Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
I 97
CORN CUR FITTING FOR ELECTRICAL BOX
Background of the Invention
,
Field of the Invention
__ ____ _ _
this invention relates to synthetic resin fittings used
in an electrical service system for interconnecting wire
carrying conduits to electrical boxes, and more portico-
laxly, for interconnecting a synthetic resin electrical box
with a synthetic resin externally corrugated conduit.
Brief Duskier of the Prior Art
_
In electrically wiring a commercial or residential
facility, wall or ceiling mounted electrical service boxes
are provided and various types of electrical conductors are
extended from these boxes to outlets or points of electrical
usage throughout the facility. A practice increasingly
favored in many installations is to encase or sheath the
electrical conductors in various types of flexible conduits.
These conduits are frequently constructed and dimensioned so
that they may be easily bent or curved to facilitate select
live directional extension of the conductors and the enclosing conduit as may be required in the course of
installation.
One technique used to impart flexibility without sign-
ficant loss of mechanical properties in such conduit is the
practice of forming the conduit in corrugated form so that
the corrugations facilitate flexture of the conduit in
substantially any direction without cracking or weakening.
More recently, and increasingly, such conduit has been
formed from various synthetic resin materials.
swoons the time required for, and the ease of, install-
lion of the described electrical systems are very important
considerations in their usage by electricians, improvements
in components ox the system which improve the ease of
installation or reduce the time required to incorporate such
components are of substantial value.
In systems ox the type described which include electric
eel boxes and externally corrugated conduits in which the
conductors are enclosed, a means of connecting the conduit
to the box is required. To this end, various types of con-
nectar fittings have heretofore been proposed and many of those proposed have been utilized. One such type is that
which is illustrated and described in US. Patent 4,248,459,
assigned to the assignee of the present application The
connector fitting there depicted is a synthetic resin struck
lure which has a cylindrical portion of tapered configu-
ration so that it may be snapped into a circular opening
formed in an electrical box. The fitting carries grooves or
ridges adapted to engage the external corrugations on a con-
dull of the type described so that the conduit is engaged
with the electrical box when the fitting has been snapped
into place in the manner described.
Other fittings of this general character and mode of
usage are those which are illustrated and described in US.
Patents 3,)331,985; 3,953,555 and 1,830,250.
Brief Description of the Present Invention
The present invention is an improved connector fitting
useful for connecting an externally corrugated conduit to
the wall of an electrical box. The fitting is especially
designed and constructed to expedite the two basic monopoly-
lions which are generally involved in every system which
requires connection of a corrugated conduit to an electrical
box, i.e. engagement of the fitting with the conduit, and
engagement of the fitting with the box so that conduit and
box are interconnected through the instrumentality of the
fitting. The fitting of the invention can be as quickly
connected to the conduit as the conduit can be placed in
contact with the fitting, and solely by manual effort, and
the fitting and conduit can then be engaged with the box by
the simple expedient of snapping a portion of the fitting
through the opening formed in the wall of the box.
Broadly described, the connector fitting of the invent
lion includes a pair of preferably identical, semi-
cylindrical conduit-engaging collars which are intercom-
netted by a hinge element to facilitate opening the collars
apart from each other, or closing them to form a cylinder-
gaily configured collar. Each of the collars includes a
concave inner side which carries alternating ribs and
grooves configured and dimensioned to interlock with Corey-
gallons on the outer side of the conduit to be engaged by
the fitting. Projecting from one side of each of the
collars are a pair of spaced, box-engaging projections.
Each of these projections includes a web portion, which is
immediately adjacent and secured to the respective collar,
and a wedge-shaped free outer end portion, which is secured
to the web portion and thereby connected to the collar.
Each of the projections defines with the collar to which it
is secured, an arcuate groove or recess between its wedge
shaped end portion and the collar.
In the use of the connector fitting, the semi-
cylindrical collars are hingedly closed about the corrugated
L19~7
conduit to be connected to the electrical box to thereby engage the ribs with the corrugations. This action places
the several box engaging projections in a generally
cylindrical array, and the fitting is then snapped into the
box by pressing the wedge-shaped end portions of the several
projections through the opening in the box so that the wall
of the box surrounding the opening there through engages the
groove or recess defined between the wedge-shaped end port
lions of the projections and the semi-cylindrica] collars.
An important object of the present invention is to pro-
vise a connector fitting which can be relatively economic
gaily constructed by the molding of a synthetic resin
material, and which can be employed to quickly interconnect
an externally corrugated conduit used in an electrical son-
vice system with an electrical outlet boy.
Another object of the invention is to provide a con
nectar fitting which can be used to connect variously sized
corrugated conduits to an electrical outlet box.
A further object of the invention is to provide a con-
nectar fitting which is characterized in having a relatively long and trouble-free operating life.
Additional objects and advantages of the invention will
become apparent as the following detailed description of a
preferred embodiment of the invention is read in conjunction
with the accompanying drawings which illustrate such pro-
furred embodiment.
General Description of the Drawings
-
Fig. 1 is a side elevation view of a connector fitting
constructed in accordance with the invention.
Fig. 2 is a side elevation view of the connector
fitting showing its appearance at a viewpoint located 90
around the fitting from the point of observation presented
in Fig. 1.
Fig 3 is a plan view of the connector fitting.
Fig. 4 is a sectional view taken through the connector
fitting of the invention along an axis thereof and showing,
in section, a portion of a corrugated conduit and an
electrical outlet box which are inter engaged by means of the
connector fitting
Fig. 5 is a partial sectional view of a modified embo-
dominate of the connector fitting of the invention as it
appears when used for interconnecting a corrugated conduit
with an electrical box.
Fig. 6 is a plan view similar to Fig. 3, but thus-
treating the connector fitting when it is opened about a
hinge forming a part of the fitting, and preparatory to
having a corrugated conduit placed within the fitting.
Detailed Description of Preferred Embodiments
of the Invention
-
The connector fitting of the invention is designated
generally by reference numeral 10, and as illustrated in
Figures 1, 3 and 5, includes a pair of semi-cylindrical
collars 12 and 14. Each of the collars 12 and 14 includes a
semi-cylindrical body portion 16 of generally rectangular
cross sectional configuration, and a peripheral, radially
outwardly extending facing flange 18. At the concave inner
side of each of the semi-cylindrical collar portions 12 and
14, each collar portion carries a plurality of arcuate ribs
19 which are separated by grooves or channels 20. The semi-
cylindrical collars 12 and 14 are movably interconnected to
t97
each other by an interconnecting hinge web 22 formed to the
flanges 18. The hinge web 22 permits the semi-cylindrical
collars 12 and 14 to be opened apart to the position
illustrated in Fig. 6.
A pair of spaced, box-engaginy projections 24 and 26
extend axially from each of the collars 12 and 14 at the end
thereof which carries the radially outwardly projecting
flange 18. As best shown in Fig. 2, the projections 24 and
26 on each of the collars 12 and 14 are circumferential
spaced from each other by a gap 28.
Each of the projections 24 and 26 includes a web port
lion 30 which is secured to, and extends axially from, the
respective collar 12 or 14. Each of the projections 24 and
26 also includes a wedge-shaped, free outer end portion 34
connected to the opposite end of the web portion 30 from the
respective collar and tapering from a relatively thin, free
outer end to a relatively thick base portion 36. It will be
perceived in referring to Figs. 1, 2 and 3 that the wedge-
shaped portions 34, web portions 30 and collars 12 and 14
define an arcuate groove or recess 38 which is disposed bet-
wren the respective wedge-shaped portion and the respective
collar.
At a time when the collars 12 and 14 are closed into
abutting contact with each other, as shown in Figure 3, the
box-engaging projections on adjacent collars are separated
from each other by a gap 39.
In Fig. 4 of the drawings, a connector fitting 10 is
shown in use for connecting an externally corrugated con-
dull, used for enclosing electrical conductors to an
electrical outlet box. The conduit is designated generally
Lo
by reference numeral 40 and is illustrated as defining a
plurality of ribs 42 and grooves 44 extending circumferen-
tidally around the outer side thereof-. An electrical box is
denominated by reference numeral 46 and includes a side wall
48 which defines a circular opening 50 facilitating access
to the inside of the box
Operation
In utilizing the connector fitting 10 of the invention,
the fitting is first opened to the position shown in Ego. 6.
This is easily accomplished by pivoting the semi-cylindrical
collars 12 and 14 about the hinge web 22 so that the collars
are opened apart as shown.
After the collars 12 and 14 have been opened apart, the
end of a corrugated conduit 40 is placed against the inner
side of one of the collars so that its corrugations register
with the grooves 20 and ribs 19 carried on the concave inner
side of the collar. The other of the collars is then
pivoted about the nine web 22 to close it upon the Corey-
grated conduit and bring its ribs and grooves into registrar
lion with the ribs and grooves of the conduit corrugations.
With the collars 12 and 14 are closed about the conduit, the body portions 16 of the two collars are gripped
between the thumb and fingers to retain the connector closed
about the conduit and permit the box-engaying projections 24
and 26 to be aligned with, and pressed into, the opening 50
in the side wall 48 of the box 46. By pressing upon the
connector 10 in an axial direction, and concurrently
retaining the collars 12 and 14 in their closed position,
the wedge-shaped end portions 34 of the box-engaging project
lions 24 and 26 are forced through the opening 50 until the
wall I of the box snaps into the groove or recess 38 to the position illustrated in Fig. 4. when the wall of the box 46
has snapped into engagement with the connector 10 in this
fashion, the two collars 12 and 14 of the connector 10 are
clamped by the box well around the conduit, and the collars
are prevented from opening apart from each other.
It will be perceived, from the described mode of utile-
ration of the connector fitting, that the fitting is suscep-
title to use on variously sized corrugated conduits. Thus,
the semi-cylindrical collars 12 and 14 need not be brought
to their completely closed position around the conduit in
order to effect engagement with the conduit assuring its
position of engagement in relation to the box. It will also
be noted that the particular number and arrangement of the
box engaging projections assure that there is sufficient
flexibility afforded by the web portions 30 that the connect
ion fitting can be pressed through variously sized openings
into electrical boxes having differing constructions.
Finally, since the depths of the grooves 20 places the
bottom of these grooves substantially in alignment with the
arcuate inner peripheral surfaces of both the wedge-shaped
end portions and the web portions of the respective box-
engaging projections, the corrugated conduit which is
engaged by the connector fitting can be located at any of a
variety of selected positions within the connector in the
axial sense. Stated differently, should it be desirable to
achieve greater mechanical stability, or for reasons die-
toted by the type of electrical connection to be made inside
the box 46, the conduit 40 may be placed within the fitting
so that its end extends into the box to a location
9 do
inwardly of the inner end of the wedye-shaped end portions
34 of the fitting.
In Figure 5 of the drawings, a slightly modified embo~
dominate of the invention is illustrated. Where identical
structural elements have been used in the portion of this
embodiment illustrated in Figure 5, such structural elements
of identical character have been identified by identical
reference numerals
The embodiment of the invention illustrated partially
in Figure 5 includes a connector fitting which differs from
the embodiment previously described principally in the shape
of the free outer end portions 60 carried at the outer ends
of the projections 24 and 26 and joined by web portions 30
to the respective collars 12 and 14. As shown in Figure 5,
the outer end portion 60 is angulated radially inwardly
toward its outer end with the angle formed along the line 61
as shown in Figure 5. The free outer edge of the outer end
portion carries a radius 62 which rounds the inner side of
the outer free end adjacent its edge located inside the
synthetic resin electrical box 48.
The embodiment of the invention depicted in Figure 5
assures that in installations where the corrugated conduit
40 is terminated outwardly from the axially inner free end
of the connector fitting, and the insulated electrical con-
doctor is connected inside the electrical box so that it extends across and in contact with the outer end portion 60
of one of the respective projections 24 and 26, the radius
provided at this location will assure that chafing or
cutting through of the insulation on the electrical conduct
ion will not occur.
Such redesign is facilitated by the relatively greater thickness of the free end portions 60 of the projections 24
and 26 and such increased thickness its attained without
sacrificing flexibility in the end portions 60 of the pro-
sections 24 and 26 by reason of the angulation which permits the outer end portions to undergo flexor and constriction
when the connector fitting is pressed through the opening 50
and the wall 48 of the electrical box 46.
Although preferred embodiments of the invention have
been herein described in order to afford guidance to those
skilled in the art as to the manner in which the invention
is to be practiced, various changes and innovations can be
made in the depicted forms of the invention without doper-
lure from the basic principles upon which it is based.
Changes and innovations of this type are therefore deemed to
be circumscribed by the spirit and scope of the invention
except as the same may be necessarily limited by the
appended claims, or reasonable equivalents thereof.
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