Note: Descriptions are shown in the official language in which they were submitted.
CA 02591638 2007-06-13
UNITARY MEMBER WITH MULTIPLE OUTLETS HAVING
SURGE PROTECTION CIRCUITRY
FIELD OF THE INVENTION
This invention relates generally to wiring devices installed in boxes mounted
in
building walls, and more particularly to a device with a unitary body having
multiple
outlets which may be placed in two standard single boxes ganged together, and
which has
voltage surge protection circuitry.
BACKGROUND OF THE INVENTION =
It is currently possible to mount a duplex receptacle in a single wiring box
(called a
gem box) installed in the wall of a building. It is also possible to.mount two
duplex
receptacles side by side in two boxes joined together or in an enlarged box
which can
accept two duplex receptacles. In a conventional arrangement, two duplex
receptacles are
wired together to enable them to function as four receptacles.
A need exists for a single unit having more than two receptacles or sockets
that can
be mounted in a single box. A need also exists for a single unit having more
than four
receptacles or sockets that can be mounted in a double box and does not
require separate
interconnecting wiring.
Furthermore, it is highly desirable to provide protection in the receptacle
against
circuit faults (such as ground faults) and/or transient voltage surges. A wide
variety of
devices (e.g. personal computers, monitors, voice and data communication
equipment)
require such protection. Often a protective device, including one or more
receptacles, is
plugged into a conventional receptacle, and the sensitive equipment is then
plugged into the
receptacles of the protective device. The protective device could include a
ground-fault
circuit interrupter (GFCI) to detect a ground fault condition and interrupt
power by
breaking a connection between the line side and the load side; a transient
voltage surge
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CA 02591638 2007-06-13
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suppressor (TVSS) to interrupt power when a spike in voltage is detected; or
any of similar
components.
It is highly desirable to integrate protective devices, such as a GFCI or
TVSS, into a
receptacle installed in a wall. Furthermore, it is desirable to provide four
or more outlets in
such a receptacle mounted in a double box.
SUMMARY OF THE INVENTION
There is disclosed a single unit triplex receptacle having three sockets
(outlets) that
can be mounted in a single box, does not require separate interconnecting
wiring and can be
covered by a single wall plate. In addition, there is disclosed a single unit
sixplex
receptacle having six sockets that can be mounted in a double box, does not
require separate
interconnecting wiring and can be covered by a single wall'plate. The single
unit triplex
receptacle and the single unit sixplex receptacle both have uninterrupted top
members. The
single unit triplex receptacle and the single unit sixplex receptacle
optionally may have an
isolated ground construction.
There is also disclosed a unitary body having both a plurality of outlets and
protection circuitry integrated therein. In an embodiment, a visual signal
indicates normal
operation of the outlets. The protection circuitry may be a transient voltage
surge
suppressor (TVSS), a ground-fault circuit interrupter (GFCI), and/or an
integrated circuit
breaker. In another embodiment, a second indicator device provides an audible
signal in
accordance with failure of the protection circuit.
According to a particular embodiment of the invention, a unitary body (a
sixplex
receptacle) includes six outlets and the protection circuitry is a transient
voltage surge
suppressor (TVSS). The visual signal is provided by an LED, and an alarm
buzzer sounds
when the TVSS is disabled.
In other embodiments, three, four or five outlets are provided in a unitary
body with
one or more openings for making connection to a variety of low-voltage devices
(voice,
data, cable TV, etc.).
=
The foregoing has outlined, rather broadly, the preferred features of the
present
invention so that those skilled in the art may better understand the detailed
description of
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the invention that follows. Additional features of the invention will be
described
hereinafter that form the subject of the claims of the invention. Those
skilled in the art
should appreciate that they can readily use the disclosed conception and
specific
embodiment as a basis for designing or modifying other structures for carrying
out the same
purposes of the present invention and that such other structures do not depart
from the spirit
and scope of the invention in its broadest form.
BRIEF DESCRIPTION OF THE DRAWINGS
Other aspects, features, and advantages of the present invention will become
more
fully apparent from the following detailed description, the appended claims,
and the
accompanying drawings in which similar elements are given similar reference
numerals:
FIG. 1 is an isometric view of a single unit triplex receptacle which can be
mounted
in a single box and a wall plate in accordance with the principles of the
invention.
FIG. 2 is an exploded view of the single box, alignment plate, triplex
receptacle and
wall plate in accordance with the principles of the invention.
FIG. 3 is an exploded view of the alignment plate, triplex receptacle and wall
plate =
illustrating in detail the captive member attached to the end of the ground
strap of the
receptacle.
FIG. 4 is an exploded view of the triplex receptacle.
FIG. 5 is a view looking at the top member 72 from bus 80 as shown in FIG. 4.
FIG. 6 is a view looking into the intermediate member 74 from bus 80 as shown
in
FIG. 4.
FIG. 7 is a view looking at the bottom of intermediate member 74 from bus 82
as
shown in FIG. 4.
FIG. 8 is a view looking at the top of bottom member 76 from bus 82 as shown
in
FIG. 4.
FIG. 9 is a front perspective view of the wall plate.
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FIG. 10 is a view along the line B-B from edge L to edge K of FIG. 9.
FIG. 11 is a side elevation sectional view of the wall plate taken along the
line 4-4
of FIG. 9.
FIG. 12 is a side elevation, partially is section of the wall plate as shown
in FIG. 9
installed on a ground strap and alignment plate.
FIG. 13 is a fragmentary enlarged side elevation of the latching pawl of the
captive
member engaging the saw-tooth rack of the wall plate.
FIG. 14 is a fragmentary, enlarged side elevation in section of the wall plate
and tab
of the alignment plate to indicate how the two components can be separated
following
latching.
FIG. 15 is an exploded view of a ganged box, a wall plate and alignment plate
for a
receptacle having four, five or six outlets, in accordance with embodiments of
the
invention..
FIG. 16 is an isometric view of a unitary body having six outlets (a single
unit
sixplex receptacle) and a wall plate in accordance with an embodiment of the
invention.
FIG. 17 is an exploded view of the alignment plate, a sixplex receptacle and a
wall
plate.
FIG. 18 is an exploded view of the sixplex receptacle.
FIG. 19 is a plan view of a sixplex receptacle including a TVSS with a visual
indicator and audible alarm, in accordance with an embodimentof the invention.
FIG. 20 is an exploded view of a sixplex receptacle including a TVSS in
accordance
with an embodiment of the invention.
FIG. 21 shows details of a middle housing assembly of a sixplex receptacle
according to an embodiment of the invention.
FIG. 22 shows the underside of a face cover assembly of a sixplex receptacle
according to an embodiment of the invention.
FIG. 23 shows a line bus assembly used in a sixplex receptacle according to an
embodiment of the invention.
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FIG. 24 shows a neutral bus assembly used in a sixplex receptacle according to
an
embodiment of the invention.
FIG. 25 shows a ground bridge assembly used in a sixplex receptacle according
to
an embodiment of the invention.
FIGS. 26A-26E show a ground strap and ground clip assembly used in a sixplex
receptacle according to an embodiment of the invention.
FIG. 27 is a schematic diagram of a TVSS device used in a receptacle according
to
an embodiment of the invention.
FIGS. 28A-28C are side, top and perspective views, respectively, of a TVSS
device
constructed according to FIG. 27.
FIG. 29 is a plan view of a receptacle having both outlets and ports for low
voltage
devices and including a TVSS with a visual indicator and audible alarm, in
accordance with
another embodiment of the invention.
FIGS. 30A-30J illustrate steps in the assembly of a sixplex receptacle unit
including
a printed circuit board (PCB) with a TVSS, in accordance with another
embodiment of the
invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to Figure 1, there is illustrated a unitary body configured as a
triplex
receptacle 20, located within a wall plate 22, in accordance with the
principles of the
invention. Triplex receptacle 20 is intended for 15 Amp. 125 V AC and
according to
NEMA specification 5-15R, where each individual receptacle has two slot
openings 24 and
26 for receiving the flat blades of a suitable plug and a semi-circular ground
blade opening
28. The opening 26 is larger than the opening 24 so that a two blade plug can
only be
inserted in one way to maintain the correct electrical polarization. The
larger slot is
connected to the neutral conductor and by maintaining the correct
polarization, the external
metal parts of appliances such as toasters, TV's etc. can be grounded through
the neutral
conductor. The presence of the semi-circular ground blade makes insertion with
the wrong
polarity impossible.
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CA 02591638 2007-06-13
The outlets in triplex receptacle 20 are arranged so that two of the outlets
have blade
openings 24 disposed along a set of parallel lines, while the third outlet has
a blade opening
24 disposed substantially at right angles to those parallel lines. It will be
appreciated that
such a triplex receptacle may also be configured having its three outlets
according to
NEMA specifications 5-20R, 6-15R or 6-20R.
Referring to Figure 2, there is shown an exploded view of a single box 30, a
single
unit triplex receptacle 44, an attachment plate 42 and cover plate 22.
Initially, in the field, a
suitable aperture is cut into a wall to provide access for mounting box 30 to
a stud 32, or to
permit installation of a suitable box to an adjacent stud or directly to the
material of the wall
(such as plasterboard). The box 30 is a single gem box. The box 30 is made of
metal or
plastic, has one or more openings in its sides or back to permit the
introduction of electrical
cables into the interior of the box 30 and has mounting means 34 to permit the
box to be
anchored to the adjacent stud 32. The box supports pairs of mounting ears 36.
Each
mounting ear contains a threaded aperture 38 to which can be fastened the
mounting screws
44 of the triplex receptacle 20. In the normal order of assembly, electrical
cables are passed
through knock out openings 40 to the interior of the box. The ends of the
electrical cables
are stripped of insulation and attached to contacts on the side or rear of the
body of the
receptacle 20. After the electrical cables are attached to contacts on the
side or rear of the
body of the receptacle, the body of the receptacle is inserted into the
alignment plate 42 and
is then pushed into the box until the back of the alignment plate 42 touches
the top of the
box 30. The receptacle and the alignment plate are now attached to the box by
means of
screws 44 that pass through clearance openings such as elongated slots 46 in
the alignment
plate 42 and are threaded into openings 38 in ears 36. Thereafter, wall plate
22 is placed
over the assembly of the receptacle 20, the alignment plate 42 and the box 30.
Referring to Figure 3, the alignment plate 42, which can be composed of metal
such
as cold rolled steel of the like, supports a centrally located rectangular
opening 48 sized to,
accept the body of the receptacle 20. Centrally located at each end of the
rectangular
opening and contiguous with the opening 48 are two clearance openings 46 which
provide
clearance for mounting screws 44 which are used to secure the receptacle 20
and alignment
plate 42 to the box. Located beyond the outer edge of each clearance opening
46 is an
alignment pin 50. The alignment pins are provided to engage openings 66
located in
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CA 02591638 2007-06-13
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captive members 52 which are attached to the ends or lugs 54 of the ground
strap 56 by
screws, rivets etc. Alignment plate 42 supports a tab 58 that projects outward
from the
lower end and is used to facilitate removal of a wall plate from around the
receptacle. The
outside dimensions of the alignment plate are such that it can extend beyond
at least one
dimension of the box to which the receptacle and plate is attached. It is to
be noted that the
alignment plate 42 illustrated in Figure 3 is for the single unit triplex
receptacle here
disclosed.
Continuing with Figure 3, there is illustrated a new improved single unit
triplex
receptacle 20 which can fit within a single box. Receptacle 20 supports a
ground strap
having a lug 54 at each end which is attached to captive members 52 by means
of screws,
rivets, spot welds or the like. Each lug 54 can be rectangular in shape and
contains two
openings 60, 62. Opening 60 is a clearance opening for mounting screw 44 which
is
normally provided by the manufacturer of the receptacle for attaching the
receptacle to the
box. The distance between centers of openings 60 in lugs 54 on the ground
strap is equal to
the distance between the centers of openings 38 in ears 36 of box 30 to allow
mounting
screws 44 in openings 60 to engage and be held captive by the threaded
openings 60.
Clearance openings 46 in the alignment plate 42 are clearance openings for
mounting
screws 44. Openings 62 in the lugs 54 are clearance openings for alignment
pins 50 of
alignment plate 42.
Continuing with Figure 3, captive member 52 can be composed of phosphor
bronze,
spring brass, spring steel or the like and is securely attached to lugs 54.
Captive member 52
contains a first opening 64 which is aligned with opening 60 in the lug and a
second
opening 66 which is aligned with opening 62 in the lug. Opening 60 can be
oval, square or
rectangular in shape to allow mounting screw 44 to be positioned off center. A
centrally
located projection 68 extends into opening 64 and is bent at a slight downward
angle
toward the body of the switch to engage and hold loosely captive the threaded
body of
mounting screw 44. Engagement of projection 68 with screw 44 provides a good
electrical
connection between the ground strap of the receptacle, the screw 44 and the
box to insure
that the receptacle is connected to ground. Screw 44, which passes through
opening 64 of
the capture member 60 of the lug and opening 46 of the alignment plate 42,
threads into
opening 38 of the box to hold the receptacle and alignment plate to the box.
Openings 64
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CA 02591638 2007-06-13
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and 60 are sized to allow the screw 44 to move laterally to compensate for
slight
misalignments that may occur. Opening 66 in captive member 52 is substantially
circular
and supports three inwardly projecting members bent upward at a slight angle
away from
the receptacle body. The ends of the three projecting members form an opening
slightly
smaller than the diameter of alignment pins 50 on alignment plate 42 and are
designed to
flex slightly as the alignment pin is inserted into opening 66 from the rear.
When the
alignment pin is inserted into opening 66, the three ends of the projecting
members
frictionally engage and hold captive the alignment pins to prevent the easy
removal of the
alignment pins from the captive member. Located at the end of captive member
52 are two
tabs 70. The end of each tab has a double bend similar to a 360 degree sine
curve and are
provided to hold the wall plate in place by engaging indents on the inside
ends of the cover
plate.
Referring to Figure 4, there is illustrated an exploded view of the single
unit triplex
receptacle 20. Receptacle 20 has a top member 72, an intermediate member 74, a
bottom
member 76 and a ground strap 78. Positioned between the top member and the
intermediate member is bus 80 having three contacts, one for each of the three
receptacles,
for receiving the flat blade of a plug which is to be connected to the neutral
conductor.
Positioned between the intermediate member and the bottom member is bus 82
having three
contacts, one for each of the three receptacles, for receiving the flat blade
of a plug which is
to be connected to the phase conductor. Positioned below the bottom member 76
is the
ground strap 78 having three ground contacts, one for each of the three
receptacles, for
receiving the ground blade of a plug.
Figure 5 is a plan view of the bottom of top member 72 looking up from bus 80;
Figure 6 is a plan view of the top of intermediate member 74 looking down from
bus 80;
Figure 7 is a plan view of the bottom of intermediate member 74 looking up
from bus 82;
and, Figure 8 is a plan view of the bottom member 76 looking down from bus 82.
Returning to Figure 4, bus 80 supports a screw terminal 92 for receiving the
neutral
wire conductor and three contacts for receiving flat blades of a plug.
Intermediate member
74 is composed of insulating material having on its top surface various
partitions selectively
spaced to provide separate compartments some of which contain openings to
provide a
serpentine passageway for receiving bus 80. Bus 80 is shaped to follows a
serpentine path
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CA 02591638 2007-06-13
around and through the various partitions in the top of intermediate member 74
to position
the commonly connected three contacts in compartments 94, 96, 98 and screw
terminal 92
in opening 100. Referring to Figs. 5 and 6, when intermediate member 74 is
assembled to
top member 72, the three contacts of bus 80 are located in compartments 106,
94 and 96 of
intermediate member and below the openings 26 of each of the three receptacles
in the top
member. Referring to Figure 6, the bottom surface of intermediate member 74 is
substantially flat and supports openings 102, 104, and 106 for receiving
contacts of bus 82
from the bottom of the member. Intermediate member 74 also contains through
openings
91, 93 and 95 for receiving ground contacts on the ground strap 78. Bus 82
supports a
screw terminal 110 for receiving a wire conductor. Bus 82 follows a serpentine
path along
the flat bottom surface of intermediate member 74 to position the commonly
connected
contacts in openings 102, 104, and 106 and screw terminal in opening 108. Bus
80 is
electrically isolated from bus 82 by the insulating bottom surface or floor of
intermediate
member 74.
Bottom member 76 is adapted to be attached to the bottom of intermediate
member
74 and supports openings 112, 114 and 116 for receiving ground contacts.
Referring to
Figure 4, when the top, intermediate and bottom members are assembled
together, openings
116, 114 and 118 in the bottom member are aligned with openings 95, 93 and 91
respectively in the intermediate member to position the ground contacts behind
the ground
openings 28 in the top member. In a similar manner, when the receptacle is
assembled,
openings 104, 106 and 102 are aligned with openings in the top member to
position the
contacts of bus 82 beneath openings 26 in the top member. Ground strap 78 is
composed of
conductive material such as iron or steel and is electrically Connected to and
supports three
ground contacts. Ground strap 78 also supports screw terminal 124 for
connecting the
receptacle ground contacts to an electrical ground.
To assemble the triplex receptacle, the bus 80 and its contacts is placed in
the top of
intermediate member 74, the bus 82 and its contacts is placed on the bottom of
intermediate
member, and the intermediate member is then assembled to top member. The
bottom
member 76 is then positioned next to the bottom of intermediate member over
the bus 82
and the ground strap is coupled to the assembled parts. In the assembled
receptacle, the
contacts which are located behind the openings 24 of each socket are connected
to a
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CA 02591638 2007-06-13-
common bus; the contacts located behind openings 26 of each socket are
connected to a
common bus; and the contacts located behind the openings 28 of each socket are
connected
to the ground strap of the receptacle.
To connect the single unit receptacle having three sockets to a box, the
electrical
cables in a box are stripped of insulation and are attached to terminals on
the side or back of
the receptacle. The alignment plate is then attached to the receptacle from
the back.
Initially, after the wires are attached to the receptacle, the alignment plate
is held vertically
in front of the receptacle and parallel to the receptacle. The top of the
receptacle is now
tilted downward from its vertical position until it is horizontal and, while
in its horizontal
position, the end of the receptacle that was initially up is passed through
opening 48 of the
alignment plate which is in its vertical position. After the receptacle is
passed completely
through the opening of the alignment plate, the receptacle is tilted back to
its initial vertical
position. At this time the alignment plate and the receptacle are now moved
toward each
other until the front face of the alignment plate contacts the back face of
the lugs 54 on the
ends of the ground strap. As the alignment plate approaches the lugs,
alignment pins 50 of
the alignment plate pass through openings 62 in the lugs and enter openings 66
in captive
members 52. As the alignment pins enter the openings 66, they force the
upwardly bent
projections to spread apart to allow the alignment pins to fully enter
openings 66. The ends
of the upwardly bent projections engage and hold captive the alignment pins
50. The
receptacle, which is now attached to the alignment plate and is connected to
the electrical
wires, is inserted into the box. As the receptacle is inserted into the box,
screws 44 located
in openings 64 of the captive member and clearance opening 46 in alignment
plate are
aligned with and threaded into openings 38 of the box to hold both the
alignment plate and
receptacle to the box. The head of screw 44 is larger than opening 64 and 60
and, therefore,
holds receptacle 20 and alignment plate 42 captive to the box.
The wall plate is now placed over the receptacle. Referring to Figure 3, each
captive member 52 supports at least two projecting latching pawls 70. Each
pawl has a
double curve similar to a three hundred sixty degree sine curve. After the
receptacle 20 is
attached to the alignment plate 42, .the two latching pawls 70 of captive
member 52 are
located on either side of a tab 58 on the alignment plate. Tab 58 functions as
a tool pivot
point to allow an attached wall plate 22 to be removed from around the
receptacle. A slot
CA 02591638 2007-06-13
in the lower edge of the wall plate 22 provides access for the insertion of a
small fiat tool
such as a screw driver to facilitate removal of the wall plate from the
receptacle.
The width of the face of the single unit receptacle having three sockets is
approximately 60% of the width of the cover plate (see Figure 9) along the
horizontal axis
and approximately 53% of the length of the wall plate along the vertical axis.
For the
triplex receptacle, the wall plate is substantially 4.92 inches in length by
3.28 inches in
width and has a rectangular opening for receiving the receptacle that is
substantially 2,82
inches in length by 1.83 inches in width. The width of the wall plate varies
depending upon
how many boxes are ganged together and the number of triplex receptacles that
are to be
located in side-by-side relationship in boxes that are ganged. The front
surface of the wall
plate has a complex contoured shape where the edge of the wall plate at the
rectangular
opening for a triplex receptacle is further from the wall than the outer edge
of the cover
plate. More specifically, referring to Figure 10, there is illustrated a view
along the line B-
B of Figure 9 of a portion of the front surface, along the horizontal
centerline, between
point K, the outer right edge, and point L, the inner edge of the opening for
the receptacle.
As illustrated in Figure 10, the surface lies between two profile boundaries
0.002 inches
apart, perpendicular to datum plane A, equally disposed about the true profile
and
positioned with respect to a datum plane. The basic dimensions and the profile
tolerance
establish a tolerance zone to control the shape and size of the surface. The
surface is 0.726
inches in length. Within that length, a contour is defined by the dimensions
of equidistant
points which are 0.0726 inches apart. Each dimension indicates that point's
distance to
define datum plane A, the back (flat) surface of the cover plate, which begins
at point K.
Moving from left to right, the dimensions increase from 0.228 to 0.287 inches.
This
progression indicates a contour of increasing height, positive first
differential, when the
points are connected by individual splines. The points are not connected by a
single arc and
the rate at which the contour height increases is not constant. The rate of
height increase of
the individual splines decreases from left to right, and the second
differential of the contour
is negative. That is, the difference between the first point's distance
dimension and the
second is larger than the difference between the second and the third, etc.
Thus, the surface
has a contour of positive first differential and negative second differential,
comprised of a
combination of splines drawn between points of varying distance from a datum
plane. This
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description substantially describes most of the wall plate's contours for
sections along lines
10A-A, D-D, and E-E of Figure 9. Section along line C-C, which runs along the
vertical
centerline of the wall plate defines a surface having a positive first
differential and zero
second differential, comprised of a combination of splines drawn between
points of varying
distance from a datum plane. This contour has zero second differential because
the rate of
height increase of the individual splines is constant; the difference between
any two
sequential point dimensions is at a uniform spacing of 0.0037 inches.
The contour along the width of the front of the triplex receptacle face is
flat and the
contour along the length of the triplex receptacle has a constant radius of
substantially
30.724 inches. The shape of the front of the receptacle face allows for the
proper seating of
an inserted plug. The wall plate has no exposed mounting screws or other.
visible metal
hardware. When the wall plate is attached to the receptacle, the only visible
parts are the
wall plate 22 and the receptacle.
Referring to Figs. 11-14, placed in the bottom end wall 200 of wall plate 22
is a slot
202 which provides access to the tab 58 on the alignment plate as seen in
Figure 14. A
small, flat tool blade such as a screw driver blade 204 is moved through slot
202 in end wall
200 to contact both the outer surface of tab 58 and the back wall of slot 202.
By moving
the blade 204 in a counterclockwise direction using the back wall of slot 202
as a fulcrum,
the force applied to tab 58 will separate wall plate 22 from the receptacle.
To attach wall
plate 22 to the receptacle, the pawls 70 of captive member 52 are made to
engage saw-tooth
shaped racks 206 located on the inner surfaces of the end walls 200 of wall
plate 22. There
are two racks on the top and bottom end walls 200. Each rack 206 contains a
number of
saw-tooth shaped teeth 208 each having an inclined front face 210 and a
vertical back face
212. As seen in Figure 13, as latching pawl 70 engages the inclined front face
210, the
pawl deflects in a counterclockwise direction and moves past the tip of the
first tooth 214.
Once pawl 70 is past the tip of tooth 214, it can return to its initial
position and take a
position between the vertical back face 212 of first tooth 214 and the
inclined front face 210
of a second tooth 214. This operation can be repeated as many times as needed
to position
the bottom edges of wall plate 22 as close to the wall as possible. Since each
of the racks
206 and pawls 70 are independently operated, it is possible to locate the wall
plate 22 to
closely follow the wall contour, even when the wall is not flat. This ability
to follow the
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CA 02591638 2007-06-13
wall contour is even more appreciated where the wall plate 22 is large, such
as with a wall
plate that is required to cover four ganged boxes where a receptacle is
located in side by
side relationship with switches.
Once the latching pawl 70 returns to its original position, any attempt to
dislodge
the wall plate 22 from the pawl 70 which is mechanically attached to the
receptacle
becomes difficult. However, since tool 204 can apply a great deal of force to
tab 58, it is
possible to separate the pawl 70 from engagement with the teeth and thus the
receptacle
from the cover plate.
Referring to Figure 15, there is illustrated two boxes joined together to
provide a
double box, an alignment plate 358 and a wall plate for two triplex
receptacles positioned
side by side in the double box. It is to be noted that there is no partition
or dividing
member located in the wall plate opening to separate the two receptacles.
Accordingly, the
double box 360 may be viewed as a single housing for the receptacle. In
different
embodiments of the invention, the receptacle may have four, five or six
outlets
accommodated in the single housing. In an embodiment, a sbcplex receptacle
having six
outlets is provided in the box. The sixplex receptacle may be formed from two
triplex
receptacles arranged symmetrically, as detailed below.
Two triplex receptacles can be placed in the double ganged box 360 (shown in
Figure 15), which is made up of two single ganged boxes and joined by
fasteners 362
extending through the threaded apertures 364 of two joining ears 166.
Alignment plate 358
has a single opening 360 for receiving two triplex receptacles, four clearance
openings 372
and four alignment pins 370.
Looking at the wall plate 338, there can be three racks 346 on the interior of
the top
and bottom end walls 348 for receiving four pawls where the center rack is
sized to receive
one pawl from each receptacle. Also, there can be two tabs 320, one for each
triplex
receptacle, which will be accessible via slots 352 in the bottom end wall 348
of wall plate
338. Because of the independent operation of the pawls of the captive members
with their
respective racks 346, the wall plate 338 is able to compensate somewhat for
lack of flatness
of the wall around the receptacle.
Referring to Figure 16, there is illustrated an isometric view of a unitary
body
configured as a receptacle 420 having six outlets, in accordance with the
principles of the
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CA 02591638 2007-06-13
invention. As with the triplex receptacle, the sixplex receptacle 420 is
intended for 15
Amp. 125 V AC and according to NEMA specification 5-15R, where each individual
receptacle has two flat blade openings 424 and 426 for receiving the flat
blades of a suitable
plug and a semi-circular opening 428 for a ground blade. The opening 426 is
larger than
the opening 424 so that a two blade plug can only be inserted in one way to
maintain the
correct electrical polarization. The larger slot is connected to the neutral
conductor and by
maintaining the correct polarization, the external metal parts of appliances
such as toasters,
TV's etc. can be grounded through the neutral conductor. The presence of the
ground blade
makes insertion of a plug with the wrong polarity impossible.
Referring to Figure 17, there is illustrated an exploded view of the sixplex
receptacle, and the alignment plate 358 and the wall plate 338 for the sixplex
receptacle.
Initially, during installation, a suitable aperture is cut into a wall to
provide access for two
boxes (see Figure 15) joined together to form a single double size box mounted
to a stud, or
to permit installation of a suitable box to an adjacent stud or directly to
the material of the
wall (such as plasterboard). The double box consists of two single gem boxes
joined
together. The double box is large enough to accept a single unit sixplex
receptacle having
six outlets as disclosed herein. The box is made of metal or plastic, has one
or more
openings in its sides or back to permit the introduction of electrical cables
into the interior
of the box and has mounting means to permit the box to be anchored to an
adjacent stud.
The box supports pairs of mounting ears each having a threaded aperture to
which is
fastened the mounting screws of the receptacle 420. During assembly,
electrical cables are
passed through knock out openings to the interior of the box. The ends of the
electrical
cables are stripped of insulation and attached to contacts on the side or rear
of the body of
the receptacle 420. After the electrical cables are attached to contacts on
the side or rear of
the body of the receptacle, the receptacle is attached to the top side of the
alignment plate
358, and the body of the receptacle is pushed into the box until the alignment
plate 358
touches the top of the box. At this time, the receptacle and the alignment
plate are attached
to the box by means of screws 444 that pass through clearance openings such as
elongated
slots 446 and threaded into openings in ears of the box to mount receptacle
420 to the box.
Thereafter, wall plate 338 is placed over the receptacle 420, the alignment
plate 358 and the
box.
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CA 02591638 2007-06-13
Referring to Figure 17, the alignment plate 358 and the wall plate 338 shown
is for
use with a single unit receptacle having six sockets and are similar to the
aligmnent plate
and wall plate shown in Figure 15. Continuing with Figure 17, there is
illustrated a new
improved single unit receptacle 420 having six sockets which can fit within a
double box.
The sixplex receptacle 420 supports two ground straps 456 each having a lug
454 at each
end which provides support for captive members 452 by means of screws, rivets,
spot welds
or the like. Each ground strap 456 with its captive member 452 is similar to
the ground
strap and captive member shown in Figure 3 and, therefore, in the interest of
brevity, the
details of their construction and operation will not again be repeated.
Referring to Figure 18, there is illustrated an exploded view of a sixplex
receptacle
having a top member 472, intermediate member 474 consisting of two sections
469, a
bottom member 476 and a ground strap 484 consisting of two sections 486 and
488.
Positioned between the top member 472 and the two intermediate members is bus
480
having a six contacts, one for each of the six sockets in the top member for
receiving the
flat blade of a plug which is to be connected to a neutral conductor.
Positioned between the
two intermediate members 474 and the bottom member 476 is bus 482 having six
contacts,
one for each of the six sockets for receiving the flat blade of a plug which
is to be
connected to a phase conductor. Positioned below the bottom member 476 is the
ground
strap 484 consisting of two sections 486, 488 which are electrically connected
together and
support six ground contacts, one for each socket for receiving the ground
blade of a plug
which is to be connected to ground.
The top member 472 of the sixplex receptacle is a single structure having, on
its top
surface, six sockets each of which contains three openings, one for the phase
line, one for
the neutral line, and one for the ground line. The top member of the sixplex
receptacle can
be considered to be two top members 72 of the triplex receptacle (see Figure
4) joined
together to form a single member. Thus, the bottom surface of the top member
472,
looking up from bus 480 is similar to the bottom surface of two top members
joined
together to form a single unit and, thus, supports partitions selectively
positioned to provide
compartments which communicate with the openings of the various sockets in the
top
surface and provides passageways for accommodating the bus 480 having six
contacts.
Thus, the top member 472 of the sixplex receptacle can be considered to be two
top
CA 02591638 2007-06-13
members of the triplex receptacle shown in Figure 4 positioned side by side
and molded as
a single unit. Continuing with Figure 18, intermediate member 474 consists of
two
individual sections 469 each of which is similar to intermediate section 74 of
the triplex
receptacle shown in Figure 4.
Bus 480 consists of two sections 483 and 485 electrically connected via a
conductive bridge where each section is similar to bus 80 of the triplex
receptacle shown in
Figure 4. Each section of bus 480 supports a screw terminal 492, either of
which can be
connected to a wire conductor. The bus is also connected to six contacts for
receiving the
flat blades of a plug which are to be connected to the neutral conductor. Each
section 469
of intermediate member 474 is similar to intermediate member 74 of the triplex
receptacle
and, thus, the top of each section 469 contains various partitions selectively
spaced to
provide a serpentine passageway for receiving the bus 480 having six contacts.
More
specifically, bus 480 follows a serpentine path around and through the various
partitions in
the top of sections 469 to position the commonly connected contacts in
openings which
communicate with openings in the top member 472 designated to receive the flat
blade of a
plug which is to be connected to the neutral conductor 494. As with
intermediate member
74, the bottom surface of each section 469 of intermediate member 474 is
substantially flat
and supports openings for receiving six contacts of the phase bus 482. Bus 482
can be
considered to consist of two halves where each half is similar to bus 82 of
the triplex
receptacle shown in Figure 4. The two halves of bus 482 are connected together
by a
conductive bridge and supports six contacts for receiving flat blades which
are to be
connected to the phase conductor. Bus 482 also supports two screw terminals
either of
which can be connected to the phase conductor. Bus 482 follows a serpentine
path along
the flat bottom =face of the two sections of intermediate member 474 to
position the
commonly connected contacts below openings in the member 470 designated to
receive the
flat blade of a plug which is to be connected to the phase conductor. Bus 480
is electrically
isolated from bus 482 by the bottom surfaces of the two sections of
intermediate member
474.
Bottom member 476 is a single member similar to the two bottom members 76 of
the triplex receptacle and joined together to form a single member. Member 476
is adapted
to fit over the bottom of the two sections of intermediate member 474 and
contains six
16
CA 02591638 2007-06-13
openings for receiving the six contacts of the ground strap 484. Ground strap
484 consists
of two sections 486 and 488, each of which is similar to the ground strap 78
of the triplex
receptacle and connected together by a conductive bridge. Ground strap 484
supports six
ground contacts which are positioned to fit in various openings in the
different members of
the receptacle which allow the ground contacts to be positioned below openings
in the top
member 470 designated to receive the half-round blade of a plug which is to be
connected
to ground. The ground strap 478 supports two screw terminals, either of which
can be
connected to an electrical ground.
= Assembly of the sixplex receptacle is basically similar to the assembly
of the triplex
receptacle. The main difference is that the assembled sixplex receptacle is
connected to
two boxes ganged together instead of one box and the alignment plate and wall
plate (see
Figure 15) are sized to accommodate the sixplex receptacle. In addition, the
various buses
and top, intermediate and bottom members of the sixplex receptacle are sized
to provide a
receptacle having six sockets rather than three sockets.
Figure 19 shows the front face of a sixplex receptacle 501 integrating a
protective
circuit and visual and audible indicator devices, constructed in accordance
with another
embodiment of the invention and suitable for mounting in a double box. The
front cover
assembly 511 has six sets of holes therein for receiving six plugs. As shown
in Figure 19,
sixplex receptacle 501 is intended for 15 Amps, 125 V AC and according to NEMA
specification 5-15R, where each individual socket 512 has two flat blade
openings for
receiving the flat blades of a suitable plug and a semicircular opening for a
ground blade.
One of the flat blade openings is larger than the other so that a two-blade
plug can only be
inserted in one way, to maintain the correct electrical polarization. The
larger opening is
connected to the neutral conductor; by maintaining the correct polarization,
the external
metal parts of appliances such as toasters, TVs, etc. can be grounded through
the neutral
conductor. The presence of the ground blade makes insertion of a three-blade
plug with the
wrong polarity impossible. A ground blade of a three-blade plug makes contact
with a
ground conductor connected to ground strap assembly 526, described in more
detail below.
It will be appreciated that the sixplex receptacle of Figure 19 may also be
configured with
its outlets according to NEMA specifications 5-20R, 6-15R or 6-20R.
17
- CA 02591638 2007-06-13
- =
In this embodiment, sixplex receptacle 501 has integrated therein a transient
voltage
surge suppressor (TVSS). An opening 514 on the front face of cover assembly
511
transmits light from an LED in the TVSS circuit; the light provides a visual
indication that
the TVSS is working and is capable of protecting appliances against voltage
surges. The
TVSS circuit also includes an alarm buzzer mounted behind openings 515; the
alarm
sounds if the TVSS fails (due to a large overvoltage or for some other
reason). Additional
details of the TVSS circuit in this embodiment are given below.
Referring to Figure 20, there is illustrated an exploded view of sixplex
receptacle
501 having a front cover assembly 511, a center assembly 522, a back cover 525
and
ground straps 526 connected by ground bridge assembly 527. Positioned between
the cover
assembly 511 and the center assembly 522 is a neutral bus assembly 521 having
six
contacts, one for each of the six openings in the front cover assembly for
receiving the flat
blade of a plug which is to be connected to a neutral conductor. Positioned
between the
center assembly 522 and the back cover 525 is a line bus assembly 524 having
six contacts,
one for each of the six openings for receiving the flat blade of a plug which
is to be
connected to a line conductor. Positioned below the back cover 525 are the
ground strap
assemblies 526, which are electrically connected together and support six
ground contacts,
one for each of the six openings for receiving the ground blade of a plug
which is to be
connected to ground. A printed circuit board (PCB) 523, having the TVSS device
mounted
thereon, is positioned beneath center assembly 522 so that the TVSS components
are
surrounded by the center assembly. Screws 251 connect the back cover 525 with
the front
cover assembly 511 through holes in the center assembly 522. The ground bridge
assembly
527 is secured to the ground strap assemblies 526 and to the back cover 525 by
pins 261.
As shown in Figure 20, the top of center assembly 522 contains various
partitions
, selectively spaced to provide a serpentine passageway for receiving neutral
bus assembly
521 and the contacts connected thereto. The contacts are thus positioned to
communicate
with the openings in front cover assembly 511 to receive the flat blade of a
plug to be
connected to a neutral conductor. Line bus assembly 524 follows a serpentine
path along
the bottom surface of center assembly 522. Center assembly 522 also has six
openings for
receiving six contacts connected to line bus assembly 524, which are
positioned to
communicate with the openings in front cover assembly 511 to receive the flat
blade of a
=
18
= 1
CA 02591638 2007-06-13
plug to be connected to a line conductor. Line bus assembly 524 and neutral
bus assembly
521 are electrically isolated from each other by the bottom surface of, and
the partitions in,
center assembly 522.
Back cover 525 is adapted to fit over the bottom of center assembly 522 and
contains six openings for receiving six contacts connected to ground strap
assemblies 526.
Each ground strap has three contacts connected thereto, positioned to fit
through openings
in the center assembly so as to communicate with the openings in the front
cover assembly
511 to receive the half-round blade of a plug which is to be connected to
ground.
Figure 21 is another view of center assembly 522, showing the bottom surface
thereof. A screw 531, of an insulating material such as nylon, connects wire
leads 532 and
533 and secures them to the center assembly; the wires are connected to the
alarm buzzer of
the TVSS device. Tightening screw 531 brings the leads into electrical
contact, while
loosening the screw breaks contact between the leads, thereby disabling the
alarm. PCB
523, with the TVSS circuit components, is positioned in a cavity 534 in the
center of
assembly 522.
Figure 22 shows the underside of front cover assembly 511, with openings 514
and
515 formed in the central portion thereof. A lens 541 for transmitting light
from the LED
of the TVSS circuit is fitted into opening 514. Another opening 516 is
provided so that a
user may have access to the head of screw 531. This opening is preferably
covered with an
adhesive label 517 (as shown in Figure 19) to discourage unnecessary disabling
of the
TVSS alarm.
The line bus assembly 524 of this embodiment is shown in more detail in Figure
23. .
The fiat surface of the bus connector is held against the underside of the
center assembly
522 by the back cover 525. The six contacts 551 are connected to the bus by
suitable
fasteners (e.g. rivets as in this embodiment). A wire leading to external line
voltage is
attached to the bus by a solder connection 552.
The neutral bus assembly 521 is shown in more detail in Figure 24. As
mentioned
above, the vertical surfaces of the bus are generally adjacent to partitions
in the center
assembly 522. The six contacts 561 are connected to the bus by rivets or other
suitable
fasteners. A wire leading to an external neutral conductor is attached to the
bus by a solder
connection 562.
19
CA 02591638 2013-08-12
The ground bridge assembly 527, located on the exterior of the receptacle 501,
also has a
wire lead as shown in FIG. 25.
Each of the two ground strap assemblies 526 in this embodiment has three
ground
contacts 581 connected thereto, as shown in FIG. 26A. The ground contacts
project through
openings in the back cover and the center assembly toward the front face of
the receptacle.
As shown in FIG. 26B, one of the strap assemblies has a wire (typically
copper) 582 welded
thereto, for making a ground connection to the TVSS device.
Multi-function clips 130, 151 are attached to the ends of the ground strap
assemblies
526, as shown in FIG. 26C. These clips may be composed of phosphor bronze,
spring brass,
spring steel or the like. FIG. 26D shows details of clip 130 which is
typically attached to the
bottom end of strap assembly 526 (when the face of receptacle 501 is oriented
vertically).
Openings 132, 134 are aligned with corresponding openings in the end portion
of ground
strap assembly 526. Opening 132 is a clearance opening for a threaded fastener
used to
couple receptacle 501 to a box. The ends of three projecting members 133 serve
to capture an
alignment pin on an alignment plate (shown in FIG. 15). Clip 130 is fastened
to strap
assembly 526 preferably by using a TOX press process through openings 143;
openings 145
provide alignment with corresponding openings at the end of strap assembly
526. The end
147 is bent upward to form a latching pawl 140, to engage the inside surface
of a wall plate
(shown in FIG. 15). FIG. 26E shows details of clip 151 which is typically
attached to the top
end of strap assembly 526. Clip 151 has openings similar to clip 130, and in
addition has a
tab 155 extending into opening 153 to engage and capture a fastener coupling
the receptacle
to a box. Further details of the function of clips 130, 151 are given in
commonly assigned
U.S. Pat. No. 7,030,318.
The TVSS circuit is integrated into receptacle 501, and in this embodiment is
positioned in cavity 534 in center assembly 522. FIG. 27 is a schematic
diagram of the circuit
according to this embodiment. The line, neutral and ground connections J1, 32,
J3 are formed
by solder joints between wires and the line bus assembly 524, neutral bus
assembly 521 and a
ground strap assembly 526 respectively. As shown in FIG. 27, voltage surge
protection is
provided by two thermal cut-off (TCO) devices F1, F2 and four metal-oxide
varistors
(MOVs) MV1, MV2, MV3, MV4 connected between line and neutral
CA 02591638 2007-06-13
=
conductors, line and ground conductors, and neutral and ground conductors.
During normal
operation of the circuit, LED LD1 conducts current and emits light through
lens 541 (see
Figure 4); the light may be any color desired, but for a hospital-grade device
a red color is
specified. In this embodiment, the MOVs will break downat 400 V. If a voltage
spike of
400 V or more is applied to the receptacle, the MOVs will fail, the light from
LD1 will go
out and the alarm buzzer PZ1 will sound. It should be noted that in this
condition, the
receptacle 501 will still deliver power, but will no longer have TVSS
protection. A user
may turn off the alarm by turning screw 531 so that contact is broken between
leads 532
and 533.
An embodiment of the TVSS device mounted on PCB 523 is shown in Figures 28A,
28B and 28C in side, plan and perspective views respectively. The four MOVs
are
arranged on edge, to make the PCB small enough to fit conveniently in the
cavity 534 of
center assembly 522. The wire ground lead 13 has a ground wire from the ground
strap 526
wrapped around it, and secured with solder.
Another embodiment of the invention is shown in Figure 29. Receptacle 611 has
four standard 120 V AC outlets, and four openings 612 to receive connectors to
low-voltage
devices. (These connectors are sometimes called QuickPort connectors.) These
device
connectors may include connectors for cable TV, satellite TV, voice, data,
audio, RS232,
USB, DVI (digital video input), AVI (analog video input), etc.
In addition, it will be understood that receptacle 501 may have a different
number of
outlets provided therein, e.g. four or five outlets in a double-gang unit.
Similarly,
receptacle 611 may have more or fewer openings 612 alongside more or fewer
outlets in a
single or multiple-gang unit as space permits. In an embodiment, receptacle
611 has three
outlets in a triplex arrangement on one side of a double-gang box, and more
openings 612
(typically six) occupying the other side of the double-gang box.
Assembly of a receptacle according to the above-described embodiments may be
performed by following the steps shown in Figures 30A-30J. Neutral bus
assembly 521
slides between partitions in center assembly 522; neutral connector wire 621
(typically
white in color) is fed through a hole in bus assembly 521 and secured by a
solder joint
(Figure 30A). Line bus assembly 524 sits flat against the underside of center
assembly 522;
line connector wire 624 (typically black in color) is fed through a hole in
bus assembly 524
21
CA 02591638 2007-06-13
and secured by a solder joint. As shown in Figure 30B, the neutral connector
wire 121 runs
through a hole in the line bus assembly 524, so that wires 621 and 624 are
adjacent and
parallel. It should be noted that the wires leading from receptacle 501 for
making external
connections are soldered to the bus assemblies, rather than attached using
screw terminals.
This is done to obtain a higher quality electrical connection and to save
space in the interior
of the receptacle.
The PCB 523, with the TVSS circuit as described above, is fitted into the
center
assembly 522 (Figure 30C). A portion of the PCB sits flat against the
underside of the
center assembly (Figure 30D). Solder joints are formed to establish line and
neutral
electrical connections to the PCB. The back cover 525 is placed over center
assembly 522,
with wires 621 and 624 led through openings in the back cover (Figure 30E).
The back
cover is then secured to the center assembly. A bare copper wire 582 is
soldered to one of
the ground strap assemblies 526. The ground strap assemblies 526 are then
fitted securely
against the back cover and the sides of the center assembly (Figure 30F), with
the bare wire
sliding adjacent to connector J3 on the PCB.
The bare wire 582 is wrapped around connector 13 and secured using solder, to
make a reliable ground connection to the PCB (Figure 30G). Front cover
assembly 511,
with LED lens 541 fitted therein, is placed over the top of center assembly
522 (Figure
3011). Screws 251 secure the front cover assembly 511 to back cover 525
through holes in
center assembly 522 (Figure 301). Ground bridge assembly 527, including ground
connector wire 627, is then secured to ground strap assemblies 26 and center
assembly 522
using pins 261 (Figure 30J).
A receptacle as described above may be mounted in a double ganged box 160
using
an alignment plate 358 and a wall plate 338 having an opening 360, as shown in
Figure 15.
The alignment pins 370 engage openings 134 in clips 130 and 151. Wall plate
338 has
racks 346 for receiving the latching pawls 140 of clips 130 and 151.
In the embodiments described above, a double gang receptacle includes three,
four,
five or six outlets with a TVSS device; in some arrangements the outlets are
alongside one
or more openings for low-voltage device connectors. In other embodiments, the
receptacle may include a ground-fault circuit interrupter (GFCI), an
integrated circuit
breaker and/or an integrated night light instead of, or in addition to, the
TVSS already
22
CA 02591638 2013-08-12
described. In still other embodiments, a single or multiple-gang unit (that
is, larger than a
double box) may have a different number of outlets and/or low-voltage device
connector
openings.
The above-described embodiments include grounding strap assemblies and bridge
assemblies for connecting the ground contacts of the receptacle to the box.
Alternatively, the
receptacle may be configured as an isolated ground receptacle in which a
ground conductor,
connected to the ground contacts of the receptacle, is led through the box to
a grounding
point but is not connected to the box. In addition, it will be appreciated
that the outlets in the
above-described embodiments may be configured as tamper-resistant outlets in
accordance
with NEC Article 517.18(C).
Furthermore, it will be appreciated that a receptacle as in the above-
described
embodiments may be constructed in a multi-gang modular configuration rather
than a single
integral unit. For example, one half of a double-box receptacle may have an
opening formed
therein for receiving a modular unit including three outlets, while the other
half has an
opening formed therein for receiving a modular unit having six low-voltage
device connector
openings. Power connections to the modules are made using a backplane in each
of the
gangs, as is understood by those skilled in the art.
While the invention has been described in terms of specific embodiments, it is
evident
in view of the foregoing description that numerous alternatives, modifications
and variations
will be apparent to those skilled in the art. Accordingly, the invention is
intended to
encompass all such alternatives, modifications and variations which fall
within the scope of
the invention and the following claims.
23
