Note: Descriptions are shown in the official language in which they were submitted.
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MANOAL MODULAR PULL STAT~CON
TECHNICAL FIELD
The invention is generally related to emergency
alarm systems and more specifically directed to
distributed manually operable switches for activating the
system.
Emergency alarm systems in public buildings often
include manually operable switches placed throughout the
building and connected to a wiring system that
communicates actuation of the switches to circuitry in a
control panel. These alarm systems include evacuation,
tornado and fire alarm systems far commercial,
industrial, municipal buildings and the like. In
conventional systems of these types, activation of one or
more of these switches causes the circuitry in the
control panel to activate sound generators, which
generate an audible alarm.
Over the years, these switches, which are
commonly referred to as pull boxes or pull stations, have
developed certain common characteristics. For example,
pull stations typically are reset after being activated
by unlocking a front panel of the station, which releases
the switch from its activated position.' Once the switch
is released and returned to its armed position, the panel
is closed and locked. Unlocking the front panel often
exposes the switch mechanism and related circuitry, which
places the pull station at risk of being damaged. It is
also typical for the housings of pull stations to have
terminal blocks mounted to the back plates of the
housing, which require special utility boxes for mounting
the stations to a wall surface.
Conventional pull stations are typically designed to
have dedicated features, meaning that a station does not
accommodate adding or removing features without
redesigning the station. This inflexibility results in
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systems employing a single design or type of pull station
throughout a building even though some areas of the
building may be best served by pull stations having
features different from those of pull stations in other
areas. For example, some areas of the building are
remote from most daily activity or primarily occupied by
children. In these areas, the pull stations may be at
higher risk to false activation than are the pull
stations in other areas of the building. Thus, a pull
station with a security feature may be desired for some
areas of a building but not all areas. Employing
different pull stations in a single alarm system,
however, may lead to compatibility problems.
BUMMARY OF THE INVENTION
The general aim of the invention is to provide a
pull station whose features can be customized for the
needs of different environments served by a common alarm
system while maintaining the compatibility of all the
2o pull stations with the common system.
A particular object of the invention is to provide a
pull station that can be reset without exposing the
switch mechanism of the station.
Still another object of the invention is to provide
a pull station having the foregoing basic features that
can be customized to incorporate optional features as
identified below without requiring retooling of the
housing for the pull station.
It is a still further object of the invention to
provide a pull station with the foregoing features and
having an optional feature for sequentially generating a
local alarm followed by a general alarm, with the general
alarm generated only after supervisory personnel have
confirmed the local alarm is genuine.
It is still another object of the invention to
provide a pull station having an optional feature for
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warning a person intending to activate a pull box that
activation will generate an alarm signal.
Yet another object of the invention is to provide a
pull station having an optional feature for allowing
easier activation by children or wheelchair-bound
persons.
Other objects and advantages will become apparent
upon reference to the following detailed description when
taken in conjunction with the drawings.
1o To achieve the foregoing objects and others, there
is provided a pull station for activating an alarm system
that includes (1) a manually actuated assembly having
armed and activated positions for opening and closing a
switch in the alarm system and (2) a mechanism accessible
from an external surface of the housing for resetting the
switch and returning the assembly from the activated
position to the armed position without opening the
housing. In the illustrated embodiment of the invention,
the mechanism also releases a coupling between a cover
and back plate of the housing in order to provide access
to the interior of the pull station. Specifically, in
the illustrated embodiment the mechanism is a lock that
is freed to turn in clockwise and counterclockwise
directions when a key is inserted into the lock, which is
accessible from the cover of the pull station. Rotation
of the lock with the key in one direction (e. g.,
clockwise direction) releases the manually actuated
assembly so that it returns to its armed position.
Rotation of the lock and key in the opposite direction
(e.g., in a counterclockwise direction), unlocks the
cover from a back plate of the housing.
The pull station of the invention accommodates a
number of optional modules that implement emergency
warning features. For example, a voice module can be
added to the basic features of the pull station during
assembly or retrofitted to the pull station thereafter.
Non-electrical optional modules can also be added to the
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basic pull station to provide optional features such as a
security mechanism that requires a two-part activation of
the pull station before the alarm system is activated,
wherein the second part of the activation can only be
accomplished by authorized personnel. To accommodate
optional modules, the housing of the pull station is
constructed to include receptacles that mate with and
fasten to complementary portions of the optional modules.
Preferably, the fastener joining the receptacle and one
of the modules is a snap-fit fastener.
One of the optional modules provides for sequential
activation of first and second switches, where the first
switch controls a local alarm circuit and the second
switch controls a general alarm circuit whose signal
extends beyond that of the local alarm circuit. Another
optional module of the pull station is a shield that is
pivotably mounted to the housing of the pull station and
controls a switch housed in the pull station for
controlling a local alarm circuit. In operation, the
shield covers a pull bar of the manually actuated
assembly, which is coupled to a switch that controls the
general alarm circuit. In order to activate the general
alarm circuit, the shield must be pivoted open in order
to access the pull bar. When the shield is opened, the
switch controlling the local alarm circuit is activated
and the local alarm signal is generated.
BRIEF DESCRIPTION OF THE DRAWIN(~8
FIGURES lA and 1B are schematic block diagrams each
illustrating an alarm system having plurality of pull
stations according to the invention distributed
throughout zones of a building for the purpose of
providing remote activation of the alarm system and for
providing an indication at the control panel of the area
of the building in which the alarm was initiated;
FIG. 2 is a perspective view of a pull station in
accordance with the invention, showing a protective
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shield pivoted open from a closed position (phantom line)
to expose a pull bar for activating the fire alarm
system;
FIG. 3 is the same perspective view of the pull
station of FIG. 2 with the pull bar moved from its armed
position (phantom line) to its activated position (solid
line);
FIG. 4 is the same perspective view of the pull
station as shown in FIGS. 2 and 3, with a key inserted
and turned in a lock accessible on a cover of the pull
station for returning the pull bar from its activated
position to its armed position;
FIG. 5 is the same perspective view of the pull
station as shown in FIGS. 2-4 after the key inserted into
the lock has been rotated in a counterclockwise direction
to release the cover of the housing of the pull station,
which exposes the back plate of the housing and the
interior mechanisms of the station;
FIG. 6 is a schematic diagram of the circuitry for
an embodiment of the pull station of FIGS. 2-5 that
incorporates three optional features that are~selectively
activated by microswitches;
FIGS. 7A-7C are perspective views of one of the
microswitches schematically illustrated in FIG. 6,
including a stackable module for retaining the switch and
mating it, using a snap-fit coupling, to the back panel
of the pull station's housing;
FIG. 8 is a perspective view of a pair of the
microswitches and the modules illustrated in FIGS. 7A-7D
in a stacked arrangement to provide for their mutual
activation in response to the same mechanical motion;
FIGS. 9A-9E are each an isolated view of the pull
bar of the pull station and a switch assembly responsive
to the movement of the bar, showing movement of the bar
and the assembly as a sequence of events leading to
activation of the alarm system and subsequent resetting
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of the pull station incorporating an optional supervisory
feature ;
FIGS. l0A-10D are isolated views of a cam in the
switch assembly illustrated in FIGS. 9A-9E that is
collar-fitted over a rotatable lock for actuating linear
plungers of the switch assembly;
FIG. 11A is an isolated view of the pivotable shield
protecting accidental activation of the pull bar of the
pull station in FIGS. 2-5, with the shield pivoted open
to illustrate its activation of one of the microswitches
in FIG. 6 for controlling an optional feature;
FIG. 11B is a top view of the illustration in FIG.
11A taken along the line 11B-11B;
FIG. 12 is an isolated view of the pull bar shield
and an optional assembly incorporated into the pull
station that hooks a lanyard to the pull bar for
actuating the pull station from below;
FIGS. 13A-13F are each an isolated perspective view
of one of the modules for optional features of the pull
station of FIGS. 2-5 that can either be added to the
station during assembly or retrofitted thereafter; and
FIGS. 14A-14H are each a schematic diagram of one of
the alternative embodiments of the pull station, where
the schematic of FIG. 14A is for a basic pull station
without any options and the remaining schematics are of
the basic pull station incorporating various ones of the
optional features of FIGS. 13A-13F.
While the invention will be described in connection
with a preferred embodiment, there is no intention to
limit it to that embodiment. On the contrary, the
intention is to cover all alternatives, modifications and
equivalents falling within the spirit and scope of the
invention as defined by the appended claims.
BRIEF DEBCRIPTION OF THE PREFERRED EMBODIMENT
Turning first to FIGURE lA, an alarm system 11 for a
building typically includes a plurality of pull stations
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12A through 12N distributed throughout the building. In
most alarm systems, activation of any one of the pull
stations 12A through 12N causes a control panel 15 to
generate a general alarm throughout the building by
delivering drive signals to a plurality of alarm
generators 17, which are also distributed throughout the
building. In some alarm systems, each of the pull
stations 12A-12N is associated with a subset of the alarm
generators 17 so that the building is divided into zones.
With such an architecture, the control panel 15 may be
designed, or programmed if it is microprocessor based, to
generate an alarm only in the zone of the pull stations
12A-12N that is activated. The control panel 15 may also
be designed or programmed to respond to the activation of
one of the pull stations 12A-12N by controlling fire
suppressers 17, which are also distributed throughout the
building and may be associated with the pull stations and
alarm generators to define zones.
In order to activate the alarm system of FIGURE lA,
a movable assembly of one of the pull stations 12A-12N is
manually moved from an armed position to an activated
position. In its activated position, the assembly of the
pull station 12 closes a switch mechanism that completes
a circuit monitored by the control panel 15 of the alarm
system. In a conventional manner, the control panel 15
responds to the closed circuit by activating the alarm
generators 17. The control panel 15 may also respond to
a closed circuit by activating suppressers 19, which
discharge water or some other type of fire retardant.
In accordance with an important aspect of the
invention, the manual assembly of one or more of the pull
stations 12A-12N sequentially activates a local alarm
circuit followed by a general alarm circuit. The local
alarm circuit provides a visual or audible alarm signal
to the immediately ambient area of the pull station 12 in
response to manual activation of the assembly. A further
manual movement of the assembly, preferably executable
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only by authorized personnel, closes the switch mechanism
monitored by the control panel 15, which activates the
general alarm circuit.
Referring to FIG. iB, the alarm system illustrated
in FIG. lA has been modified to incorporate pull stations
in accordance with the foregoing aspect of the invention.
Specifically, each of pull stations 12A' and 12C'
includes a manually movable assembly for sequentially
activating a local alarm circuit followed by the general
alarm circuit controlled by the control panel 15. Manual
activation of the assembly of either pull station 12A' or
12C' energizes a local alarm generator that is
schematically illustrated as part of the alarm generators
21. Although the local alarm generator may be external
to the pull station 12A' or 12C', the preferred
embodiment of the invention incorporates the alarm
generators for the local alarm circuit into the housing
of the pull stations 12A' and 12C'.
In the schematic illustration of FIG. iB, lead lines
23 and 25 indicate activation of local alarm generators
within alarm generator 21 in response to actuation of a
first switch. Upon closure of the second switch (i.e.,
the switch monitored by the control panel 15), a general
alarm circuit is activated, which includes line 27
connecting the pull stations 12A', 12B, 12C' and 12D-12N
to the control panel 15. Specifically, closure of the
second switch at either pull station 12A' or 12C'
provides.a signal to the control panel 15, which in turn
provides drive signals to the alarm generators 21 on line
29, which is also part of the general alarm circuit.
Like FIG. 1A, the alarm system of FIG. iB includes
suppressors 19 under the control of the control panel 15.
Those skilled in the art will appreciate that both the
first and second switches may be monitored by the control
panel 15 for controlling both the local and general alarm
circuits.
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In keeping with the invention, each of the pull
stations 12A' and 12C' in FIG. iB includes a security
mechanism that allows the second switch of the pull
station to only be activated by qualified personnel.
After the manually movable assembly activates the first
switch and the local alarm circuit is activated, further
movement of the assembly is inhibited by a keyed security
mechanism. Authorized personnel using the appropriate
keying device may move the security mechanism and free
the assembly to activate the second switch, which
energizes the general alarm circuit.
As explained in greater detail hereinafter, the
keying device is preferably a lock with a tumbler for
receiving a mechanical key that frees the lock to rotate.
It will be appreciated by those familiar with security
locks, however, that both the mechanical and electrical
locking devices may be employed as the security mechanism
in keeping with the invention. For example, the second
switch may be a solid state switch responsive to an input
from a keypad either mounted to the housing or connected
to it by way of a port on the housing. In a further
alternative, authorized personnel are provided with a
security card imbedded with an appropriate RF transponder
containing a code that is read by an RF receiver within
the pull station when the card is held close to the
housing of the pull station.
FIGS. 2-4 illustrate one of the pull stations 12A-
12N of FIGS. lA or 1B. The following detailed description
of one of the pull stations 12A-12N of FIG. lA or iB is
referenced hereinafter simply by the reference no. 12. A
manually movable assembly of the pull station 12 for
actuating the switches of the alarm circuits includes a
pull bar 31 that is accessible for manual activation
through a window 33 of a housing. In order to provide an
ergonomic grip for the right hand, the pull bar 31 is
angled at approximately il degrees to match the natural
curl of the right hand. Accordingly, the opening or
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window 33 of the housing has upper and lower sides that
are angled at 11 degrees.
The pull station 12 in FIGS. 2-4 includes a shield
37 pivotably mounted to the housing 35 for movement
between closed (illustrated in phantom) and opened
positions as shown in FIGS. 2-4. In its closed position,
a notch (not shown) in a side arm 37A of the shield 37
receives a rib 35A formed in a side of the housing 35.
The rib 35A and the notch form a closure for retaining
the shield 37 in its closed position. In order to access
the pull bar 31, a user first uses his/her fingers to
release a snap-fit engagement formed between the notch
and the rib 35A. In this regard, the user bends the side
arm 37A outwardly in order to release the rib 35A from
the notch. As will be appreciated in those skilled in
the art, the bending of the side arm 37A is maintained
within its elastic limit in accordance with conventional
snap-fit fasteners of this type. With the shield 37
pivoted into its open position as illustrated in FIGS. 2-
4, the pull bar 31 is exposed and accessible. As best
illustrated in FIG. 3, the pull bar 31 is moved
downwardly from an armed position (shown in FIG. 2 and in
phantom in FIG. 3) to an actuated position (shown in FIG.
3) .
In the embodiment of the invention discussed above
in connection with FIG. 1B and pull stations 12A' and
12C', movement of the pull bar 31 from its armed position
to its actuated position causes a first switch to become
activated and sound a local alarm. In order for the
general alarm circuit to sound an alarm, a second switch
is actuated by rotation of a lock 39 shown in FIGS. 2-4.
This embodiment will be discussed in greater detail
hereinafter in connection with FIGS. 9A-9D. In an
alternative embodiment, movement of the pull bar 31 of
the movable assembly from its armed position to its
activated position caused the general alarm circuit to
sound as will be appreciated from the more detailed
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description of the manually movable assembly set forth
hereinafter.
Other features of the invention shown in the
illustration of FIGS. 2-4 that are discussed in greater
detail hereinafter are a display of light emitting diodes
(LEDs) 41, a grill 43 for communicating sound and a notch
45 in the movable assembly that mates with a projecting
wedge 47 formed in the shield 37. The notch 45 and wedge
47 cooperate to automatically open the shield in
accordance with an alternative embodiment also discussed
hereinafter. Finally, the housing 35 includes a recessed
area for receiving a legend plate 49, which in the
illustrations of FIGS. 2-4 is labeled "FIRE ALARM." In
keeping with the invention, however, alternative legend
plates can be substituted to reflect different types of
alarm systems in which the pull station 12 may be used --
e.g., "EMERGENCY ALARM" and "EVACUATION ALARM."
Moreover, in appropriate situations, legend plates with
raised dots for braille can be used. As an alternative,
braille may be added to the housing at an area
immediately below the grill 43. The shield 37 may also
include braille.
In accordance with another important aspect of the
invention, after the pull bar 31 of the pull station 12
is pulled down from its armed position to its activated
position as indicated by the downwardly pointing arrow in
FIG. 3, it is reset and returned to its armed position by
rotation of the lock 39. A key 51 is first inserted into
the lock, which is accessible from the housing 35 of the
station 12. The key 51 frees the lock 39 to rotate. In
the illustrated embodiment as best seen in FIG. 4,
clockwise rotation of the key 51 and the lock 39
withdraws a valve (not shown) from a spring-biased
position that prevents the pull bar 31 from returning to
its armed position. When the valve is withdrawn, a
spring under tension draws the pull bar 31 back to its
armed position as indicated by the arrow in FIG. 4. The
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key 51 is then rotated counterclockwise back to its
original position illustrated in phantom line in FIG. 4
and withdrawn, leaving the pull station 12 reset and
primed to again activate the alarm system. Thus, the
pull station 12 may be reset and primed for future
activation of the alarm system without opening the
housing 35.
As best shown in FIG. 5, the housing 35 of the pull
station 12 includes a cover 35(FRONT) and a back plate
35(BACK) pivotably mated in a clam-shell configuration,
which allows the internal mechanisms of the pull station
12 to be easily accessed. In this regard, the lock 39
serves the dual function of resetting the pull bar 31 as
described above and also unlocks the cover 35(FRONT) from
the back panel 35(BACK) of the housing 35 and frees the
cover to pivot downwardly to expose the internal
mechanisms of the two sections of the housing.
The cover 35 (FRONT) may be color coded to indicate
its function. For example, a fire alarm pull station 12
may have a red color whereas a tornado alarm pull station
may have a blue cover. By color coding the pull station
12, the control panel 15 can then be programmed to
evaluate the type of emergency based on which color coded
pull station was activated and initiate an appropriate
response.
In accordance with yet another important aspect of
the invention, the interior of the housing 35 includes
receptacles for mounting modules for one or more optional
features of the pull station 12. The receptacles allow
the modules to be easily added during assembly of the
pull station 12 or retrofitted thereafter. Preferably,
the cover 35(FRONT) and back plate 35(BACK) of the
housing 35 are formed of molded plastic, such as
polystyrene and polycarbonate. As best illustrated in
FIG. 5, the back plate 35(BACK) of the housing 35 is
molded to include several receptacles for receiving
microswitch assemblies that are held in the receptacles
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by fasteners forming a snap-fit engagement. In the
illustrated embodiment, the fasteners comprise flexible
ribs extending from a body of the microswitch assembly
that mate with slots in the receiving receptacle as
explained in greater detail hereinafter in connection
with FIGS. 7 and 8. Other receptacles include flexible
ribs that cooperate with modules to fasten the module to
the housing 35. Other receptacles comprise several guide
surfaces for receiving slidable members of optional
modules installed into the pull station 12 as also
explained in greater detail hereinafter.
In the embodiment of the pull station 12 illustrated
in FIG. 5, several modules for optional features are
mounted into their mating receptacles. Specifically, a
microswitch assembly 53 is fitted to a mating receptacle
in the back panel 35(BACK) and positioned to be in
registration with a caroming portion of the shield 37 so
that the switch 53 is closed and opened in response to
the opening of the shield 37. This feature is described
2o in greater detail hereinafter in connection with FIGS.
11A and 11B. After the shield 37 is opened, the
activation of the microswitch assembly 53 passes energy
to a load from either a battery 55 mounted within the
housing or from an external power source connected into
the pull station 12 by way of a pair of terminals 57A and
578. In the pull station 12 of FIG. 5, the load
controlled by the microswitch assembly 53 is a voice
module comprising a printed circuit board 87 and a
speaker 85. Alternatively, the microswitch assembly may
control any of the optional modules described hereinafter
that require electrical power.
The wiring of each of the modules is captured in a
harness comprising a series of strain release receptacles
such as the receptacle 60 in FIG. 5. A number of these
receptacles are positioned on the back plate 35(BACK) in
order to hold in place the wiring of the electrical
modules such as the voice module or the LEDs 41.
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In keeping with the modular construction of the pull
station 12, the battery 55 as illustrated in FIG. 5 is
received by a receptacle 58 formed by resilient arms
extending from the interior surface of the back panel
35(BACK). Likewise, a receptacle 59 comprising resilient
arms extending from the interior surface of the back
panel 35(BACK) mate to a substrate 57C to which the
terminals 57A and 57B are mounted. In FIG. 5, the back
panel 35(BACK) includes four receptacles 59 for receiving
external wiring through a pair of ports 61 in the back
panel 35(BACK). The details of one of the receptacles 59
is best illustrated in one of the two lower receptacles
59, which are not mated with terminal pairs 57A and 57B.
Each of the receptacles 59 includes opposing flexible
ribs or fingers 59A and 59B that fasten the terminals to
the housing 35 in a snap-fit engagement. To position the
substrate 57C and prevent its lateral movement, a
centering post 59A projects into a mating recess or hole
in the substrate.
After the shield 37 is open (FIG. 2), the pull bar
31 is moved from its armed position to its actuated
position (FIG. 3), which in the embodiment of FIG. 5
activates the microswitch assembly 63. In keeping with
the invention, each of the microswitch assemblies 53 and
63 may be part of one of several possible modules for
optional features. As explained hereinafter, each of the
microswitch assemblies 53 and 63 may control any one of
the electrical modules, such as the LEDs 41 or the voice
module. In the illustrated embodiment of FIG. 5, the
microswitch assembly 63 alternately activates one of two
light emitting diodes (LEDs) 41. One of the two LEDs 41
radiates green light and is active when the pull bar 31
is in its armed position. The other one of the pair of
LEDs 41 radiates red light and is alternately activated
by the microswitch assembly 63 to when the pull bar 31 is
in its actuated position.
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Further in keeping with the modular construction of
the pull station 12, a follower 65 in FIG. 5 follows the
movement of the pull bar 31 and blocks a plunger 67 from
activating a microswitch assembly 69, which is the switch
for activating the general alarm circuit. A pair of
springs 71 bias the follower 65 against a caroming surface
of a plate 73 from which the pull bar 31 is formed. The
plate 73 is slidable along slots in the plate that mate
with posts 74 projecting from the interior of the cover
35(FRONT). A collar 75 fitted about the barrel of lock
39 releases the plunger 67 and frees its spring bias to
move the plunger into engagement with the microswitch
assembly 69 and activate the general alarm circuit. The
collar 75 is fitted about the barrel or body of the lock
39 and includes caroming surfaces that engage the follower
65 when the key is rotated in a counterclockwise
direction as explained more fully hereinafter in
connection with FIGS. 9A-9E: Rotation of the lock 39 and
the collar 75 raises the follower 65 against its spring
bias provided by springs 71 and frees the plunger 67 to
release its spring bias and move into engagement with the
microswitch assembly 69.
With the pull station 12 fully activated, a valve
67A of the reciprocating plunger 67 extends over an arm
73A, which is an extension of the plate 73, and prevents
the pull bar 31 from returning to its armed position,
even though a spring 77 biases the pull bar upwardly. In
order to release the plate 73 and allow the spring 77 to
draw the pull bar 31 back to its up position, the collar
75 of the lock 39 includes a caroming surface that engages
the reciprocating or linear plunger 67 when the lock is
rotated in a clockwise direction. Rotation of the lock 39
in its clockwise direction withdraws the plunger 67 and
its valve 67A from over the top of the arm 73A and frees
the plate 73 to return the pull bar 31 to its armed
position.
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Like the optional modules, the plunger 67 is snap
fitted into a receptacle of flexible fingers or ribs 79
in the back panel 35(BACK) of the pull station 12. A
second reciprocating or linear plunger 81 is snap fitted
into a similar receptacle and is also responsive to a
caroming surface of the collar 75, but it does not control
a microswitch assembly. Instead, the valve 81A of the
plunger 81 mates with the cover 35(FRONT) to lock the
cover to the back panel 35(BACK). Rotation of the lock
39 in a counterclockwise direction withdraws the valve
81A of the plunger 81 from a mating contact with the
cover 35(FRONT) and frees the cover to pivot downwardly
as illustrated by the arrow in FIG. 5. Hinge assemblies,
one of which is illustrated and indicated by the
reference no. 83 in FIG. 5, define a pivot axis between
the cover 35(FRONT) and the back panel 35(BACK).
Several additional modules for optional features are
also included in the embodiment shown in FIG. 5.
Specifically, the voice module for providing voice
messages includes the speaker 85 mounted to the interior
of the grill 43 and a printed circuit board 87 fitted in
a sliding engagement with a receptacle in the front cover
35(FRONT), which includes voice synthesizing electronics.
In the embodiment of FIG. 5, the voice synthesizing
electronics is powered by the battery 55 and is activated
by the microswitch 53, whereas power to the LEDs 41 is
provided from an external source connected through the
terminal pairs 57A and 57B.
Yet another module for an optional feature included
in the embodiment illustrated in FIG. 5 is a lanyard 89
slidably fitted into a receptacle 91 formed in the back
panel 35(BACK). The lanyard 89 is biased upwardly by a
spring 93 under compression between upper and lower
opposing surfaces of the receptacle 91. The top of the
lanyard 89 includes a projecting lip 89A that mates with
an outrigger 95 of the plate 73 to form a coupling. This
coupling allows downward movement of the lanyard 89,
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which is responsive to a pulling force applied to a chain
97 coupled to the lanyard, to move to the activated
position the plate 73 and the pull bar 31 formed from it.
As explained in more detail hereinafter, the notch 45
shown in FIGS. 2-4 kicks out the shield 37 when the
lanyard 89 is used to move the pull bar 31 to its
activated position.
Finally, the back panel 35(BACK) in FIG. 5 includes
two upwardly extending and opposing prongs 99A and 99B.
These prongs 99A and 99B mate with complementary ribs in
the cover 35(FRONT) and provide a weak spring bias to the
cover that is released when the cover is unlocked so that
the cover pops away from the back panel, which makes it
easier for the cover to be grabbed and pivoted
downwardly.
Although not shown in FIG. 5, the switch assemblies
are stackable so that a second switch assembly can be
piggy-backed onto the switch assembly 63 in FIG. 5: With
this additional switch assembly, the pull station 12
includes four switches that are each capable of
controlling a function of the pull station 12. Figure 6
is a high-level electrical schematic of a pull station 12
incorporating the microswitch assemblies 53, 63, 69 and a
fourth assembly 101 that is piggy-backed onto the switch
assembly 63.
In operation, when the shield 37 is in its closed
position, the microswitch assembly 53 is in the position
shown in solid line in FIG. 6 and the position of the
shield 37 is shown symbolically by the solid rectangle 1.
When the shield 37 is opened as illustrated in FIGS. 2-4,
the surface of the shield engaging the microswitch 53
moves from the position represented by the solid
rectangle 1 to the position symbolized by the dashed
rectangle 2. With the shield 37 open, the microswitch
assembly 53 closes on contact 103, which connects a power
source 105 (e.g., battery 55) to a load 1, which in the
embodiment of FIG. 5 is the voice module.
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With the shield 37 open, the pull bar 31 is
accessible to be moved from its armed position to its
actuated position as illustrated in FIGS. 2 and 3. In
FIG. 6, as the pull bar 31 moves downwardly, it moves the
plunger 67 from position 3 to position 4 illustrated by a
dashed rectangle line. With the plunger 67 in the
position of rectangle 4, the microswitch assemblies 63
and 101 are freed to close on contacts 105 and 107,
respectively. These microswitch assemblies then provide
the power from the power source 105 to loads 2 and 3.
Each of the loads 1, 2 and 3 is preferably one of the
optional features shown in FIGS. 13A, 13B and 13C.
The plunger 67 moves from position 4 to position 5
as shown symbolically in FIG. 6 after the lock 39 has
been rotated to raise the follower 65 as described above
and hereafter in connection with FIGS. 9A-9E. With the
plunger 67 in position 5, the microswitch assembly 69
closes on contact 109, which energizes the system alarm
circuit. In contrast, closure of the switch assemblies
53, 63 and 101 on contacts 103, 105 and 107 respectively
energizes a local alarm circuit realized by one or more
of the loads 1, 2 and 3.
FIG. 7 illustrates microswitch assembly 63, its
component parts and its mating to a receptacle 111 formed
on the interior surface 113 of the back panel 35(BACK).
It will be appreciated that each of the other microswitch
assemblies 53, 69 and 101 is identical to the microswitch
assembly 63 illustrated in FIG. 7 and described
here inaf ter .
As illustrated in FIG. 7, the microswitch assembly
63 comprises a cradle 115 that receives a microswitch
117. Alignment pins 119 in the cradle 115 are received
by bores 121 in the microswitch 117 in order to provide a
registration between the cradle and the microswitch, as
can be best seen in FIG.7B.
Opposing flexible arms 123A and 123B each includes a
finger extending inwardly toward the other arm as best
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illustrated in FIG. 7A. As the microswitch 117 is
received by the cradle 115, the sides of the switch
contact the fingers of the arms 123A and 1238, causing
the arms to bend outwardly. When the microswitch 117 is
fully received onto the pins 119, the fingers of the arms
123A and 1238 are extending above the body of the
microswitch 117, which frees the arms to snap inwardly
and bring the fingers over the top of the body. Thus,
the microswitch 117 is fastened to the cradle by a snap-
to fit engagement provided by the arms 123A and 1238.
After the microswitch 117 and cradle 115 are
fastened to form the microswitch assembly 63 (FIG. 7C), a
second pair of flexible arms 125A and 1258 of the cradle
115 positioned outboard of the flexible arms 123A and
1238 are aligned with and fitted into slots 127A and 1278
of the receptacle 111 as illustrated in FIG. 7C. The
flexible arms 125A and 1258 flex outwardly as the
microswitch assembly 63 is joined to the receptacle 111.
Outwardly extending fingers at the ends of the arms 125A
and 1258 snap over lower edges of the slots 127A and 1278
when a pair of ribs 129A and 1298 integral with the arms
125A and 1258 contact the surface of the receptacle 111.
FIG. 8 illustrates the microswitch assembly 101
piggy-backed onto the microswitch assembly 63. As can be
seen in FIGS. 7B and 7C, the cradle 115 includes a base
portion 115A that comprises slots of the same type and
position as the slots 127A and 1278 of the receptacle
111. Thus, the cradle 115 enables the microswitch
assemblies to be stacked so that a single mechanical
motion activates both of the switches as can be easily
appreciated from the illustration of the stacked
microswitch assembles 63.and 101 in FIG. 8.
Referring now to the drawings of FIGS. 9A through
9E, an assembly is illustrated for manually actuating the
microswitch assembly 69 of the general alarm circuit.
Although this assembly includes the follower 65 so that
the plunger 67 moves through three sequential positions
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in activating the microswitch assembly 69 as explained
hereinafter, an alternative assembly without the follower
65 provides for the plunger 67 to move only through two
positions in actuating the microswitch assembly 69 (see
FIGS. 14A-14C). Either assembly for actuating the
microswitch assembly 69 is in keeping with the present
invention.
In FIG. 9A, the assembly comprises the plunger 67
and the mechanisms that control its movement; namely, the
plate 73 (shown in phantom), the lock 39 and the collar
75. In its initial position, the assembly is as
illustrated in FIG. 9A. Specifically, the arm 73A of the
plate 73 engages a distal end of the reciprocating
plunger 67 to tension a biasing spring 131 of the plunger
and to bring a flange 132 of the plunger into engagement
with the microswitch assembly 63. With the microswitch
assembly 63 in the position shown in the position in FIG.
9A, the green LED 41 in FIG. 5 is active and the red LED
41 is turned off.
When the pull bar 31 is pulled downwardly as
indicated by direction arrow 1 in FIG. 9B, the follower
65 follows the downward movement of the plate 73 as the
tension in the springs 71 is released. The valve 67A of
the plunger 67 moves to the right in FIG. 9B as indicated
by the direction arrow 2 and releases part of the tension
in spring 131. The distal end of the valve 67A contacts
the surface of the follower 65 with tension remaining in
the spring 131. The movement of the plunger 67 releases
microswitch assembly 63, causing power to be removed from
the green LED 41 and applied to the red LED. In keeping
with the invention, the microswitch assembly 63 may
alternatively control the speaker 85 or any other
optional module snap-fitted into the pull station 12.
In order to actuate the general alarm circuit, the
key 51 is inserted into the lock 39 in order to release
it for rotation. With the key 51 inserted, the lock 39
is free to rotate counterclockwise as indicated by the
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directional arrow 1 in FIG. 9C. The counterclockwise
rotation of the lock 39 rotates the collar 75 and brings
a radially extending finger of the collar into a caroming
engagement with a flange 65A extending from the follower
65. Further counterclockwise rotation of the lock 39
moves the follower 65 upwardly as indicated by the
directional arrow 2 in FIG. 9C. Once the follower 65 has
been moved upwardly by a distance greater than the
thickness of the valve 67A, the plunger 67 is free to
move to the right in FIG. 9C as indicated by arrow 3 and
release further tension from the spring 131. The distal
end of the valve 67A engages an inner side wall of the
housing 35 and extends over the top of the arm 73A of the
plate 73, which prevents the pull bar 31 from being
raised back to its armed position. In its position in
FIG. 9C, the plunger 67 activates the switch 69, which in
turn actuates the general alarm circuit.
In order to reset the assembly of FIG. 9C, the lock
39 is rotated in a clockwise direction as indicated by
the directional arrow 1 in FIG. 9D. This clockwise
rotation of the lock 39 rotates the collar 75 and brings
a finger of the collar into contact with a flange 134 of
the plunger 67 extending upwardly toward the collar. As
the finger of the collar 75 engages the flange 134 of the
plunger 67 and continues a clockwise rotation, the
plunger is moved to the left in FIG. 9D as indicated by
the directional arrow 2. Movement of the plunger 67 to
the left in FIG. 9D withdraws the valve 67A from above
the arm 73A of the plate 73, which frees the plate to
release tension in the spring 77 (FIG. 5) and move
upwardly as indicated by directional arrow 3 in FIG. 9D.
Thus, the assembly is now reset to its armed position.
In order to open the cover 35(FRONT), the lock 39 is
rotated in a counterclockwise direction as indicated in
FIG. 9E by the directional arrow 1. The lock 39 is
rotated past the counterclockwise position illustrated in
FIG. 9C to a position wherein yet another finger of the
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collar 75 engages a flange 136 of the plunger 81 and
draws the valve 81A of the plunger downwardly and free of
a lip 138 of the cover 35(FRONT). With the plunger 81
pulled downwardly as indicated by the directional arrow 2
in FIG. 9E, a spring 135 is placed under tension. When
the valve 81A moves free of the lip, the cover 35(FRONT)
pops open to release the tension from the fingers 99A and
99B (FIG. 5). The cover 35(FRONT) is closed by again
turning the lock 39 in a counterclockwise direction as
shown in FIG. 9E, pressing the cover into the fingers 99A
and 99B and then releasing the key 51, which allows the
tension in the spring 35 to be released. The spring 135
then pushes the valve 81A of the plunger 81 upwardly and
into an interference engagement with the lip 138.
The collar 75 fitted over the lock 39 includes three
caroming surfaces as referenced above and as best
illustrated in FIGS. 10(A)-10(D). The collar 75 includes
a bore 75A that is approximately rectangular in shape to
match the cross-sectional shape of the lock 39. The
collar 75 is preferably made of the same material as that
of the housing 35. In this regard, the housing 35, the
collar 75, the cradle 115 of the microswitch assemblies
are all manufactured using conventional injection molding
techniques. The three caroming surfaces of the collar are
supported on an arcuate ridge 75B on the circumference of
a circular substrate 75C that includes the bore 75A for
receiving the lock 39. The first caroming surface 75D
engages the follower 65 as described above. The second
caroming surface 75E engages a tab of the plunger 67 and
withdraws the valve 67A from above the arm 73A as
described above. Finally, caroming surface 75F engages a
tab of plunger 81 and draws the plunger downwardly in
order to free the valve 81A from the lip 138 of the cover
35(FRONT) as described above.
FIGS. 11A and 11B illustrate the coupling between
the roicroswitch assembly 53 and the shield 37. In its
open position as illustrated in FIGS. 11A and 11B, a
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finger 37A of the shield has been rotated about a pivot
axis 37B of the shield 37B to a position that is clear of
a reed 53A of the microswitch assembly 53. In its closed
position indicated in phantom in FIGS. 11A and 11B, the
finger 37A draws into contact with the reed 53A, which
moves the switch contact from pole 103 to pole 137 (FIG.
6) .
FIG. 12 illustrates the response of the coupling
between the notch 45 in the plate 73 and the wedge 47 in
the shield 37 when the lanyard 89 is pulled downwardly as
indicated by the direction of arrow 1 in FIG. 12. When
the lanyard 89 is pulled downwardly, the coupling between
the lanyard and the plate 73 (i.e., the outrigger 95 and
the lip 89A) causes the plate and the pull bar 31 to also
move downwardly as indicated by the direction of arrow 2
in FIG. 12. As the plate 73 moves downwardly, the notch
45 engages the beveled surface 47A of the wedge. The
coupling between the notch 45 and the wedge 47 at the
bevel 47A causes the downward force applied to the plate
73 and the pull bar 31 by the pulling force on the
lanyard 89 to be translated to a lateral force that kicks
out the shield 37 as indicated by the direction of arrow
3 in FIG. 12.
FIG. 13 illustrates in isolation each of six
optional modules for the pull station 12 in keeping with
the invention. FIG. 13A illustrates the voice module
comprising the microswitch assembly 63, the speaker 85,
the printed circuit board 87 and the battery 55.
Alternatively, the microswitch assembly for the module
could be the microswitch assembly 53 or 101, depending on
the particular configuration of optional features
incorporated into the pull station 12 as discussed in
greater detail hereinafter in connection with FIGS. 14A-
14H. The optional module illustrated in FIG. 13B
provides a piezoelectric buzzer 139 for mating to the
inside of the cover 35(FRONT) at the area of the grill
43. Like the voice module of FIG. 13A, the module of
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FIG. 13B includes the microswitch assembly 63 and the
battery 55. Also like the module of FIG. 13a, the module
of FIG. 13B can incorporate any one of the microswitch
assemblies 53, 63 or 101. A third optional module that
incorporates a microswitch is illustrated in FIG. 13C.
This module includes the red and green LEDs 41 described
above. These LEDs 41 are controlled by a microswitch
assembly 63 or, alternatively, 53 or 101. Power is
provided to the LEDs 41 by way of terminals 57A and 57B
mounted to substrate 57C. FIGS. 13E and 13F illustrate
in isolation the lanyard 89 and the follower 65,
respectively. Each of these two modules is formed from
the same plastic as used for the housing 35 and they are
made using the same molding techniques.
In accordance with another aspect of the invention,
a fireman's jack 141 as illustrated in FIG. 13D is
incorporated into the pull station 12. The fireman's
jack 141 receives a handset and couples the handset into
an emergency voice communication network in a manner that
is well-known in the art of emergency voice communication
systems. In keeping with the modular design of the pull
station 12, a nose 141A of the fireman's jack 141 is
received through a hole in the side of the cover
35(FRONT). Although not shown in the cover 35(FRONT) of
the illustrated embodiment, the cover may include a
"knock-out" section for creating the hole necessary to
receive the nose 141A of the fireman's jack 141. In a
conventional manner, the fireman's jack is retained in
the hole by way of a nut 142 that is secured over a
threaded surface of the nose 141A. As those skilled in
the art will appreciate, the fireman's jack 141 provides
a port to a voice line 144 of an emergency voice system
that a fireman may employ to communicate to a supervisor
positioned at the control panel 15 as illustrated in FIG.
lA.
With the various optional modules available for
incorporation into the pull station 12 as described
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above, a number of different embodiments of the station
can be realized. Some of these different embodiments
employing different configurations of the microswitch
assemblies are illustrated in FIGS. 14A through 14H. In
each of the illustrations in FIGS. 14A through 14H, a
common convention is employed in order to represent the
motion of the plunger 67 as it activates the microswitch
assembly 69 and the motion of the shield 37 as it swings
open and activates the microswitch assembly 53.
Specifically, in the embodiments of FIGS. 14A through
14C, the plunger 67 is represented as moving from a
position 1 shown by a solid rectangle to a position 2,
which is illustrated by a rectangle of dashed lines. In
the embodiments of FIGS. 14D-14H, the plunger 67 moves
through three positions as indicated by the three
rectangles labeled 1, 2 and 3. The pull stations of
FIGS. 14D-14H include the follower 65, which introduces
an intermediate position for the plunger 67 as
illustrated in the sequence of FIGS. 9A-9E. Likewise,
the embodiments of FIGS. 14D, 14C, 14G and 14H illustrate
two rectangles labeled A and B, which represent movement
of the shield 37 from a closed position (rectangle A) to
an open position (rectangle B).
FIG. 14A illustrates the basic configuration of the
pull station 12 wherein the pull bar 31 moves the plunger
67 from position 1 to position 2, which activates the
microswitch assembly 69.
In FIG. 14B, the optional module illustrated in FIG.
13C has been added. This optional module includes the
addition of microswitch assembly 53 and the green and red
LEDs 41 as illustrated. In operation, the shield 37 is
opened,. which draws the finger 37A away from the reed 53A
of the microswitch assembly 53. In keeping with the
convention of the illustrations in FIGS. 14A-14H, solid
rectangle A in FIG. 14B indicates the initial position of
the finger 37A -- i.e., when the shield is closed. When
the shield opens, the finger moves to a position away
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from the microswitch 53, which is represented by the
rectangle B. After the shield 37 has been opened and the
microswitch assembly 53 activated to turn on the red LED
41, the pull bar 31 is pulled downwardly. As the pull
bar 31 is pulled downwardly, the plunger 67 moves from
its initial position represented by the rectangle 1 to
the position represented by rectangle 2. As in the basic
unit of FIG. 14A, the plunger activates the microswitch
assembly 69 in position 2 of FIG. 14B.
As an alternative to activating the LEDs 41 as
illustrated in the embodiment of FIG. 14B, the embodiment
of FIG. 14C substitutes the voice module for activation
by the microswitch assembly 53 in response to opening the
shield 37.
In the embodiment in FIG. 14D, the follower 65 has
been added to the pull station 12. Thus, the plunger 67
now moves through three positions identified by
rectangles 1, 2 and 3. When the pull bar 31 is moved
from its armed position to its activated position, the
plunger 67 moves from position 1 to position 2, which
activates the microswitch assembly 63. Rotation of the
lock 39 frees the plunger to move from position 2 to
position 3, which activates the microswitch assembly 69.
In the embodiment of FIG. 14D, the microswitch assembly
63 controls the LEDs 41, which receive power from an
external source.
In the embodiment of FIG. 14E, the pull station 12
includes the follower 65 and the microswitch assembly 63
activates the voice module, which receives power from a 9
volt battery 55.
In the embodiment in FIG. 14F, the microswitch
assembly 101 is stacked on the microswitch assembly 63 as
illustrated in FIG. 8. Like the embodiments of the pull
station 12 in FIGS. 14D and 14E, the pull station of FIG.
14F includes the follower 65 so that the plunger 67 moves
through three positions as indicated by the rectangles 1,
2 and 3. In this embodiment of the pull station 12, the
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microswitch assembly 63 controls the LEDs 41 and the
microswitch assembly 101 controls the voice module of
FIG. 13A or, alternatively, the piezoelectric buzzer 139
of FIG. 13B.
FIG. 14G illustrates an embodiment of the pull
station 12 that includes the follower 65 and microswitch
assemblies 53, 63 and 69. The microswitch assembly 53
controls either the voice module of FIG. 13A or the
buzzer module of FIG. 13B, which are powered by the 9
volt battery 55. The microswitch assembly 63 controls
the LEDs 41 and provides power to them from an external
source.
Finally, the embodiment of the pull station in FIG.
14H reverses the connections of the microswitch
assemblies 53 and 63 with respect to the embodiment in
FIG. 14G. Specifically, the microswitch assembly 53
controls the LEDs 41 and the microswitch assembly 63
controls either the voice module of FIG. 13A or the
buzzer module of FIG. 13B.
The invention has been described in connection with
a preferred embodiment for implementing the modular
construction of the invention. Other embodiments for
implementing a modular construction in which modules of
optional features can be selectively added to a basic
unit are also within the scope of the invention as
defined by the claims set forth below.
