounds said buffer spring guide and is compressively engaged between said buffer spring guide and said solenoid link, and wherein said manual latch retraction mechanism is operatively connected to said solenoid link by a pin slidably engaged in said slot such that said second retraction force moves said solenoid link to retract said latch and said first retraction force moves said solenoid link to retract said latch regardless of the position of said operator and manual latch retraction mechanism.
- 10. The exit bar of claim 9, further comprising a main spring having an axis and operatively connected to bias said manual latch retraction mechanism and operator toward said first latched position, said buffer spring having an axis parallel to said main spring axis.
- 11. The exit bar of claim 10, wherein said latch is biased toward said projected latched position by a latch preload spring having an axis parallel to said main spring axis and buffer spring axis.
- 12. An exit bar comprising:a retractable latch biased toward a projected latched position; a solenoid comprising a coil and a plunger, an electrical current applied to said coil generating a first retraction force; a mechanical connection between said latch and said solenoid plunger comprising a solenoid link, said solenoid link defining a slot; a manual latch retraction mechanism including an operator for receiving a manual latch retraction force which, when applied to said operator is translated by said manual latch retraction mechanism into a second retraction force, said operator and manual latch retraction mechanism movable between a first latched position and a second latch retraction position; and a buffer spring arranged such that said first retraction force is applied to said manual latch retraction mechanism through said buffer spring; wherein said solenoid link comprises two spaced apart arms defining a yoke and said buffer spring is disposed between said arms, and wherein said manual latch retraction mechanism is operatively connected to said solenoid link by a pin slidably engaged in said slot such that said second retraction force moves said solenoid link to retract said latch and said first retraction force moves said solenoid link to retract said latch regardless of the position of said operator and manual latch retraction mechanism.
- 13. The exit bar of claim 12, comprising a main spring having an axis and operatively connected to bias said manual latch retraction mechanism and operator toward said first latched position, said buffer spring having an axis parallel to said main spring axis.
- 14. The exit bar of claim 13, wherein said latch is biased toward said projected latched position by a latch preload spring having an axis parallel to said main spring axis and buffer spring axis.
US Referenced Citations (6)