Note: Descriptions are shown in the official language in which they were submitted.
CA 02775681 2012-09-30
MAGNETICALLY ACTUATED AC POWER CONNECTOR
FIELD OF INVENTION
[0001] This invention relates to a power connector and, in particular, a power
connector without
probes for electrical connection.
BACKGROUND OF THE INVENTION
[0002] Conventional power cords comprises a male plug component having contact
prongs
extending outwards for inserting into a corresponding receiving member in a
female plug
component or a socket, where the receiving member holds the prongs in place
and the male and
female plug components are electrically connected using frictional force. In
some situations, for
example in very low temperatures, the insertion and removal of the prongs
becomes difficult and
may cause damage to the cord and to devices connected the cord.
[0003] US patent 7,311,526 disclosed a magnetic connector that connects a
direct current (DC)
voltage source to a device. Such connector has safety issues if used for
transmitting high voltage
alternative current (AC) signal, as electric shock will occur when the user
touches electrically live
exposed contacts. Therefore an improved power connector design is desired to
accommodate high
voltage AC electric power supply. Other power connector system that may share
common design
features with the current system are shown in the following patents:
7,621,753 Pal
7,874,844 Fitts
7,442,042 Lewis
6,739,915 Hyland
7,339,205 McNeely
6,770,986 Nagao
5,584,715 Ehrenfels
4,748,343 Engel
7,351,066 DiFonzo
7,517,222 Rohrbach
7,645,143 Rohrbach
CA 02775681 2012-09-30
SUMMARY OF THE INVENTION
[0004] In the light of the foregoing background, it is an object of the
present invention to provide an
alternate power connector..
[0005] Accordingly, the present invention, in one aspect, is an apparatus for
electrically connecting
a power source to an electrical device. The apparatus comprises a first
component and a second
component. The first component has a substantially planar contoured first
face, and the first face
comprises, in part, a set of 3 electrical pad contacts, one for each: hot,
neutral, and ground connected
to the power source. The second component has a substantially planar contoured
second face
complementary to the first face, and the second face comprises, in part, a set
of 3 electrical pad
contacts, one for each: hot, neutral, and ground connected to the electrical
device. The first set of
contacts becomes electrically coupled to the second set of contacts upon
connecting the first face
with the second face, thereby establishing a first (primary) electrical path
between the power source
and the electronic device.
[0006] In an exemplary embodiment of the present invention, the power source
may be any standard
household AC supply outlet and the primary electrical path is an AC supply
path between the outlet
and the electronic device. The first plug component further comprises power
rectifier circuitry
which branches off from the primary path and supplies DC power via a secondary
electrical path to
internal power switching circuitry.
[0007] In a another exemplary embodiment, the power connector further
comprises at least one
electrically operated switch and one actuating sensor. The switch is initially
in the off position and is
disposed in the primary electrical path. The actuating member is disposed in
the secondary
electrical path. When the first and second faces are attached, the actuating
sensor is triggered by the
presence of the magnet and closes the switch located in the first electrical
path resulting in power
conduction to the electronic device.
[0008] In another exemplary embodiment of the present invention, the male plug
face comprises a
ferromagnetic element and the female plug face comprises a magnetic element.
The primary
electrical path is established upon connecting the male plug face comprising
of a ferromagnetic
element, to the female plug face comprising a magnetic element, whereby the
presence of the
magnet on the female plug face triggers the actuating sensor inside the male
plug component and
closes the switch disposed in the primary electrical path and results in power
conduction. In
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addition to actuating power conduction, the attractive force between the
ferromagnetic and magnetic
plates, on the male and female faces respectively, binds the plug components
together allowing the
electrical coupling between the pad contacts lobe maintained during plug
operation.
[0009] There are many advantages to the present invention. First of all, the
male plug component
and the female plug component (i.e. the first component and the second
component) are held
together by non-frictional forces such as magnetic forces, and the contact
face between the
components is substantially planar and contoured. Attaching the components is
simply completed by
contacting the male plug face with the female plug face. Seperating the
components requires
minimal pulling force and as a result will not cause any damage to the
components in low
temperatures due to excessive friction force caused by variable temperature
induced contraction of
components. The performance of the substantially planar contoured contact face
is not affected by
contraction and expansion due to changes in ambient temperature. As a result,
the force required to
separate the plug components is also independent of ambient temperature.
[0010] The strength of the magnetic force is chosen to be removable with
deliberate force but is
considerably less than the maximum connective force of other connections, such
that in situations
where the device is pulled from the power supply with excessive force, the
magnetic coupling
between the male plug component and the female plug component of the power
cord is always first
to break, preventing damage to the device and the power supply. An example of
such situation is in
engine block heaters in vehicles where the user may drive a vehicle away from
its parked position
without noticing that the block heater cord is connected to a wall socket via
an extension cord, a
common practice used to keep the engine warm enough to be started in cold
climates.
[0011] Another advantage of the present invention is that the circuit is
designed to prevent the
electrical contacts from being live with AC power when the male plug component
is connected to
the power source but not to the female plug. In the absence of the safety shut
off mechanism, a user
would suffer electric shock upon touching an electrically live contact.. Using
an electrically operated
switching mechanism as a part of the circuit ensures that the power
transmission components are
only actuated when the male plug face is in contact with the female plug face,
which in the case of
the present invention means that the contacts are accurately connected between
the corresponding
male and female plug components.
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[0012] Another advantage of the present invention is that the power connector
has no moving parts
and the surface of contact is substantially planar and contoured, therefore
debris such as dust, dirt or
ice will not easily collect on the components and potentially affect the
operation of the connector
such as shorting the circuit, especially so if the power connector is to be
usable in outdoor
environments. Where debris does collect on the contact surfaces, the surfaces
can be readily wiped
clean due to their substantially planer nature.
[0013] An additional advantage of the present invention is that the electrical
contacts located on the
male plug face will be slightly recessed below the contact surface of the
ferromagnetic plate located
on the contact face. This is primarily a safety feature which further reduces
the chance of electric
shock if a metal object is accidentally lodged between the male and female
plug face when they are
connected and the system is actuated to the on-position by the presence of the
magnet.
BRIEF DESCRIPTION OF FIGURES
[0014] Fig. 1 is a block diagram of the power connector male and female faces
according to an
embodiment of the present invention.
[0015] Fig. 2 is a front view of a male plug face according to an embodiment
of the present
invention.
[0016] Fig. 3 is a front view of a female plug face according to an embodiment
of the present
invention.
[0017] Fig. 4a is a cutaway cross-section (X-Y) of the contoured male plug
face according to an
embodiment of the present invention.
[0018] Fib. 4b is a front view of the male plug face showing the location of
cross-section (X-Y)
according to an embodiment of the present invention.
[0019] Fig 5a is a cutaway cross-section (X'-Y') of the contoured female plug
face according to an
embodiment of the present invention.
[0020] Fig 5b is a front view of the female plug face showing the location of
cross-section (X'-Y')
according to an embodiment of the present invention.
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[0021] Fig. 6 is a complete circuit diagram of the power connector circuitry
of the male plug
component according to an embodiment of the present invention.
[0022] Fig. 7 is a complete circuit diagram of the power connector circuitry
of the female plug
component according to an embodiment of the present invention.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] As used herein and in the claims, "comprising" means including the
following
elements but not excluding others.
[0024] As used herein and in the claims, "couple" or "connect" refers to
electrical coupling or
connection either directly or indirectly via one or more electrical means
unless otherwise stated.
[0025] Referring now to Figs. 1, 2 and 3, the first embodiment of the present
invention is a power
connector 1 comprising a male plug component 2 and a female plug component 3.
The male plug
component 2 has a standard male power supply connector at the rear (not shown)
adapted to connect
to a power supply such as a wall socket. The female plug component 3 has a
standard female
connector at the rear (not shown) adapted to connect to an external electrical
device to be powered.
The male plug component 2 further comprises a male plug face 4 which is
substantially planar and
contoured, and the female plug component 3 further comprises a female plug
face 5 which is also
substantially planar and contoured. There is at least one set of contacts on
the male plug face 4. In
the specific example as shown in Fig. 2, there are three (3) electrical pad
contacts, one for each: hot,
neutral, and ground denoted by 6a, 66 and 7 respectively. There is also at
least one set of contacts on
the female plug face 3. In the specific example as shown in Fig. 3, there are
three (3) electrical pad
contacts, one for each: hot, neutral, and ground, denoted by be, 8b and 9
respectively. The contour
of the male plug face 2 and the female plug face 3 are complementary to each
other such that the
entire male plug face 2 can be contacted to the female plug face 3.
[0026] In operation of the power connector 1, the male plug component 2 is
brought into contact
with the female plug component 3. The entire male plug face 4 is in contact
with the female plug
face 5 due to their substantially planer and complementary construction. When
the two faces are in
contact, the first set of three contacts 6a, 6b and 7 are electrically coupled
to the corresponding
second set of three contacts,8a, 8b and 9. This completes the electrical path
between the power
supply and the electrical device. As a result, electric power can flow from
the power supply to the
electrical device.
[0027] In an exemplary embodiment, referring to Fig.2 and Fig 3, one
ferromagnetic element 10 is
disposed on the male plug face 4, and at least one magnetic element 11 is
disposed on the female
plug face 5. The ferromagnetic element 10 and the magnetic element 11 become
connected through
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magnetic attractive force when the male plug face 4 is brought into contact
with the female plug face
5, thus attaching the male plug component 2 to the female plug component 3 and
vice versa. In a
further embodiment, the ferromagnetic element 10 and the magnetic element 11
are installed at
predetermined locations in the male plug component 2 and the female plug
component 3
respectively, such that the male plug component 2 can only be attached to the
female plug
component 3 in a predetermined orientation, where the predetermined
orientation ensures the
electrical path to be established in a safe manner and isolates the individual
electrical pad contacts
located on each of the plug faces.
[0028] Magnetic elements generate magnetic fields. When one magnetic element
10 is brought into
proximity of a ferromagnetic element 11, a magnetic attractive force is
generated between the two
elements. The magnetic force acts substantially along the axis of the magnetic
element. As such, in
the present invention, when the male plug face 4 is brought into proximity of
the female plug face 5,
a magnetic attractive force is generated perpendicular to the male plug face 4
and the female plug
face 5 causing them to attach. The magnetic force prevents the components from
detaching once
connected unless sufficient external force is applied to detach the
components.
[0029] .In another exemplary embodiment, Fig. 4a and Fig. 4b show cross-
section cutaways of the
male plug face 4, and Fig. 5a and Fig. 5b show cross-section cutaways for the
female plug face 5.
The cross-sections show the substantially planer and complementary contoured
design of the plug
faces. The electrical contacts on the male plug face 4 are 6a, 6b and 7 and
are recessed within the
contoured folds of the male and plug. Since the electrical pad contacts (6a,
6b and 7) on the male
plug face 4 have to potential to be live when the system is actuated, this
recessed design ensures
additional safety and creates asymmetrical contours on the substantially
planer face which ensure
that the male plug face 4 and female plug face 5 only connect in one specific
orientation.
[0030] In an exemplary embodiment, the magnetic element 11 is a permanent
magnet, made of
neodymium-iron-boron or samarium cobalt type disc or ring magnet. The magnetic
force generated
will be calibrated to be strong enough to prevent unintentional detachment but
not too strong for
possible damage to other parts, such as the power supply cable or the
electrical device, before the
connector components can be detached either accidentally or intentionally.
Preferably, a force
between approximately 3lbs to Sibs should be produced between the magnetic and
ferromagnetic
elements.
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[0031] In another exemplary embodiment, a disc-type magnet has a diameter of
0.375 inch or 0.5
inch and a thickness ranging from 0.1 inch to 0.125 inch. In yet another
exemplary embodiment, a
ring-type magnet has an outer diameter of 0.375 inch to 0.5 inch, an inner
diameter of 0.125 inch
and a thickness ranging from 0.1 inch to 0.125 inch.
[0032] In an exemplary embodiment, an electric circuit is provided to control
the establishment of
the electrical path. Referring to Fig. 6, three circuit component-groups are
disposed in the male plug
component 2 each of which perform a separate function while working together
to activate the plug
system. The AC/DC power supply component-group 12 converts conventional
household power
(120volt AC) into a low-voltage direct current (DC) supply, The AC/DC power
supply component-
group 12 is connected to the 120volt AC power source (house power plug) on one
end and on the
other end is connected to the sensor and switching component-group 13. The
sensor and switching
component-group 13 performs the function of detecting the presence of a
magnetic field. As shown
in Fig. 6õ this component-group is connected to the AC/DC power source
component-group 12 at
one end, and on the other is connected to the power transmission component-
group 14. The power
transmission is attached to a standard residential power supply at one end,
and to the hot and neutral
contacts (6a, 6b) on the male plug face 4 on the other. A final component
group is place between
the power transmission component-group and the contacts 6a and 6b on the male
plug face 4. This
is the indicator light component group 15 which consists of two light-emitting-
diodes (LED) in
parallel, and a capacitor in series with the LEDs. The indicator light
component group informs the
plug system operator that the relays are engaged and that power is being
transmitted by the system.
[00331 Referring to Figs. 2, 3 and 6, at least one electronic sensor and one
electrically operated
switch is disposed in the male plug component 2. In a specific embodiment as
shown in Fig. 6, one
hall-effect switch 16 is disposed inside the male plug component 2, and two
power relay type
switches 17are disposed inside the male plug component 2. The system is
powered on when the
hall-effect sensor 16 in the male plug component 2 senses the presence of a
magnetic field from the
magnet disposed on the female plug face 5. When the male plug component 2 and
female plug
component 3 are connected, they attach by magnetic attraction force between
the magnet 11
disposed on the female plug face 5 and the ferromagnetic plate 10 disposed on
the male plug face 4.
Simultaneous with the connection of the plug components, the hall-effect
sensor 16 detects the
presence of the magnetic field and begins to provides current to the coil of
the power relay switches
17. This triggers the relays into the "on" position where they begin to
conduct AC power to the
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attached electric device. The relay power output terminals are electrically
connected to contacts 6a
and 6b disposed on the male plug face 4.
[0034] In a further exemplary embodiment, with reference to Fig. 1, Fig, 6 and
Fig. 7, when the
male plug component 2 and female plug component 3 are attached, contacts 6a,
6b and 7 disposed
on the male plug face 4 are in direct contact with contacts 8a, 8b and 9
disposed on the female face.
The connection of the In turn the electric device is connected via the female
plug component 3 to
contacts 8a and 8b internally (Fig. 7). As a result power is transferred to
the electronic device.
When the user detaches the male plug component 2 from the female plug
component 3, the magnet
13 and associated magnetic field is also removed from the vicinity of the Hall-
Effect sensor 16
causing the Hall-Effect sensor to terminate current transfer to the coils of
the relays. This causes the
relays to return to the "off' position and stop the transition of power to
contacts 6a and 6b making
the system electronically inactive.
(0035] In an exemplary embodiment, the AC/DC conversion circuit is a
transformer-based
conversion circuit that outputs a 6V DC voltage.
[0036] In one embodiment, with reference to Fig. 7, an indicator circuit 19 is
provided within the
female plug component 3 electrically parallel to the device connecting wires
of the female
component 3 to alert the user when electric power is supplied to the
electrical device. In an
exemplary embodiment, the indicator 19 is a visual indicator light emitting
diode (LED) circuit.
[0037] The exemplary embodiments of the present invention are thus fully
described. Although the
description referred to particular embodiments, it will be clear to one
skilled in the art that the
present invention may be practiced with variation of these specific details.
Hence this invention
should not be construed as limited to the embodiments set forth herein.
[0038] For example, the casing or external housing of the male 2 and female 3
plug components can
be constructed of any rigid synthetic, semi-synthetic or organic composite
polymeric material such
as polyvinyl chloride, and can be constructed in any shape conductive to the
adapted use, so long as
the design parameters and functional constrains previously described are
maintained.
[0039] In another example, a gasket can be provided surrounding the male plug
face 6 and the
female plug face 7. The gaskets then push against each other when the male
plug face 2 is in contact
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with the female plug face 3, preventing external particles such as dust or ice
to enter, causing
damage to the power connector system.
[0040] .In yet another example, the actuating element may be spring loaded
piston witin the male
plug component upon which live electrical contacts are mounted. Once the male
and female plug
components are connected, the piston is drawn forward and electrically coupled
with contacts on the
female component thus transmitting power to a connected electronic device.
[0041] An AC/DC conversion circuit with transformer-less or capacitative
elements can be used in
place of a transformer conversion circuit with the same function. A
transformer-less conversion
circuit generally occupies less space.
[0042] It is obvious to one skilled in the art that the plug faces can be
contoured in away to improve
alignment of the components, as long as an axial frictional force is not
created during attachment.
The construction and assembly of the embodiments previously described is
accomplished through
conventional means and uses conventional components and therefore should be
consistent with the
common general knowledge of a person skilled in the art.
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