Hinged plastic duct for conduit

A duct assembly for enclosing conduits, cables, wires, lines and the like, comprising a base having a generally U-shaped cross section along its longitudinal axis, and a cover having a generally U-shaped cross section along its longitudinal axis. The base includes a generally planar central portion with first and second legs extending substantially perpendicular thereto. The cover includes an intermediate portion having third and fourth legs extending substantially perpendicular thereto. The cover is pivotally and releasably coupled to the base at one end and releasably coupled to the base at the other end. The pivotal and releasable coupling is made up and released via a snap fit resulting from forces exerted substantially perpendicular to the longitudinal axes of the cover and the base. The pivotal coupling allows angular movement of the cover relative to the base through about 45.degree. to about 60.degree..

FIELD OF THE INVENTION 
The invention relates to a duct assembly for enclosing conduits, cables, 
wires, lines, and the like. More specifically, the invention relates to a 
duct assembly including a base having a cover pivotally and releasably 
coupled thereto at one end and releasably coupled thereto at the other 
end. The pivotal and releasable coupling is made up and released via a 
snap fit. The relative pivotal movement between the cover and base is 
limited to about 45.degree. to about 60.degree. . 
BACKGROUND OF THE INVENTION 
Numerous duct assemblies are known in the prior art for mounting conduits 
therein. There are, however, several disadvantages to many of the prior 
art assemblies. For example, most of the prior art duct assemblies that 
have a removable cover require the conduits to be placed in the base of 
the duct assembly before the cover is attached. This makes installation 
difficult, since the conduits have a tendency to fall out of the base 
before the cover is attached. In addition, some of the prior art duct 
assemblies have hinged covers which require numerous parts, and thus are 
costly to manufacture. Moreover, the hinged covers of the prior art duct 
assemblies are difficult to attach to the base and typically have 
unrestricted pivotal movement through 180.degree. . 
Examples of these prior art devices are disclosed in U.S. Pat. Nos. 
3,727,644 to Kagan; 3,927,698 to Johannsen; 4,627,469 to Buard; 4,640,314 
to Mock; and 4,720,768 to Schindele. 
SUMMARY OF THE INVENTION 
Accordingly, a primary object of the invention is to provide a duct 
assembly that can readily receive and maintain conduits therein. 
Another object of the invention is to provide a duct assembly with a 
pivotal cover which can easily be coupled to the base of the duct assembly 
via a snap fit and is limited in its pivotal movement. 
Another object of the invention is to provide a duct assembly which can be 
easily manufactured at a relatively low cost. 
The foregoing objects are basically attained by providing a duct assembly 
for enclosing conduits therein, the combination comprising: a base having 
a generally U-shaped cross section along its longitudinal axis, including 
a generally planar central portion having first and second legs extending 
substantially perpendicular thereto; a cover having a generally U-shaped 
cross section along its longitudinal axis, including an intermediate 
portion having third and fourth legs extending substantially perpendicular 
thereto; coupling members, coupled to the first and third legs, for 
releasably coupling the first and third legs together; and coupling 
members, coupled to the second and fourth legs, for pivotally coupling the 
second and fourth legs together through a maximum angular movement of 
about 60.degree. , the coupling members for pivotally coupling including a 
mechanism for releasably coupling the second and fourth legs including an 
elongated rib, an elongated groove having an elongated opening being 
defined at least partially by a resilient arm, the rib having a maximum 
transverse thickness greater than the height of the opening, and wherein 
the rib and the groove are coupled and released via application of forces 
in directions substantially perpendicular to the longitudinal axes of the 
base and the cover. 
Other objects, advantages and salient features of the invention will become 
apparent from the following detailed description, which, taken in 
conjunction with the annexed drawings, discloses three preferred 
embodiments of the invention.

DETAILED DESCRIPTION OF THE INVENTION 
Referring now to FIGS. 1 and 2, the first embodiment of the duct assembly 
in accordance with the invention comprises a base 10 and a cover 12 which 
are adapted to be releasably and pivotally coupled together to enclose 
conduits therein. Both the base 10 and the cover 12 are preferably formed 
by extrusion of a somewhat resilient polymeric material. 
The base 10 has a generally U-shaped cross section along its longitudinal 
axis. The base 10 includes a central portion 14 which is capable of being 
secured to a mounting wall (not shown) by using conventional fasteners, 
such as nails or screws. A locating recess 16 is provided in the central 
portion 14 for receiving the fasteners. The central portion 14 is 
generally planar having a first elongated leg 18 at one end extending 
substantially perpendicular thereto and a second elongated leg 20 at the 
other end extending substantially perpendicular thereto. The first leg 18 
and the second leg 20 are integral with the central portion 14. 
As seen in FIG. 3, the first leg 18 includes a planar shank portion 22 and 
an outwardly extending flange 24 forming a hook 25. The second leg 20 
includes a planar shank portion 26 having an elongated rib 28 extending 
outwardly therefrom. The rib 28 includes a first curvilinear surface 30, a 
second curvilinear surface 32, and a third curvilinear surface 34. The rib 
28 further includes a first planar stop surface 36 extending radially 
outwardly from the rib 28 connecting the first curvilinear surface 30 and 
the second curvilinear surface 32, and a second planar stop surface 38 
extending radially outwardly from the rib 28 connecting the second 
curvilinear surface 32 and the third curvilinear surface 34. The planar 
shank portion 26 of the second leg 20 includes an outwardly facing planar 
stop surface 40. The angle defined between stop surfaces 36 and 38 is 
about 105.degree. . 
The cover 12 has a generally U-shaped cross section along its longitudinal 
axis. The cover 12 includes an intermediate portion 42 having a third 
elongated leg 44 extending substantially perpendicular thereto at one end, 
and a fourth elongated leg 46 extending substantially perpendicular 
thereto at the other end. The third leg 44 and fourth leg 46 are integral 
with the intermediate portion 42. The third leg 44 is integrally coupled 
to the intermediate portion 42 by a reduced portion or curvilinear recess 
47 to permit the third leg 44 to flex inwardly and outwardly. The third 
leg 44 includes a planar portion 48 having an inwardly extending flange 50 
and a recess 52 adjacent thereto. The flange 50 and recess 52 form an 
inwardly facing hook 54. The inwardly facing hook 54 is adapted to engage 
the outwardly extending hook 25 of the first leg 18 on the base 10 via a 
snap fit. 
As seen in FIGS. 1-3, the fourth leg 46 includes a planar portion 56 having 
a curved resilient arm 58 extending therefrom and an inwardly extending 
flange 68 forming an elongated groove 60 which is adapted to receive the 
rib 28. The flange 68 includes a first complementary planar stop surface 
62 adjacent to the arm 58 and facing inwardly towards the groove 60. The 
arm 58 is coupled at one end to the planar portion 56 adjacent to the 
first planar stop surface 62 and includes a second complementary planar 
stop surface 64 at the free end, and an inner curvilinear surface 66 
extending through about 180.degree. between the first complementary planar 
stop surface 62 and the second complementary planar stop surface 64. The 
flange 68 forms the first planar stop surface 62 on one side and an outer 
stop surface 70 on its other side with a curvilinear surface 72 extending 
therebetween and including about 51.degree. . Thus, the groove 60 and rib 
28 have complementary configurations for permitting pivotal movement 
therebetween. The flange 68 and the free end of the resilient arm 58 form 
an elongated opening 74 for receiving the elongated rib 28 therethrough. 
The elongated opening 74 has a height between the inner ends of surface 64 
and surface 72 which is less than the maximum transverse thickness of the 
elongated rib 28 between the outer ends of surfaces 36 and 38. 
Preferably, the radius of curvature of surface 32 on the rib and surface 66 
in the groove are the same, and the radius of curvature of surface 30 on 
the rib and surface 72 on the fourth leg 46 are the same. 
As is evident from FIGS. 3-5, the cover 12 can be transversely snap-fitted 
to the base 14 by application of a force in a direction substantially 
perpendicular to the longitudinal axes of the base and the cover and the 
rib 28 and groove 60. This snap, or friction, fit results from forcing the 
resilient arm 58 over the rib 28 and allowing the arm to be biased 
outwardly under the influence of the widest thickness of rib 28 between 
stop surfaces 36 and 38 and then snapped inwardly due to its own 
resilience once surfaces 62 and 64 are past surfaces 36 and 38. The making 
up and releasing of the snap fit coupling preferably takes place when the 
base and cover are oriented at about 20.degree. as seen in FIG. 3. This 
pivotally couples the elongated rib 28 in the elongated groove 60 and the 
rib 28 is retained in groove 60 by the various opposed stop surfaces. The 
coupling can be transversely released via exertion of a force tending to 
pull the rib 28 from the groove 60 which is substantially perpendicular to 
the longitudinal axes of the rib and groove when the cover and base are 
oriented as seen in FIG. 3. 
The second stop surface 38 of the rib 28 can abut the second stop surface 
64 of the cover to limit the outward angular movement of the cover 12 as 
shown in FIG. 4 to about 60.degree. . The first stop surface 36 of the rib 
28 abuts the first stop surface 62 of the groove 60 to limit the inward 
angular movement of the cover 12 as shown in FIG. 5 when first leg 18 and 
third leg 44 are snapped together. The first curvilinear surface 30 of rib 
28 slidably engages and coacts with the curvilinear surface 72 of flange 
68, while the second curvilinear surface 32 of rib 28 slidably engages and 
coacts with the inner curvilinear surface 66 of the resilient arm 58 to 
provide smooth pivotal movement between the base 10 and the cover 12. As 
seen in FIGS. 4 and 5, the second curvilinear surface 32 is smaller than 
the inner curvilinear surface 66 to allow the pivotal movement of the 
cover relative to the base through about 60.degree. from a position in 
which the cover and base are essentially at a zero angle, i.e., they are 
parallel, as seen in FIG. 5. 
EMBODIMENT OF FIGS. 6-9 
Referring now to FIGS. 6-9, a second embodiment of the duct assembly in 
accordance with the present invention is shown. The duct assembly of the 
second embodiment includes a base 110 and a cover 112 which are adapted to 
be releasably and pivotally coupled together. The base 110 includes a 
central portion 114 having at opposite ends a first leg 118 extending 
substantially perpendicular thereto and a second leg 120 extending 
substantially perpendicular thereto. The first leg 118 includes a planar 
shank portion 122 having an inwardly extending flange 124 forming a hook 
125 at its free end. The second leg 120 includes a planar shank portion 
126 having an elongated rib 128 at its free end. The rib 128 includes a 
first curvilinear surface 130 having an arc of about 135.degree. and a 
second curvilinear surface 132 having an arc of about 180.degree. and a 
planar stop surface 136 extending radially outwardly from the rib 128 
connecting the first curvilinear surface 130 to the second curvilinear 
surface 132. The shank 126 of the second leg 120 includes an outer radial 
stop surface 140. 
The cover 112 includes an intermediate portion 142 having at opposite ends 
third leg 144 extending substantially perpendicular thereto and a fourth 
leg 146 extending substantially perpendicular thereto. The third leg 144 
includes a planar portion 148 having an outwardly extending hook 154 
coupled to its free end for snap-fitting to hook 125 on the first leg 118. 
The outwardly extending hook 154 is formed by an outwardly extending 
flange 150 and an inwardly extending recess 152. 
The fourth leg 146 includes a planar portion 156 including a resilient 
curved arm 158 and a flange 168 extending therefrom. The arm 158 and the 
flange 168 form a groove 160 therebetween. The flange 168 has a 
curvilinear surface 172 including an arc of about 90.degree. facing 
inwardly towards the arm 158. The arm 158 has an inner curvilinear surface 
166 With an angular extent of about 170.degree. and with complementary 
planar stop surface 162 extending radially between the curvilinear surface 
172 and the inner curvilinear surface 166. The transverse thickness of rib 
128 between surfaces 130 and 132 is greater than the height of the opening 
of groove 160. 
As seen in FIGS. 8 and 9, the cover 112 is snap-fitted to the base 110 by 
application of a force in a direction substantially perpendicular to the 
longitudinal axes of the base and cover and the rib and groove, thereby 
pivotally but releasably coupling the elongated rib 128 in the elongated 
groove 160. In the closed position shown in FIG. 9, legs 118 and 144 are 
snap-fitted together to retain conduit within the duct assembly. This snap 
fit can be released by pushing down on leg 144. 
The outward angular movement of the cover 112 relative to the base 110 is 
limited to about 45.degree. by the abutment of the outer stop surface 140 
of the shank portion 126 with the outer stop surface 170 of the fourth leg 
146. The inward movement of the cover 112 is limited by the planar stop 
surface 136 of the rib engaging with the planar stop surface 162 of the 
fourth leg. The snap fit of the cover and base is made up and released in 
a manner similar to that described above regarding the embodiment of FIGS. 
1-5 with curved arm 158 being biased outwardly on making up and releasing 
the coupling. The cover 112 and base 110 are preferably oriented at an 
angle of about 20.degree. to about 30.degree. during the snap fit coupling 
and releasing. 
EMBODIMENT OF FIGS. 10-13 
Referring now to FIGS. 10-13, a third embodiment of the duct assembly in 
accordance with the present invention is shown. The duct assembly of the 
third embodiment includes a base 210 and a cover 212 which are adapted to 
be releasably and pivotally coupled together. This embodiment is 
substantially identical to the first embodiment, as seen in FIGS. 1-5, 
except for the means for coupling the first leg 218 and the third leg 244 
together. Thus, only the means for coupling the first leg 218 and the 
third leg 244 will be discussed in detail below. 
The base 210 includes a central portion 214 having at opposite ends a first 
leg 218 extending substantially perpendicular thereto and a second leg 220 
extending substantially perpendicular thereto. The first leg 218 includes 
a planar shank portion 222 having an outwardly extending flange 224 
forming a hook 225. The outwardly extending flange 224 includes an 
inwardly sloping extension member 276 having a free end 278. The second 
leg 220 has an elongated rib 228 thereon which is substantially identical 
to rib 28 shown in FIGS. 1-5. 
The cover 212 includes an intermediate portion 242 having at opposite ends 
third leg 244 extending substantially perpendicular thereto and a fourth 
leg 246 extending substantially perpendicular thereto. The third leg 244 
includes a substantially planar portion 248 having an inwardly extending 
hook 254 coupled to its free end for snap-fitting to hook 225 on the first 
leg 218. The inwardly extending hook 254 is formed by an inwardly 
extending flange 250 and an inwardly extending recess 252. The fourth leg 
246 has an elongated groove 260 thereon which is substantially identical 
to groove 60 shown in FIGS. 1-5 and which slidably and pivotally receives 
rib 228 therein as in FIGS. 1-5. 
As seen in FIGS. 12 and 13, the cover 212 is snap-fitted to the base 210 by 
application of a force in a direction substantially perpendicular to the 
longitudinal axes of the base and cover and the rib and groove, thereby 
pivotally but releasably coupling the elongated rib 228 in the elongated 
groove 260. In the closed position shown in FIG. 13, legs 218 and 244 are 
snap-fitted together to retain conduit within the duct assembly via 
engagement of hooks 225 and 254. The extension member 276 on leg 218 
serves as a ramp for the third leg 244 to facilitate the snapping action 
therebetween. The extension member 276 also facilitates unsnapping the 
snap fit by forming a pocket 280 in which a screwdriver may be inserted to 
pry the duct assembly open and increases the structural strength of the 
cover. 
The cover 212, as seen in FIGS. 11-13, includes a longitudinal abutment 282 
extending from the interior surface of the intermediate portion 242. The 
longitudinal abutment 282 is transversely spaced from the third leg 244 to 
accommodate the free end 278 of extension member 276. When a downward 
force is applied to the third leg 244, the extension member 276 will abu 
the longitudinal abutment 282 to prevent the duct assembly from 
uncoupling. 
INSTALLATION 
In installing the duct assembly of FIGS. 1-5, the base 10 is mounted to a 
wall by using screws or the like in the locating recess 16 of the base 10. 
Then, the cover 12 is snap-fitted to the base 10 by inserting the rib 28 
into the groove 60 as shown in FIG. 3 and the cover is pivoted away from 
the base as shown in FIG. 4. Next, conduits (not shown) are placed in the 
open duct assembly and are supported between the cover and the base. 
Finally, the cover 12 is pivoted upwardly and towards the base so that the 
hook 25 engages with the hook 54 to enclose the conduits therein as seen 
in FIG. 5. The duct assemblies of FIGS. 6-9 and FIGS. 10-13 are assembled 
and used in a similar manner. Since the cover and base in FIGS. 1-5, FIGS. 
6-9 and FIGS. 10-13 can be snap-fitted together, they can also be 
disassembled via release of the rib in the corresponding groove by means 
of a force, which is perpendicular to their longitudinal axes, tending to 
pull them apart. Before this is done, the upper snap fit of legs 18 and 
44, or legs 118 and 144, or legs 218 and 244 is released. 
While only three 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.