Note: Descriptions are shown in the official language in which they were submitted.
CA 02289821 1999-11-17
BACKGROUND OF THE INVENTION
This invention relates to an improved electrical adapter to be used with a
split/multiple circuit
duplex receptacle and provide firstly a single 240 volt 15 amp circuit outlet
as well as two 120 volt 1 ~
amp circuit outlets.
Commonly found in residential and commercial kitchens in Canada, the
split/multiple circuit
duplex receptacle provides power for up to two separate appliances which
consume large amounts of
power, such as deep fryers, electrical kettles, griddles, broilers and ovens,
each having 120 volt power
rcq~irements of ~p tp 1500 watts. C~_rrent Canadian electrical_ Codes require
that all kitchen CQ~nter
outlets be split/multiple circuit duplex wall receptacles and further that the
two circuits of a
split/multiple receptacle be 180 degrees out of phase and therefore have a
voltage potential of 240
volts.
Conventionally, kitchen appliances in Canada are designed for use with 120
volt 15 arnp
alternating current outlets that are configured as per the North American
Standard 120 volt 15 amp
"NEMA 5-15R" receptacles and utilise a 2 or 3 pronged male plug configured as
per the North
American Standard 120 volt 15 amp "NEMA 5-15P" plugs (2 vertical parallel
prongs and 1 round).
Certain appliances, such as those mentioned above, can under-perform at
wattages limited
conventionally to 1500 watts and could benefit substantially in their
operation by an increase in power
to between 1500 and 3000 watts. European kitchen appliances are designed for
use with 240 volt
alternating current and certain appliances such as those mentioned above have
power requirements of
up to 3000 watts. Power can be supplied to these European appliances by
utilizing a 2 or 3 pronged
male plug co~gured as per the North American Standard 240 volt 15 amp "NEMA 6-
15P" plugs (2
horizontal inline prongs and 1 roundj.
An adapter, having 6 male prongs comprising 2 sets of NEMA 5-15P configured
prongs, can,
when plugged into both halves of a split/multiple circuit duplex receptacle,
supply both of the circuits
(180 degrees out of phase) to one single 240 volt 15 amp NEMA 6-15R
receptacle. A split circuit
indicator light incorporated into the adapter can visually distinguish between
single and split/multiple
circuit household duplex receptacles, which are unidentifiable otherwise.
Need has existed arising from the requirements for flexibility in outlet
voltages for either 120
volts or 240 volts, without altering the household wiring connected to the
split circuit duplex wall
receptacle, and to accommodate this need, prior art teachings, such as
Canadian Patent Application by
Ollenberger CA2002984 (abandoned) dated November 15, 1989, have described an
adapter to be used
with a split circuit receptacle and provides a single 240 volt r 5 amp outlet
with an indicator light to
identify the type of duplex receptacle being used.
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CA 02289821 1999-11-17
One of the improvements comprised in the present invention is two additional
120 volt 15 amp
NEMA 5-15R receptacles on the adapter that can be used in the event the 240
volt receptacle is not in
use. This is a significant improvement and benefit to the adapter as it allows
for the use of both 240
volt and 120 volt appliances on the kitchen counter without the need for the
removal of the adapter
from the wall receptacle.
BRIEF DESCRIPTION OF THE INVENTION
Accordingly, it is the pri_n_ciple objective o_f t_h_is invention to provide
an electrical a~[apter that,
when used in combination with a common split/multiple circuit duplex
receptacle, will provide a 240
volt 15 amp circuit to a NEMA 6-1 SR outlet for use with any European style
240 volt appliance with
power requirements up to 3000 watts.
It is also another objective of this invention to provide an adapter that,
when used in
combination with a common split/multiple circuit duplex receptacle, will
provide two 120 volt 15 amp
circuits to two NEMA 5-15R receptacles only when the 240 volt 15 amp NEMA 6-
15R outlet is not in
use.
It is a further objective of this invention to provide an electrical adapter
with visual indication
means, such as an indicator light, to distinguish between split/multiple
circuit and single circuit
kitchen duplex receptacles.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic of a split/multiple circuit of a type in common use in
residences for
connection to duplex wall receptacles.
Figure 2 is a plan view partly in schematic of an adapter in accordance with
the preferred
embodiment of the present invention.
Figure 3 is a side view of the adapter of Figure 2.
Figure 4 is a plan view depicting the housing of the adapter of Figure 2.
Similar numerals of reference designate corresponding parts in the drawings.
DESCRTPT1ON OF TAE PREFERRED EMBODIMENTS
Referring to the drawings and with particular reference to Figure 1, a
schematic showing of a
split/multiple wire circuit of a type conventionally available in modern
residential kitchen
construction is depicted, in which a grounded duplex electrical receptacle 10,
comprising a pair of
outlets 11 and 11', to which are connected, respectively, hot leads 12 and 13
designated respectively
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CA 02289821 1999-11-17
as "red" and "black", and connected to the power supply through a double pole
single throw 240 volt
breaker 14. Female connectors 15 and 16 are positioned in the insulated
housing 17 at opposite ends,
as depicted in Fig. 1 to which the hot leads 12 and 13 are connected. Neutral
connectors 18 and 19
are spatially aligned conventionally with hot wire connectors 15 and 16 and
are connected in parallel
to a neutral lead 19, designated "white" in Fig. 1. Grounding connectors 20
and 21 centred on the
housing 17, are electrically connected to ground 22, Fig. 1.
Referring to Fig. 2, a preferred embodiment of the adapter of the invention is
depicted. The
adapter generally designated 23 comprises a_n_ . _i.ns~l_ated _h_ousing 24 pf
npn-cpndt~ctive plastic,
preferably of phenolic resin conforming to CSA specifications for 240 volts
and 3000 watts. The
moulded housing 24 is of generally rectangular box like hollow configuration
constituted to hold the
electrically operative elements in rigid configuration, and can be either two-
part construction or
unitary. Prongs or blades generally indicated at 25 project from the face of
the housing 24, as
indicated in Fig. 3, to register with the connectors of the outlet 10, Fig. 1,
as will now be described.
Referring again to Fig. 2, the prongs 25 includes power prongs 26 and 27 are
connected
solidly to female connectors 32 and 33 and electrically via leads 41 and 42 to
female connectors 38
and 39 of adapter 23 and aligned on the face of the housing 24 with the hot
connectors 15 and 16
respectively of Fig. 1.
Neutral prongs 28 and 29 are similarly aligned on the housing 24 to register
with neutral
female connectors 18 and 19 Fig. 1, and are solidly connected to female
connectors 34 and 35 of
adapter 23, Fig. 2. Ground prongs 30 and 31, normally round or u-ground type,
are positioned
centrally of the housing 24 and aligned with ground female connectors 20 and
21, Fig. 1, and are
solidly connected to female connectors 36 and 37 of adapter 23, Fig. 2.
The prongs or blades 25 are normally formed of brass or other conducting
metal, and extend
through the face of the housing 24, Fig. 2 into the housing interior and
connect solidly to
corresponding female connectors 32, 33, 34, 35, 36 and 37 that are also formed
of brass or other
conducting metal and are designed to accept and hold through friction other
prongs or blades of cord
sets attached to appliances. Female connectors 38 and 39 are similarly
fashioned and are connected
electrically with soldered or continuous brass/conductive metal strips 41 and
42, to power prongs 26
and 27.
Referring further to Figs. 2 and 3, an indicator light 44 is included and
electrically connected
through electrical leads or brass/conductive metal strips 40, 41 and 43 across
power prongs 26 and 27,
Fig. 2, and will be mounted rigidly on the back surface 45 of housing 24, Fig.
3. The indicator light
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CA 02289821 1999-11-17
will accommodate 250 volts, as the maximum voltage potential between two
halves of the split
voltage supplied to the adapter.
Refernng to Fig. 4, the back surface 45 of the housing 24 is illustrated with
openings through
the housing 24 to coincide with all female connectors 32, 33, 34, 35, 36, 37,
38, and 39 and are
grouped into three North American standardised outlet configurations, two 120
volt 15 amp NEMA 5-
158 outlets 46 and 47 are positioned as per a standard common duplex
receptacle illustrated in Fig. 1
and one 240 volt 15 amp NEMA 6-15R outlet, 48 is positioned between the other
two outlets to
purposely share the ground female connector 36.
In operation:
( 1 ) with the adapter inserted into a split/multiple circuit duplex
receptacle the indicator light 44
will respond to visually indicate that a split/multiple circuit receptacle has
been utilised and either a
single 240 volt 15 amp circuit is available for use or two 120 volt 15 amp
circuits are available. With
a 240 volt 15 amp NEMA 6-15P plug of an appliance inserted into the 240 volt
15 amp NEMA 6-15R
outlet, both of the 120 volt 15 amp NEMA 5-15R outlets will be blocked from
use.
(2) with the adapter inserted into a single circuit duplex receptacle, the
indicator light 44 will not
respond and indicate that only a single circuit receptacle has been utilised
and only on 120 volt circuit
is available for use.
The foregoing system offers the following improvements and advantages:
(1) with the adapter inserted into a split/multiple circuit duplex wall
receptacle on a permanent
basis, both the existing two120 volt 15 amp NEMA 5-15R outlets of the wall
receptacle will continue
to be available for use with 120 volt appliances. The 240 volt 15 amp NEMA 6-
15R outlet will be
available for 240 volt appliances only when both NEMA 5-15R outlets are not in
use, thus preventing
an overload on the split/multiple circuit.
(2) with the adapter inserted into a single circuit duplex receptacle and a
240 volt 15 amp plug is
inserted into the NEMA 6-15R outlet of the adapter, no electrical potential
will exist between the
electrical connectors and no under voltage damage will occur to an appliance.
(3) the maximum power limitation of 1500 watts for all Canadian kitchen
countertop appliances
can now be increased to 3000 watts with a significant improvement in operation
of a number of
previously under powered appliances.
The present invention is not limited to the specific embodiments disclosed by
way of example.
It will be understood that the scope of the invention is only limited as
defined in the appended claims.
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