CA1167553A

CA1167553A - Screw retaining and aligning cover plate

Info

Publication number: CA1167553A
Application number: CA000386320A
Authority: CA
Inventors: Albert J. Gartland, Jr.
Original assignee: Harvey Hubbell Inc
Current assignee: Harvey Hubbell Inc
Priority date: 1981-01-19
Filing date: 1981-09-21
Publication date: 1984-05-15
Also published as: AU7955382A; DE3201302A1; ZA82181B; JPH0359651B2; GB2091369A; US4355198A; JPS57173315A; IT1149705B; IT8219189A0

Abstract

Abstract Of The Disclosure A cover plate for completing the enclosure of an outlet box, the plate having a mounting screw retaining and aligning assembly integrally formed in an aperture in the plate. This assembly engages and aligns the screw so that the screw will not ina-dvertently fall out of the plate and the longitudinal axis of the screw is substantially perpendicular to the plate for ease of insertion of the screw into an internally threaded bore coupled to the box. The assembly comprises a pair of opposed, spaced flexible major webs integrally formed with the plate and extending into the aperture; and a pair of opposed, spaced flex-ible minor webs also integrally formed with the plate and the major webs and extending into the aperture. The major webs have parallel, straight distal edges which form chords of a circular aperture in the plate. The minor webs are in the form of ring segments. The assembly further comprises a countersink formed in the aperture and coaxial with that part of the aperture con-taining the webs. The outlet box can contain an electrical de-vice such as a switch or receptacle and can be located in a wall.

Description

~7S53 SCREW RETAINING AND ALIGNING
COVER PLATE

Field Of The-rnvention The invention relates to a cover plate for completin~ the enclosure of an outlet box, the plate having a mounting screw re-taining and aligning assembly integrally formed in an aperture in the plate. The cover plate can be used as a wall plate to complete the enclosure of an outlet box located in a wall. The outlet box may be used to house and mount various types of electrical wiring or connective devices, such as switches, receptacles, motor outlets, telephone and television connective devices and the like. If there is no device in the box, the wall plate is designed as a blank having only apertures for receiving the mounting screws. In all other cases, the plate has openings to suit the purpose of the de-vice.

r~

~ ~6'7S~3 Back~round Of The Invention As anyone who has removed and tried to replace a co~er plate for an electrical wall switch or outlet knows, the screws used are very small and tend to fall out of the aperture in the plate. This can occur during removal or installation of the plate.
Sometimes the screw merely falls to the floor where it can be re~
trieved easily? although this does waste time. In other situa-tions, sometimes the screw falls into an inaccessible area and thus another screw must be obtained, which wastes even more time.
This problem is of course also encountered by the commercial con-struction electrician who, for examplel is installing literally thousands of these cover plates in a new large office building.
Complicating this problem is the widespread use of plastic cover plates of various different colors, such as ivory, brown, black and red, which have prepainted mounting screws to match the color of the plate. Thus, the installer cannot substitute just any extra screw if a color matched screw is lost and must waste addi-tional time obtaining a substitute screw of the correct color.
Another problem associated with installing such cover plates is the difficulty of ali~ning the relatively small screw with the internally threaded bore provided on the switch or out-let assembly and inserting the screw into the front of the bore to make the necessary threaded connection. It is difEicult to align the screw and find the threaded bore because the screw tends to pivot in the aperture in the cover plate. Of course, when there is a misalignment, the screw ~ends to fall out of the cover plate, especially since the screw and therefore the notch in the head is so small and easily slips from a screw driver used therewith.

Summar~ of the Inventio~ ~ ~ d ~3 Accordlngly the present invention seeks to provide a screw retaining and aligning cover plate for completing the enclosure of an outlet bo~ so that the screw does not fall from the pla~e and the screw is easily inserted into an internally threaded bore coupled to the box.
The invention in one aspect pertains to a plate for completing the enclosure of an outlet box and being securable adjacent the box by means of a threaded member receivable in an aperture in the plate and an internally threaded bore coupled to the box and by means of a frustoconical surface on the head of the threaded member receivable in a countersink in the plate.
The improvement comprises flexible web means) integrally formed with the plate and extending into the aperture, for engaging a threaded portion of the threaded member when the threaded portion is fully inserted into the aperture to align the longitudinal axis of the threaded member substantially perpendicular to the plate for ease of insertion of the threaded member into the threaded bore.
Another aspect of the invention pertains to a plate for completing the enclosure of an outlet box, the plate being adapted to be secured adjacent the box by means of a threaded member having a head, the member being receivable in a threaded bore coupled to the box. The plate comprises a generally planar body portion composed of a polymeric material with means defining an aperture in the body portion for receiving the threaded member therethrough, the aperture having a countersink portion for seating the head or the threaded member thereon.
Flexible means integral with the body portion and extending into the aperture is provided for engaging a threaded portion of the threaded member when the member is fully inserted into the aperture to align the longitudinal axis o the threaded member substantially perpendicular to the body portion for ease of insertion of the threaded member into the threaded bore coupled '5~3 to the box.
Another aspect of the invention comprehends a plate for completing the enclosure of an outlet box including a flexible body portion composed of thermoplastic material with means defining a substantially circular aperture in the body portion and a pair of opposed, flexible webs integrally formed with the body portion and extending into the aperture. The webs each have a distal edge forming a chord of the circular aperture, the distal edges of the webs being substantially parallel. An inwardly and downwardly tapered frustoconical bore is formed in the body portion coaxial with the circular aperture with a cylindrical bore formed in the body portion between the frustoconical bore and the webs and coaxially aligned with the frustoconical bore. An opening in the body portion is provided for receiving a part of an electrical wiring device coupled to the outlet box.
Another aspect of the invention pertains to a plate for completing the enclosure of an outlet box comprising a body portion, means defining a substantially circular aperture in the body portion, and a pair of opposedl flexible webs integrally formed with the body portion and extending into the aperture.
The webs each have a distal edge forming a chord of the circular aperture. In one aspect, the ratio of the largest radial width of each of the webs to the diameter of the aperture is between about 1:3.70 to about 1:~.88. In another aspect, the ratio of the thickness of each of the webs to the largest radial width of each of the webs is between about 1:2.86 to about 1:5.00.
Other aspects, advantages and salient features of the present invention will become apparent from the following detailed description which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.

~7.5~3 Drawings Referring now to the drawings which form a part of this original disclosure:
Figure lA is a top plan view, not ~o scale, of a prior art upper jaw for a cable clamp having an annular flange located lnside a bore for receiving a screw;
Figure lB is a sectional view taken along lines lB-lB
in Figure lA;
Figure 2A is a top plan view, not ~o scale, of another prior art upper jaw for a cable clamp with a pair of opposed fins located in a bore receiving a screw therein;
Figure 2~ is a sectional view taken along lines 2B-2B
in Figure 2A;
Figure 3 is a fragmentary~ front elevational view of a cover plate in accordance with the present invention substan-tially to scale and showing the two opposed major webs, two opposed minor webs and the frustoconical bore, all integrally formed in the cover plate;
Figure 4 is a bottom plan view in section taken along lines 4-4 in Figure 3;
Figure 5 is a ~ide elevational view in section taken along lines 5-5 in Figure 3;
Figure 6 is a front elevational view of a duplex re ceptacle cover plate in accordance with the present invention;
Figure 7 is a rear elevational view of the cover plate shown in Figure 6;
Figure 8 is a fragmentary 6ide elevational view in section taken along lines 8-8 in Figure 6 showing a screw about to be inserted into the cover plate;

7~3 Figure 9 is a side elevational view in vertical sec-tion of a cover plate in accordance with the present invention having a screw inserted therein and aligned with the internal threaded bore in a duplex receptacle located in an outlet box with the screw about to be inserted into the bore;
Figure 10 is a top plan sectional view taken along lines 10-10 in Figure 9 showing a screw retained and aligned in a cover plate and about to be inser~ed into an internally threaded bore, this figure being to scale where one inch equals 0.1 inch;
Figure 11 is a front elevati.onal view of a cover plate in accordance with the present invention having two screw receiv-ing apertures therein;
Figure 12 is a rear elevational view of the cover plate shown in Figure 11 with two ribs extending outwardly from each of the screw receiving apertures Figure 13 is a side elevational view in section taken along lines 13-13 in Figure 11;
Figure 14 is a top plan sectional view taken along lines 14-14 in Figure 12 and enlarged; and Figure 15 is a top plan sectional view taken along lines 15-15 in Figure 12 and enlarged, this enlargement being less than the enlargement of Figure 140 Prior Art In the patent literature, applicant is unaware of any prior device that addresses the problem as set forth above and solves it in the manner set forth herein. However, there are a number of U.S. patents that are relevant to the claimed inven-tion including U.S. Patents 1,927,780 to Anderson; 2,3~9,958 to ~3 6~75~3 Tinnerm~n; 3,155,808 to ~iley; 3,173,265 to Bixby; 3,432,793 to Muska e~ al; 3,969,011 to Yamada; 4,00~,797 to ~ee; and Re. 29,752 to Jaconette, Jr.
In addition to khis patent literature, applicant is aware of two prior art devices, the first being shown in Figures lA and lB an~ the other being shown in Figures 2A and 2B~
Referring to Figures lA and 1~, a removable part or upper jaw 12 of a cable clamp is illustrated, these drawings not being to scale. A full description of this jaw 12 in general is found in U.S.
1~ Patent 3,571,781 issued to Gartland et al. Although not shown in the patent, devices have been made and sold which include, as seen in Figures lA and lB, an annular flange 14 located in an aperture and having a slightly larger cylindrical bore 15 above the flange and a frustoconical bore 16 below the flange, the smaller diameter of the frustoconical bore being substantially the same as the base diameter of the annular flange 14 and cylindrical bore 15.
This combination of the annular flange, cylindrical bore and frustoconical bore are duplicated at the other end of the jaw 12 which is illustrated having a screw 17 received therein.
Since Figures lA and lB are not to scale, set forth below is Table 1 which includes the various pertinent dimension~
and ratios of the annular flange 14 relative to bores 15 and 16 PRIOR ART FLANGE OF FIGS. lA AND lB

1. Diameter of bore 15 from which annular flange 14 extends - 0.145-0.147 inch

2. Inner diameter of flange 14 - 0.134-0.136 inch

3. Flange 14 radial width - 0.009-0.013 inch

4. Minor radial width none i75s~

TABLE 1 (Cont.) PRIO~ ART FLANGE OF FIGS. lA and lB

5~ Th.icknes~ of flange 14 - 0~009-0.011 inch

6. Ra~io of flange 14 radial width ~3) to diameter of bore 15 from - O.061-0.089 which 1ange extends (1) (1:16.39-1:11.23)

7. Ratio of flange 14 thickness (5) - 0.692-1.222 ~o flange 14 radial width (3) (1:1.45-1:0.82)

8. Screw 17 used with flange 14 - No. 6/20 (a) major diameter - 0.138 inch (b) minor diameter - 0.0974 inch As seen in Table 1, the ratio of the flange 14 radial width to the diameter of the bore 15 from which the flange ex-tends is from about 1:11.23 to 1:16.39. Thus, the flange is ex-tremely small relative to the bore size, substantially smaller than is shown in the non-scale drawing of Figures lA and lB.
In addition, from Table 1 it is seen that the ratio of the flange 14 thickness to the flange radial width is about 1:0.82 ~ to 1:1.45 so that the thickness is substantially the same as the width of the flange.
The material used to construct jaw 12 is thermoplastic such as nylon sold by DuPont under the trademark Zytel.
The purpose of the flange 14 used in jaw 12 is merely to maintain the screw 17 in the aperture in the upper jaw so that it does not easily fall out when the jaw is inverted. This occurs since the major diameter of the threads of screw 17 is greater than the inner diameter of the undeformed annular Elange 14. As '75S3 seen in Figure lB, a smooth part of the screw shank is received by he annular flange 14 after the threaded part is pushed through the flange, unlike the present invention where the webs grip a threaded part of a screw. The jaw 12 and annular flange 14 provide no alignment capability, especially because of the play between the outer diameter o~ the smooth shank and the inner diameter of the annular 1ange 14. Due to the relatively small size of the flange~s width, it can be sheared by the threads of the screw being pushed therethroughO The upper jaw 12 also ~ends to be backed off by the screw on unscrewing.
Referring now to Figures 2A and 2B, another prior art upper jaw 20 for a cable clamp is shown, not to scale, which in-cludes in an aperture two opposed fins 21 and 22 with two cylin-drical bores 23 and 24 formed on opposite sides of the fins, bore 24 having a slightly larger diameter than bore 23. A general de-scription of jaw 20 is provided in U.S. Patent 3,784,961 to Gartland, Jr. which, however, does not disclose the fins shown in Figures 2A and 2B.
As seen in these figures, a screw 25 is received in bores 23 and 24 as well as between fins 21 and 22. In opera-tion the smooth shank is received between fins 21 and 22, the major diameter of the threads being slightly greater than the distance between the fins to maintain the screw 25 in jaw 20, if for example jaw 20 were inverted. ~owever, there is no alignment capability vr requirement in this jaw 20.
Since Figures 2A and 2B are not to scale, set forth be-low is Table 2 which includes particular dimensions and ratios of fins 21 and 22 relative to bores 23 and 24.

~6~7S~;3 PRIOR ART FINS OF FIGS. 2A AND 2B

1. Diameter of bore 23, 24 from - 0.171 inch ~above~
which fins 21, 22 extend 0.180 inch (below) 2. Separation of distal edges - 0.156-0.158 inch of fins 21,22 3. Laxgest fin 21, 22 - 0.0065-0.0075 (above) radial width 0.0110-0.01~0 (below) 4. Minor fin 21, 22 radial width - none 5. Thickness of fin 21, 22 - 0.008-0.010 inch 6. Ratio of largest fin 21, 22 radial width (3) to diameter of bore 23, - 0.038-0.043 (above) 24 from which fins extend ~1) (1:26,32-1:23.26) 0.061-0.066 (below) (1:16.39-1:15.15) 7. Ratio of fin 21, 22 thickness (5) to largest fin 21, 22 ~ 1.066-1.538 (above) radial width (3) (1:0.94-1:0.65) 0.666-0.909 (below) (1:1.5-1:1.1) 8. Screw 25 used with fins 21, 22 - No. 8/18 (a) major diameter - 0.1640 inch (b~ minor diarneter - 0.1234 inch As seen from Table 2, the ratio of the laryest fin radial width to the diameter of bores 23 and 24 from which the fins extend is about 1:26.32-1:23.26 rela~ive to bore 23 and about 1:16.39-1-~5.15 relative to bore 24. Thus, the fins are extremely small relative to the bores receiving them.
In addition, the ratio of the fin thickness to the larg-est fin radial width is about 1~0.94-1:0.65 for bore 23 and about 1:1.5 to 1:1.1 for bore 24. Thus, each of the fins is about as thick as it is wide in .its largest radial width.
The flexihility of these fins is not especially critical in these devices because these screws are initially installed at the factory with the aid of machine-powered screwdrivers. In 55~

addition, the use of a No. 8/18 screw, rather than a No. 6/3~ as in the present invention, means that a lesser number of threads per inch are present and thus the threads are coarser. This allows greater latitude in displacing the screw transversely so that the threads can be "walked" through the less flexible fins, either inwardly or outwardly of the aperture.

The material used to construct jaw 20 is also thermoplastic such as nylon sold by DuPont under the trade mark Zytel.

Detailed Description of the Invention Referring now to Figures 3 ~ 10, the present in~ention is illustrated in a duplex receptacle cover plate 30 having, as seen in Figure 6, upper and lower openings 31 and 32 for two female connectors and a central aperture 34. As seen from the rear in Figure 7, the cover plate 30 is comprised of a generally planar, main body portion 35 with a peripheral flange on the inner surface of the body portion`35. The plate is resilient and flexible and is made from thermoplastic nylon such as that material sold by DuPont under the trade mark Zytel FE-3221.

As best seen in Figures 3, 4 and 5, the central aperture 34 comprises a frustoconical bore 38, a cylindrical bore 39, two opposed major webs 40 and 41, two opposed minor webs 42 and 43 and a cylindrical bore 44. All of these form a retaining and aligning assembly for a threaded member or screw 46, as seen in Figure 8, to be inserted in the aperture 34 and carried by the plate 30.

The frustoconical bore countersink 38 is downwardly and inwardly tapered, includes an angle of about 8~ and extends into the body portion 35 from the outer substantially planar ...
~, ~'r ~.,.''~

5~3 surface 48.

The cylindrical bore 39 is coaxial with frustoconical bore 38 and extends inwardly from the innermost and smallest diameter end of the frustoconical bore 38.

As seen in Figure 3, the part of aperture 34 into: which the major and minor webs 40 - 43 extend, is substantially circular being defined by cylindrical bores 39 and 44. These webs are initially molded with and are therefore integral or uniti2ed with the main body portion 35 of the plate.

The distal ed~es 50 and 51 of the major webs 40 and 41 are straight and parallel and form chords of a circle defined by the bores 39 and 44. In plan view each major web is a chordal segment. The major webs have the same size and shape and their outer surfaces are substantially planar and coplanar and their inner surfaces are also substantially planar and coplanar as saen in Figures 3, 4 and S.

The two opposed minor webs 42 and 43 are also integrally formed with the body portion 35 and are also integrally formed with each of the major webs 40 and 41 during the molding of the plate. In plan ~iew each of the minor webs is a ring segment, the distal edges thereof being a por-tion of a cylinder. The outer surfaces of the minor webs are substantially planar and coplanar and the lower surfaces are also substantially planar and coplanar. In addition, all of the outer surfaces of all four webs are substantially coplanar and all of the inner surfaces of all four webs are subs~antially coplanar.

The cylindrical bore 44 is formed from a cylindrical boss 53 integrally formed with the body portion 35 and extending inwardly therefrom, the cylindrical bore 44 extending inwardly -,E3 ~7~

from the base of each of the major and minor webs. Bores 39 and 44 have substantially the same inner diameter.
While the various parts shown in ~igures 3 5, and 10, are to scale, Table 3 is set forth below including the important dimensions and ratios of the webs relative to the plate 30.

WEBS OF FIGS. 3 - 15 1. Diameter of bore 39 from which - 0.190 + 0.Q05 inch major webs 40, 41 extend 2. Separation of major web 40, 41 - 0.100 + 0.005 inch distal edges 3. Largest major web 40, 41 radial - 0.045 + 0.005 inch width 4. Minor web 42, 43 radial width - 0.010 + 0.005 inch 5. Thickness of major and minor webs - 0.012 ~ 0.002 inch 6. Ratio of major web radial width - 0.205 - 0.270 (3) to diameter of bore from (1:4.88 - 1:3.70) which major web extends (1) 7. Ratio of major web thickness (5) - 0.200 - 0.350 to major ~eb radial width (3) (1:5.00 - 1:2.86) 8. Screw used with webs - No. 6/32 (a) major diameter - 0.134 + 0.003 inch ~b) minor diameter - 0.099 + 0.002 inch As seen from Table 3, the ratio of the major web radial width to the diameter of the bore 39 from which the webs extend is between about 1:3.70 to about 1:4.88. Thus, the ma~or web~ are flexible.
In addition, the ratio of the major web thickness to the major web radial width is between about 1:2.86 to about 1:5.00, which contributes to the flexibility of the major webs.

~ ra~

;7~

As seen in Figures 8, 9 and lO, the screw 46 is a conventional No. 6/32 screw, illustrated in Figure lO to scale.
The designation "No. 6" indicates that, based on the American Standard Coarse and Fine Threads definition, the basic major diameter, or the outer diameter, of the threads at the crest is 0.134 inch and the basic minor diameter, or the diameter of the roots of the threads, is 0.099 inch. The designation "132"
indicates that there are 32 threads per inch on the screw externally threaded body or shank 55 as seen to scale in Figure lO.

In addition to the shank 55, the screw 46 includes a head 56 having a round top surface 57 penetrated by a notch 58 and a frustoconical bottom or underlying surface 59 tapered inwardly and downwardly and including about 45.

Insertion of the Screw into the Plate As seen in Figure 8, the screw 46 is longitudinally aligned with aperture 34 in the plate 30. To insert the screw 46 into a retaining and aligning position in the plate 30, the screw is pushed through the aperture so that the screw threads flex and push the major webs 40 and 41 inwardl~ to the plate~
away from the head 56 of the screw and radially outward of the shank 55 as best seen in Figure lO. The webs are also slightly inelastically deformed. Thus, as insertion takes place, the threads on shank 55 index past the major webs and these webs engage and retain the screw therebetween, thus captivating the screw to the plate and preventing the screw from falling out of the plate. This insertion is complete when the frustoconical surface 59 on the bottom of the head 56 engages and seats on the frustoconical bore 38 in the aperture 34, as shown in Figure lO.

In this configuration, the major webs 40 and 41 ~ - 14 -~7~
tightly grip and engage the opposing threads of the screw and retain, or captivate, the screw in the aperture. Moreover, this engagement of -the major webs with the screw in combination with the seating of the frustoconical surface 59 of the screw head against the frustoconical bore 38 centers the head relative to the bore 38, thereby aligning the longitudinal axis of the screw shank 55 substantially perpendicular to the outer surface 48 of plate 30. This alignment is maintained by the substantially equal and opposite forces applied inwardly against the threads by the two webs.

In this configuration, the screw 46 is easily inserted into a threaded bore formed in an electrically insulated portion of an electrical receptacle or switch, such as a duplex receptacle 61 shown in Figures 9 and 10.

As is evident, the number of threads per inch in the No. 6/32 screw used with the present i:nvention is much greater than the number of threads per inch in the No. 8/18 screw used with the prior art device of Figs. 2A and 2B. With these finer threads of the No. 6/32 screw, pushing the screw axially of an aperture containing webs therein would tend to significantly shear these webs, if they were not very flexible. However, by making the webs rather flexible, as are major webs 40 and 41, they will flex significantly to permit passage of the threads without undue shearing.

Coupling the Plate_to the Outlet Box As seen in Figure 9, a conventional duplex receptable 61 having two sets of female contacts in portions 62 and 63 is secured via screws 64 and 64' within a metallic or plastic outlet box 65 which is rigidly and conventionally secured in an opening 66 in a wall 67.

~ .~

~6~75~3 Centrally formed in the receptacle 61 between the female contact portions 62 and 63 is an in-ternally threade~
female connection or bore 68 for receiving the threaded shank 55 of the plate screw 46. If desired, this bore 68 can have a countersink 69 at its entrance and may be lined with a metal sleeve which is internally threaded to receive the wall plate screw.
After -the screw 46 is secured in plate 30, as seen in Figures 9 and 10, the plate is maneuvered adjacent wall 67 and the shank 55 of the screw is inserted into internally threaded bore 68, at which time the screw is rotated clockwise relative to the plate and is threadedly coupled to the bore and the receptacle in a covering position~ As this clockwise rotation takes place, the threads index relative to the webs, these webs flexing and sliding relative to the rotating threads. There is little tendency Eor the screw to back the plate outwardly.
Because the screw 46 is retained in the plate and aligned substantially perpendicular to the plate~ the accurate insertion of the screw into the bore 68 is readily facilitated and the screw does not tend to fall out of the plate.
Once the screw 46 is fully threaded into bore 68, the cover plate 30 completes the enclosure of outlet box 65 and is secured against wall 67 with flange 36 contacting the wall.
Cover Plate of Figures 11 - 15 _ As seen in Figures 11 - 15, a slightly modified cover plate 70 is shown which has a plurality of apertures 34' formed therein, like aperture 34 described above, except for two differences. These include a shorter cylindricalbos$ 53' and two integral inwardly facing ribs 72 and 73 extending radially outward from the cylindrical boss 53' and transverse of the plate 70.

~ 16 -, ,., ~
.,:

These ribs 72 and 73 extend inward from the main body portion 75 of plate 70, stopping short of the plane containing the edge of the peripheral 1ange 76 surrounding the main body portion 75.
This type of cover plate 70 can be used to close off an empty outlet box in a wall or, if a central rectangular aper-ture 7~ shown in phantom in Figure 11 were used, then the plate 70 could be used to cover a switch located in an outlet box. In an electrical switch, the metallic strap which is available to mount the plate is relatively thin, on the order of 0~ 06a inch.
With this thi~kness only two threads can be formed in a bore in the strap for receiving the plate mounting screw and thus no countersink is available for guiding the mounting screw tip.
Therefore, prepositioning and captivating the screw in the plate is very important.
Of course, any number of receptacles or switches can be covered by the plate illustrated herein with the aperture and webs in accordance with the present invention ~eing provided in the necessary locations. Rather than merely using the plate illus-trated herein for electrical receptacles or switches, it could beutilized with any type of electrical device having a cover plate coupled to a box receiving the device therein by means of a threaded member. One example would be a cover for a telephone modular jack supported in the wall. Others would be motor out-lets and televi.sion connective devices.

While various advantageous embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made there-in without departing from the scope of the invention as defined in the appended claims.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A plate for completing the enclosure of an outlet box, the plate being adapted to be secured adjacent the box by means of a threaded member having a head, the member being receivable in a threaded bore coupled to the box, the plate comprising:
a generally planar body portion composed of a poly-meric material;
means defining an aperture in said body portion for receiving the threaded member therethrough, said aperture having a countersink portion for seating the head of the threaded member thereon; and flexible means integral with said body portion and extending into said aperture, for engaging a threaded portion of the threaded member when the member is fully inserted into said aperture to align the longitudinal axis of the threaded member substantially perpendicular to said body portion for ease of insertion of the -threaded member into the threaded bore coupled to the box.

2. A plate according to Claim 1, wherein said means for engaging comprises a pair of opposed, spaced flexible webs integrally formed with said body portion and extending into said aperture.

3. A plate according to Claim 2, wherein said countersink comprises an inwardly and downwardly tapered frustoconical bore formed in said body portion.

4. A plate according to Claim 2, wherein said means for engaging further comprises a pair of opposed, spaced flexible minor webs integrally formed with said body portion and said webs and extending into said aperture.

5. A plate according to Claim 4, wherein each of said minor webs is in the form of a ring segment.

6. A plate according to Claim 2, wherein each of said webs is in the form of a chordal segment of a circle.

7. A plate according to Claim 2, wherein said webs have straight, parallel distal edges receiving the threaded member therebetween.

8. A plate for completing the enclosure of an outlet box comprising:
a body portion;
means defining a substantially circular aperture in said body portion; and a pair of opposed, flexible webs integrally formed with said body portion and extending into said aperture, said webs each having a distal edge forming a chord of said circular aperture, the ratio of the largest radial width of each of said webs to the diameter of said aperture is between about 1:3.70 to about 1:4.88.

9. A plate according to Claim 8, wherein the ratio of the thickness of each of said webs -to the largest radial width of each of said webs is between about 1:2.86 to about 1:5.00.

10. A plate according to Claim 8, and further comprising an inwardly and downwardly tapered frustoconical bore formed in said body portion coaxial with said aperture.

11. A plate according to Claim 10, and further comprising a cylindrical bore formed in said body portion between said frustoconical bore and said webs and coaxially aligned with said frustoconical bore.

12. A plate according to Claim 8, and further comprising a cylindrical boss integrally formed with said body portion, extending from said webs and being coaxially aligned with said aperture.

13. A plate for completing the enclosure of an outlet comprising:
a body portion;
means defining a substantially circular aperture in said body portion; and a pair of opposed, flexible webs integrally formed with said body portion and extending into said aperture, said webs each having a distal edge forming a chord of said circular aperture;
the ratio of the thickness of each of said webs to the largest radial width of each of said webs is between about 1:2.86 to about 1:5.00.

14. In a plate for completing the enclosure of an outlet box and being securable adjacent the box by means of a threaded member receivable in an aperture in the plate and an internally threaded bore coupled to the box and by means of a frustoconical surface on the head of the threaded member receivable in a countersink in the plate, the improvement comprising:
flexible web means, integrally formed with said plate and extending into said aperture, for engaging a threaded portion of said threaded member when said threaded portion is fully inserted into said aperture to align the longitudinal axis of said threaded member substantially perpendicular to the plate for ease of insertion of the threaded member into the threaded bore.

15. The plate according to Claim 14, wherein said web means. comprises two webs located on opposite sides of said aperture.

16. The plate according to Claim 15, wherein said aperture is substantially circular, and said webs each have a distal edge forming a chord of said circular aperture.

17. The plate according to Claim 16, wherein said distal edges are substantially parallel.

18. The plate according to Claim 17, wherein the distance between said distal edges is less than the major diameter of said threaded member and greater than the minor diameter of said threaded member.

19. The plate according to Claim 16, wherein said distal edges of said two webs are substantially equal in length.

20. The plate according to Claim 16, wherein the ratio of the largest web radial width to the diameter of said circular aperture is between about 1:3.70 to about 1:4.88.

21. The plate according to Claim 16, wherein the ratio of each of said webs thickness to the largest web radial width is between about 1:2.86 to about 1:5.00.

22. The plate according to Claim 16, and further comprising two minor webs integrally formed with said plate and said webs and extending between said webs.

23. The plate according to Claim 22, wherein each of said minor webs is in the form of a ring segment.

24. The plate according to Claim 15, wherein the outer surfaces of said two webs are substantially parallel.

25. The plate according to Claim 15, wherein the inner surfaces of said two webs are substantially parallel.

26. The plate according to Claim 15, wherein said two webs have substantially the same thickness.

27. The plate according to Claim 14, wherein said web means is formed of polymeric material.

28. The plate according to Claim 14, and further comprising a hollow boss integrally extending from the inner surface of said plate and axially aligned with said aperture.

29. The plate according to Claim 14, and further comprising a cylindrical bore formed in said aperture between said countersink and said web means.

30. The plate according to Claim 14, and further comprising a pair of ribs extending radially outward of said aperture and integrally formed with the inner surface of said plate.

31. In a plate composed of a polymeric material for completing the enclosure of an outlet box and being securable adjacent the box by means of a threaded member receivable in an aperture in the plate and an internally threaded bore coupled to the box and by means of a frustoconical surface on the head of the threaded member receivable in a countersink in the plate, the improvement comprising:
flexible web means composed of a polymeric material, integrally formed with said plate and extending into said aperture, for engaging a portion of said threaded member when said portion is inserted into said aperture to captivate, retain and align the threaded member in the plate for ease of insertion of the threaded member into the threaded bore.

32. The plate according to Claim 31, wherein said web means comprises two webs located on opposite sides of said aperture.

33. The plate according to Claim 32, wherein said aperture is substantially circular, and said webs each have a distal edge forming a chord of said circular aperture.

34. The plate according to Claim 31, wherein said web means is formed of a thermoplastic material.

35. In the combination of a wall plate having an aperture extending through the plate and a screw member inserted into the aperture, the screw member having an externally threaded body and a head, the outermost peripheral portion of said head having an underlying surface, the improvement comprising:
the plate being comprised of a polymeric material having first and second opposite respective sides, said aperture having an annular portion tapering inwardly from the first side of the plate upon which the underlying surface of the screw head seats; and at least one flexible web means unitary with the plate and extending into said aperture, said web means located adjacent the second side of the plate for engaging said threaded body of said screw member when said screw member is fully inserted into said aperture with the underlying surface of said screw head seating against said tapering portion of the plate, whereby said screw member is retained therebetween substantially perpendicular to the plate.

36. A plate for completing the enclosure of an outlet box comprising:
a flexible body portion composed of thermoplastic material;
means defining a substantially circular aperture in said body portion;
a pair of opposed, flexible webs integrally formed with said body portion and extending into said aperture, said webs each having a distal edge forming a chord of said circular aperture, said distal edges of said webs being substantially parallel;
an inwardly and downwardly tapered frustoconical bore formed in said body portion coaxial with said circular aperture;
a cylindrical bore formed in said body portion between said frustoconical bore and said webs and coaxially aligned with said frustoconical bore; and an opening in said body portion for receiving a part of an electrical wiring device coupled to the outlet box.