Note: Descriptions are shown in the official language in which they were submitted.
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WIRE RETAINING ASSEMBLY
Field Of The Invention
The invention relates to an electrical device,
such as a switch or receptacle, having an anchoring bore
and a guide slot formed in a wall adjacent each terminal
screw to retain the exposed wire on an electrical con-
ductor which i5 bent around the screw.
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Back~round Of The Invention
Making an electrical connection between the
exposed wire on an electrical conductor and a terminal
screw located on the side of an electrical device, such
as a switch or receptacle, is intricate and difficult
because the screws are small and the end of the wire must
be bent closely around the shank of the screw. Accord-
ingly, this operation is time consuming and potentially
frustrating. Moreover, it is quite important to make a
good connection in order to prevent short circuits or
other electrical hazards.
Various prior art devices have been directed
towards facilitating such a wire connection; how~ver,
they have not been totally successful. This is because
some of the prior art devices tend to bend the exposed
wire in more than one plane, which can weaken or break
the wire and tends to prevent a secure electrical connec-
tion. In addition, some of these devices require pre-
bending of the exposed wire, which is difficult and time
consuming in and of itself, or do not securely receive
the end of the exposed wire so it is free to move trans-
versely of its longitudinal axis, thereby making the
connection more time consuming. Some of these devices
also require stripping a precise length of the insulation
from the conductor, which is time consuming and dangerous
if done inaccurately.
One exampl~ of these devices includes a pocket
and a slot formed in an electrical device having a
terminal plate located in a recess. A rear wall partial-
ly spans the rear edge of the terminal plate and the end
of this wall together with a lower wall extending along
the lower edge of the terminal plate define the slot,
which is outwardly opening and has a rectangular cross
section. The rear wall and an upper wall extending along
the upper edge of the terminal plate define a 90 corner
with a triangular fillet therein at the bottom and a
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larger triangular web above the ~illet to form the pocket.
The pocket receives an end of the wire and the slot receives
another part of the conductor after the exposed wire is bent
around the terminal screw. This device allows transverse
movemen-t of the end of the wire which makes the connection
difficult and time consuming.
Other examples of such prior art devices are dis-
closed in the following U.S. patents: 2,73~,080 to Littman;
3,423,724 to Clement; and 3,861,773 to Triantaellow et al.
Thus, there is a continl7ing need for improvement
in an assembly for facilitating electrical wire connection
to an electrical device.
Summary Of The Invention
Accordingly, the invention seeks to provide a wire
retaining assembly for use with an electrical device, such as
a switch or receptacle, that can facilitate a quick and secure
connection between the wire and the device.
The invention in one broad aspect pertains to an
electrical device having a front, ~ rear, a right side and a
left side with a substantially planar portion on one of the
sides having a threaded bore perpendicular thereto. A screw
having a threaded shank is adapted to be threaded into the
threaded bore substantially perpendicularly to the planar
portion and exte~ding outwardl~y therefrom or electrical con-
nection to a conductor having an exposed wire. The improvement
comprises means, extending outwardly from the planar portion,
defining an anchoring opening for receiving and surrounding the
end of the exposed wire of the conductor to restrict movement
of the wire in all directions transverse to its longitudinal
axis. The anchoring opening comprises a bore having a diameter
slightly larger than the diameter of the exposed wire and the
bore has a longitudinal portion which is co-planar with the
planar portion, the anchoring opening being located above the
planar portion and extending outwardly therefrom.
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Advantageously, a guide slot is located adjacent
the anchoring bore fsr receiving another part of the
exposed wire on the conductor so that the exposed wire
between the anchoring bore and the guide slot is bent
around the screw shank in a sub~tantially U-shaped
configuration in a single plane.
Other aspects, advantages and salient features
of the invention will become apparent from the following
detail~d description which, taken in conjunction with the
annexed drawings, discloses preferred embodiments of the
invention.
Drawings
Referring now to the drawings which form a part
of thi~ original disclosure:
Figuxe 1 is a right side elevational view of
the wire retaining assembly in accordance with the
invention located on an electrieal switch;
Figure 2 is a right side elevational view
similar to that shown in Figure 1 except that the exposed
wire on an electrical conductor has been located in the
anchoring bore in the wire retaining assembly and par-
tially bent around the shan~ of a terminal screw;
Figure 3 is a right side Pl~vational view
similar to that shown in Figure 2 except that the exposed
wire has been fully bent around the screw shank and
received in a guide slot in the wire retaining assembly,
the bottom of Figure 3 showing the initial step of
locating the exposed wire in the anchoring bore;
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Figure 4 is a rear elevational view of the
electrical switch shown in Figure 1 with the wire retain-
ing assembly thereon;
Figure S is a front elevational view of the
electrical switch shown in Figures 1 and 4;
Figure 6 is an enlarged, fragmentary perspec-
tive view of the wire retaining assembly seen in Figure 1
but without a terminal screw;
Figure 7 is a side elevational view of a duplex
electrical receptacle having the wire retaining assembly
in accordance with the invention thereon;
Figure 8 is a bottom plan view of the recepta-
cle shown in ~igure 7; and
Figure 9 is an enlarged fragmentary perspective
view of a pair of wire retaining assemblies shown in
Figure 7 except with electrical conductors being connect-
ed thereto.
Detailed Descri tion Of The Invention
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Referring now to Figures 1-6, a pair of wire
retaining assemblies 10 and 12 in accordance with the
invention are shown located on an electrical device such
as switch 14 for use in facilitating connection of elec-
trical conductors 15 and 18 to the switch. As best seen
in Figure 1-3 and 6, the wire retaining assembly 10
comprises an anchoring bore ~0 and a guide slot 22 for
receiving the exposed wire 24 extending from the end of
the electrical conductor 16.
By initially locating the end of the exposed
wire 24 in the anchoring bore 20, then bending the wire
around the terminal screw 26 and finally locating the
other end of the wire in the guide slot 22, electrical
connecticn to switch 14 is very quickly and securely
accomplished~ with the substantially U-shaped configura-
tion of the finally bent exposed wire ~4 lying in sub-
stantially a single plane.
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As seen in Figures 1-5, the electrical switch
14 comprises a housing 28 formed of insulating material,
a metallic conducting bridge 30 having mounting holes 32
and 34 at opposite ends, and a handle 36. The housing 28
is typically formed of a plurality of parts but in all
events includes a front 38, a rear 40, a right side 42
and a left side 44.
Formed in the right side 42 are a pair of
rectangular recesses 46 and 48 t each receiving a flat
rectangular metallic terminal plate 50 and 52, respec-
tively. Each plate has an internally threaded bore, only
bore 54 being shown for terminal plate 50 in Figure 6.
Each terminal plate forms a planar portion as
the bottom wall of each recess and each of the threaded
bores is substantially perpendicular to the planar
portion.
As seen in Figure 6, recess 46 has a front wall
56, a rear wall 58, an upper wall 60 and a lower wall 52,
each of these walls being substantially perpendicular to
terminal plate 50, rectangular and planar.
As seen in Figures 1 4, terminal screw 26 has a
slotted head 64 and a threaded shank 6~, shank 66 beiny
threadedly engaged with threaded bore 54 in terminal
plate 50 in a position perpendicular to the planar
portion formed by the planar surface of the terminal
plate 50. The second screw 68 shown with regard to the
second wire retaining assembly 12 is similarly construct-
ed and positioned.
As seen in Figures 2 and 3, the electrical
conductor 16 has an insulating outer jacket 70 covering
the conducting wire 24, which can be a single wire or
stranded wire, except for the exposed end. Similarly,
the second electrical conductor 18 has an insulating
outer jacket 72 and an exposed wire 74, as seen in ~igure
3.
Referring now to Figure 6~ the wire retaining
assembly 10 is shown formed in ~h~ rear wall 58 in
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housing 28, this wall extending outwardly on the right
side 42 of the housing from the planar portion or termin-
al plate 50. The wall is adjacent and extends to the
rear 40 of the housing as seen in Figures 1-4 and 6.
The anchoring bore or first opening 20 in the
wire retaining assembly 10 is formed as a blind, cylin-
drical bore having a diameter greater than the diameter
of the exposed wire 24. The opening of bore 20 faces
screw ~6, as seen in Figure 1, and is formed directly in
the front facing surface in wall 58. Bore 20 is perpen-
dicular to the front facing surface and extends rearward-
ly therefrom.
The guide slot or second opening 22 is formed
completely through wall 58 and is outwardly opening,
being loca~ed adjacent the anchoring bore 20 and adjacent
the rear 40 of the housing. Guide slot 22 is generally
U-shaped in transverse cross section and hasl as best
seen in Figure 1 r at its bottom a first semi-cylindrical
portion 76, a semi-frustoconical portion 78 extending
from the first semi-cylindrical portion and a second
semi-cylindrical portion 80 extending from the semi-
frustoconical portion; the second semi-cylindrical
portion having width less than the width of the first
semi-cylindrical portion. As seen in Figure 3, the f irst
semi-cylindrical portion 76 will receive the outer jacket
70 and thus has a width slightly greater than the dia-
meter of that jacket and the second semi-cylindrical
portion 80 will receive the exposed wire 24 and thus has
a width greater than the diameter of the wireD
As seen in Figure 6, ~he second semi-cylindri-
cal portion 80 of the slot opens through the face of wall
58 and extends towards the rear 40 of the housing, the
first semi-cylindrical portion 76 continuing to that rear
40.
As seen in Figure 6, the bottom surfaces of
anchoring bore 20 and the second semi-cylindrical portion
80 are substantially co-planar in a plane that is
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parallel and substantially co-planar with the plane
containing the top of the terminal plate 50. In
addition, the longitudinal axes of bore 20 and slot 22
are substantially parallel, receive the screw shank 66
therebetween, and are perpendicular to the threaded bore
54 as well as the screw shank 66 as seen in Figures 2 and
3.
The second wire retaining asser~ly 12 includes
an anchoring bore 82 and a guide slot 83 similar to bore
20 and slot 22.
Installation Of The Electrical Conductor
_ _ _
Referring now to Figure 3, the first step in
installing an electrical conductor on the electrical
switch 14 is best illustrated at the bottom of Figure 3.
There, electrical conductor 18 has the exposed wire 74
received in and surrounded completely by anchoring bore
82 which is similar to anchoring bore 20 discussed above.
This is accomplished after the terminal screw 68 is
unthreaded sufficiently for passage of the exposed wire
74 into bore 82. As seen in Figure 3, the exposed wire
74 lies adjacent the shank of screw 68 below the head and
extends straight into bore 82, the inner edge of wire 74
following tangentially the outer circular edge of the
shank. Since the wire is received in and surrounded by
the bore, move~ent of the wire transverse to its longi-
tudinal axis is restricted facilitating the bending or
forming of the wire around the screw shank.
The next step is illustrated in Figure 2 with
regard to the first electrical conductor 16 which has
been pivoted counterclockwise relative to shank 66, the
exposed end 24 being received in bore 20.
The counterclockwise pivoting continues as the
exposed wire 24 is bent around shank 66 and then the
exposed wire 24 and jac~et 70 are located in guide slot
22.
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When the jacket 70 and exposed wire 24 are
fully received in slot 22, as seen in Figure 3, the
terminal screw 26 is rotated downwardly to bind the
exposed wire 24 between the head 64 of the screw and the
terminal plate 50, thereby providing a secure electrical
connection between the wire 24 and the plate 50. Since
the bottom surfaces of anchoring bore 20 and the second
semi-cylindrical portion 80 in the slot 22 are in sub-
stantially the same plane which is substantially co-
planar with the top of plate 50, the U-shaped exposed
wire 24 also lies in substantially one plane, which
assures a secure electrical connection. In this regard,
the plane containing the U-shaped exposed wire is sub-
stantially perpendicular to the shank 66 and parallel to
the terminal plate 50. As seen in Figure 3, the exposed
wire is bent around the shank less than 360.
Embodim~nt Of Figures 7-9
As seen in Figures 7-9, the wire retaining
assembly in accordance with the invention can be utilized
with a duplex receptacle 84 having a pair of female
connectors 86 and 8~.
Receptacle ~4 has a bridge 90 and our terminal
screws for use with four wire retaining assemblies in
accordance with the present invention. Since the basic
configuration of the wire retaining assemblies shown in
Figures 7-9 are the same as those discussed above and
shown in Figures 1-6, like reference numerals are used
with the addition of a prime.
The only basic difference between the wire
retaining assemblies shown in Figures 7-9 and those shown
in Figures 1-6 is that the anchoring bores 20' and 82'
extend completely through wall 58'.
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While various advantageous embodiments have
been chosen to illustrate the invention, it will be
understood by those skilled in the art that various
changes and modifications can be made therein without
departing from the scope of the invention as defined in
the appended claims.
