Note: Descriptions are shown in the official language in which they were submitted.
216912
Title: SHIELD FOR ELECTRICAL OUTLET
FIELD OF THE INVENTION
The present invention relates to devices for electrical outlets
and is particularly directed at outlet covers or shields for use with exposed
electrical outlets of the type intended to have plugs inserted in the
receptacles.
BACKGROUND OF THE INVENTION
Conventional household electrical outlets normally consist
of a pair of vertically aligned receptacles fastened to a wall mounted
1 0 electrical box and covered by a face plate. The receptacles usually have
sockets to receive two or three prong plugs. Typically the face plate is
attached via a one screw aperture centrally located in the receptacle pair, or
by two screw apertures located just above and below the receptacles. The
receptacles, face plate and screw fastener may be referred to as an outlet
1 5 assembly. Conventional two receptacle electrical outlets are known as well
as cable outlets, and multiply ganged outlets.
Domestic electrical outlets assemblies are normally located
just above floor level in easy reach and sight of small children. Children
can easily pull or pry on plugs, or put foreign objects into the receptacles
2 0 exposing themselves to electrical shocks and possible injury. Children
tend
to be particularly attracted to night lights which may also be pried or pulled
free of the receptacle. Therefore there is a need for a device which can
address these concerns.
Domestic electrical outlet assemblies may also be located in
2 5 high visibility or high traffic areas with plugs, cords or small night
lights
emanating which may be unsightly or easily dislodged. It is desirable that
an outlet cover be aesthetically attractive and protect plugs from being
accidentally dislodged.
There are a number of devices that have attempted to address
3 0 these concerns. Some of the devices exemplified in U.S. patent No.
4,793,818 by Poirer, U.S. patent No. 4,302,624 by Newman, and U.S. patent
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No. 2,516,464 by Hooser, cover the electrical receptacles when not in use,
but leave the plugs exposed when a protective cover must be moved to
permit plugging into the receptacles.
Other devices have attempted to cover the receptacle with
plugs in place, exemplified in U.S. patent No. 3,491,327 by Thomas, U. S.
patent No. 2,526,606 by Gregg and U.S. patent No. 4,070,078 by Chrones. To
install the Thomas device, the outlet face plate is slightly loosened, and a
cover designed to slide behind the face plate is wedged in place. The
installation is somewhat by trial and error and there is no positive lock
1 0 provided for the cover. The Chrones device utilizes separate hinged covers
for each receptacle and contains many components making it relatively
complex and expensive to manufacture. The Gregg device is awkward to
use and once the cover is removed, it can be lost or misplaced. None of the
above devices have considered the protection of night lights.
1 5 There is a need for a simple, inexpensive, and attractive
electrical outlet cover which can cover unsightly receptacle outlets (in use
or otherwise) and prevent accidental dislodging of plugs.
There is also a further need for providing an electrical outlet
cover which is tamper resistant to children, and prevents foreign objects
2 0 from accidently making contact with the plugs or receptacles. There is a
further need to have a universal device to fit on conventional and
contemporary outlets that others are not able to fit to.
There is a further need for an attractive device which can
prevent unwanted tampering by children with night lights plugged into
2 5 such a receptacle or with conventional and contemporary cords and plugs
plugged into such a receptacle.
SUMMARY OF THE INVENTION
The present invention is a shield for an electrical outlet
3 0 assembly opening which has at least one plug receptacle and a fastening
aperture. The shield comprises a base plate which is securable to the
electrical outlet assembly and has openings to permit electrical cords to
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plug into the receptacle when the base plate is secured to the electrical
outlet.
A cover cooperates with the base plate and has an open
position enabling access to the plug receptacles, and a closed position
wherein the cover together with the base plate defines an enclosed space.
The enclosed space is of sufficient size to enclose the outlet assembly and
most conventional plugs inserted in the receptacles. There is a means for
slidably engaging the cover to the plate, wherein the cover slides in a
given direction relative to the base plate from the open position to the
1 0 closed position and vice versa. The slidably engaging means provides
resistance to removing the cover in other directions.
There is also a passageway through the shield dimensioned
for the passage of one or more electrical cords out of the shield. The
passageway is defined by the base plate or the cover or both, and in the
1 5 closed position the outlet assembly and plugs are covered by the shield
with the cords emanating from the passageway.
The shield is preferred to further comprise a means for
locking the cover to the base, such that in the closed position the shield is
resistant to opening by a child, and a means for holding the cover to the
2 0 base in the open position, such that the cover is held in the open
position.
The base plate is preferred to be adapted to fit over an existing
face plate using the fastening apertures in the existing face plate to secure
the base plate to the electrical outlet assembly.
The preferred base plate also further comprises an enclosure
2 5 element extending outwardly from the base plate and the cover, an open
portion which co-operates with the base plate to form the enclosed space in
the closed position, and a means for blocking the passageway to prevent
foreign objects from making contact with the plugs and receptacles.
BRIEF DESCRIPTION OF THE DRAWINGS
3 0 The invention will now be described by way of example only,
with references to the following drawings in which:
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Fig. 1 is an exploded perspective view of the base plate and
cover, showing the base plate mounted over an electrical outlet and a co-
operating cover;
Fig. 2 is a front elevational view of the base plate a preferred
embodiment of the present invention;
Fig. 3 is a side elevational view of the base plate and
enclosure element shown in Fig. 2;
Fig. 4 is a cross sectional view taken along line A-A of Fig. 3;
Fig. 5 is a front elevational view of a preferred embodiment
1 0 of the cover;
Fig. 6 is a side elevational view of the cover shown in Fig. 5;
Fig. 7 is a cross sectional view of the cover taken along line B-
B shown in Fig. 5; and
Fig. 8 is a cross sectional view of the cover taken along line C-
1 5 C shown in Fig. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Fig. 1, a preferred embodiment of the present
invention is a shield shown generally as 10, comprising a base plate 12, and
2 0 a cover 14. The base plate is shown mounted over a conventional electrical
outlet having two receptacles 16.
Referring to Figs. 1, 2, 3 and 4 base plate 12, is provided with
openings 20 to permit electrical cords to plug into receptacles 16 when base
plate 12 is secured to the electrical outlet. Base plate 12 is screwed to the
2 5 electrical outlet through one or more apertures 22 which register with the
fastening screw holes in the electrical outlet. Base plate 12 can be placed on
or over an existing face plate or the face plate can be removed prior to
installing the base plate. Placing the existing base plate on or over the
existing face plate is preferred, because if the existing face plate is
removed,
3 0 the base plate will have to be formed from flame resistant plastic and
dimensioned in accordance with UL and CSA safety code regulation and
testing. Thus a preferred form of the invention is one which merely fits
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over an existing face plate. Also, this allows for the existing cover to be
readily available when no longer using shield.
Referring now to Figs. 1, 5, 6, 7 and 8, cover 14 co-operates
with base plate 12 by sliding over base plate 12 via a slidably engaging
means in the form of dovetail shaped rails 24 extending along the outer
sides 26 of base plate 12 and the inner sides 28 of cover 14. Rails 24 on base
plate 12 slidably interlock in tongue and groove fashion with rails 24 on
cover 14. Cover 14 slides over base plate 12 in a direction parallel to the
rails, from an open to a closed position and vice versa. Rails 24 provide
1 0 resistance to removing the cover in any other directions in the closed
position.
The cover is preferably generally semicircular in cross section,
having an internal diameter. While the cover 14 can be dimensioned to
exactly engage the base plate 12, the most preferred form of the invention
1 5 is for cover 14 to be slightly smaller at the base in internal diameter,
than
the width of rails 24 on base plate 12. In this manner, in the unstressed
state of cover 14 (when cover 14 is not engaging base plate 12), there is an
overlap between cover 14 and base plate 12 causing an interference fit
between these elements which adds a frictional component or stickiness to
2 0 their engagement. The amount of friction required is not great, and the
amount of interference will vary depending upon the type of plastic used.
Satisfactory results have been achieved with a 1/64 to 1/32 inch of overlap.
It will now be appreciated that by using such an interference fit the cover
will be trying to spring back to its unstressed position, which will have the
2 5 effect of urging the cover 14 outwardly, away from the wall. This ensures
the cover 14 is urged outwardly from the wall during use.
Referring now to all figures, in the open position the outlet
assembly is exposed enabling access to the plug receptacles 16. A holding
means in the form of male tabs 30 spaced from the bottom of cover 14 and
3 0 located on inner sides 28, register in the open position with depressions
32
spaced from the top of base plate 12 and located on the outer sides 26. Tabs
30 registering with depressions 32 are sufficient to hold cover 14 in the
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open position. Urging cover 14 over base plate 12 releases tabs 30 from
depressions 32, allowing cover 14 to be moved into the closed position.
These may not be essential if enough friction arises from the interference
fit described above, but are nonetheless preferred to be included. It will be
appreciated that the male tabs 30 and depressions 32 could be reversed to
suit molding preferences if desired.
In the closed position cover 14 together with base plate 12
define an enclosed space of sufficient size to house the outlet assembly and
most conventional plugs inserted in receptacles 16. In this sense
1 0 conventional plugs means plugs of the type typically found at the end of
conventional electrical devices such as lamps, small appliances, and
Christmas tree light strings. While heavy duty appliances and extensions
cords may also be accommodated in some cases, it will be appreciated that
the very largest plug types may require a slightly larger cover than would
1 5 otherwise be the case. For home use it is preferred to keep the device
generally smaller and more compact, although the cover size may be
varied to suit the application for instance. Further, the contemporary flat
cords will work and may allow for a smaller depth.
A locking means in the form of wedge shaped ridges 34 on
2 0 outer side 26 spaced from the top of base plate 14, registers with
corresponding female wedge shaped indentations 36 on inner sides 28
spaced from the top of cover 14 thereby locking cover 14 in the closed
position. Tab 30 registers with a recess 38 in base plate 12 which provides
geometrical relief for tab 30 in the closed position. Using one wedge shaped
2 5 ridge 34 will work, however a plurality are preferred, as this improves
the
child resistance as explained more fully below. Molding cost may make it
too expensive to form wedge shaped ridges 34 and therefore tab 30 at base
can be the additional locking arrangement. Note, if tabs 30 are used for
locking at base then this would require rear of cover to be pulled out and
3 0 raised, which again is a two-step in-locking arrangement.
With the wedge shaped ridges 34, pushing laterally, toward
the wall (against the outward urging caused by the interference fit), on the
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top portion of cover 14 using finger grips 40 and simultaneously urging it
into the open position will release the engagement of ridges 34 from
indentations 36 unlocking cover 14 and may be positioned at base as well.
Finger grips 40 are located on a outer surface 41 of cover 14 to provide
additional contact friction between fingers and outer surface 41 of cover 14
to aid in unlocking. The geometry of the locking means, and the strength
and dexterity required, make it difficult for a child to unlock cover 14 from
the closed position.
Base plate 12 has an enclosure element 44 extending
1 0 outwardly from the lower edge 46 of plate 12, and cover 14 an open portion
48, such that the enclosure element 44 forms a bottom wall of the shield
10, and in the closed position base plate 12 and cover 14 form a generally
complete enclosure around the electrical outlet. It is also preferred to
oversize enclosure element 44 relative to cover 14, to again cause an
1 5 interference or friction fit. This ensures that the first disengagement of
the
cover from the base plate from the closed position requires some initial
effort to overcome any stickiness. This also results in a slight outward
taper of cover towards the bottom, when the cover is mounted on the base
plate 12.
2 0 The shield has a passageway in the form of an inlet 50 in the
enclosure element 44 which is dimensioned for the passage of one or more
electrical cords out of the shield 10. A blocking means in the form of a stop
plate 52 extends outwardly from base plate 12 such that stop plate 52
prevents foreign objects like spoons, forks, and knives, or other metal
2 5 objects from making electrical contact with the outlet assembly. The
horizontal section 54 of stop plate 52 is spaced from and parallel to
enclosure element 44. The blocking means, therefore, blocks the cord
passageway or inlet 50 when no cord is in place.
The design of this passageway is such that it will accept round
3 0 cord or wide flat cord (3/4 inch) or so on Noma bars. Others may not be
able to use flat cords.
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Cover 14 is preferred to have a means for venting, such as
small vent louvres or holes 56 to provide air exchange, and is preferably
made of translucent material to allow light to pass through cover 14. The
position, size and shape of the vent holes can vary, depending upon
various parameters, such as the size of the enclosed space and air exchange
necessary. In some cases, there may be enough air exchange through the
outlet assembly itself.
It is apparent by changing the size of the shield various types
and sizes of electrical outlets can be accommodated including multiply
1 0 ganged outlets containing more than two receptacles. Various types and
sizes of plugs, night lights, and other electrical devices plugged into the
receptacles can also be accommodated by varying the size of the shield.
Preferably the present invention is moulded from plastic,
such as polypropylene, polyethylene, polyester or others that will be
1 5 known to those skilled in the art which are preferably clear or
translucent
(although solid opaque materials may also be used), readily mouldable,
relatively strong and impact resistant and available in a range of colours
and finishes. Preferably the dimensions of cover 14 are approximately:
vertical height of 5.06", horizontal width of 3.5", depth of 2.4", a
2 0 hemispherical outer radius of 1.75". The thickness of cover 14 is normally
0.13" except near the rails where it increases to .25". Base plate 12 is
dimensioned to co-operate with cover 14 with preferably some
interference of 1/32 to 1/64" between cover 14 and base 12 as discussed
above.
2 5 In use, base plate 12 is placed over top of an existing face plate,
typically flush against a wall, or the face plate can be removed before base
plate 12 is placed flush against the wall. In either case the base plate is
screwed to the outlet using apertures) 22 which register with the fastening
screw holes in the electrical outlet. Slightly longer screws may be required,
3 0 because of the additional thickness of the base plate 12 overlying the
existing face plate.
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Cover 14 is positioned vertically above base plate 12 and then
lowered such that the tongue and groove dovetail shaped rails 24 slidably
engage in a vertical motion until tab 30 registers with depression 32. A
chamfered upper portion of rails 24 on base plate 12, namely shoulder 58,
helps to ensure that the initial engagement of cover 14 with base plate 12 is
smoothly and easily achieved. Cover 14 is now in the open position
relative to base plate 12.
In the open position electrical plugs can be plugged into
receptacles 16 and electrical cords emanating from the plugs are positioned
1 0 to pass through inlet or passageway 50. The number and geometry of inlets
50 may vary, including a serrated inlet geometry that impinges on
electrical cords passing through the inlet, such that the serrations provide
resistance to pulling on the cords. The serrations may be generally
rectangular, as shown at 150, to accommodate conventional household
1 5 wires, or may be generally rounded, as shown at 152, and sized with
approximately 3/8" radius to accommodate larger sized wires. Inlet 50 may
also be placed relative to the blocking means or plate 52 so that pulling on
a cord results in a force on the plug approximately parallel to a slot axis 60
passing through the longitudinal direction of a receptacle slot 62. This
2 0 maximizes the resistance to pulling plugs out of the receptacle. The plate
52 also adds additional strain relief to the cord by causing the cord to bend
around the plate 52 prior to exiting passageway 50.
From the open position, cover 14 can be vertically slidably
lowered until tab 30 registers with recess 38 and ridge 34 registers with
2 5 indentation 36 locking the cover in the closed position forming an
enclosed space of sufficient size to house the outlet assembly and plugs
inserted into the receptacles. Cover 12 cannot be easily removed from base
plate 14 in the closed position due to the tongue and grove dovetail shaped
rails 24 and ridge 34 and indentation 36 locking means.
3 0 In the closed position cover 14 can be unlocked by pushing
toward the wall, on the top portion of the cover disengaging ridge 34 from
indentation 36 and simultaneously urging the cover vertically upwards
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laterally or if tabs 30 are used, then by pulling away sides of cover at base
and raising while still needing to overcome friction. Finger grips 40 can be
used to aid in the unlocking. It will now be appreciated that to be
successful in unlocking the cover, both sides of the top of cover 14 will
have to be pushed in towards the wall and an upward force sufficient to
overcome the stickiness of the fit between cover 14 and enclosure element
44 is required. It has been found that the necessity for two simultaneous
actions is sufficient to render the cover substantially child resistant.
Small night lights may also be plugged into receptacles 16 and
1 0 housed within the enclosed space of shield 10. Cover 14 or entire shield
10
may be made of translucent plastic to allow light from a night light to pass
through and illuminate surrounding areas. It will also be appreciated by
those skilled in the art that shield 10 may have a number of geometries
including but not limited to the generally semi-circular cross sectional
1 5 shape shown in Fig. 1, or alternatively, a box shape, a silo shape, a
wedge
shape or a combination of these shapes. All that is required is that the
closed position be one which forms an enclosure of sufficient size to
accommodate, on the one hand conventional plugs, and on the other
hand, a night light.
2 0 Also, it will be appreciated that various colours and finishes,
textures such as chrome, bronze, and the like, could be used to allow the
device to blend into the surrounding decor of the room which it is used in.
Thus in addition to being a safety device, the present invention offers
improved aesthetics over a conventional uncovered wall receptacle.
2 5 Various covers could be used with the same base plate to suit changes in
interior decorating. Further it will be appreciated that a sealing gasket
(shown as 200) could be added to the rear of base 12, to facilitate outdoor
use. The sealing gasket would be in the shape of a rectangular strip to
follow the inside edge of base plate 12. It will now be appreciated that for
3 0 outdoor use the dovetail groove between the cover and the base plate will
add to the water and weather resistance of the device. Essentially water
will have a difficult time in climbing back up around the dovetail.
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It should also be apparent to persons skilled in the art that
various modifications and adaptations of the structure described above are
possible without departure from the spirit of the invention, the scope of
which is defined in the appended claims.
