CA1152198A - Cable entry port means for electrical outlet box - Google Patents

Abstract

IN THE UNITED STATES PATENT AND TRADEMARK OFFICE
PATENT OPERATIONS

FOR: CABLE ENTRY PORT MEANS FOR
ELECTRICAL OUTLET BOX

BY: THOMAS S. SLATER and WADE R. BOWDEN, JR.

ABSTRACT OF THE DISCLOSURE
An electrical outlet box has electrical power cable entry ports in which one or more closure panels are each mounted adjacent the rim of the aperture along one edge portion only of the panel, the remaining portion of each panel being free and extending substantially across the aperture in a direction angular-ly inwardly from the plane of the aperture. The closure panels are each either hingedly mounted ox sufficiently flexible and resilient so as to be self-opening, such that each free end portion is deflected away from the opening Upon passage of the cable into the aperture by manual force, and thereafter resist-ingly bears against the installed cable. Each panel may be tapered so as to have increased thickness at the base, in which case the panels are self-clamping against removal of the cable from the aperture, and may include supplementary cable gripping projections of their outwardly facing surfaces. The closure panel or panels may also be self-locating and self-adjusting for different cable sizes up to a maximum size equal to the size of the aperture. Access to the box through the cable entry port may be substantially prevented by a frangible closure member, either as a thin web joining the free end of a single closure panel to the wall structure of the box or joining the free ends of two or more panels together, or as a separate conventional knockout panel frangibly interconnected to the rim of the cable entry aperture. The closure panel or panels and outlet box also may be formed as an integral structure.

Description

6'' BACKGROUND AND OBJECTS OF THE INVENTION
7 !, . 1 . Field of the Invention 1 ~ , l~ I The present invention relates generally to electrical . :~ 19 I ouLlet boxes and the like and relates more particularly to 20 ¦ certain new and useful improvements in the configuration and 21 1 structure of the cable entry ports in such boxes which facili~ate 22 ¦ the admission o electrical power cable into the outlet box 23 ~ and retention of the installed cable in the box.
.~ 24 ¦ The usual electrical outlet box is constructed in a 25 ,1 ~enerally open top, box-like configuration with a generally 26 I~, continuo1ls side wall 7nember depending rom a back or bo~tom 27~j, wall, and fo~ned with one or more cable entry ports (hereinafter 28 some~imes referred to as "knockout windows") in the side wall ~ ~29~ me7nber, whlch are adapted to permi~ access of electrical power - :30 cables ~n~o the interior of the box. One or more electrical .

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, power cables are inserted into the box, each th~ough a cable port opening, for connec~ion,of the conductor wires to, or 3 'termination wi~h, ~he electrical fixture to be ~ounted in the box, 4 . Moreover, ln order to prevent debris from entering the box 5 ~through cable ports that are no~ utilized, and to minimize ~i~e 6 ,spead in the event that t~e electrical appliance housed in ~he 7 box mal~unctions, the typical cable entry ports in electrical 8 ,.outlet boxes axe su~stantially'completely closed by."knockout"
g .panels which are removabiy''attached to the box wall structure 10 'across each port open mg.
~1 It will be understood that.although the present 12 jinvention is descri~ed with particular re~erence to elec~rical ,3 2 outlet boxes w~ich are adapted to house the termination, i.e., 14 lelectrical connection, between the con-~uctor wires of an elec-~: ~5 'trical power cable'a~d an electrical fixture'such'as an "
~! ~6 ",electrica~ outlet receptacle or'an electrica~ switc,~t the presen~
,invention may be adapted~ where desired, for use in other 18 ¦housings ~or electrical distribution appliancee, such as elec lg trical junction boxes, 1ush type boxes~ etc. Accordingly, when 20 ¦used herein, the 'cerm "electrical outlet box~' is i:ntended to 21 ¦embrace such add~t~orlal stxuctures~ ~
: ~ 22 ¦ Also, although the present. invention is described 23 !~particular re:ference to an electrical outlet box foImed from a-~oldable plastic material and to insulated electr~cal power cab~e .;having a~ oval Jacket o~ a molded pl~stlc composition which i5 26 ' soft and readily de~ormable~ known in the art as "RO~ X" cable, 27 ;the pxesent invention may be adapted for use in an electrical 28 outlet box ormed from a metallic material7 in which case 29 it will be understood that either the aforesai~ "RO~X" cable ~' 3~ or the helical ~etal jacketed cable, ~nown in the art as '`BXI~' * Trademark - 3-,. . . . . . . . .

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c 1 cable, may be used. Accordingly, the term "electrical power cable"

2 is intended to embrace both plas.ic and metal jacketed cables.

3 It will also be understood that although the present

4 invention is described with respect to rectangularly-shaped electrical outlet boxes, the invention is equally applicable 6 to other conventionally shaped boxes, including round boxes.
7 : i 2. Description of the Prior Ar~
9 It is conventional for electrical outlet boxes to have a number of ~able entry ports in which a panel or closure 11 member normally substantially closes the port aperture and is 12 removed, or "knocked-out", to permit passage of electrical 13 power cable into the box.
14 As previously known, however, electrical outlet box lS ."knockouts" have been disadvantageous from several standpoints. I
16 Thus, removal or deflection of the "knockout" from the port 17 has heretofore required the use of a separate tool, such as 18 , a screwdriver or ha~mer or the like, resulting in a time-19 ¦I consuming two-step operation in order to insert the cable into 20 !¦ the box. Also heretofore, the port aperture and the closure 21 ¦I panel have been o a single fixed size, usually to accommodate 22 ~ the largest size standard electrical power cable possible 23 ¦, under t'le applicable electrical code regulations, such that, 24 l upon removal of the closure panel, there is a substantial gap 25 ~ be~ween smaller-sized standard power cables and the rim o~ the 26 aperture, which subjects the installation to th~ aforementioned 27 haza~ds of debris collection and fire spread. I
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2~ '; In some applications, it also has been found that the 29 connection between the conductor ~ires of the cable and the electrical appliance may be stressed or dailgerously loosened , . . .
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l by forces exerted on the cable or wires at other locations after j 2 installation. In addition, during construction of the wall 3 structure in which the outlet box is installed, the cable ; 4 conventionally is inser~ed through the cable entry port af~er

5' the box is mounted ln place, but the electrical appliance

6; may not be connec~ed to the cable and installed in the outlet box until after the wall structure is secured in place. The 8 cable is thereby susceptible to accidental removal from the g cable entry port before it is connected to the appliance, and a significant, further time-consuming effort may be required 11 to reinsert the cable into the box.
12 In Qrder to fi~edl~ retain the cable in the box for preventing such stressing on the connections or or preventing ~; 14 removal from the knockout window, clamping devices have been ; 15 previously developed or proposed, which are adapted to be 16 t secured in or adjacent each knockout window opening and to grasp 17,, the cable firmly for preventing withdrawal from the box. In 18 1I fact, such clamping devices are presently required by the 19 1! National Electric Code for multigang boxés and or so-called 20 j "old work" boxes. -~' 21 ¦ Heretoore, however, most cable clamping devices have 1 22 I been formed as independent structures which have to be fabricated 23 ¦ separately from the box itsel, in relativèly complicated 24 il structures, such as shown in U. S. Patent l~os. 3,788,5~2 issued 25 ! to Sw2nquist, and 3,493,205 issued to Bromberg. These structures 26 involve sub~antial fabrication costs over and above tho~e of 27 making the box alone. In addition, slnce clamping devices have 28 to be affixed to the box, they also entail additional installa-29 tion time and consequent labor expense. Moreover, in order to be fixedly secured in the knockout window of the box, the J~5 ~
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1 engaging means for the separate clamping device must be propor- i 2; tioned to fit the particular configuration or the knockout window' 3 Thus, unless all knockout window apertures are standardized in 4i size and shape, numerous different sized and/or shaped devices are needed, thereby greatly increasing the costs of manufacture, 6 inventory and installation time.

7 Altho~gh a metal electrical outlet box has been proposed in which a cable clamp is formed integrally with the g box structure, such as ~. S. Patent No. 3,112,938 issued to I- P. Karlin in 1963, the clamping structure there proposed ll does not automatically grasp nor resistingly bear a~ainst 12 the installed cable and several manipulative steps with separate ¦
13 tools are necessary in order to assemble the cable port closure 14 structure into a clamping position. Thus, the Karlin structure is not self-opening nor self-clamping nor self-adjusting.
16j- Moreover, the Karlin ?atent 3,112~938 s~ructure is disadvantageouc 17i since it is possible to erect Karlin's port structure with too 18 ¦ larve of a space between the cable engaging edge of the port l9 structure and the cable, so that cIamping either is not effected at all or necessitates more manipulation to es~ablish 21 the proper spacin~ in order to obtain a clamping action.
22 ¦1 A thermoplastic electrical junction box with an 23i! intégral locking and sealing structure also has been proposed 24 ¦1 in Swiss patent 349,319 lssued to F. Meili in 1960. In that 25 1 patent, the entry ports of the box are nor~ally closed by 26 knockout or cut-out covers which, when removed in the conventional i~, , .
27 ~anner, leave a circular rim OL slightly smaller diametex than 23 ' that of the port aperture, which is inclined inwardly of the ~' 29 aperture to form a relatively rigid and relatively sharp circular;
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inner edge. Thermoplastlc insulating pipe for carrying ~' , .
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1 electrical conductor wires is formed with transverse cuts in the 2 surface thereof and then inserted into the box aperture, whereupor ;
the aforesaid relatively sharp inner edge of the aperture rim 4 ' enters the cu~ in the manner of a barb to both seal and lock 5 ~ the pipe within the aperture against reverse outward ~ovement. ¦
6 As in the Karlin U.S. patent, 3,113,938, the lg60 Swiss patent 7 349,319 is therefore not self-opening and is not self-cla~ping ¦ -

8 as the structure does not aueo~atically grasp nor deflect g laterally so as to resistingly bear against the installed pipe.
The Swiss patent's entry port structure is aiso not self-adjusting 11 to difIerent sizes of pipe and is otherwise disadvantageous since 12 the require~ent for cuts in the surface of the installed pipe 13 would be difficult to obtain in conventional metal jacketed cable 14 and unacceptable in conventional insulated plastic jacketed cable.
Finally, Swiss patent 459,323 issued to A. Grossauer in 16 ! 1968 discloses an injection-molded plastic electrical ~unction 17 1'l box having entry ports for electrical conduit piping w'nich 18 j include relatively thin tongues molded integrally with the box, 19 ~¦ which are spaced radially about the ri~ of the entry aperture and .
20 1¦ extend in the plane of the aperture. The entlre box is covered 21 ¦I with a sheath of rubber or plastic, including the entry ports~
22 ll Although this patent indicates that the tongues clamp tightly 23 ll against the conduit piping when tbe latter is a~tempted to be 24 l, ~ithdrawn, the tongues are said to be relatively thin and are 25 ' formed in the plane of the aperture and therefore very lit~le 26 cla~ping strength is availablé due to the large amount of 27 deflection required to pass a conduit through the aperture.
28 ' Also, due to their location and orientation in the plane of the 29 aperture, it is believed that the tongues would be easily broken 30 upon application of a reverse outward force on the conduit and, ,, ~ ~ ,.; , .

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I ' l at best, only a small range of different-sized cables could be 2 accommodated by any one length of tongue. Also, the provision 3 of a rubber or plastic sheath enveloping the entire box in 4 order to close the conduit entry ports is believed to be 5 , impractical and tends to disguise their location, making instal-6 lation o the conduit more difficult.

8 3. Objects of the Invention g It is therefore an object of this invention to provide a new and improved electrical outlet box.
; 11 Another object of this invention is to provide a new 12 and improved electrical outlet box having a novel and improved , 13 cable entry port structure.
14 Another object of this invention is to provide a new and improved electrical outlet box which facilitates entry and 16 retention of electrical power cable in the cable en~ry ports.
17 Another object of the present invention is to provide 18 ~I new and improved cable clamp means for electrical outlet boxes 19 ¦, and the like, 20 ¦ Another object of this inven.ion is to provide a 21 ¦ novel and improved cable entry port structure for an electrical 22 , outlet box which is self-opening by manual ~orce of the end of 23 il tne electrical power cable against the port structure.
24 l~ Another object of this invention is to provide a 25 !~ novel and improved cable entry port structure for an electrical 26 outlet box which is self-clamping against removal of the 27 electrical power cable from the entry port.
28 ; Another object of this invention is to provide a novel 29 and improved cable entry port structure for an electr~cal outlet box which is self-adjusting to different sizes of electricai ' ', ~
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2 Another object of this invention is to provide a novel ¦
3 and improved cable entry port structure for an electrical outlet j 4 box which is self-locating, such that the electrical power cable 5 ! is installed in the entry port aperture at the same predeter~ined ¦
6 position, regardless of size. ~ -7 Another object of this invention is to provide a noYel ; 8 and improved cable entry port structure for an electrical outlet ,

9 box which can be relatively easily and inexpensively formed 2S ¦ -an intevral part of an electrical outlet box, and yet which ' 11 is unexpectedly durable and strong in use.
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12 Another object of this invention is to provide a 13 novel and improved cable entry port structure for an electrical .
14 outlet box which includes frangible closure means substantially ' -15 ' preventing access into the box through the cable entry port 16 structure and adapted to rupture when subjected to a predetermine~
17 , force to permit entry of the electrical power cable into the box 18 ¦ hamber 19 1', Another object of this invention is to provide a new 20 jl and improved electrical outlet box having a novel and improved 21 ¦~ cable éntry port structure which eliminates or overcomes the ~2 ¦I disadvantages of previously known cable entry ports for electrical i 23~¦1 outlet boxes or the like.
24 ll Another object o the invention is to provide a 25 !~ novel and improved cable entry port structure 'or an electrical 6 ' outlet box which enables the cable to be quickly and easily 27 ~ installed and-automatically clamped to the wall structure o 28 the box in the installed position without the use of tools or 29 parts separate rom the cable and box.
Objects and advantages of the invention are set forth ,' . j :: ~ , -'3 , , '~ ' ~ '','. ' ' ' 1,1 ' in part herein and in part will be obvious herefrom, or ~ay be 2 learned by practice with ~he invention, the same being realized 3 and attained by means of the instrumentalities and combinations 4 ; pointed out in the appended claims. I
The invention consists in the novel parts, constructions, 6 arrangements, combinations and improvements herein shown and described.

g SUlDM~RY OF THE INVENTIO~ i Briefly described, the present invention is directed 1~ to a new and i~proved cable entry port structure for an electrical 12 outlet box which facilitates both entry of the electrical power 13 cable into the box and subsequent retention of the installed 14 cable within the box chamber. , -lS ' As preferably embodied, the cable entry port structure I -16 of the invention is formed as an integral part of the wall 17 '' structure of the electrical outlet box and comprises one or more 18 , clos~lre panels, each of which are mounted adjacent the rim of 19 1¦ the port aperture along one edge portion only of the panel, 20 1l the remaining portion of each panel being free and extending ¦ :
21 1¦ substantially across the aperture in a direction angularly 22 11 inwardly from the plane of the aperture. The closure panels are 23 ¦1 each either hingedly mounted to the rim of the port aperture or 24 11 are suficiently flexible and resilient such that the ree end 25 1l portion of each panel is deflected away from the opening upon 26 manually pushing the end of the cable into the aperture, and 27 ' thereafter resistingly bears against the installed cable~ i 28'' In another preferred e~bodi~ent of the inventionj 29 each o the clo9ure panels are tapered so as to have increased thickness at the base, in which case the panels are self-clamping ~,. .
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1 against removal of the installed cable from the aperture, and 2 preferably also include supplemen~ary cable gripping projections ' -3 bn their outwardly facing surfaces.
, Also as preferably embodied, access to the box through ¦
the cable entry ports is substantially prevented by a frangible 6 closure member, which may be either a thin web joining the free 7 end of a single closure panel to the wall structure of the box ~ or joining the free ends o two or more panels together, or as g a separate conventional knockout panel frangibly interconnected to the rim of the cable entry aperture.
11 It will be apparent from the foregGing general descrip- ' 12 tion that the objects of.the invention specifically enumerated 13 herein are accomplished by the invention as here embodied.
~4 Thus, it has been found that one or more closure ;
" 15 panel members may be ormed integrally with the wall structure of an electrical outlet box adjacent the rim o the aperture . I "
17 orming the cable entry port and extending angul2rly inwardly ~; ~ 18 j therefrom. It has also been found that one or more of the a ore-;` l9 li said closure panel members may be surprisingly easily and rela-` 20 1~ tively inexpensively integrally molded into a mDldable electrical 21 ,j outlet box, 22 ~l By providing the angularly inwardly extending closure 23 j panel members wi~th free in~er end portions and also with both 4-1i ~flexibility and resiliency, either by means of the material of 2g ,' const~uction and/or the proportions thereof or by mounting the `i, 26 panel members to the wall structure of the box by means of a ; 27 living hinge, the closure panels will deflect away rom the 28 aperture to permit the electrical power cable to enter into the ~1 29 box chamber and will thereafter resistingly bear against the ~ 30 cable so as to maintain an opening which is always essentia;ly ,; ,,~ . . - -,. ,~, . . . . .
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l equal in size to the cross-section of the installed cable. It 2 has also been unexpectedly found that this port closure structure ' 3 may be deflected with no more force than is developed by simply 4 manually pushing the end of the cable against the closure panels, including, in particular, the ~foresaid soft plastic jacketed 6 "ROMEX" cable. As a result, the port closure structure of the invention is seLf-opening since no separate ~ool is required to 8 open the port closure panels. In addition, the inwardly angled g closure panels automatically self-adjust the size of the port opening to that of the installed cable, thereby at 211 times 11 minimizing debris collection in the box and the aforementioned 1~ potential ha7ard of fire-spread,without being broken away. A
13 fur~her advantage found from this port closure structure where 14 the closure panel or panels angle inwardly from the plane of the aperture is that it serves to automati,ally positively locate !
16 ~ the electrical cable at a predeter~ined position for entrance ,. ,.
17 , into the box chamber.
18 1 It has also been found, in the embodiment of the inven- ¦
19 ! tion where the closure panel members are tapered so as to be 20 11 thicker at the base thereof adjacent the rim of the cable entry 21 port structure, that the camming action of the panel members 22 against the cable upon the application of a reverse out~ard force 23 lj to the cable is unexpectedly and surprisingly strong, such that 24 1 the cable is securely and positively clamped against reverse outward movement without the need for any separate or external 26 parts. In particular, it has been found that although the 27 closure panel members are molded from plastic th~ aforesaid 28 structure resistingly bear5 against the soft plastic jacketed 29 electrical power cable with such force that it indents the outer surface o the jacket, and provldes a surprisingly strong ànd -12- .

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1 effective clamping action against such cable.
2 Moreover, by formin~ supplementary, sharp-ed~ed rib-like 3 projections on the outwardly facing surfaces of the closure panel 4 members, provision is made for~grasping a full range of sizes ; of cable up to the maximum size cable that will be accepted 6 by the aperture. Thus, there is no need for abricating separate !
cable clamp devices for different sized cables, or providing 8 separate boxes for use with different si~ed cables or conduit.
~- 9 It has also been found that by recessing the base of

- 10 the closure panel members from the rim of the cable entry port

11 apertùre, in addition to permitting the panel members to deflect -;12 and clamp against cables equal in si~e to the size of the aperture 13 without breaking, the closure panel members may be formed ~ 14 integrally with the wall structure of the box along with the , -;; 15 usual cable entry port "knockout" panels frangibly removably ', :.,:.i 16 attached across the cable por~ aperture.
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17 , rt will be understood that the foregoing general 18 j descrip~ion and the follo~Jing detailed description as well are 19 1 exemplary and explanatory or the invention but are not res~rictive 20 ¦' thereof~
2LIi The accompanying drawings, referred to herein and 22 iI constituting a part hereof, illustrate preferred embodiments of 23 il, the invention, and together with the description, serve to 24 e-~plain theq~principles of the invention.
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,1 i 1 BRIEF DESCRIPTIO~ OF THE DRAI~INGS
, j 2 FIGURE 1 is a top plan view of an electrical outlet 3 box embodying the present invention, the view illustrating a : 4l first panel member frangibly interconnected across each cable ¦
5 ! entry port aperture and an additional pair of tapered closure 6 panel members converging angularly inwardly toward one another 7 from opposite sides of the aperture for clamping an electrical 8 power cable inserted into the entry port against reverse outward j g movement;
FIGURE 2 is an elevation view of one end wall of the 11 box shown in Figure l;

12 FIGURE 3 is a view along section 3-3 of Figure 2;

13 FIGURE 4 is a VieW along section 4-4 of Figure 2;
~' . 14 FIGURE 5 is a partial bottom plan view of the back or ~ . .
~` 15 botto~ of the box shown in Figures 1 and 2, taken as indicated i: 16 at 5-5 of Figure 4;
-.~ . 17l" FIGURE 6 is a section view similar to that shown in ¦ .
8 li Figure 3, illustrating the opposed tapered and angled closure : 19 ll panels in deflected position, and resistingly bearing agains~
: I :. 20 the installed cable;
~ 21 FIGURE 7 is a fragmentary perspective view of an elec-: 22 trical outlet box constructed ln accordance with another e~bodi-23 ¦¦ ment of the present invention, wherein the cable entry port 24 1! structure includes only the opposed tapered and algled closure 25 !I panel me~bers as shown in Figure l,the convergent inner free ; .
1~ 26 ends being joined by a frangible web;.
27 FIGURE 8 is a view along section 8-8 of Figure 7;
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. 28 FIGURE 9 is a view along section 9-9 of Figure 7; ~, 29 FIGURE 10 is a section view similar to that shown in ~;~`. 30 Figure 8, showing the closure panel members with supplementary 31 &ripping projections;
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1 FIG~E 11 is a frag~entary longitudinal sec~ional view, 2 partly in elevation, similar to that of Figure 9, of an 3 electrical outlet box constructed in accordance with a still 4 i further embodiment of the invention, wherein the opposed conv2rg- ¦
ing closure panel meMbers are of essentially unifor~ thickness 6 and are joined at their inner convergent ends by a frangible 7 web;
8 FIGURE 12 is a view along section 12-12 of Figure 11;
g FIGURE 13 is a section view similar to that shown in Figure 12, showing the opposed panel members deflec,ed from the 11 aperture and resistingly bearing against the installed cable; .l 12 FIGURE 14 is a view si~ilar to Figure 11, illustrating j 13 the opposed closure panel members joined by a frangible web at

14 their approYimate mid-sections only;

15 . FIGURE 15 is a fragmentary bottom plan view of an

16 : electrical outlet box constructed in accordance with another

17 , embodiment o the invention, ~herein a single tapered closure

18 I panel extends angular~y inwardly from one side of the cable entry

19 ¦! port aperture and is franglbly interconnected with the side

20 il wall of the box adjacent the wall in which the aperture is

21 ~ formed;

22 ! FIGURE 16 is a ~fragmentary sectional view partly in

23 1' plan, of the:structure of Figure 15, illustrat~ng the closure

24 ' panel in deflected position and resistingly bearing against the installed cable, the view also illustrating supplementary 26 gripping projections on both the panel and the wall structure 27 ~for grasping the installed cable;
,.~ " i ;: 28 FIGURE 17 is~ a rag~entary elevational view of an 29 electrical outlet box constructed similar to that shown in Figures 7^10, wherein a pair of opposed tapered and angled . ., . ~.s .
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l closure panels converge ~oward one another from the longitudinal ~i 2 side ril~s of the cable entry aperture and a third tapered 3 closure panel converges angularly downwardly from the box wall 4 ' structure toward the convergent inner ends of the pair of opposed closure panels;
6 FIGURE 18 is a view taken along lines 18-18 of Figure 17;
8 FIGURE 19 is a vlew taken along lines 19-l9 of g Figure 17;
FIGURE 20 is a fragmentary perspective view of an ll electrical outlet box constructed in accordance with a further 12 embodiment of the invention, wherein a group of four tapered 13 closure panel ~embers each converge angularly toward one another ¦
14 and a center ~rangible web joins one opposed pair of converging 15 ! panel members, the cable entry port aperture and closure 16 structure being located in an angled corner of the outlet box 17 ,. joining the bott~m wall and the ad acent front-to-rear wall;
18 1l . FI~URE 21 is a bottom plan view of the diagonal wall 19 ~l portion o Figure 20 joining the bottom wall and the adjacent 20 j front-to-rear wall; .
21 FIG~RE 22 is a sectional view, partly in elevation, 22 taken along line 22-22 o~ Figure 21;
23 il . FIGURE 23 is a fragmentary cross-section view, similar 24 ,I to Figure 8, o a further embodiment o~ a cable entry port

25 ; structure for an electrical outlet box constructed in accordance

26 with the invention, illustratin~ ~'ne pair of opposed tapered . I

27 and converging closure panel members each mounted at one end

28 adjacent the rim of the cable entry aperture by a live, integrally

29 molded-in hinge;-, c~ t Fl~, I
IGU~E 24¦is a fragm~ntary -ross-section ViPW similar ~ '' ' ' ' 1 to Figures 15-16 of another embodiment of a cable entry por~ j 2 structure for an elec~rical outlet box constructed in accordance j 3 with the invention, wherein the closure panel is mounted at the 4 ' base thereof by means of a live, inteOrally molded-in hinge located relatively inwardly of the wall structure of the box 6 containing the cable entry port aperture, the view also illustra-7 ting a plurality of rib-like gripping projections forming a 8 serrated outwardly facing surface on the closure panel; and qcl~actnt fl~ 16 9 FIGUP~ 25~is a similar fragmentary cross-sectional view of the embodiment shown in Figure 24 illustrating the 11 closure panel member in a defiected condition and in cammed, 12 clamping engagement with an installed electrical power cable.

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18 ; : DESCRIPTIOI~ OF THE PREFE~RED EMBODIMENTS
19 ! Referring ~enerally~to the embodiments of the inven-20 ¦j tion shown in the accompanying drawings, wherein like reference Zl~ numerals refer to like parts,~there is illustrated an electrical 22 Jj o~utlet box, indicated generally by reference numeral 1, which 23 1l advantageously may be~of~a generally~rectangular:shape and 24 l~includes a bottom wal~l 2,~a~pair of~opposed end walls~3, 4, a 25 ' pair~of opposed side walls ~5,~ 6 extending between the;aforesaid ;26 ~jend walls, eac~ of the end~and side;walls terminating in a 27 continuous~front edge~7 lylng in a frontal plane which is 28i ~parallel to the bottom wall 2 and defines the front opening 8 o 29 ¦the box. Outlet box 1 also advantageously includes an opposed ¦ .
pair of conventional mounting post members 9 adjacent each of the ' -,, .

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~- end walls 3, 4 for securing an electrical fixture to the box, as is well known in the art. Advantageously, each of posts 9 includes an unthreaded borehole 9a (see Figure 1) for slidably receiving a unting clip (not shown) in each of the posts adjacent the borehole for quick fastening of a threaded screw thereto, such as is more fully described in U.S. Patents 3,955,463 and 4,105,862.
As previously mEntioned, it will be understood that, although a rectangular outlet box is illustrated in the drawings and referred to in describing the invention, the invention is not limited to any particular box configuration, and its application to boxes of other configurations, such as round boxes, will-be readily apparent to those of ordinary skill in the art. Also, it will be und~rstood that box 1 may be suitably adapted for attachment to a stud, to wallboard and the like in any desired fashion.
However, for convenien oe in describing the present invention, such mounting means are not shGwn on box 1.
Referring now more particularly to Figures 1-6 of the accompanying drawings, there is illustrated a first embodiment of cable entry port means constructed in accordance with the invention, indicated generally by reference number 10, which is adapted to be formed integrally with the wall structure of electrical outlet box 1, and which is self-clamping against removal of a cable installed in the entry port.
In accordance with the invention, cable entry port means 10 includes a pair of closure panel members, both indicated by reference - nu~ber 14, which depend from opposite sides of the rim of cable entry apertures, preferably formed in end walls 3 and 4 of outlet box 1, and converge angularly inwardly t~ard , ;~ - .
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1 each other, terminating in free ends 25 separated by a distance 2 which is preferably less than the narrowest dimension of the 3 electrical power cable to be inserted into the box. The cable 4 entry apertures are indicated generally at 22 and provide access for admitting an electrical power cable to the interior 6 of box 1.
7 . . As here preferably embodied, each closure panel 14 8 extends from a portion of its corresponding end wall 3 or 4, ~` 9 so that its outwardly facing surface forms an angle, indicated at oC in Figure 1, of about 45 with end walls 3, 4. In addition, 11 the angle, ~ , formed by the inwardly facing surface of each ; 12 panel member and the adjacent end wall 3 or 4 is, advzntageo--sly, ~ 13 slightly smaller, preferably on the order of about 35~-40~, than `~ 14 that made by its outwardly facing surface, so that the panel :~ , members 14 each taper slightly towards their convergent inner 16 free ends 25, providing a generally rigid portion where the panel 17 is attached to the end wall at the rim of the aperture, while also 18 l providing flexibility at the COnVergent inner free ends 25, 19 ,~such that the panel members 14 deflect laterally away fro~ one 20 jl another upon pas9age of the cable into the aperture 22.
21 ¦¦~ Also as preferably embodied, and as is more fulIy 22 i described hereinaf~er, closure panel members 14 are ormed from 23 ,, a material having suitable resiliency such that, upon being 24 i deflected laterally away from one another and also relative to aperture 22, the free end portions thereafter resistingly bear 26 against the installed cable. . -,~ .
27 For additional flexibility, the thickness of the free 28 end portion of each closure panel 14 advantageously may be reduced 29 by about half, as hy notch 24 preferably formed at about 1l16"
to about 1/8" from the end edge 25 of each panel member LO provide '':~ ' ", ,~j .
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1 a ~enerally flexible and resilient end to grasp a cable. Thus, 2 the end edge of each panel 14 is much more flexible than the 3 rest of the panel 14 so that relatively thin cables (such as indicated in phantom at 26 in Figure 3) can be inserted between 5I the inner grasping edges without ca~sing the cable to bend.
6 ~oreover, the reduced thickness inner end edges enable secondary j grasping points to be provided with substantial rigidity while 8 the thin ends move out of the way of thicker cables, as will be g' described more fully below with reference to Figure 6.
Accordingly, when electrical power cable 26 is inserted 11 into an open cable entry aperture 22, the cooperating opposed 12 tapered and angled panel members 14 will resiliently flex 13 inwardly of the box to permit relatively easy insertion of the 14 cable and thereafter resistingly bear against the installed cable. Thereafter, upon application of a reverse outwardly 16~ directed force on the cable, tending to remove the cable from 17 !~ opening 22, the convergent inner free ends 25 of panels 14 are 18 i urged by means of a caFming action progressively more tightly 19 ~' against the cable, into increasing gripping engagement therewith, thereby effectively clamping the cable against reverse outward 21 movement.
22 . It has been fo~nd that, where the plastic ~acke~ed 23 "ROMEX" cable is used, the inner ends 25 of panels 14 resistingly 24 ¦~ bear against the cable with sufficient force to indent the cable jacket, which force remains even at high temperatures, on 26 the order of 90C., enabling the aforesaid camming action to be 27 obtained under high temperature conditions for both plastic 28 and metal jacketed cable. To the foregoing end, the free end 29 edge 25 of each closure panel 14 advantageously is formed with a ' generaily sharp corner, facing the other panel in each cooperating , ,, ' ' , ' - :
' pair of panel me~bers to provide a rib-like structure for wedyirlg into cable 26. In addition, the distance between such cooperating sharp edges is advantageously proportioned to accommodate the variety of thicknesses for the cables which may be received within the cable entry apertures 22 in box 1. m us, for example, for the usual residential single- and double-gang outlet boxes, adapted to acccm~odate AWG (American Wire Gauge) #14, #12 or #10 wires, the spacing between the inner end edges 25 of panel members 14, indicated at d in Figure 1, is advantageously dimensioned at about 0.15 inches.
~en a relatively large diameter cable, indicated at 27 in Figure 6, is inserted into the cable opening 22, the cooperating pair of closure panels 14 spread apart in a generally elliptically-shaped curved configuration,-as shown in ~igure 6, since they are essentially cantilever beams. As a result, the end edges 25 of closure panels 14 may be unable to grasp the cable. merefore, in accordance with the invention, supplementary gripping means is provided for grasping and clamping the cable agalnst reverse outward movement. To this end, secondary grasping means, in the form of a rib-like projection, indicated at 25a in Figure 3 and formed by notch 24, are preferably formed on each panel 14, recessed frcm the - 20 end edge 25 to grasp the insulation on thick cable 27 for preventing withdrawal thereof. M~reover, projections 25a can be stiffened, or buttressed, by providing any desired thickness to the portion of each panel ; bet~een the notch 24 and the wall portion to which the panel is attached, to ensure a firm grasp on such large cables. Alternatively, paneI 14 ~- may be formed with rib-like projections, such as shown at 35 and described below with reference to Figure 10, either instead of or in addition to the notch/edge configuration 24, 25a.

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l As preferably embodied, closure panel members 14 2 extend lengthwise, from a point just in front of bottom wall 2 3 of outlet box l, as described more fully hereinafter with 4 respect to Figure 5, to a point forward of the front edge of aperture 22, as shown in Figures 2 and 4. Accordingly, if 6 cable 26 is inserted into opening 22 frem behind box 1 so that 7 it curves towards the front of the box, as indicated in phantom 8 in Figure 4, the cable will still be retained in the box by the g portion of the closure panel members 14, which lies forward of the front edge of opening 22.
11 According to the invention, as illustrated in Figures 12 1-6, cable entry port structure 10 may advantageously be 13 adapted to permit the usual "knockout" closure panel to be for~ed 14 across each cable entry port 22 for preventing fire spread as well as preventing any debris from entering any cable entry 16 port that is not utilized for allowing access into the box 17 for an electrical power cable. To this end, each closure panel 18, member 14 is preferably attached to its corresponding end wall 19 , portion 3,4 by a projection, or base portion, 14a, as best sho~m 20 ~ in Figures 1 and 3, which is slightly recessed from the rim of 21l aperture 22 and spaces the panel 14 inwardly from its associated 22 ! end wall. In this way closure panels 14 themselves are suffi-23 1I ciently spaced inwardly and laterally of the ri~ o aperture 22 24 Ij to accommodate the usual knockout closure panel, indicated at 28, ¦
which is removably attached across each cable entry port 22.
26 Advantageously, knockout panels 28 are attached to end wall ~ , .
27 portions 3, 4 by frangible web members 30, with shoulder 32 28 formed on bottom wall 2 to facilitate removal, similar to the ;; 29 knocXou~ panel means disclosed in U. S. Patent 4,007,852, assigned to the same assignee as the present application and which patent ", . . :

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is of interest. However, other conventional knockout wind~w closure panels may be used, the structure of which will be apparent to those of ordinary skill in the art.
As preferably embodied, the side edges of knockout panel 28 are chamfered, or beveled, slightly, as shcwn in Figures 1 and 3, in order to permit the-portions of the ld which form knockout panels 28 and closure panels 14 to be proportioned for sufficient structural strength to withstand the stresses generated during molding. Advantageously, shoulder 32 may be provided by forming bottGm wall 2 with a generally ; 10 thickened portion as shcwn in Figure 4. In addition, it will be found that the base portions 14a associated with the panels 14 ~hich are ; positioned adjacent the screw-mounting post 9 may, in part, extend directly frcm the post and those portions 14a associated with the panels 14 which are positioned adjacent a side wall portion 5 or 6 may, in part, extend directly from that side wall portion.
; Also as preferably e~bodied and as shcwn in Figure 4, the bottom edges of closure panels 14 are formed separate from bottom wall 2 to enable them to be free and act indepPndently of the bottom wall. To this end, :~ the portion of the injection mold which forms the exterior surface of bottom wall 2 may be formed with projections proportioned and positioned to correspond to the cross-sectional area of each panel 14, formlng holes 21 which éxtend oompletely thrcugh bottam wall 2 to defLne the bottom edge of each panel 14. m e bottom edge of éach panel is thereby visiblP
; ~ frcm the botb~m of box 1 through slots 21 as shcwn in Figure S. In this context, it will be understood that by forming bottom wall 2 with a thickened portion, as shcMn in ' ''', :.' ~ ' ' ' ' ' . " .
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( l, 1 Figure 4, the bottom wall will be sufficiently strong to with- j 2 stand all the stress, impact, etc. required by Underwriters' 3 Laboratories and any Code writing associatlon.
4 It will be understood that the present invention is not limited to any particular size of electrical outlet box or 6 cable entry port structure and the following dimensions are given¦
7 as an example of a box incorporating the invention, from which 8 other equivalent dimensions will be apparent to those of g ordinary skill in the art. Thus, it has been found in an electrical outlet box molded from an injection moldable thermo- ¦
. I
11 plastic resin material, more fully described hereinafter, that 12 apertures 22 advantageously may be approximately one-half inch 13 (1/2") wide and one-half inch (1/2") long; the point of conver-14 gence of closure panels 14 may be approximately three-eighths inch (3/8") from the inside surface of end walls 3 or 4, and 16 panels 14 may preferably taper from a thickness of about 0.030"
17 (approximately 1/32") thick at their convergent inner free ends to about 0.060" (approximately 1116") thick at their bases 19' adjacent the rim of aperture 22~
20,' The 1exible inner edge portions of panels 14 may range 21¦i rom about 0.030"-0.050" thick when formed of the aforementioned 22l thermoplastic material to provide the flexibility described above ¦
23~l with the thicknesses of the remaining panel portions determined 24 ,I by the angles ~ and ~ if they are formed without secondary grasping means or projections 35. However, if the panel is 26 ~ormed with the notch and edge 24, 25a, the panel portion between 27 the notch and the point of attachment may be made in a somewhat 2~ greater thickness, i desired.
29 Re~erring now more particularly to Figures 7-9 of the .accompanying dra~7ings, there is illustrated a preferred alternate , , .
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( 1 embodiment of the electrical outlet box of the present invention, 2 wherein the cable entry port means is self-opening, such that 3 a conventional electrical power cable ~ay be installed without 4 the use of separate ~ools such!as a screwdriver or the like.
To that end, as best seen in Figure 8, the adjacent 6 convergent inner ends 25 of closure panel members 14 are joined 7 by a frangible web member 34, which is adapted to be readily 8 broken by manually forcing the end of a conventional plastic or g metal jacketed elect~ical power cable against the web. Although web 34 is shown extending along the entire length of the 11 convergent inner ends of panels 14, alternatively, and with 12 equally satisfactory results, web 34 may extend between the 13 convergent ends 25 of panels 14 along only 2 short portion of 14 their length, on the order of approximately 1/8-1/4 inch, pref-erably at the mid-section thereof, in a manner similar to that 16 shown in Figure 14.
17 Web 34 advantageously is attached to the free end edges 18l; 25 of panels 14 by additional intermediate web sections 36 which 19,~ are recessed back from the oppositely dis~osed pointed edges 25a which project to~7ards eac~ other in each cooperating opposed 21 pair of panels 14. In this way, if web 34 is complately removed 22 (as will be described ~ore fully below), the remnants of web 23' portions 36 left on closure panels 14 will be spaced from 24 . grasping edges 25a so as not to interfere with their cable grip-ping function.
26 As preferably embodied, each cable entry aperture 22 is 27 formed with a component portion, designated at 22a, exter.ding into~
28 bottom wall 2. The shape of aperture portion 22a is generally 29 V-shaped and conforms to the cross-sectional configuration provided by the closure panel members 14, as indica~ed in Figure 7, ~5~ .
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1 In this way, outlet box L, panels 14 and frangible webs 34 and 2 36 can be integrally formed from a moldable plastic material 3 and the bottom edges of panel members 14 can be formed 4 separated from bottom wall 2 to provide freedom for each panel 14 to flex independently of bottom wall 2 when cable 6 26 is inserted therebetween. .
7 ~ Also, as preferably embodied, the generally V-shaped . 8 space between closure panels 14, which opens in a direction i g perpendicular to the frontal plane 7 of the box, is at least - 10 substantially closed by a third closure panel 38 extendingll transversely and closely adjacent to the frontmost edges of the 12 angled closure panels 14. Advantageously, a reiniorcing rib 13 or strut 38b is formed to extend between the top of port clo~ure ¦
~- 14 panel 38 and the inside surface of end walls 3, 4.
;
~ lS Of course, the front-facing edges of panel members 14 ,, ~: ~ 16 are formed independently of third closure panel 38 and as 17 previously mentioned, the bottom-facing edges of panels 14 ~` 18, are formed independently of the bottom wall 2 of the outlet box (: 19l~ 1, as shown in Figure 9, to permit deflection of panel m~mbers 14.
.~ 20 I,i To thi5 end, the innermost surface of web~34 preferably ter~inatec - 21 ¦l even with the backwall upper lip, indicated at 2a, and the 22 ,l edges of rigid closure panel 38 are proportione~d to correspond ~ ~ 23 ! to the generally V-shaped contour of the opposed facing surfaces :~ ~ 24 ',; o panels 14 and web 34, or they may be slightly spaced therefrom, : 25 as indicated by the letter s in Figure lOo In this way, ~he 26 appropriate mold elements may be accommodated for.forming the I -~c -~ 27 various surfaces and edges of panels 14 and 38, webs 34, 36 and 28 bottom wall 2 in a two-part molding machine, 29 Third closure panel 38 serves not only to prevent fire

30 spread and debris from falling into the interior of box l when ,'''`` ' ~ ' ' ' :
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1 . .,.,................... _, , , l web 34 is not opened bu~ also to prevent a cable 26 from 2 slipping forward, i.e. mo~ing laterally towards the front of 3 ~ox 1, out of grasping engagement with the edges 25 of panel 4 members 14. T~us, each cable entry port which is not utilized will remain substantially closed by the combination of closure 6 panels 14, webs 34 and 36 and closure panel 38.
7 Referring now more particularly to Figure 10, as 8 previously mentioned, the supplementary cable gripping means g of the invention may also include the formation of one or more additional relatively sharp-edged rib-like projections 35 extend-'.
ll ing along the length of the outwardly facing surface of each ~ -12 of panel members 14. Advantageously, projections 35 are located j 13 about l/16" to about l/8" from edge 25a, and enable the panels 14 14 to grasp thick cables despite substantial bending such as l; shown in Figure 6. Furthermore, in order to form projections 35 ¦
16 by a two-part molding machine as described above, rigid closure :
17 panel 38 is preferably formed with corresponding notches, ~` 18 i indicated at 35a, in registry with projections 35.
g l~ As previously mentioned, as preferably embodied 20 ! frangible web 34 is readily pierceable by the force developed 21 I upon manually pushing the end of an electrical power cable agains ~ 22 the web, so as to thereby be self-opening. To that end, web 34 ; 23 , may advantageously be formed with a reduced thicknecs center 2~ portion, indicated at 34a on Figures 8 and lO. It has been ~;~ 25 ~ound that when formed rom a thermoplastic resin materia~ as is 26 more fully described hereinafter, web 34 will withstand a force ;~ ~- 27 of 10 pounds and yet be readily pierceable merely by pushing the 28 end of an electrical power cable thereagainst, where the reduced ~;~ 29 thickness center portion is approximately 0.010" thick and the 3d .web increases in thickness to approximately 0.020" thick at~ its , ., ,, . _ - a~1-.

( l ; 1 attachment to webs 36, the latter also approximately 0.020" thick.
2 Alternatively, it will be understood that if desired 3 frangible web 34 ~ay be formed somewhat thicker so as to be 4 rupturable only with the aid of a separate tool such as a screwdriver or the like. Accor~ing to one such embodiment, web 6 portions 36 may be formed relatively thin so tLat web 34 resembles a narrow knockout panel which can be removed by pushing it 8 inwardly with a screwdriver or similar tool, thereby breaking g the webs 36. Alternatively, the tip of a prying tool may be inserted between the projecting end portion 38a of third panel 11 38 and the front-facing edge of web 34 to break webs 36 by - 12 prying web 34 inwardly, using the edge of projecting portion 1~ 38a, reinforced by rib 38b, as a fulcrum. Thereafter, a cable 1~ may be reinserted into the space between the oppositely disposed 1~ lS convergent ends 25 of panels 14 which will grasp the cable, as 16 previously described 17 l~ It will be seen from the foregoing that the cable entry 18 i port means of the invention as preferably e~bodied is both 19 1' sel-opening and self-clamping. The port means is self-opening ~1~ 20 1 in that no separate tool such as a screwdriver or the like is - ~ 21 ¦ required in order ~o break the frangible closure web 34. The 22 1l tapered closure panels are also self-clamping since, upon in~ard 23 ~1 movement of the cable into the box chamber, the angularly inwardly i~ 24 ' directed closure panels are slightly spread apart and their ~ 25 resiliency causes them to resistingly bear against the ,~ 26 cable. Consequently, a reverse outward orce thereafter applied 27 to the cable causes the inner end portions of the closure 28 panels to be urged by means of a camming action progressively ~:.
29 more tightly against the cable, into increasing gripping engage--~ 30 mén~ therewith, thereby efectively clamping the cable "' "

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against reverse outward movement.
It will alxo be seen that the cable entry port means of the invention as preferably embodied is also both self-locating and self-adjusting for different sizes of electrical power cables passing into the box chamber. Thus, the provision of opposed inwardly angled clo$ure panels serves to locate the electrical power cable within the box at a predetermined, consistent location, which is at the apex of the converging panels, irrespective of the cable size. Also, the preferred lengths and thicknesses of the closure panels, particularly when formed from a moldable plastic material, as is more fully .
described hereinafter, provide the panels with sufficient flexibility and- resiliency so that they deflect laterally away from the point of convergence, thereby permitting the panels to adjust to the different cable sizes, and yet resistingly bear against the cable in their deflected condition. By recessing the base of the closure panels away from the aperture rim, as best seen in Figures 3 and 8, cables having thicknesses up to a thickness equal to the width of the entry aperture can .
be accommodated with satisfactory results.
Referring now more particularly to Figures 11-14 of the accompanying drawings, there is illustrated an alternative embodimen~ of the invention, wherein the cable entry port closure panels extend angularly inwardly from the rim of the port opening and are self-opening for quick entry of the cable therethrough, as well as self-locating and self-adjusting, but provide only slight clamping action against the installed -; electrical power cable. As alternatively embodied, the opposed closure panels 44 are of a uniform thickness throughout which ,:

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, , is relatively thin, on the order of about 0.030" (appro~imately 1/32") thick, and the frangi~le connecting web 45 is on the order of ahout 0.010" thick, as indicated at t on Figure 12, when injection molded from a thermoplastic resin material, more fully described hereinafter. In addition, the angle formed between each panel 44 and the end walls 3, 4 to which each is attached is preferably on the order of about 30.
Pigure 13 illustrates panels 44 in their deflected condition and resistingly bearing against the installed cable, indicated by reference numeral 460 Figure 14 illustrates at 45a a modification of the frangible web joining panels 44, wherein the web is attached to the clo~sure panels along only a short section of their length, on the order of approximately 1/8 - 1/4 inch.

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(' 1 In the embodiment shown in Figures 11-14, the inwardly 2 converging closure panels 44 have been found to be advantageous ~; 3 in use since, in a manner similar to closure panels 14, they flex `~ 4 only a distance sufficient to permit the cable to pass through th2, ~ 5 port aperture, thereby maintaining a substantially closed opening I
- 6 even in use and hence minimizing debris collection and the hazard !
7 of fire spread.
8 Referring no~ more particularly to Figures 15-16 of g the accompanying drawings, ther~ is illustrated a further ~` 10 embodiment of the invention, wherein the cable entry port means ~; 11 includes only a single closure panel member, indicated by refer-12 ence numeral 50.
13 As shown in Figures 15 and 16, panel 50 is formed 14 integrally with end wall 3 at a point adjacent but recessed from one longitudinally extending side rim of aperture 22 and 16 eY.tends angularly inwardly therefrom terminating in a free end portion 51 adjacent the slde wall 6 ad~oining end -~all 3.
18 Advantageously, and as here embodied, panel 50 is tapered so as 19 to have increased thic~ness at the base 52 thereof adjacent the 20 ~ ,!rim of aperture 22, and is frangibly joined to side wall 6, by 21 'web 53 similar to any of the manners previously lllustrated and 22 described. ~Also advantageously, the outwardly facing surface 23 54 of panel 50 is provided ~ith a supplemental gripping project~on 24 35, as shown in panels 14 in Figure 10, and a~further gripping ;25 projection 55, similar in configuration to projection 35, is 26 provided on the inside surface of side wall 6 at the point 27 of the frangible attachment of panel 50 thereto. A rigid closure 28 panel 56, similar to panel 38 but formed in the general shape of .~ ~ 29 a right triangle~ the hypotenuse of which extends generally parallel to panel 50, substantially closes the right triangularly-, ~".;~

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, 1 shaped opening formed in the bottom wall 2 and facing the front 2 opening 8 of the outlet box.
3 It will thus be seen that, in a similar manner to that 4 previously described and illustrated in connection with the inwardly converging pair of tapered closure panels 14 joined 6 by frangible web 34, and as illustrated in Figure 16, web 53 may 7 be broken by manually pushing the end of an electrical power 8 cable against panel 50, whereupon panel 50 will deflect laterally g ~way from aperture 22 and thereafter resistingly bear against the installed cable. Exertion of a reverse outward force on l cable 26 thereafter causes panel end 51 and/or projections 35 12 and 55 to be cammed into progressively tighter gripping 13 engagement with the cable, thereby clamping the cable against 14 reverse outward movement.
15 ~ Although the embodiment of the invention in Figures lS-16 16 is thus also self-opening and self-clamping, as well as 17 l~ self-locating and self- djusting to different cable sizes, it 18 1i will be understood that panel 50 need not be tapered and 19 I may be of substantially uniform thickness, similar to panels 44, ¦
20 j if clamping action is not required. .
I .
21 j It will also be understood that closure panel 50 may 22 , be spaced inwardly of its adjacent~end wall 3, 4 by a base 23 .I projection similar to 14a, as best shown in Figure 3, to permit 24 ,, use of a conventional entry port "knockout" closure panel.
Other modifications o panel 50 based on the description and 26 illustrations herein will likewise be apparent.
27 Re~erring now more particularly to Figures 17-19 of ,~. .; .
28 the accompanying drawings, there is illustrated another embodi-.. 2g ment of the cable entry port means of the invention similar to . , - ,: , .
. Figures 7-10. As here embodied, a pair of oppose~ converging : ' ' .
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1 tapered panel members, each designaLed 60, de~end fro~ the ins~.de 2 surface of end wall 3, substantially as described with reference to Figures 7-10. A third closure panel 62 is attached to the 4 inside of end wall 3 adjacent ~he fron~ rim portion of aperture 22, and projects towards bottom wall 2 at an acute angle relative 6 to end wall 3. To accommodate the angular configuration of 7 third panel 62, the front facing edges of both panels 60 are 8 inclined toward bottom wall 2 at essentially the same angle as g panel 62.
The inward edges 61 of each panel member 60 are 11 coupled by a frangible web 64 in any of the ways previously 12 described. Here, web 64 is attached along each of the edges 61 13 by a recessed web 65. The web also includes a central portion ~!
~; 14 of reduced thickness, indicated at 64a in Figure 19, as previously discussed.
16 The innel~ost edge 63 of third panel 62 is also .
17 coupled to web 64 by another frangible web portion 65a, which is ¦
1~ recessed like web portions 65 to provide a sharp grasping edge.
:;
19 ' It will be understood that third paneI edge 63 could be fo~med without attachment to web 64.
21 ~,~ As in the various embodiments previously described, ~;~ 22 the outwardly facing surfaces of panels 60, 62 may be for~ed ; I
23 with suitable secondary, or supplementary,grasping means. Thus, I
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24 panels 60, 62 are sho~m with rib-like pro~ections 68, 69, ', respectively, si~ilar to projections 35, and third panel 62 is 26 further formed with notches 69a or accommodating the mold 27 parts needed to form projections 68.
28 Referring now more particularly to Figures 20-22 of 9 the accompanying dra~Jings, there is illustrated a further 3, embodimen~ o ~he invention, wherein the cable en~ry port means ' ' ~ " ' ' ' ', ' ' ' . ...

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1 includes a group of four closure panel members, each adapted to 2 deflect laterally away from the aperture upon passage of a cable ~; 3 therethrough and to thereafter resistingly bear against the 4 installed cable. As here embodied, electrical ou~let box 1 is ~ - 5 advantageously formed with diag~nal wall portions 70 joining ;~ 6 bottom wall 2 with each of end walls 3 and 4 and the cable ; 7 entry apertures 72, substantially square in shape, are formed 8 in diagonal sections 70. Four closure panel members 74, g separated by narrow openings 76, each converge angularly . .
10 inwardly from a side rim of aperture 72 toward a common central , -11 o~ening i8 which is smaller than the cross-sectional dimensions 12 of the electrical power cable. Advantageously, opening 78 is 13 substantially closed by a frangible web 80 joining an opposed 14 pair OL panel members 74. Also advantageously, frangible webs 82 connect web 80 to panel members 74 in any of the various ~;
16 ~2nners previously discussed.
17 Referring now more particularly to Figure 23, there 18 is illustrated a further embodiment of the invention, wherein 19 ' the pair of opposed tapered inwardly convçrging closure panel 20 ,i members illustrated in Figures 7-9 are joined to end wall 3 21 1 of outlet box 1 by means of a live, integrally molded-in hinge, ~2 , indicated generally by reference numeral 90. As is well known 23 by persons of ordinary skill in the molding art, plastic 24 materials may be molded with a constricted area, such as sho~m atl 90. in such a manner that the molecular structure becomes oriented, 26 50 zs to be flexible, while the surrounding material remains 27 relatively riid. The term "live hinge'l is commonly used in the -28 art to refer to such an integral fleY~ible constriction in a molded 29 article.
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Figures 24-25 illustrate a further embodiment of

31 ~he invention including modified forms of the live hinge ; - ' - ' 3~ Y ~
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,, : -, , 1 construction shown in Figure 23 and the rib-like supplementary 2 cable gripping projections shown in Figures 10 and 15. Thus, as 3 here embodied, a single inwardly angled closure panel member 100 .
is formed integrally with a projection or lug 101 extending relatively inwardly of end wall 3 a distance approximately 6 equal to the point of attachment 103 of the free end portion 102 7 of panel 100 with the adjoining side wall 6 of outlet box 1.
8 End 102 o~ panel 100 is advantageously frangibly attached to g side wall 6 in the manner previously described in connection with Figures 15-16. As here embodied, panel 100 is also mounted ', 11 to lug 101 on end wall 3 by means of a live hinge construction, 12 indicated generally at 104.
Also, as here embodied9 the outwardly facing surface 14 f panel 100 is provided with a plurality of rib-like projections lS lOj extending over the length thereof, each being similar to 16 projections 35, so as to provide a serrated surface for 17 resistingly bearing against installed cable 26 and for gripping lg the cable upon reverse outward movement thereof. 7 19 '' It will be seen from the foregoLng that hingedly mounting ciosure panel 100 relatively im~ardly of the cable entry 21 ~.' aperture 22 locates the rotation point about which panel 100 22 develops its ca~ming action closer to the point of gripping 23 enga ement with cable 26 to thereby provide maximum gripping 24 force of panel 100 against cable 26. Also, the provision of a serrated surface on panel 100 serves to ensure gripping engage-2~ ment o~ panel 100 with all sizes of electrical cable installed 27 in the cable entry aperture 22.
28 I?hile it will be understoo~ from the foregoing descrip-29 tion that the outlet box of the present illvention is not limited to the use of particular materials, the outlet box and the cable , . ~ . . . .
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' 1 entry port structure are preferably formed integrally from a 2 molded thermoplastic resin material. In this regard, a certain 3 injection moldable thermoplastic resin material has been found 4 to produce highly satisfactory results and is given as an example of the preferred mode of carrying out the invention, together 6 with other examples of suitable materials, from which still 7 further equivalent materials will be apparent to those of ordinary 8 skill in the art. Thus, it has been found that a thermoplastic g resin blend of ABS (i.e., acrylonitrile-butadiene-styrene) and P~O (i.e., polyphenylene oxide) sold by the General Electric 11 Company under the trade name "NORYL", Grades SE-100 or SE-l, is 12 a particularly preferred material from the standpoint of ease 13 of moldability, strength and high temperature resistance. More-i 14 over, the "NORYL" material is sufficiently strong to meet the -current standards of Underwritersl Laboratories, Inc. for 16 electFical outlet box cable clamping devices. It has also been 17 found that a vinyl resin material such as PVC (i.e., polyvinyl 18 chloride) sold by the Ethyl Corporation under the trade designa-19 tion "Ethyl 7042" o~erates satisfactorily where only slight 20 Ij clamping action against the cable is desired or necessary, as in 21 ¦ the embodiment of the invention shown in Figures 11-14. However, 22 1 this material does not meet the aforementioned current 23 I Underwriters' Laboratoriesl standards for cable clamps in 24 ,, electrical outlet boxes. In addition to the foregoing, the outlet box and cable entry port structure of the present inven-26 tion may be formed integrally from a metallic material, for 27 example, by cast molding from aluminum or an aluminu~ alloy, I
28 or by die stamping the closure panel members from a ~etal having 2a suitable flexibility and resiLienc~, such as, e.g., spring steel ,, , the latter being thereafter bent inwardly to provide the cable , .
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entry port structure.
To the extent not already indicated, it also will be understood by those of ordinary skill in the art that any one of the various specific embodiments herein described and illustrated may be further modified to incorporate features shown in other of the specific embodiments, as desired. Thus, for example, the provision of a serrated gripping surface on panel 100 as shown in Figures 24-25 may be utilized on each of the opposed pair of closure panels 14 shown in Figures 1-10.
Similarly, the hinged mounting shown in Figures 23-25 may be utilized with the closure panels 44 shown in Figures 11-14.
- ~ The invention in its broader aspects t~erefore is not limited to the specific embodiments herein shown and described but departures may be made therefrom within the scope of the accompanying claims, without departing from the principles of the invention and without sacrificing its chief advantages.

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Claims (91)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In an electrical outlet box having a wall structure providing front to rear wall means and a bottom wall interconnected therebetween, the front to rear wall means and bottom wall defining a chamber within the wall structure which opens through the front of the box, and wherein said wall structure houses cable entry port means for the passage of electrical power cable into said box chamber, the improvement therein which comprises, said cable entry port means including:
at least one aperture in a first portion of said wall structure, closure panel means depending from a rim adjacent said aperture and extending angularly inwardly from a plane defined by said aperture, said closure panel means terminating in a free end portion which is separated from a second portion of said wall structure of said box by a distance which is less than the narrowest dimension of said electrical power cable, and said free end portion of said closure panel means adapted to deflect away from said second portion of said wall structure upon passage of said cable into said aperture and to thereafter resistingly bear against the installed cable.

2. An electrical outlet box as claimed in claim 1, wherein said front to rear wall means includes a pair of opposed side walls and a pair of opposed end walls interconnected between said side walls.

3. An electrical outlet box as claimed in claim 1, wherein said front to rear wall means terminate in a common frontal plane which defines a front opening of said box.

4. An electrical outlet box as claimed in claim 1, wherein said closure panel means is self-opening, such that said closure panel means opens to admit said electrical power cable into said box chamber upon manually forcing the end of said electrical power cable against said closure panel means.

5. An electrical outlet box as claimed in claim 1, wherein said closure panel means is self-clamping against removal of said electrical power cable from said cable entry port means.

6. An electrical outlet box as claimed in claim 1, wherein said closure panel means is self-adjusting to different sizes of electrical power cables passing into said box chamber.

7. An electrical outlet box as claimed in claim 1, wherein said closure panel means is self-locating, such that said electrical power cable is installed in said aperture at a predetermined position.

8. An electrical outlet box as claimed in claim 1, including frangible closure means substantially preventing access into said box through said cable entry port means, said frangible closure means adapted to rupture when subjected to a predeter-mined force to thereby permit said electrical power cable to enter into said box chamber through said cable entry port means.

9. An electrical outlet box according to claim 1, wherein each said aperture is formed at the intersection of said front-to-rear wall means and said bottom wall and includes a first generally rectangular opening extending upwardly.
into said front-to-rear wall means from said bottom.
wall, and a second generally V-shaped opening converging inwardly into said bottom wall from the longitudinally extending side rims of said first rectangular opening, said generally V-shaped opening facing said front of said box, and said closure panel means includes a pair of opposed closure panels converging angularly inwardly toward one another from said longitudinally extending side rims of said first rectangular portion of said aperture, the convergent inner free ends of said converging pair of closure panels extending generally perpendicular to said bottom wall and separated from each other by said distance less than the narrowest dimension of said electrical power cable.

10. An electrical outlet box as claimed in claim 1, wherein each said aperture is formed at the intersection of said front-to-rear wall means and said bottom wall and includes a first generally rectangular opening extending upwardly into a first front-to-rear wall portion of said front-to-rear wall means from said bottom wall, and a second opening facing the front opening of said box that is formed in the general shape of a right triangle, the hypotenuse of said right triangle shaped opening extending from a longitudinally extending side rim of said first rectangular opening to a second front-to-rear wall portion of said front-to-rear wall means, said first and second front to rear wall portions comprising intersecting end and side walls, respectively, of said outlet box, and said hypotenuse extending between said side wall and the longitudinally extending side rim of said first rectangular opening remote from said side wall; and said closure panel means includes a single closure panel extending angularly inwardly from said longitudinally extending side rim of said first rectangular opening remote from said side wall portion substantially along said hypotenuse of said second right triangle opening formed in said bottom wall.

11. An electrical outlet box as claimed in claim 1, wherein each said aperture is formed at the intersection of said front-to-rear wall means and said bottom wall and includes a first generally rectangular. opening extending upwardly into said front to rear wall means from said bottom wall, and a second generally V-shaped opening converging inwardly into said bottom wall from the longitudinally extending side rims of said first rectangular opening, said generally V-shaped opening facing said front of said box;
said closure panel means includes a pair of opposed closure panels converging angularly inwardly toward each other from said longitudinally extending side rims of said first rectangular portion of said aperture, the convergent inner free ends of said converging pair of closure panels extending generally perpendicular to said bottom wall and separated from each other by said distance less than the narrowest dimension of said electrical power cable, and the front facing converging edges of said closure panels extending downwardly from said front-to-rear walls toward said convergent free ends at an acute angle;
and including a third closure panel member extending inwardly from the inside surface of said front-to-rear wall means at an acute angle thereto and terminating closely adjacent to the front facing convergent edges of said converging closure panels, said third closure panel member substantially closing said generally V-shaped opening formed between said opposed converging closure panels facing said front of said box.

12. An electrical outlet box as claimed in claim 1, wherein said front-to-rear wall means and said bottom wall are interconnected by an intermediate wall portion extending generally diagonally therebetween, said aperture is located in said diagonally extending intermediate wall portion and has a plural-sided configuration; and said closure panel means comprises a plurality of closure panels converging angularly inwardly toward each other from each side rim of said plural-sided aperture, the convergent inner free ends of said plurality of converging closure panels separated by said distance less than the narrowest dimension of said electrical power cable.

13. An electrical outlet box as claimed in claim 4, including a frangible web joining at least a portion of said free end portion of said closure panel means to said second portion of said wall structure, said frangible web being really pierceable upon manually forcing the end of said electrical power cable thereagainst.

14. An electrical outlet box as claimed in claim 5, wherein said closure panel means is tapered so as to have a base of increased thickness adjacent the rim of said aperture from which said closure panel means depends, the free end portion of the tapered closure panel means having sufficient flexibility and resiliency so as to be deflected upon passage of said cable into said aperture and to thereafter resistingly bear against the installed cable, whereby a reverse outward force applied to said cable causes said free end portion of said closure panel means to be urged by a camming action progressively more tightly against said cable-to thereby clamp said cable against removal from said aperture.

15. An electrical outlet box as claimed in claim 5, including hinge means mounting said closure panel means to said rim of said aperture, said hinge means permitting said closure panel means to deflect upon passage of said cable into said aperture and to thereafter resistingly bear against the installed cable, whereby a reverse outward force applied to said cable causes said free end portion of said closure panel means to be urged by a camming action progressively more tightly against said cable to thereby clamp said cable against removal from said aperture.

16. An electrical outlet box as claimed in claim 5, including supplementary cable gripping means for resisting outward movement of said electrical power cable from said cable entry port means.

17. An electrical outlet box as claimed in claim 1, wherein said closure panel means has sufficient flexibility and resiliency so as to be deflected upon passage of said cable into said aperture and to thereafter resistingly bear against the installed cable.

18. An electrical outlet box as claimed in claims 1 or 3, including hinge means mounting said closure panel means to said rim of said aperture, said hinge means permitting said closure panel means to be deflected upon passage of said cable into said aperture and to thereafter resistingly bear against the installed cable.

19. An electrical outlet box as claimed in claim 1, wherein said closure panel means comprises a pair of closure panels depending from opposite sides of the rim of said aperture, and converging angularly inwardly from the plane of said aperture toward each other, the convergent inner free ends of said pair of converging closure panels separated from each other by said distance less than the narrowest dimension of said electrical power cable.

20. An electrical outlet box as claimed in claims 1 or 3, wherein said closure panel means comprises at least more than two closure panels depending from the rim of said aperture and converging angularly inwardly from the plane of said aperture toward each other, the convergent inner free ends of said converging closure panels separated from each other by said distance less than the narrowest dimension of said electrical power cable.

21. An electrical outlet box as claimed in claims 1 or 3, wherein said closure panel means and said wall structure are formed integrally from a moldable plastic material.

22. An electrical outlet box as claimed in claims 1 or 3, wherein said closure panel means and said wall structure are formed integrally from a blend of acrylonitrile-butadiene-styrene and polyphenylene oxide thermoplastic resins.

23. An electrical outlet box as claimed in claims 1 or 3, wherein said free end portion of said closure panel means is separated from said second portion of said wall structure by a distance of approximately 0.150" (inch).

24. An electrical outlet box as claimed in claims 1 or 3, wherein said closure panel means and said wall structure are formed integrally from a blend of acrylonitrile-butadiene-styrene and polyphenylene oxide thermoplastic resins and said closure panel means is approximately 0.030" (inch) thick.

25. An electrical outlet box as claimed in claim 8, wherein said frangible closure means comprises a frangible web joining substantially the entire length of said free end portion of said closure panel means to said second portion of said wall structure of said box.

26. An electrical outlet box as claimed in claim 8, wherein said frangible closure means comprises a further panel member disparate from said closure panel means, said further panel member being substantially of the same size and shape as that of said aperture, and frangible web means interconnecting said further panel member to said rim of said aperture.

27. An electrical outlet box as claimed in claim 9, wherein said opposed angled closure panels are tapered so as to have a base of increased thickness adjacent the longitudinally extending side rims of said first rectangular portion of said aperture, the free end portions of the tapered and angled closure panels having sufficient flexibility and resiliency so as to be deflected away from one another upon passage of said cable into said aperture and to thereafter resistingly bear against the installed cable, whereby a reverse outward force applied to said cable causes said free end portions of said tapered and angled closure panels to be urged by a camming action progressively more tightly against said cable to thereby clamp said cable against removal from said aperture.

28. An electrical outlet box as claimed in claim 9, including a third closure panel member extending inwardly from the inside surface of said front to rear wall means generally parallel to said bottom wall, transversely of and closely adjacent to the converging front facing edges of said opposed converging closure panels, said third closure panel member substantially closing said generally V-shaped opening formed between said opposed converging closure panels facing said front of said box.

29. An electrical outlet box as claimed in claim 10, wherein said single closure panel is tapered so as to have a base of increased thickness and adjacent said longitudinally extending side rim of said first rectangular portion of said aperture remote from said side wall portion, the inner free end portion of the tapered and angled closure panel having sufficient flexibility and resiliency so as to be deflected upon passage of said cable into said aperture and to thereafter resistingly bear against the installed cable, whereby a reverse outward force applied to said cable causes said free end portion of said tapered and angled closure panel to be urged by a camming action progressively more tightly against said cable to thereby clamp said cable against removal from said aperture.

30. An electrical outlet box as claimed in claim 10, including a second closure panel member extending inwardly from the inside surface of said first front to rear wall portion generally parallel to said bottom wall, transversely of and closely adjacent to the angularly inwardly extending front facing edge of said single closure panel, said second closure panel member substantially closing said generally right triangularly-shaped opening formed in said bottom wall and facing said front opening of said box.

31. An electrical outlet box as claimed in claim 10, wherein said closure panel means and said wall structure are formed integrally from a blend of acrylonitrile-butadiene-styrene and polyphenylene oxide thermoplastic resins, said closure panel is approximately 0.030" (inch) thick and extends angularly inwardly at an angle of approximately 30° with respect to said first front to rear wall portion.

32. An electrical outlet box as claimed in claim 11, wherein said third closure panel member and said front facing converging edges of said opposed pair of closure panel members each extend at an angle of approximately 40° to said front to rear wall means.

33. An electrical outlet box as claimed in claims 9 or 11, wherein said closure panel means and said wall structure are formed integrally from a blend of acrylonitrile-butadiene-styrene and polyphenylene oxide thermoplastic resins, each of said closure panels is approximately 0.030" (inch) thick and each of said closure panels converge toward one another at an angle of approximately 30° with respect to said front to rear wall means.

34. An electrical outlet box as claimed in claim 12, wherein said plurality of closure panels are each tapered so as to have a base of increased thickness adjacent each of said side rims of said plural-sided aperture, the free end portions of each of the tapered and angled closure panels having sufficient flexibility and resiliency so as to be deflected away from one another upon passage of said cable into said aperture and to thereafter resistingly bear against the installed cable, whereby a reverse outward force applied to said cable causes said free end portions of each of said tapered and angled closure panels to be urged by a camming action progressively more tightly against said cable to thereby clamp said cable against removal from said aperture.

35. An electrical outlet box as claimed in claim 12, wherein said plurality of closure panels substantially closes said aperture.

36. An electrical outlet box as claimed in claim 13, wherein said frangible web joins substantially the entire length of said free end portion to said second portion of said wall structure.

37. An electrical outlet box as claimed in claim 13, wherein said closure panel means and said wall structure are formed integrally from a blend of acrylonitrile-butadiene-styrene and polyphenylene oxide thermoplastic resins and said frangible web is approximately 0.010-0.015" (inch) thick.

38. An electrical outlet box as claimed in claim 14, wherein said closure panel means comprises a pair of tapered closure panels depending from opposite sides of the rim of said aperture, and converging angularly inwardly from the plane of said aperture toward each other, the inner free ends of said pair of tapered converging closure panels separated from each other by said distance less than the narrowest dimension of said electrical power cable.

39. An electrical outlet box as claimed in claim 14, wherein said closure panel means comprises at least more than two tapered closure panels depending from the rim of said aper-ture, and converging angularly inwardly from the plane of said aperture toward each other, the inner free ends of each of said at least more than two tapered converging closure panels separated from each other by said distance less than the narrowest dimension of said electrical power cable.

40. An electrical outlet box as claimed in claim 14, including hinge means mounting said tapered closure panel means to said rim of said aperture.

41. An electrical outlet box as claimed in claim 14, wherein said base of said tapered closure panel means is recessed from the rim of said aperture.

42. An electrical outlet box as claimed in claim 14, wherein said closure panel means and said wall structure are formed integrally from a blend of acrylonitrile-butadiene-styrene and polyphenylene oxide thermoplastic resins and the thickness of said base of said tapered closure panel means is approximately double the thickness of said free end portion thereof.

43. An electrical outlet box as claimed in claim 15, wherein said hinge means comprises a live, integrally molded-in hinge.

44. An electrical outlet box as claimed in claim 15, wherein said hinge means is mounted relatively inwardly from said first portion of said wall structure containing said aperture, whereby said camming action substantially uniformly applies increasingly greater gripping force by said closure panel means against said cable upon application of said reverse outward force to said cable.

45. An electrical outlet box as claimed in claim 15, wherein said hinge means is recessed from the rim of said aperture.

46. An electrical outlet box as claimed in claim 16, wherein said supplementary cable gripping means includes gripping means formed on said second portion of said wall struc-ture adjacent said free end portion of said closure panel means.

47. An electrical outlet box as claimed in claim 16, wherein said supplementary cable gripping means includes a first relatively sharp-edged rib-like projection on the outwardly facing surface of said closure panel means adjacent said free end portion thereof.

48. An electrical outlet box as claimed in claim 16, wherein said supplementary cable gripping means includes a second relatively sharp-edged rib-like projection provided on the outwardly facing surface of said closure panel means intermediate said free end portion and the portion thereof depending from said rim of said aperture.

49. An electrical outlet box as claimed in claim 16, wherein said supplementary gripping means includes a plurality of closely spaced relatively sharp-edged rib-like projections extending in a serrated manner along the outwardly facing surface of said closure panel means in a direction transverse to the direction of movement of said cable into said aperture.

50. An electrical outlet box as claimed in claim 17, wherein said closure panel means and said wall structure are formed integrally from a blend of acrylonitrile-butadiene-styrene and polyphenylene oxide thermoplastic resins and said closure panel means is approximately 0.030-0.050" (inch) thick.

51. An electrical outlet box as claimed in claim 19, wherein said closure panel means and said wall structure are formed integrally from a blend of acrylonitrile-butadiene-styrene and polyphenylene oxide thermoplastic resins and said pair of closure panels are each approximately 0.030-0.050" (inch) thick.

52. An electrical outlet box as claimed in claim 25, wherein said frangible web is readily pierceable upon manually forcing the end of said electrical power cable thereagainst, whereby said frangible web is self-opening.

53. An electrical outlet box as claimed in claim 26, wherein said closure panel means depends from the inner facing surface of said first portion of said wall structure at a point which is recessed from said rim of said aperture

54. An electrical outlet box as claimed in claim 27, wherein said closure panel means and said wall structure are formed integrally from a blend of acrylonitrile-butadiene-styrene and polyphenylene oxide thermoplastic resins and the thickness of said base of said tapered and angled closure panels is approxi-mately double the thickness of said free end portions thereof.

55. An electrical outlet box as claimed in claim 28, including a reinforcing strut extending between the top of said third closure panel and the adjacent inside surface of said front to rear wall means.

56. An electrical outlet box as claimed in claim 32, wherein each of said opposed pair of converging closure panels and said third inwardly and downwardly angled closure panel member include at least one relatively sharp-edged, elongated rib-like projection extending in a direction transverse to the direction of the passage of said cable into said box.

57. An electrical outlet box as claimed in claim 34;
wherein each of said plurality of closure panels have a generally trapezoidal shape.

58. An electrical outlet box as claimed in claim 34, wherein said closure panel means and said wall structure are formed integrally from a blend of acrylonitrile-butadiene-styrene and polyphenylene oxide thermoplastic resins and the thickness of said base of each of said tapered and angled closure panels is approximately double the thickness of said free end portions thereof.

59. An electrical outlet box as claimed in claim 41, wherein said closure panel means and said wall structure are formed integrally from a blend of acrylonitrile-butadiene-styrene and polyphenylene oxide thermoplastic resins, the free end portion of said closure panel means is approximately 0.030" (inch thick and said base thereof is approximately 0.060" (inch) thick, and said base is recessed from said rim of said aperture approxi-mately 0.050" (inch).

60. An electrical outlet box as claimed in claim 42, wherein the free end portion of said tapered closure panel means is approximately 0.030" (inch) thick and said base thereof is approximately 0.060" (inch) thick.

61. An electrical outlet box as claimed in claim 42, wherein the outwardly facing surface of said closure panel means forms an approximately 45° angle with said first portion of said wall structure and the inwardly facing surface of said closure panel means forms an approximately 35-40° angle with said first portion of said wall structure.

62, An electrical outlet box as claimed in claim 44, wherein said hinge means is recessed from said rim of said aperture.

63. An electrical outlet box as claimed in claim 46, wherein said gripping means on said second portion of said wall structure comprises a relatively sharp-edged, elongated rib-like projection extending over a distance substantially the length of said adjacent free end portion of said closure panel means.

64. An electrical outlet box as claimed in claim 47, wherein said first relatively sharp-edged rib-like projection is provided by forming a notch in said closure panel means, said notch extending generally parallel to the inwardly facing surface of said closure panel means so as to define said relatively sharp edge adjacent to but spaced from said free end portion of said closure panel means, the portion of said closure panel means between said relatively sharp edge and said free end portion being of reduced thickness relative to the remainder of said closure panel means.

65. An electrical outlet box as claimed in claims 47 or 57, wherein said first and second relatively sharp-edged rib-like projections extend in a direction transverse to the direction of movement of said cable into said aperture over a distance substantially the length of said closure panel means.

66. An electrical outlet box as claimed in claim 53, wherein said closure panel means depends from a point relatively inwardly of said inner facing surface of said first portion of said wall structure.

67. An electrical outlet box as claimed in claim 54, wherein said free end portions of each of said closure panels is approximately 0.030" (inch) thick and said base thereof is approximately 0.060" (inch) thick.

68. An electrical outlet box as claimed in claim 54, wherein the outwardly facing surface of each of said closure panels forms an approximately 45° angle with said front to rear wall means and the inwardly facing surface of each of said closure panels forms an approximately 35-40° angle with said from to rear wall means.

69. An electrical outlet box as claimed in claim 56, wherein said third closure panel member is generally triangularly shaped, having an apex which terminates adjacent said convergent inner free ends of said pair of opposed closure panels.

70. An electrical outlet box as claimed in claim 57, including a frangible web joining at least two of said convergent inner free ends of said plurality of closure panels, said frangible web being readily pierceable upon manually forcing the end of said electrical power cable thereagainst, whereby said frangible web is self-opening.

71. An electrical outlet box as claimed in claim 67, wherein said base of said tapered and angled closure panels is recessed from said rim of said aperture approximately 0.050"
(inch).

72. An electrical outlet box as claimed in Claims 2, 3 or 4, wherein said closure panel means has sufficient flexibility and resiliency so as to be deflected upon passage of said cable into said aperture and to there-after resistingly bear against the installed cable.

73. An electrical outlet box as claimed in Claims 5, 6 or 7, wherein said closure panel means has sufficient flexibility and resiliency so as to be deflected upon passage of said cable into said aperture and to thereafter resistingly bear against the installed cable.

74. An electrical outlet box as claimed in Claim 8, wherein said closure panel means has sufficient flexibility and resiliency so as to be deflected upon passage of said cable into said aperture and to thereafter resistingly bear against the installed cable.

75. An electrical outlet box as claimed in Claims 4, 5 or 6, including hinge means mounting said closure panel means to said rim of said aperture, said hinge means permitting said closure panel means to be deflected upon passage of said cable into said aperture and to thereafter resistingly bear against the installed cable.

76. An electrical outlet box as claimed in Claims 7 or 8 including hinge means mounting said closure panel means to said rim of said aperture, said hinge means permitting said closure panel means to be deflected upon passage of said cable into said aperture and to thereafter resistingly bear against the installed cable.

77. An electrical outlet box as claimed in Claims 2, 3 or 4 wherein said closure panel means comprises a pair of closure panels depending from opposite sides of the rim of said aperture, and converging angularly inwardly from the plane of said aperture toward each other, the convergent inner free ends of said pair of converging closure panels separated from each other by said distance less than the narrowest dimension of said electrical power cable.

78. An electrical outlet box as claimed in Claims 5, 6 or 7 wherein said closure panel means comprises a pair of closure panels depending from opposite sides of the rim of said aperture, and converging angularly inwardly from the plane of said aperture toward each other, the convergent inner free ends of said pair of converging closure panels separated from each other by said distance less than the narrowest dimension of said electrical power cable.

79. An electrical outlet box as claimed in Claim 8 wherein said closure panel means comprises a pair of closure panels depending from opposite sides of the rim of said aperture, and converging angularly inwardly from the plane of said aperture toward each other, the convergent inner free ends of said pair of converging closure panels separated from each other by said distance less than the narrowest dimension of said electrical power cable.

80. An electrical outlet box as claimed in Claims 4, 5 or 6 wherein said closure panel means comprises at least more than two closure panels depending from the rim of said aperture and converging angularly inwardly from the plane of said aperture toward each other, the convergent inner free ends of said converging closure panels separated from each other by said distance less than the narrowest dimension of said electrical power cable.

81. An electrical outlet box as claimed in Claims 7 or 8 wherein said closure panel means comprises at least more than two closure panels depending from the rim of said aperture and converging angularly inwardly from the plane of said aperture toward each other, the convergent inner free ends of said converging closure panels separated from each other by said distance less than the narrowest dimension of said electrical power cable.

82. An electrical outlet box as claimed in Claims 4, 5 or 6 wherein said closure panel means and said wall structure are formed integrally from a moldable plastic material.

83. An electrical outlet box as claimed in Claims 7 or 8 wherein said closure panel means and said wall structure are formed integrally from a moldable plastic material.

84. An electrical outlet box as claimed in Claims 4, 5 or 6 wherein said closure panel means and said wall structure are formed integrally from a blend of acrylonitrile-butadiene-styrene and polyphenylene oxide thermoplastic resins.

85. An electrical outlet box as claimed in Claims 7 or 8 wherein said closure panel means and said wall structure are formed integrally from a blend of acrylonitrile-butadiene-styrene and polyphenylene oxide thermoplastic resins.

86. An electrical outlet box as claimed in claims 4,5 or 6 wherein said free end portion of said closure panel means is separated from said second portion of said wall structure by a distance of approximately 0.150" (inch).

87. An electrical outlet box as claimed in claims 7 or 8 wherein said free end portion of said closure panel means is separated from said second portion of said wall structure by a distance of approximately 0.150" (inch).

88. An electrical outlet box as claimed in claims 4, 5 or 6 wherein said closure panel means and said wall structure are formed integrally from a blend of acrylonitrile-butadiene-styrene and polyphenylene oxide thermoplastic resins and said closure panel means is approximately 0.030" (inch) . .
thick.

89. An electrical outlet box as claimed in claims 7 or 8 wherein said closure panel means and said wall structure are formed integrally from a blend of acrylonitrile-butadiene-styrene and polyphenylene oxide thermoplastic resins and said closure panel means is approximately 0.030" (inch) thick.

90. An electrical outlet box as claimed in claim 11 wherein said-opposed angled closure panels. are tapered so as to have a base of increased thickness adjacent the longitudinally extending side rims of said first rectangular portion of said aperture, the free end portions of the tapered and angled closure panels having sufficient flexibility and resiliency so as to be deflected away from one another upon passage of said cable into said aperture and to thereafter resistingly bear against the installed cable, whereby a reverse outward force applied to said cable causes said free end portions of said tapered and angled closure panels to be urged by a camming action progressively more tightly against said cable to thereby clamp said cable against removal from said aperture.

91. An electrical outlet box as claimed in Claim 90 wherein said closure panel means and said wall structure are formed integrally from a blend of acrylonitrile-butadiene-styrene and polyphenylene oxide thermoplastic resins and the thickness of said base of said tapered and angled closure panels is approximately double the thickness of said free end portions thereof.