Note: Descriptions are shown in the official language in which they were submitted.
CA 02615375 2007-12-14
Traffic Signal Transfer Switch with Interlock Constructions
BACKGROUND OF THE DISCLOSURE
1. Field of the Invention
[0001] The present invention relates in general to transfer switches
configured
for use with portable electrical power generation devices, for powering
traffic signals
and the like, during periods of unavailability of utility line power.
2. Background
[0002] When the utility line power to an electrically powered and
controlled traffic
signal fails, it is imperative to arrange for an alternative power supply as
quickly as
possible, so that the traffic signal can resume operation. Otherwise, police
officers
typically must man the intersection where the non-functioning traffic signal
is located,
or else the motoring and pedestrian public is placed in danger from traffic
through an
uncontrolled intersection. Using police officers or other personnel not only
is an
inefficient use of manpower, but also can be dangerous to the individuals
manning the
intersection, as they typically must position themselves in the midst of
traffic in order to
be seen, to provide traffic control guidance.
[0003] Usually, the method of supplying auxiliary power comprises the
placement
of a small portable generator, usually powered by a gasoline internal
combustion
engine, next to the traffic signal control pedestal, and electrically
connecting the power
output connections of the generator to the power input connections of the
traffic signal
control pedestal.
[0004] However, simply breaking the hardwire connection between the
traffic
signal controller and the utility line, and making a hardwire connection
directly between
the generator output and the traffic signal controller input, is a time
consuming,
inefficient and inelegant solution. One cannot splice in the generator input
without
disconnecting the utility line, as failure to do so could result in the
accidental driving of
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current back up the utility line, which could, in turn, result in utility
equipment damage
as well as grave personal injury.
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SUMMARY OF THE INVENTION
[0005] The invention includes, in part, a transfer switch, operably
configured to
be connected to a portable electrical power generator, a traffic signal
controller and a
utility electrical power source, for enabling repeated switching between the
portable
electrical power generator and the utility electrical power source to provide
electrical
power to the traffic signal controller. A housing is provided, having a cavity
therewithin
and at least a first opening thereto. Transfer switch circuitry is disposed in
the cavity in
the housing. The transfer switch circuitry includes a power inlet for
receiving the power
outlet connector of a portable electrical power generator; a switching
mechanism for
reciprocably switching between at least a first position, enabling power to be
supplied
from the portable electrical power generator to the traffic signal controller,
and a
second position, enabling power to be supplied from the utility electrical
power source
to the traffic signal controller; a first electrical input connection,
associated with the
switching mechanism, and operably configured to be connected to a utility line
power
supply; a second electrical input connection, associated with the switching
mechanism,
and operably connected to the power inlet, and at least one electrical output
connection, associated with the switching mechanism, and operably configured
to be
connected to a traffic signal controller; and an interlock device, operably
associated
with the switching mechanism, for preventing the switching mechanism from
being
positioned so as to enable power from both the portable electrical power
generator and
the utility electrical power source from being supplied to the traffic signal
controller.
[0006] The housing may further comprise at least one pivotable cover
for
protecting the cavity from intrusion by undesired materials. The housing may
be
operably configured to be mounted to an exterior surface of a cabinet of a
traffic signal
controller. The traffic signal transfer switch may further comprise a face
plate, disposed
in the at least first opening, for enclosing transfer switch circuitry within
the housing.
The cover may further comprise a cord access opening in an outwardly-facing
panel of
the cover; and a movable cord access door mounted on an inside surface of the
outwardly-facing panel of the cover, so as to be movable between a position
covering
the cord access opening, and a position exposing the cord access opening.
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[0007]
The switching mechanism may further comprise at least a first circuit
breaker electrically connected between the first electrical input connection
and the at
least one electrical output connection; and
at least a second circuit breaker
electrically connected between the second electrical input connection and the
at least
one electrical output connection.
[0008]
The traffic signal transfer switch may further comprise an indicator,
operably connected to the switching mechanism, and operably configured to
provide an
indication when utility line power is available.
[0009]
An indicator may be operably connected to the at least first circuit
breaker, to indicate when utility line power is available. The indicator may
be a light.
The light may be mounted on an exterior surface of the traffic signal
controller.
[0010]
The housing may be operably configured to be mounted within a suitably
configured recess in a cabinet for a traffic signal controller. The housing
may comprise
a top wall, a bottom wall, two opposed side walls and a rear wall, and a front
opening.
[0011]
The housing may further comprise a plurality of run-off channels
extending along the top wall, and two opposed side walls, between the front
opening
and the at least one mounting flange. Each of the run-off channels may have a
J-
shaped cross-sectional configuration.
[0012]
The at least one pivotable cover may comprise a front cover panel,
hingedly mounted to the at least one mounting flange, the front cover panel
being
pivotable between at least a first, upward open position, and a second,
downward
closed position; and a plurality of side flanges emanating rearwardly from at
least top
and side edges of the front cover panel, when the front cover panel is in its
second,
downward closed position. The side flanges may be configured to extend over
the run-
off channels, when the front cover panel is in its closed position.
[0013]
The switching mechanism may comprise two first circuit breakers
electrically connected between the first electrical input connection and the
at least one
electrical output connection; and two second circuit breakers electrically
connected
between the second electrical input connection and the at least one electrical
output
connection.
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[0014] The transfer switch circuitry may further comprise a first
electrical neutral
connection, associated with the switching mechanism, and operably configured
to be
connected to a neutral connection of a utility line power supply; a second
electrical
neutral connection, associated with the switching mechanism, and operably
configured
to be connected to a neutral connection of the power inlet; and a third
electrical neutral
connection, associated with the switching mechanism and operably configured to
be
connected to a neutral electrical connection of a traffic signal controller.
[0015] The switching mechanism may further comprise a first neutral
circuit
breaker, connected to the first electrical neutral connection and the third
electrical
neutral connection; and a second neutral circuit breaker, connected to the
second
electrical neutral connection and the third electrical neutral connection.
[0016] The invention also includes, in part, a switch interlock
apparatus, for
functionally interconnecting the handles of functionally and physically paired
switches
mounted in tandem on a switch panel, the switch panel having a front face and
a
housing portion disposed distal to the front face, wherein the handles are
arranged in
tandem to pivot in a common plane about parallel, spaced apart axes, such that
when
each handle is in its respective "OFF" position, the handles are pivoted away
from one
another and when each handle is in its respective "ON" position, the handles
are
pivoted toward one another. An elongated slider member, having a longitudinal
axis
and first and second end faces, is operably configured to slidably move
between the
handles. A rocker member is operably disposed to pivot about an axis disposed
perpendicular to the longitudinal axis of the elongated slider member, the
rocker
member having two inner cam surfaces adjacent the pivot axis, two outer cam
surfaces
distal to the pivot axis, and two interference surfaces disposed between the
respective
inner and outer cam surfaces. The rocker member is operably configured so as
to
engage the respective handles, toward movement in cooperation with the slider
member, so as to engage the handle of a breaker which is being moved from an
"OFF"
position to an "ON" position, and prevent its movement to a top dead center
position,
before a corresponding breaker has moved from its respective "ON" position to
its
respective "OFF" position.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Fig. 1 is a simplified schematic illustration of the
electrical connections
between utility power, a traffic signal controller, a portable power generator
and traffic
signal transfer switch.
[0018] Fig. 2 is a schematic illustration of transfer switch circuitry
according to an
embodiment of the invention.
[0019] Fig. 3 is a schematic illustration of transfer switch
circuitry according to
another embodiment of the invention.
[0020] Fig. 4 is a schematic illustration of transfer switch
circuitry according to
another embodiment of the invention.
[0021] Fig. 5 is an exploded perspective view of a lockout device for
use with the
transfer switches of the present invention.
[0022] Fig. 6 is a top, front, perspective view of a surface-mounted
traffic signal
transfer switch according to an embodiment of the invention, in a closed
orientation.
[0023] Fig. 7 is a bottom, rear, perspective view of the surface-mounted
transfer
switch, in a closed configuration.
[0024] Fig. 8 is a top, front, perspective view of the surface-
mounted traffic
signal transfer switch, in an open configuration.
[0025] Fig. 9 is a bottom, front, perspective view of the surface-
mounted traffic
signal transfer switch, in an open configuration.
[0026] Fig. 10 is a front elevation of the surface-mounted traffic
signal transfer
switch, in closed configuration.
[0027] Fig. 11 is a side elevation, in section, taken along line A-A
of Fig. 10.
[0028] Fig. 12 is a top elevation, in section, taken along line F-F
of Fig. 10.
[0029] Fig. 13 is a fragmentary front elevation, in section, taken along
line E-E of
Fig. 11.
[0030] Fig. 14 is an enlarged detail of the housing of the surface-
mounted traffic
signal transfer switch, of detail 3, shown circled in Fig. 11.
[0031] Fig. 15 is a top, front, perspective view of the top, sides
and back portions
of the housing for the surface-mounted traffic signal transfer switch.
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[0032] Fig. 16 is a side elevation of the top, side and back
portions of the
housing for the surface-mounted traffic signal transfer switch.
[0033] Fig. 17 is a front elevation of the front cover for the
housing for the
surface-mounted traffic signal transfer switch.
[0034] Fig. 18 is a top plan view of the front cover of the housing for the
surface-
mounted traffic signal transfer switch.
[0035] Fig. 19 is an inside perspective view of the front cover of
the housing for
the surface-mounted traffic signal transfer switch.
[0036] Fig. 20 is a side elevation of the front cover of the housing
for the
surface-mounted traffic signal transfer switch.
[0037] Fig. 21 is a perspective view of the face plate for mounting
the electrical
components for the surface-mounted transfer switch.
[0038] Fig. 22 is a front elevation of the face plate.
[0039] Fig. 23 is a top plan view of the face plate.
[0040] Fig. 24 is a side elevation of the face plate.
[0041] Fig. 25 is a fragmentary rear view of the face plate.
[0042] Fig. 26 is a perspective view of a flush-mounted traffic
signal transfer
switch according to an alternative embodiment of the invention, shown in a
closed
configuration.
[0043] Fig. 27 is a perspective view of the flush-mounted traffic signal
transfer
switch according to an alternative embodiment of the invention, shown in an
open
configuration.
[0044] Fig. 28 is an exploded, perspective view of a flush-mounted
traffic signal
transfer switch according to an alternative embodiment of the invention.
[0045] Fig. 29 is a front elevation of the flush-mounted traffic signal
transfer
switch, shown in closed configuration.
[0046] Fig. 30 is a partially exploded side elevation of the flush-
mounted traffic
signal transfer switch.
[0047] Fig. 31 is a partially exploded top elevation of the flush-
mounted traffic
signal transfer switch.
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[0048] Fig. 32 is a perspective view of the run-off channel
structure, for the
flush-mounted traffic signal transfer switch.
[0049] Fig. 33 is a perspective view of the housing and cover for
the flush-
mounted traffic signal transfer switch, in an open configuration.
[0050] Fig. 34 is a perspective partially exploded view of the flush-
mounted
traffic signal transfer switch.
[0051] Fig. 35 is a top view of a housing for a flush-mounted
traffic signal
transfer switch according to an alternative embodiment of the invention.
[0052] Fig. 36 is a front elevation thereof.
[0053] Fig. 37 is a perspective view thereof.
[0054] Fig. 38 is a side elevation thereof.
[0055] Fig. 39 is a front elevation of the cord access door for the
flush-mounted
traffic signal transfer switch, according to the embodiment of Fig. 35.
[0056] Fig. 40 is a side elevation thereof.
[0057] Fig. 41 is a top elevation thereof.
[0058] Fig. 42 is a front elevation of the cord access door for the
flush-mounted
traffic signal transfer switch according to the embodiment of Fig. 35, showing
also the
mounting tab and hinge structure.
[0059] Fig. 43 is a side elevation thereof.
[0060] Fig. 44 is a perspective view of the cover for the flush-mounted
traffic
signal transfer switch according to the embodiment of Fig. 35, without the
cord access
door.
[0061] Fig. 45 is a front elevation thereof.
[0062] Fig. 46 is a side elevation thereof.
[0063] Fig. 47 is a top view thereof.
[0064] Fig. 48 is a rear perspective view of the cover for the flush-
mounted traffic
signal transfer switch according to the embodiment of Fig. 35, with the cord
access
door in place, in its closed position.
[0065] Fig. 49 is a top view thereof, showing the cover hinge.
[0066] Fig. 50 is a front elevation thereof.
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[0067] Fig. 51 is a side elevation thereof.
[0068] Fig. 52 is a front elevation of the face plate for the flush-
mounted traffic
signal transfer switch, according to the embodiment of Fig. 35.
[0069] Fig. 53 is a rear perspective view thereof.
[0070] Fig. 54 is an exploded perspective view of the flush-mounted traffic
signal
transfer switch according to the embodiment of Fig. 35, which is configured
for a two-
phase circuit, or for a single phase circuit with neutral circuit breakers.
[0071] Fig. 55 is a top view of an interlock member according to the
embodiment
of Fig. 35.
[0072] Fig. 56 is a side elevation thereof.
[0073] Fig. 57 is an end elevation thereof.
[0074] Fig. 58 is an inverted, sectional side elevation of a portion
of a pair of
tandem breaker switches, showing the positioning of the interlock member.
[0075] Fig. 59 is a plan view thereof.
[0076] Fig. 60 is an exploded perspective view of the flush-mounted traffic
signal
transfer switch according to the embodiment of Fig. 35, which is configured
for a
single-phase circuit, without neutral circuit breakers.
[0077] Fig. 61 is a schematic illustration of the flush-mounted
traffic signal
transfer switch of the sub-embodiment of Fig. 60.
[0078] Fig. 62 is a perspective view of the housing for traffic signal
transfer
switch according to the embodiment of Fig. 35.
[0079] Fig. 63 is a front elevation thereof.
[0080] Fig. 64 is a side elevation thereof.
[0081] Fig. 65 is a top view thereof.
[0082] Fig. 66 is a perspective view of a bracket, to be installed within
the
housing, for mounting the face plate of the traffic signal transfer switch
according to
the embodiment of Fig. 35.
[0083] Fig. 67 is a front elevation thereof.
[0084] Fig. 68 is a side elevation thereof.
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[0085] Fig. 69 is a perspective view of a rocker member for an
alternative
interlock construction.
[0086] Fig. 70 is a top view thereof.
[0087] Fig. 71 is a front view thereof.
[0088] Fig. 72 is a front view of a slide member for an alternative
interlock
construction.
[0089] Fig. 73 is a top view thereof.
[0090] Fig. 74 is an end view thereof.
[0091] Fig. 75 is a perspective view of a mounting member for an
alternative
interlock construction.
[0092] Fig. 76 is an end view thereof.
[0093] Fig. 77 is a bottom view thereof.
[0094] Fig. 78 is a front view thereof.
[0095] Fig. 79 is an exploded perspective view of an alternative
interlock
construction employing the rocker member of Figs. 69 - 71, the slide member of
Figs.
72 - 74, and the mounting member of Figs. 75 - 78.
[0096] Fig. 80 is a front elevation of the assembled alternative
interlock
construction of Fig. 79.
[0097] Fig. 81 is a side elevation, in section, of the alternative
interlock
construction of Fig. 79, taken along line A-A of Fig. 80.
[0098] Fig. 82 is a schematic illustration of the alternative
interlock construction
of Figs. 79 - 81, shown at a position corresponding to the beginning of a
transfer
process.
[0099] Fig. 83 is a schematic illustration of the alternative
interlock construction
of Figs. 79 - 81, shown at a position corresponding to a position generally
midway in a
transfer process.
[0100] Fig. 84 is a schematic illustration of the alternative
interlock construction
of Figs. 79 - 81, corresponding to a position at the completion of the
transfer process.
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DETAILED DESCRIPTION OF THE INVENTION
[0101] While this invention is susceptible of embodiment in many
different forms,
there are shown in the drawings and will herein be described in detail,
several
embodiments with the understanding that the present disclosure should be
considered
as an exemplification of the principles of the invention and is not intended
to limit the
invention to the embodiments so illustrated. Further, to the extend that any
numerical
values or other specifics of materials, etc., are provided herein, they are to
be
construed as exemplifications of the inventions herein, and the inventions are
not to be
considered as limited thereto.
[0102] Fig. us a simplified schematic illustration of the electrical
connections
between utility power 2, a traffic signal controller 4 connected to one or
more traffic
signals 6 (not shown), a portable power generator 8 and a traffic signal
transfer switch
10, in accordance with the present invention.
[0103] The present invention contemplates three different transfer
switch
-- circuitry configurations, and two different housing configurations. The
three different
circuitry configurations are: 1) single pole (Fig. 2); 2) double pole (Fig.
3); and 3) single
pole with switched neutral (Fig. 4). The reasons for the different
configurations are as
follows. Most, but not all, traffic signal controllers at the present time,
operate on 120
VAC, so a single pole transfer switch is adequate for most applications. Some
-- municipalities and other applications may have a 120/240 VAC system, so a
two-pole
device is required. With respect to the single-pole, switched neutral transfer
switch, it is
believed by some that potentially dangerous "stray" currents may run through
the
neutral wire, during operation of the portable generator, so some municipal
(or other)
regulations require that the neutral wires be switched as well.
[0104] In the basic version of the transfer switch apparatus 2, see Fig. 2,
traffic
signal transfer switch 10 is electrically connected to the utility power feed,
to ground,
and to the load (the traffic signal controller). As would be readily perceived
by one of
ordinary skill in the art, having the present disclosure before them, this
would be
accomplished by gaining access to the utility power feed 2 (Fig. 1), and to
the power
-- inputs to the traffic signal controller 4, via a suitable access aperture
either already
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provided (e.g., by conventional knock-outs), or cut into the side of the
housing of the
traffic signal controller.
[0105] Traffic signal transfer switch 10 will be provided with a
weatherproof
housing (as discussed in further detail hereinafter), in which is contained a
male power
inlet 12, having a suitable socket for receiving the power outlet cord of a
portable
generator 8 (Fig. 1). Transfer switch 10 also includes two break-before-make
circuit
breakers 14, 16 for the generator circuit and the utility power circuit,
respectively. By
way of example, and not to limit the invention thereto, the circuit breakers
may be of
the type manufactured by Carling Technologies, C-Series Circuit Breakers
(without
microswitch for breaker 14 and with microswitch for breaker 16).
Representative model
numbers for such breakers could be CA1-130-24-620-121-KG, CA1-130-24-630-121-
KG,
and CA1-130-24-650-121-KG (for 20, 30 and 50 amp single pole breakers without
auxiliary microswitches); CA2-130-24-620-121-CG, CA2-130-24-630-121-CG, and
CA2-
B024-650-121-CG (for 20, 30 and 50 amp 2 pole breakers without auxiliary
microswitches), CA1-62-24-620-121-KG, CA1-62-24-630-121-KG and CA1-62-24-650-
121-KG (for 20, 30 and 50 amp single pole breakers with microswitches), and
CA2-62-
24-620-121-CG, CA2-62-24-630-121-CG and CA2-62-24-650-121-CG (for 20, 30 and
50
amp 2 pole breakers with auxiliary microswitches), but the invention is in no
way
intended to be limited to these specific switches; any other suitable switches
may be
used. Lockout mechanism 18 is provided, which is configured (as shown
hereinbelow)
to slide back and forth over the switch handles of the respective circuit
breakers, to
ensure that at any given time, only one of the circuit breaker switch handles
can be in
its "ON" position. An interlock mechanism, in which the two breaker switch
handles are
mechanically connected so that their movements are coordinated, may
alternatively be
used, to prevent both switch handles from being in their respective "ON"
positions
simultaneously.
[0106] In addition, transfer switch 10 is provided with a "pilot
light" 20 (and
associated pilot light circuit breaker 22), which is connected to the utility
power circuit
in such a manner that whether the switch handle of circuit breaker 16 is in
its "OFF"
position, if there is a voltage of a minimum required value across the utility
power
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circuit breaker 16, then pilot light 20 will be lit, indicating that the
utility power circuit
has been restored and is available, so that an operator, such as a police
officer, or
municipal or county employee can turn off the generator, shift the lockout
device, and
flip the utility power circuit breaker to "ON", to restore operation of the
traffic signal
controller to utility power. The generator 8 can then be disconnected from the
transfer
switch 10, and removed. Specifically, breaker 16 is provided with an auxiliary
microswitch (used elsewhere for powering a light for a remote panel to
indicate position
of the breaker, depending upon how the microswitch is wired), in the form of a
single-
pole, double-throw (SPDT) switch 15 built into the circuit breaker, and
operated in slave
fashion by the main circuit breaker handle. When the utility circuit breaker
16 is flipped
to "ON", then microswitch 15 opens, so that current to pilot light 20 is cut
off. One of
ordinary skill in the art of electrical circuit design may substitute circuit
breakers from
other manufacturers, which also provide optional microswitches, for those
described
hereinabove, without departing from the scope of the invention.
[0107] Fig. 3 is a schematic illustration of the circuitry of a two-pole
traffic signal
transfer switch. To the extent that two-pole traffic signal transfer switch
10' is provided
with components having identical, similar or analogous structures and/or
functions as
that of single pole transfer switch 10, like reference numerals, augmented by
a prime C)
and, as necessary, letters, will be employed. The circuitry of transfer switch
10' differs
from that of transfer switch 10 primarily in that two breakers (14'a, 14'b and
16'a, 16'b)
are provided for each of the generator and utility power circuits, mostly for
enabling
larger voltage loads to be supplied, e.g., up to 250 volts for the two-breaker
transfer
switch 10', versus up to 125 volts for the single pole transfer switch 10.
Alternatively,
breakers 14'a, 14'b and 16'a, 16'b may be formed by two two-pole breakers,
wherein
one side of one of the two-pole breakers is provided with a microswitch, such
as may
be commercially obtained from Carling Technologies, as mentioned above.
Lockout
mechanism 18' will be provided so as to cover the (usually interconnected)
switch
handles of either circuit breakers 14'a and 14'b, or 16'a and 16'b. Pilot
light 20' and
associated circuit breaker 22' will be connected to one or the other of
circuit breakers
16'a, 16'b (having a microswitch 15'), again, to indicate when there is power
available
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in the utility power circuit, when the utility power circuit breakers are in
their respective
"OFF" positions.
[0108] Fig. 4 is a schematic illustration of the circuitry of a
single-pole switched
neutral traffic signal transfer switch. To the extent that two-pole traffic
signal transfer
switch 10" is provided with components having identical, similar or analogous
structures
and/or functions as that of single pole transfer switch 10, like reference
numerals,
augmented by a double prime C) and, as necessary, letters, will be employed.
Transfer
switch 10" differs from the single-pole transfer switch 10, in that in
addition to
generator circuit breaker 14" and utility circuit breaker 16", neutral
generator breaker
24 and neutral utility breaker 26 are provided.
[0109] Fig. 5 is a perspective exploded view of an interlock
(lockout) device 28,
which may be employed with any of transfer switches 10, 10' or 10". Lockout
device 28,
which may be of the type commercially available from Carlingswitch, Inc. of
Plainville,
CT, incorporates two end caps 30, 32, which are attached (e.g., via machine
screws 34)
preferably to the front surface 33 of the inner faceplate of the transfer
switch (details of
the transfer switch housings to be discussed hereinafter), or to the faces of
the circuit
breakers themselves. Handle lockout 36 is configured to be slidingly inserted
onto pins
38, 40. Typical assembly would be to mount one end cap 30 to the transfer
switch,
then insert pins 38, 40 into cap 30. Lockout 36 is then slid onto pins 38, 40.
Finally,
remaining end cap 32 is fitted to the free ends of pins 38, 40, and fastened
to the
transfer switch face. Lockout 36 includes two webs 42, 44, extending normal to
the
faceplate, each of which has a notch 46, configured for providing clearance
for
accommodating the switch handle(s) of the generator or utility circuit
breakers, when in
their "OFF" (typically down) positions. The foregoing description represents
one
particular structure for a lockout device for side-by-side breaker switches.
Other lockout
structures may be employed, without departing from the scope of the present
invention.
[0110] Figs. 6 ¨ 9 illustrate views of the outside of a housing for a
transfer switch
unit, according to the present invention. In an embodiment of the invention,
housing 50
includes top 52 (with top face 53), sides 54 and 56, back 58, hinged front 60
(with front
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surface 61) and hinged bottom 62. Preferably, housing 50 may be fabricated
sheet
metal (e.g., rust-resistant steel or aluminum) which has been suitably cut or
stamped,
bent and molded, as desired. In an embodiment, top 52 may be formed from a
separate piece of material, apart from sides 54 and 56, and back 58, which may
be
formed from a single piece of metal, and suitably attached thereto, by any
suitable
method, such as welding.
[0111] Front 60 includes two side flanges 64, 66 which cover the
front edges of
sides 54, 56, when front 60 is in its down/closed position. Front 60 is
pivotably
connected to sides 54, 56, via, e.g., rivets 68 passing through side flanges
64, 66, and
sides 54, 56, respectively. Bottom 62 includes two side flanges 70, 72, which
fit inside
the bottom edges of sides 54, 56, when bottom 62 is in the up/closed position.
Front 60
does not simply pivot about rivets 68. Rather, rivets 68 pass through
elongated slots
(see Figs. 19, 20). Movement of front 60 first involves unlocking lock 86
(discussed
below), then sliding front 60 downwardly relative to sides 54, 56, and then
pivoting
front 60 upwardly relative to housing 50. Bottom 62 is pivotably attached to
sides 54,
56 also by suitable fasteners, e.g., rivets 68. Front 60 also includes a
bottom flange 74,
which covers the leading edge of bottom 62, when bottom 62 is in its up/closed
position. Top 52 includes downwardly extending flanges 76, 78, 80 and 82,
which cover
(or shield) the upper edges of sides 54 and 56, back 58 and front 60. By
providing
coverage for otherwise exposed edges, as described hereinabove, housing 50 is
constructed to be substantially rainproof, for ordinary weather conditions
that may be
encountered. If necessary, where rivets 68 are used to pivotably mount front
60,
additional protection in the form of rectangular seals 96 (preferably
fabricated
from a suitable plastic material, such as polycarbonate film) may be provided
to
cover the opening created by slots 102, 104 (see Fig. 19).
[0112] Housing 50 includes for security purposes key-operated lock
84, which
includes hook member 86, which engages behind flange 88 of bolt 90, in
faceplate 92.
The breaker switches shown positioned in faceplate 92 (e.g., Fig. 9) are shown
solely
by way of example, and not intended to limit the scope of the present
invention.
Faceplate 92 may also include a pilot light 94 (as described above), which may
be
CA 02615375 2007-12-14
physically positioned at any suitable location on faceplate 92. Alternatively,
pilot light 94
may be positioned on sides 54 or 56, or in top 52 (if suitable gasketing is
provided to
create a weatherproof interface between the pilot light and the surface of the
respective side or top).
[0113] Fig. 10 is a front elevation of the surface-mounted traffic signal
transfer
switch, in closed configuration. Fig. 11 is a side elevation, in section,
taken along line A-
A of Fig. 10. Fig. 12 is a top elevation, in section, taken along line F-F of
Fig. 10. Fig. 13
is a fragmentary front elevation, in section, taken along line E-E of Fig. 11.
Fig. 14. is an
enlarged detail of the housing of the surface-mounted traffic signal transfer
switch, of
detail J, shown circled in Fig. 11. Any internal structures illustrated
therein are shown
strictly by way of example, and the present invention is not intended to be
limited to
any specific combination or positioning of the internal electrical components
shown in
these figures.
[0114] Fig. 15 is a top, front, perspective view of the top 52,
sides 56 and 56 and
back 58 portions of the housing for the surface-mounted traffic signal
transfer switch.
Fig. 16 is a side elevation thereof.
[0115] Fig. 17 is a front elevation of the front cover for the
housing for the
surface-mounted traffic signal transfer switch, showing, in particular,
opening 100 for
receiving lock 86. Fig. 18 is a top plan view thereof. Fig. 19 is an inside
perspective
view thereof, showing slots 102, 104 (through which rivets 68 pass), which
permit
cover 61 to slide vertically, as well as pivot, relative to the sides, top and
back of the
housing 50. Fig. 20 is a side elevation thereof.
[0116] Fig. 21 is a perspective view of the faceplate 110, for the
surface-mounted
transfer switch. Fig. 22 is a front elevation thereof. Fig. 23 is a top plan
view thereof.
Fig. 24 is a side elevation thereof, and Fig. 25 is a rear fragmentary
elevation thereof.
Faceplate 110 includes front plate 112, bottom plate 114 for attaching the
generator
power inlet socket (not shown), side mounting flanges 116, 118, and bottom
mounting
flange 120. Side mounting flanges 116, 118 include notches 122, 124, which are
configured to pivotably engage suitably positioned pins or rivets, extending
inwardly
from the inside surfaces of sides 54, 56, so that faceplate 110 can hang on
and pivot
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around those pins or rivets, unless and until bottom mounting flange 120 is
releasable
attached (to permit access for maintenance purposes) to the inside surface of
back 58,
such as by bolts or machine screws.
[0117] Front plate 112 includes aperture 126, suitably dimensioned
for from 2 ¨ 4
circuit breakers to be aligned therewith and affixed, such as by machine
screws
(through bores 127), as well as apertures 128, 130 for the pilot light and
pilot light
circuit breaker, as described hereinabove. Bottom plate 114 includes aperture
132, for
receiving a generator power inlet socket, to be attached via suitable
fasteners into
bores surrounding aperture 132, as illustrated.
[0118] The surface-mounted transfer switch of the embodiment of Figs. 6 ¨
25 is
generally configured to be provided as an "after-market" piece of equipment,
to be
retro-fitted onto existing traffic signal controllers. To provide a traffic
signal transfer
switch which is to be integrated into the housing/cabinet of the traffic
signal controller
(for original installation), as well as to provide for a more streamlined or
aesthetic
appearance, and as well to provide for a transfer switch construction which is
less
susceptible to weather as well as tampering or vandalism, a flush-mounted
traffic signal
transfer switch is provided in the alternative embodiment of the present
invention, as
shown in Figs. 26 - 34. Apart from the structural details of the housing, the
electrical
components and connections will be the same as in the surface-mounted
embodiment
of Figs. 6 ¨ 25; therefore the electrical schematics of Figs. 1 ¨ 5 are
applicable to both
the surface-mounted and flush-mounted transfer switch configurations.
[0119] Flush-mounted transfer switch 200 is configured to be fitted
into an
aperture within the cabinet of a traffic signal controller, a portion of the
wall 300 of
which is shown in Figs. 29 - 31, such that the electrical components are
within the
interior of the traffic signal controller, as well as being surrounded by the
housing of the
transfer switch itself.
[0120] Flush-mounted transfer switch 200 includes housing 202,
gasket 204 (for
the interface between the traffic signal controller cabinet 300 and housing
202), hinge
206, cover 208, lock 210, face plate 212, housing mounting side flange 214,
housing
mounting bottom flange 216, housing mounting side flange 218, power inlet
power inlet
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220, breaker switches 222 covered by lockout mechanism 224, and locking bolt
226.
Between one leaf of hinge 206 and rectangular mounting frame 204 is vertically
extending housing mounting top flange 228 (shown in Fig. 28). Two face plate
mounting flanges 230 (one of which is shown in Fig. 28) extend inwardly from
opposing
side wall inside surfaces of housing 202, and are provided with suitable
fastener
apertures (or other means) for mounting face plate 212.
[0121] Housing 202 may be fabricated from suitable metal material
using any
suitable fabrication method, to produce a top wall, a bottom wall, two side
walls, and a
rear wall, and a front opening. Such a basic structure may be readily formed
and
fabricated by one of ordinary skill in the art, having the present disclosure
before them.
Rear wall 232 of housing 202 will have one or more suitably positioned
apertures (e.g.,
aperture 302) or knockouts, to provide required access to make the necessary
electrical
connections.
[0122] The outermost edges of housing 202, extend outwardly beyond
flanges
214, 216, 218 and 228. Cover 208 is provided with rearwardly extending flanges
234,
236, 238, 240, which cover the outermost edges of housing 202, to
substantially
preclude intrusion by water, dust, etc.
[0123] To provide transfer switch 200 with the required degree of
weatherproof
capability, without the need for gaskets, seals or other structures, housing
202 is
provided with water run-off channels, extending across the top edge of the
opening of
housing 202, and down along the side edges of the opening of housing 202, so
that
should any rainwater or snowmelt get past cover 208, or between hinge 206 and
flange
228, it will be directed to the sides and downwardly, and not back under the
top edge
of the opening, toward the face plate. These run-off channels (e.g., channel
242, Fig.
30) have J-shaped cross-sectional configurations. In an embodiment of the
invention
(see Fig. 32, not to scale), the horizontally extending run-off channel 242
and vertically
extending run-off channels 244, 246 are all originally formed as a single
elongated
member 241 having a 3-shaped cross-section, which is cut at two locations A
and B,
corresponding to the corners where the top edge of the housing opening meets
the side
edges of the housing opening, and then bent at those locations. Thus, flanges
214, 228
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and 218 are formed integrally with channels 242, 244 and 246. This results in
the
structure shown in Fig. 32, having rectangular gaps. However, in ordinary
usage, these
gaps are not believed to enable any significant infiltration of water toward
the interior
of transfer switch 200. Alternatively, the rectangular gaps may be filled with
a sealing
structure, such as silver caulk or a bead of welding material appropriate to
the metal of
the run-off channels, though using a bead of welding material is typically
more difficult
to maintain in position and fill the gap, compared to a metal caulking
material.
[0124] The use of the run-off channels is believed to provide for a
substantially
weatherproof construction, without requiring the use of elastomeric gaskets or
seals.
Member 241 is then spot welded to the outside of housing 202. As a 3-shaped
channel
is not believed required for the bottom of housing 202, flange 216 may simply
be
provided by a straight length of L-shaped material that is welded along the
outside of
the bottom wall of housing 202. Alternatively, a 3-shaped section may be
employed if
desired.
[0125] Figs. 35 - 68 illustrate another embodiment of the invention, in
which
flush-mounted transfer switch 400 is configured to be fitted into an aperture
within the
cabinet of a traffic signal controller 4 (see Fig. 61), in a manner similar to
that of the
embodiment of Figs. 26 - 34, such that the electrical components are within
the interior
of the traffic signal controller, as well as being surrounded by the housing
of the
transfer switch itself.
[0126] Flush-mounted transfer switch 400 includes housing 402, a
gasket 404
similar to gasket 204 (for the interface between the traffic signal controller
cabinet and
housing 402), hinge 406, cover 408, a lock (not shown, but may be similar to
lock
210), face plate 412, housing mounting side flange 414, housing mounting
bottom
flange 416, housing mounting side flange 418, power inlet power inlet 420,
breaker
switches 422 covered by interlock mechanism 424, and locking bolt 426. Between
one
leaf of hinge 406 and rectangular mounting frame 404 is vertically extending
housing
mounting top flange 428. Two face plate mounting flanges 430 (having L-shaped
cross-
sections) extend inwardly from opposing side wall inside surfaces of housing
402, and
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are provided with suitable fastener apertures (or other means) for mounting
face plate
412.
[0127] Housing 402 may be fabricated from suitable metal material
using any
suitable fabrication method, to produce a top wall, a bottom wall, two side
walls, and a
rear wall, and a front opening. Such a basic structure may be readily formed
and
fabricated by one of ordinary skill in the art, having the present disclosure
before them.
Rear wall 432 of housing 402 will have one or more suitably positioned
apertures (e.g.,
aperture 402) or knockouts, to provide required access to make the necessary
electrical
connections.
[0128] The outermost edges of housing 402, extend outwardly beyond flanges
414, 416, 418 and 428. Cover 408 is provided with rearwardly extending flanges
434,
436, 438, 440, which cover the outermost edges of housing 402, to
substantially
preclude intrusion by water, dust, etc.
[0129] As in the embodiment of Figs. 26 - 34, to provide transfer
switch 400 with
the required degree of weatherproof capability, without the need for gaskets,
seals or
other structures, housing 402 is provided with water run-off channels,
extending across
the top edge of the opening of housing 402, and down along the side edges of
the
opening of housing 402, so that should any rainwater or snowmelt get past
cover 408,
or between hinge 406 and flange 428, it will be directed to the sides and
downwardly,
and not back under the top edge of the opening, toward the face plate. These
run-off
channels (similar to channel 242) have 3-shaped cross-sectional
configurations. In an
embodiment of the invention, the horizontally extending run-off channel and
vertically
extending run-off channels (like channels 242, 244 and 246) are all originally
formed as
a single elongated member having a 3-shaped cross-section, which is cut at two
locations A and B, corresponding to the corners where the top edge of the
housing
opening meets the side edges of the housing opening, and then bent at those
locations.
Thus, flanges 414, 428 and 418 may be formed integrally with channels 442, 444
and
446. This results in the structure having rectangular gaps. However, in
ordinary usage,
these gaps are not believed to enable any significant infiltration of water
toward the
interior of transfer switch 400. Alternatively, the rectangular gaps may be
filled with a
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sealing structure, such as silver caulk or a bead of welding material
appropriate to the
metal of the run-off channels, though using a bead of welding material is
typically more
difficult to maintain in position and fill the gap, compared to a metal
caulking material.
[0130] In still another alternative embodiment, the structures
forming the
channels may be formed as separate components, which are then attached, e.g.,
via
welding, brazing, etc., to housing 402; however, the function of the resulting
channel
structures will be the same.
[0131] The use of the run-off channels is believed to provide for a
substantially
weatherproof construction, without requiring the use of elastomeric gaskets or
seals.
Member 241 is then spot welded to the outside of housing 402. As a J-shaped
channel
is not believed required for the bottom of housing 4021 flange 416 may simply
be
provided by a straight length of L-shaped material that is welded along the
outside of
the bottom wall of housing 402. Alternatively, a 3-shaped section may be
employed if
desired.
[0132] In order to further improve the weather-resistance of transfer
switch 400,
transfer switch 400 is provided with cover 408, which has a further cord
access opening
442 and cord access door 444. Cord access opening 442 comprises a notch formed
(e.g., by stamping, die-cutting, etc.) in cover 408, to provide an elongated
opening or
gap, which positioned to align with the location of power inlet 420. Cord
access opening
442 extends from a position on the interior of cover 408, outwardly, to an
edge region
of flange 438. Cord access door 444 is, in side elevation, an L-shaped member,
which is
pivotably mounted, relative to cover 408, via mounting tab 446, and hinge
structure
448 formed in mating portions of cord access door 444 and mounting tab 446,
with
hinge pin 450 joining the respective mating portions together. Mounting tab
446 is
attached to an inner surface of cover 408, above cord access opening 442. In
this way,
cord access door 444 is configured to pivot inwardly and upwardly relative to
cover 408.
Thus, when a power inlet cord and plug 452 is inserted into power inlet 420,
and cord
access door 444 has been pivoted upwardly, cover 408 may be closed completely
leaving only a small gap in the area surrounding and below power inlet cord
and plug
452.
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[0133] While cord access door 444 has been shown as being configured
for
upward/downward pivoting, in an alternative embodiment of the invention, the
cable
access door may be configured for pivoting movement around a vertical hinge.
Alternatively, it may be configured for sliding vertical or lateral movement.
In addition,
a biasing structure, such as a spring, may be provided to prompt the cord
access door
into a closed position, when a power inlet cord is not plugged into the
transfer switch.
[0134] Transfer switch 400 uses, in the illustrated embodiment, one
pair of
breaker switches 422, which are mounted in tandem (in which the pivot axes of
cooperating breaker switch handles are parallel), and not side-by-side (in
which the
pivot axes of cooperating breaker switch handles are coaxial, as in the
embodiment of
Figs. 26 - 34). One breaker will be associated with the power circuit between
the utility
and the load (e.g., household circuit), and the other breaker will be
associated with the
power circuit between the auxiliary generator and the load. If each breaker
422 is a
single pole breaker, it will typically have a single switch handle (as shown
in Fig. 60),
which is analogous to the switching arrangement of the embodiment of Fig. 2
hereinabove. If each breaker is a two-pole breaker or actually a pair of side-
by-side
tandem breaker sets (for accommodating two-phase circuits or a switched
neutral
circuit, respectively, as described relative to the embodiments of Figs. 3 and
4
hereinabove), then each breaker will have two side-by-side switch handles (as
seen in
Fig. 54, where two interlock members are provided). The utility and generator
breakers
will be oriented "facing away" from one another, so that the respective "ON"
positions
of the respective switch handles are "toward" the other adjacent breaker, and
the
"OFF" positions of the respective switch handles are "away" from the adjacent
breaker.
[0135] In order to prevent both breaker switches from being in the
"ON" position,
sliding interlock member(s) 424 are provided. Each interlock member 424 is, in
an
embodiment of the invention, a shallow U-shaped member, having a pair of
oblong
openings 454 positioned in the base of the "U". Each interlock member is then
slidingly
bolted to the face of the tandem breakers 422 between the handles of the
generator
and utility breakers, so that, as a result of the positioning of the openings
454, and the
orientation of the openings, when the interlock is positioned between the
respective
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switch handles of the adjacent utility and generator breakers, the switch
handles of
both breakers cannot physically be both in their respective "ON" positions.
Further, by
pushing on the switch handle of the breaker which is in the "OFF" position,
toward the
"ON" position for that switch handle, the interlock will push the handle of
the adjacent
breaker switch out of its "ON" position, before the other switch handle can
arrive at its
own "ON" position, thus establishing a "break before make" tandem breaker
switch
arrangement.
[0136] Traffic signal transfer switch 400 of the embodiment of Figs.
35 - 68
enables the switching between utility and generator power in a single
movement, as
compared to the illustrated embodiments of the traffic signal transfer
switches of Figs. 1
- 34, in which a first breaker must be flipped, to enable the lateral movement
of the
lockout device, to cover the now "OFF" breaker, and enable access to the
breaker which
is to be flipped to its "ON" position.
[0137] Fig. 61 illustrates a representative electrical wiring
schematic for a traffic
signal transfer switch for a single phase circuit, with no neutral breakers.
Transfer
switch 400 will be fitted into an aperture in the housing of traffic signal
controller 4, and
"pilot light" 450, which may be in the form of a LED light, is positioned on
the top or
other advantageous position, on the outside of the housing for traffic signal
controller 4.
As can be seen from the schematic of Fig. 61, pilot light 450 will only be
illuminated
when the breaker switch connected to the utility is in its "OFF" position, and
utility
power is actually available, to thus provide an indication, without having to
closely
approach traffic signal controller 4, or open the cover to traffic signal
transfer switch 4.
[0138] Figs. 69 - 84 illustrate an alternative rocker construction
which is
provided, to enable enhanced control over the transfer process. Many breakers
have
switch handles that have a wide actuation range; that is, e.g., a switch may
be in its
"OFF" position at 60 , but it may not reach its top dead center position (at
which point
the spring bias will flip over to drive the switch to its "ON" position) until
approximately
90 (perpendicular to the face of the breaker), and may not actually arrive at
its "ON"
position, until approximately 120 . With such breakers, it is usually not an
issue that the
"break" of one circuit will be accomplished (and the arc extinguished), long
before the
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other circuit connection is "made". However, some breakers have a much
narrower
actuation range, in that "ON", top dead center (flip-over point) and "OFF" are
all very
close to 900. Electrical codes typically require that the arc from the breaker
being
switched to "OFF" must be fully extinguished, before the arc begins for the
breaker
being switched to "ON". The arcs actually begin and end for a finite time
before and
after, respectively, a breaker switch arrives at its "ON" and "OFF" positions,
respectively.
[0139] The alternative breaker configuration of Figs. 69 - 84
provides for a
further added measure of control over the movements of the breaker switches,
so that
it is assured that the breaker being switched "ON" cannot be actuated or
brought close
to the arc initiation, before the arc from the breaker being switched to "OFF"
is fully
extinguished.
[0140] Interlock 536 includes rocker member 500, having interference
surfaces
502, outer cam surfaces 504 and inner cam surfaces 504; slide member 508,
having
web 510, end faces 512, notches 514 (for receiving rocker member 500), and
slot 516
(to permit slide member 508 to move back and forth); and mounting member 518,
having base 520, apertures 522, vertical flange 524 and aperture 526. Upon
assembly,
bolt 530 passes through washers 532 and 534, and is threaded into aperture
526, so
that while slide member 508 is free to move from side to side, rocker member
500 is
free to pivot, in a manner shown in Figs. 82 - 84.
[0141] Specifically, as "OFF" breaker switch handle 538 is pushed,
from left to
right, toward its "ON" position (see Fig. 82), handle 538 moves to the left
along outer
cam surface 504 until it encounters interference surface 502, and the left end
face 512
of slide member 508. Rocker member 500 cannot pivot, until/unless slide member
508
moves to the right, upon being pushed to the right by handle 538. In a
coordinated
movement, while slide member 508 moves to the right and rocker member 500
pivots
clockwise, the right end face of slide member 508 pushes handle 540 until it
reaches
top of its arc, sliding along the underside of right inner cam surface 506,
until right
interference cam surface, at which point, right breaker switch handle 540 is
free to
move to its fully "OFF" position, under the impetus of its spring bias. This
occurs, in Fig.
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83, long before left breaker switch 538 has yet reached the top of its arc,
and can move
to its "ON" position.
[0142] While this interlock construction is described with respect to
breakers
having the "tight" movement ranges where ON, OFF and top dead center are all
near
the 90 position, it can be readily modified to be used with other more
forgiving
breakers, simply by adjustment of the cam and interference surfaces, relative
to the
length and range of movement of the slider member, by one of ordinary skill in
the art
having the present disclosure before them, without departing from the scope of
the
invention.
[0143] The foregoing description and drawings merely explain and illustrate
the
invention, and the invention is not so limited as those skilled in the art who
have the
disclosure before them will be able to make modifications and variations
therein without
departing from the scope of the invention.
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LISTING OF ELEMENTS BY REFERENCE NUMERAL
2 utility power
4 traffic signal controller
6 traffic signal
8 portable power generator
10, 10', 10" traffic signal transfer switch
12 male power inlet
14,14', 14'a, 14'b, 14" circuit breaker
15 single-pole, double-throw switch
16, 16', 16'a, 16'b, 16" circuit breaker
18 interlock/lockout mechanism
20, 20' pilot light
22, 22' pilot light circuit breaker
24 neutral generator breaker
26 neutral utility breaker
28 interlock/lockout device
30 end cap
32 end cap
33 front surface
34 machine screws
36 handle lockout
38 pin
40 pin
42 web
44 web
46 notch
50 housing
52 top
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53 top face
54 side
56 side
58 back
60 hinged front
61 front surface
62 hinged bottom
64 side flange
66 side flange
68 rivet
70 side flange
72 side flange
74 bottom flange
76 flange
78 flange
80 flange
82 flange
86 lock
88 flange
90 bolt
92 faceplate
94 pilot light
96 seal
100 opening
102 slot
104 slot
110 faceplate
112 front plate
114 bottom plate
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116 side mounting flange
118 side mounting flange
120 bottom mounting flange
122 notch
124 notch
126 aperture
127 bore
128 aperture
130 aperture
132 aperture
200 flush-mounted transfer switch
202 housing
204 gasket
206 hinge
208 cover
210 lock
212 face plate
214 housing side mounting flange
216 housing mounting bottom flange
218 housing side mounting flange
220 power inlet
222 breaker switches
224 lockout mechanism
226 locking bolt
228 housing mounting top flange
230 face plate mounting flange
232 rear wall
234 flange
¨236 flange
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238 flange
240 flange
241 elongated member
242 channel
244 channel
246 channel
300 traffic signal controller cabinet/wall
302 aperture
400 traffic signal transfer switch
402 housing
404 gasket
406 hinge
408 cover
410 lock
412 face plate
414 housing mounting side flange
416 housing mounting bottom flange
418 housing mounting side flange
420 power inlet
422 breaker switch
424 interlock
426 locking bolt
428 housing mounting top flange
430 face plate mounting flange
432 housing rear wall
434 flange
436 flange
438 flange
440 flange
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442 cord access opening
444 cord access door
446 mounting tab
448 hinge structure
450 hinge pin
452 power inlet cord and plug
454 opening
456 pilot light
500 rocker member
502 interference surface
504 outer cam surface
506 inner cam surface
508 slide member
510 web
512 end face
514 notch
516 slot
518 mounting member
520 base
522 aperture
524 vertical flange
526 aperture
530 bolt
_
532 washer
534 washer
536 assembled interlock
538 breaker handle
540 breaker handle
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