Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
TITLE: ~lectrical Plug Restraint System
The present invention relates to electrical plug
restraint systems for use with the common duplex wall
receptacles. In particular, -the invention is rela-ted to
electrical plug restraint systems which require removal of a
cover component to allow an electrical plug to be removed or
inserted in a wall receptacle.
The problems associated with wa~l receptacles and
particular, the danger these wall receptacles present to small
children has lnitiated the marketing of a number of different
systems to reduce this danger. For example, United States
Patent 4,045,108 which issued to Olsen, October 30, 1977,
discloses a plug restraint system which has paired flan3es
extending outwardly from a centrally secured portion which
flanges are adapted to contact the rear of the plug and hold
the same in the inserted position in the associated socket.
These flanges act as spring legs which may be manually flexed
to allow insertion or removal of the plug, however, the
pressure created thereby is sufficient to prevent inadvertent
withdrawl or withdrawl by a small child. A similar type
structure is disclosed in United States Pa-ten-t 4,105,274 which
issued to Casey, August 8, 1978. A further system is shown in
United States Patent 2,659,059, which issued to Johnson3
November 10, 1953.
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1 These systems satisfactorily retain -the plug in an
electrical outlet, however, the ease of inserting a plug in the
outlet and/or removal of the plug from the outlet, is difficult
and the structures are not particularly aesthetically
pleasing. An additional saFety feature of these prior art
patents, is the positioning of -the spring arms to generally
overlie the apertures of each receptacle thereby making it
difficult for a child to insert a straight object into the
receptacle.
The present invention in con-trast to the approach
adopted in the prior art patents previously referred -to,
operates on a different principle, in that a post element is
permanently secured to the wall receptacle and is adapted to
releasably engage a separate cover member. The cover member
has been adapted to allow plugs to be placed to the interior of
the cover with the cords of the plugs passing out of the cover
to the particular appliance. The cover engages the plug
adjacent the back face of the plug and preven-ts removal of the
plug as the cover is held in the locked position on the
permanent member secured to the duplex receptacle.
According to a Feature of the invention, the outer
surFace of the permanent member secured -to -the duplex
receptacle includes a surface for locking with bias arms oF -the
cover member, which can be engaged at a number of positions on
the permanent member and locked -therewith with removal oF cover
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1 belng possible by spreading the arms and withdrawing the cover
member. In -the preferred form, the permanen-t member has a
number of teeth for engaging a cooperating surface of the bias
arms.
According to a further feature of the invention, the
permanent member which i.s secured to the duplex receptacle
includes a projection which can be receivecl within the ground
aperture of one of the electrical outlets, which serves to lock
the permanent member against rotation in the plane parallel to
the face of the duplex receptacle. Securement of the permanent
member i.s possible as a screw passes through the permanent
member and is received within the central bolt receiviny
aperture provided in the duplex receptacle for securing of wall
plates.
Preferred embodiments of the invention are shown in
the drawings wherein,
Figure 1 is an exploded perspective view of the
electrical wall plug accessory and an associa-ted duplex
receptacle;
2û Figure 2 is a perspective view of the accessory with
one component thereof secured to the wall receptacle and the
cover member in an non-engaged position;
Figure 3 shows the accessory with the cover in place
on the permanent member;
Figure 4 is a cross sectional view through the
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1 accessory showing the pre-ferred locking of the cover -to the
permanent member;
Figure 5 is a view similar to the Figure 4 with -the
cover in a fixed position relative to the permanent member; and
Figure 6 is a front view of the cover member showing
details of the interior ribbing used to increase the strength
of the cover.
The plug restraint device 2, has a securing post 4
adapted to be essentially permanently secured to the duplex
receptacle generally shown as 32. The post is secured as
screw 12 passes through the back wall 14 of the post and is
received within the central aperture of the duplex receptacle
normally used for receiving the screw used to secure the face
plate 34 to the receptacle. With locking projection 28,
received within the female ground connector of the upper
electrical outlet and wi-th screw 12 secured within the
receptacle, -the securing post 4 is essentially permanently
secured to the receptacle and maintains the face plate 34 in
position. ûnce the post has been secured, the cover 6 may be
inserted thereon and removed therefrom withou-t requiring
additional tools. This is accomplished as the arms 36 are
forced outwardly as the inward projections 38 of the arms are
forced over the tooth surface generally shown as 8 on the
post 4. Therefore, the cover may be pushed over the post and
the projections 38 will be forced over surface 8 and provide a
1 lock therewith due to the biasing of the arms inwardly as the
arms require some outward spreading to be forced over the
post. Once secured, the cover cannot be inadvertently removed
without spreading of the arms 36 causing the projections 38 to
clear the tooth surface 8, whereby the cover is free to be
removed.
The cover 6 includes a central aperture for allowing
the post 4 to partially pass therethrough, and allow
projections 38 to engage the tooth surface 8. The upper
surface 16 of the post 4, cooperates with the complementary
surfaces 18 of the cover, and the lower edges 20 of the pos-t
cooperate with edges 22 of a cover to lock the cover against
rotation about the axis of the post 4. The cover 6 includes a
slot 44 to allow the cords of the electrical plugs to pass
through the cover. It can also be appreciated that the open
central area which receives one end of the post 4, could be of
a size -to allow the plugs to be inserted there-through, whereby
-the cord ports 40 and 42 would only have to be opened to the
central opening. In this case -for convenience, slot 44 has
been provided which allows the cover to be inserted over each
of the electrical cords. The securing post 4 includes
outwardly located flanges 24 for engagement with the walls ~6
of the cover to again generally fix the cover 6 so that it is
not rotatable about the post 4. Flanges 24 are received
~L~
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1 interior to the cover and are adjacent the walls 26.
As shown in Figure 2, the securlng post 4 has been
secured to the duplex receptacle and two elec-trical plugs 46
and 48 have each been inserted within electrical sockets. The
cords 47 and 4~ of plugs 46 and 4~ are positioned to allow
passage thereof -through cord ports 40 and 42 and cord 49 is
shown passing through the slot l~4 of the cover. The cover is
shown in locked position on the securing post 4 in Figure 3,
and cord 47 and cord 49 are passing through cord ports 40 and
~2 of the cover with the cover engaglng the rear face 45 of
each plug to hold the same in the received position relative to
the duplex receptacle. The cover and the plugs may not be
inadvertenly removed as arms 36 are retaining projections 38 in
locking engagement with the tooth surface 8. Details oF this
locking arrangement are clearly visible from the cross
sectional view of Figure 5.
Removal of the cover from the securing post 4 is
illustrated in Figure 4. ~ere the arms 36 have been biased
outward].y either by using two hands or using the thumb and the
2~ index ~inger oF one hand to spread the arms such that -the
projections 38 are no longer in locking engagemen-t with the
tooth sur~ace ~. Once these arms have been so positioned that
cover may be slipped off the securing post in a direction
generally indicated by arrow 50.
Further details of the cover member are illustrated in
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1 Figure 6, where the upper area of the cover has been provided
with a number of cell-like regions 52, defined between the
peripheral wall 54 and the interior reinforcing rib 56. This
upper region of -the cover connects the left hand side of the
cover with the right-hand side of the cover and must carry any
forces required to cause the outward biasing of arms 36. This
area is prone to breakage and therefore has been reinforced in
this simple manner. Such ribbing would be of reduced
significance if the central area and the access therein was
lû sized to allow the electrical plugs to be inserted therethrough
rather than allowing the cover to be inserted over the
electrical cords of the plugs to be retained by the cover.
The cover 6 and the securing post 4, can be made in
various colours and are preferrably made of a copolymer
polypropylene or ABS material. These materials should have the
appropriate fire rating required by the certifying body and
meet or exceed the appropriate building codes. It can
appreciated with this structure, the cover member 6 can be
removed from the securing post 4 without requiring any tools.
2û The arms 36 which require outward biasing to allow
removal of the cover, is an action which is not easily
accomplished by a young child, as it requires a fair degree of
dexterity and this device reduces the accessibility of -the
receptable to the child.
Although various preferred embodiments of the present
1 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.
