Note: Descriptions are shown in the official language in which they were submitted.
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TITLE: PLUG LOCK FOR ELECTRICAL APPLIANCES
FIELD OF THE INVENTION
The present invention relates in general to the
locking of an electrical plug in an electrical receptacle
and has particular application for wall suspended
electrical appliances.
BACKGROUND OF THE INVENTION
Electrical heater fans have become more and more
popular over time. One of the reasons for their
popularity is that rather than being dedicated to a
15 specific location they can be moved from room to room.
In recent years electrical heater fans have been
made such that they can plug directly into and be
suspended from an electrical outlet on a wall. This
20 eliminates the requirement for floor space for the heater
fan and also raises the heater fan to a position where
the flow of heater air from the fan is off of the floor.
To date, wall mounted heater fans include a
relatively standard electric plug which is supported on
the back surface or casing of the heater fan. The heater
fan is then simply pushed by its plug into the electrical
outlet where its plug holds it suspended from the wall.
However, because there is no interlock, other than the
standard fit between the plug and the receptacle, the
plug on the heater fan is not capable of supporting a
substantial load. Therefore, the known wall mounted
heater fans are relatively light in weight having a
maximum operating capacity of 1200 watts. A ground
supported heater fan on the other hand typically has a
maximum operating capacity of 1500 watts and is
therefore, capable of producing more heat than the wall
mounted heater fan.
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SUMMARY OF THE INVENTION
The present invention relates to a locking member
which is releasably lockable within a standard wall
fitted electrical receptacle and can for example be used
in a suspension system for a wall mounted electrical
appliance such as a heater fan or the like.
The locking member itself has an insulated body
portion presenting first and second slot fitting prongs
and a ground opening fitting post arranged in a
triangular pattern with the prongs so that the locking
member fits into a standard electrical receptacle. The
post of the locking member is adjustable between a
receptacle insertion position and a receptacle locked in
position by a control member rotatably supported by the
insulated body portion of the locking member.
The locking member can be used in association with
a mounting bracket for an electrical appliance such as a
heater fan and is capable of supporting a substantial
load such that the heater fan can be of a size to operate
at up to 1500 watts of power.
BRIEF DESCRIPTION OF THE DRAWINGS
The above as well as other advantages and features
of the present invention will be described in greater
detail according to the preferred embodiments of the
present invention in which:
Figure 1 is a perspective view of a heater fan
suspended from a wall by a mounting assembly behind the
heater fan according to a preferred embodiment of the
present invention;
Figure 2 is a rear perspective view of the heater
fan of Figure 1;
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Figure 3 is an enlarged exploded perspective view
showing the bracket mount over the electrical outlet and
the bracket mount for the bracket used to suspend the
heater fan of Figure 1;
Figure 3a is an exploded perspective view showing
the same bracket as found in Figure 3 with a slightly
modified bracket mount for an electrical outlet different
from that found in Figure 3;
Figure 4 is a rear view of the bracket of Figures
3 and 3a;
Figure 5 is a bottom view of the operating part of
the plug lock from the bracket mount of Figure 3;
Figure 6 is a side view of the part shown in
Figure 5;
25 Figure 7 is a sectional view through the housing
used to receive the operating part of Figures 5 and 6;
Figures 8 is a top view of the housing shown in
Figure 7;
Figure 9 is a top view of the main plate of the
bracket mount of Figure 3 without the plug lock in
position;
Figure 10 is a sectional view of the plate of
Figure 9 when fitted with the plug lock;
Figure 11 is a sectional view of the bracket mount
similar to Figure 10 but showing the plug lock in a
different operating position;
Figure 12 is a bottom view of the bracket mount of
Figure 3 in the receptacle insertion position;
Figure 13 is a further bottom view of the bracket
mount of Figure 3 with the plug lock in the receptacle
locked in position;
Figure 14 is a bottom view of the bracket mount of
Figure 3a;
Figure 15 is a sectional view of the bracket and
bracket mount of Figure 3 when locked at the electrical
receptacle;
Figure 16 is a sectional view through the heater
fan as it is being fitted to the bracket of Figure 3.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Figure 1 shows a heater fan generally indicated at
1 supported on a building wall W above the floor F. The
wall 1 is fitted with a standard electrical outlet which
has a pair of plug receptacles. Such an outlet is shown
in Figure 3 of the drawings, located behind a mounting
bracket generally indicated at 21 for supporting the
heater fan and suspending it from the wall.
The heater fan itself comprises a casing 2 which
is preferably made from plastic. This casing encloses
the known fan and heater elements which are operated by
manual controls 3 and 5 on the front of the casing. Also
provided on the front of the casing is a grill 7 through
which air is blown from the heater fan. Again, as is
known in the art, this air can either be room temperature
or heated air, depending upon whether the heater part of
the fan is being operated.
Figure 2 shows that the rear of the heater fan is
provided with an electrical cord 9, terminating with a
plug 11. Electrical cord 9 is substantially shorter than
a conventional appliance cord and plug 11 is a relatively
low, flat profile plug providing advantages for reasons
which will be described later in detail.
Also provided to the rear of the casing is a
recess generally indicated at 15. This recess can be
used as a handle for picking up and holding the heater
fan and is additionally used as a receiving recess for
the mounting bracket for the heater fan. To this end,
recess 15 is provided with a downwardly depending hook
portion 17 and a lower sloped surface 19.
Mounting bracket 21 as shown in Figure 3, which is
again preferably made from a lightweight strong plastic,
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has a main wall 23 provided with a cross-shaped opening
27. This opening has a vertical part 27a and a
horizontal part 27b.
In the set up shown in Figure 3 of the drawings,
the cover plate over the electrical outlet extends in the
vertical direction and the two plug receptacles in the
cover plate are exposed through the vertical portion 27a
of opening 27.
If the cover plate over the electrical outlet
extends in the horizontal position, then the two plug
receptacles will be exposed through the horizontal
portion 27b of opening 27.
The main wall 23 of bracket 21 is bordered by a
raised edge 25. A pair of stops 29 are provided near the
bottom of the bracket. Bumpers 30 which are preferably
made from rubber, are provided on stops 29.
The upper end of the mounting bracket is provided
with an appliance hanger comprising an upwardly
projecting hook like portion 31 and a pair of webs 32,
each of which has a radiused undersurface 32a. Hook
portion 31 and webs 32a fit into the recess 15 on the
back of the heater fan as will be described later in
detail.
Provided on the outer ends of the hook like
portion 31 are a pair of again, preferably rubber sleeves
33, which cooperate with bumpers 30 to act as dampeners
between the bracket and the heater fan to essentially
eliminate vibration noises during operation of the heater
fan.
Bracket 21 is sized such that it is completely
covered by and hidden behind the heater fan. When the
heater fan and bracket are fully interlocked with one
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another, they appear to be a single one piece unit. The
electrical cord of the heater fan, along with its plug,
are hidden in the space between the bracket and the
heater fan which is created by the raised wall 25 which
provides a standoff between the main wall 23 of the
bracket and the back of the heater fan. As earlier
noted, the cord on the heater fan is short, i.e., it only
needs to be long enough to fit through the bracket into
the electrical outlet while the heater fan is off the
bracket and does not have to be long enough to allow the
heater fan to reach the floor. Also the flat profiling
of the plug allows it to easily fit into the storage gap
between the bracket and the heater fan.
The bracket mount such as bracket mount 35, shown
in Figure 3 of the drawings, is a very important feature
of the present invention. This bracket mount includes a
main plate portion 37 which carries a plug lock generally
indicated at 39. The plates 37 of the bracket mount
includes raised walls 38 to either side of the plug lock.
The walls provide grips for holding the bracket mount and
for pushing it into and pulling it from the wall
receptacle. They also act as stops for holding the plug
lock with the mounting bracket as will be described later
in detail.
The plug lock itself is formed from an operating
component generally indicated at 61 in Figures 5 and 6 of
the drawings, and a housing generally indicated at 75 in
Figures 7 and 8 of the drawings. The operating component
61 fits within the housing 75, and housing 75 in turn,
fits within the main body portion 37 of the bracket
mount.
Operating component 61 is formed from a
cylindrical body portion 63 having an elongated
cylindrical post 65 depending from the bottom surface of
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body portion 63. As is well shown in Figure 5, post 65
is mounted off center of body portion 63.
A lever 69 is provided on the top surface of body
portion 63 while a small rectangular tooth 67 extends
from the side of the body portion, diametrically opposite
lever 69.
As can be seen in Figure 6 of the drawings, a
small gap 71 is provided between the bottom side of lever
69 and the side wall of body portion 53.
The housing 75 for receiving operating member 61
comprises a main circular body portion 77 provided with a
25 circular neck 80 with an opening 79 provided through the
neck. A small rectangular notch 81 is provided along the
side wall of neck 80.
Depending downwardly from the main body 77 of
housing 75 are a pair of flat prongs 85 and 87. Prong 85
is slightly longer and wider than prong 87 to fit with
corresponding prong openings in most up-to-date plug
receptacles.
As shown in Figure 8, opening 79 is not centered
with respect to the two prongs, but rather is slightly
offset towards the smaller prong 87.
A side wall extension 83 is provided around the
main body of housing 75. This side wall extension
presents upper and lower shoulders 83a and 83b,
respectively.
Operating member 61 and housing 75 are preferably
made from polyester with a 30o glass filler. This
combination of elements makes the plug lock flame
retardant and makes it extremely strong.
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The plates 37 of the bracket mount, again
preferably having a plastic construction, includes a
central circular opening 51. This opening is defined by
an upper side wall 53 and a lower smaller diameter side
wall 55. A pair of flexible barbs 57 are located to
either side of opening 51.
In the first step of putting the bracket mount
together, operating member 61 is fitted into housing 75.
The tooth 67 of the operating member is aligned with
notch 81 of the housing allowing the main cylindrical
portion 63 carrying post 65 of the operating member to be
sleeved into the opening defined by circular wall 80 of
the housing. This wall provides a bearing for rotating
the operating member. The operating member drops down
sufficiently far, such that tooth 70 completely clears
through wall 80 which rides up into the opening 71
between the lever 69 and the cylindrical body portion 63
of the operating member. As soon as the operating member
is rotated such that tooth 67 of the operating member is
out of alignment with notch 81 on the housing, the
operating member and the housing are rotatably coupled
with one another. The fitting of the plug lock 39 which
comprises operating member 61 and housing 75 with the
plate 37 of the bracket mount prevents the operating
member from rotating back to a position where it can come
out of its housing, thereby maintaining the rotatable
interlock between the operating member and the housing.
This will be described Later in further detail,
Once the operating member and housing have been
assembled as described above, they are pushed as a single
unit into the opening 51 in the plate 37 of the bracket
mount. Figures 10 and 11 show that the orientation of
the plug lock can be varied relative to the orientation
of the plate of the bracket mount.
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Regardless of the orientation, the housing 75 of
the plug lock is rammed through the flexible barbs 57 to
either side of opening 51 with these barbs locking on the
upper shoulders of the protruding side wall 83 on housing
75. The lower shoulders of protruding side wall 83 sits
against the inner wall 55 around opening 51 in the
bracket mount plate 37. The housing of the plug lock is
now effectively trapped with the bracket mount.
Post 65 extends to one side of the bracket mount
in a triangular pattern with the two prongs 85 and 87
while the operating lever 69 for the plug lock is located
to the other side of plate 37 and swingable within the
raised walls 38 of plate 37. When the plug lock is
inserted in plate 37, sidewalls 38 stop the lever from
swinging and cylindrical portion 63 from rotating far
enough to allow tooth 65 to line up with notch 80 and
therefore prevent the operating member from pulling out
of the plate.
The swinging of the lever produces rotation of the
cylindrical body portion 63 of the plug lock and this in
turn produces an oscillating or orbiting motion of the
post relative to the circular housing portion 77 on the
plug lock. This orbiting motion occurs because of the
off-centering position of the post, relative to the
cylindrical body portion of the operating member.
As a result of the orbiting motion of the post on
the plug lock, it is adjustable between a plug receptacle
insertion position and a plug receptacle locked in
position. This is well demonstrated in comparing Figures
12 and 13 of the drawings.
More particularly, Figure 12 shows that the
cylinder 63 of the operating member is in a position such
that post 65 is aligned in a position centrally offset
from the two prongs 85 and 87. Figure 13 shows that the
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cylinder 63 has been rotated about 90° from position,
causing post 65 to orbit such that it is moved away from
the Figure 12 position to a position more directly
beneath and closer to prong 85.
The positioning of the two prongs and the posts in
Figure 12 is the same as the positioning as the prong
slots and ground opening in a standard plug receptacle
which allows the plug lock to be easily pushed in the
Figure 12 position into the plug receptacle. Once the
plug lock is fitted into the receptacle, the operating
member of the plug lock is turned by its lever 69 which
provides substantial leverage to produce the orbiting of
the post. When the post is adjusted to the Figure 13
position, the post wedges against the face plate over the
receptacle as the separation between the post and the
prongs and in particular, prong 85 is decreased with the
orbiting of the post. This causes both the post and the
prongs to clamp onto the face plate.
The orbiting motion of the post to the clamped or
interlocked position is enhanced by the off center
location of the bearing wall 80 for cylindrical portion
63 relative to prongs 85 and 87. This off center
location enables the post to more easily move within the
ground opening to the lacking position.
The initial step in suspending the heater fan is
to first mount bracket 21 at the electrical outlet, and
more particularly, with the face plate of the electrical
outlet. Here it should be noted from Figure 4 of the
drawings that bracket 21 on its front side, i.e., the
side that faces the wall, has four corner members 34 and
a wall 34a level with these four corner members. The
main wall 23 of the bracket is recessed relative to
corner members 34 and wall 34a. Therefore, when the
bracket is fitted over the face plate on the wall, the
face plate in fact fits into the bracket with the four
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corner members 34 of the bracket locking onto the sides
of the face plate and the wall 34a of the bracket locking
onto the ends of the face plate. This happens regardless
of the direction of the face plate, i.e., whether the
face plate is set in the vertical orientation of Figure 3
or at 90° to the Figure 3 orientation where the face
plate sits horizontally.
Once the bracket is properly positioned over the
face plate, the face plate itself stops the bracket from
twisting and the four corner members 34, as well as the
wall 34a of the bracket, fit flushly against the wall
supporting the face plate.
After the bracket has been properly positioned as
described above, over the face plate, the plug lock is
adjusted or set to the plug receptacle insertion
position, is fitted into one of the plug receptacles
leaving the other receptacle exposed. The plug lock is
then adjusted to the receptacle locked in position, to
prevent separation of the bracket mount from the
receptacle. The plate portion 37 of the bracket mount
overlaps the back surface of the wall 23 of the bracket
trapping the bracket between the building wall and the
bracket mount.
It is the bracket mount which prevents the bracket
from releasing in a horizontal direction from the wall
and it is the face plate secured to the outlet in the
wall which prevents the bracket from moving in a vertical
direction. This is well seen in Figure 15 of the
drawings. It is therefore, the actual wall itself which
supports the load of the heater fan once it is hanging
from the bracket.
Once the bracket has been mounted to the wall, it
is a very simple matter to plug the heater fan in at the
remaining exposed plug receptacle and to then hang the
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heater fan from the bracket as shown in Figure 16 of the
drawings. By tipping the heater fan, the hook 17 at the
upper side of receptacle 15 on the back of the heater fan
can be fitted over the hook 31 on bracket 21. The heater
fan is then simply allowed to drop down to its normal
upright positioning whereby the lower sloped wall 19 of
the heater fan recess 15 locates beneath the radiused
lower surface 32a on the webs 32 of the bracket. There
is a slight gap between the web under surface 32a of the
bracket and the bottom wall 19 of the fan recess which
allows the fan to effectively float on the rubber bumpers
33 of the hook 31 of the bracket hanger. This insulated
hanging, as well as the fitting of the rubber bumpers 30
on the bracket against the back surface of the heater
fan, provides an extremely effective vibration dampener
during operation of the heater fan.
The description above refers to the fact that the
face plate over the electrical outlet can be set in
either a vertical or horizontal orientation. When the
face plate is in the horizontal position and as earlier
described, the two plug receptacles will be located
within opening portion 27b of the cross shaped opening in
the bracket. The bracket mount will then be used in a
position where the main body portion of the bracket mount
is turned 90° from the Figure 3 position. Therefore, the
bracket and bracket mount can accommodate both
orientations of the face plate without having to change
the orientation of the bracket.
Figure 3a shows an arrangement in which the face
plate over a plug receptacle extends in a vertical
direction but the plug receptacles themselves are turned
at 90° from the direction that they are set in Figure 3.
This orientation of the plug receptacles is easily
accommodated according to the present invention by simply
installing the plug lock into the main body portion 37 of
the bracket mount in the Figure 11 position rather than
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the Figure 10 position. In comparing the two figures, it
will seen that in Figure 11, housing 75 carrying the
operating member 61 is turned at 90° from the Figure 10
position. The positioning of the prongs and the post on
the plug lock when the bracket mount is set up as shown
in Figure 11, can be seen in Figure 14 of the drawings.
This produces a bracket mount 35a which only differs from
bracket mount 35 with respect to the orientation of the
plug lock. The actual components used to make bracket
mounts 35 and 35a are identical.
As will be understood from the above, the entire
assembly, regardless of the direction of the face plate
over the receptacle, and regardless of the orientation of
the plug receptacles within the face plate, is set up
without requiring the need for any tools whatsoever. The
amount of support provided by the bracket is
substantially more than the holding force provided by a
convention plug on the back of a currently in use heater
fan and is more than sufficient to support the weight of
a substantially larger wall mounted heater fan than has
been usable in the past. Accordingly, this system is
capable of supporting the load of larger heating
components to make the heater fan capable of operating at
up to 1500 watts of power.
A conventional electrical outlet is designed to
accept a maximum load of about 1500 watts. Therefore,
the plug lock of the bracket mount, in effect, provides a
safety feature because the plug lock acts as a block at
one of the receptacles while the other plug receptacle
feeds power to the heater fan.
Although the description above relates
specifically to a heater fan, it will be appreciated that
the mounting system can be used for various other
different types of small electrical appliances to be
suspended from a wall. The wall mounting system in the
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present invention thereby eliminates the need for floor
space and in the case of the heater fan, raises the
heater fan to the point where the air flow is desirably
up off of the floor in the building.
Again, in accordance with the present invention,
the plug lock, using a combination of prongs with a cam
operated grounding post, can easily be adapted into a
standard electrical plug where the prongs are conductive
elements to produce a live locking plug.
Although various preferred embodiments of the
present invention have been described herein in detail,
it will be appreciated by those skilled in the art, that
variations may be made thereto without departing from the
spirit of the invention or the scope of the appended
claims.
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