CA1277409C - Screw attachment for electrical box - Google Patents
Screw attachment for electrical boxInfo
- Publication number
- CA1277409C CA1277409C CA000529281A CA529281A CA1277409C CA 1277409 C CA1277409 C CA 1277409C CA 000529281 A CA000529281 A CA 000529281A CA 529281 A CA529281 A CA 529281A CA 1277409 C CA1277409 C CA 1277409C
- Authority
- CA
- Canada
- Prior art keywords
- box
- cavity
- cam member
- screw
- arcuate surface
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Abstract
ABSTRACT OF THE DISCLOSURE
A molded electrical box is provided with attach-ment housings at opposite ends thereof. The attachment housing include a fixed arcuate surface and a movable partial threaded cam member to engage a screw inserted therein. The housing are positioned between knockouts formed in the end walls to avoid interference during the molding production thereof. A channel extends from the rear of each attachment housing along the outer surface of the and wall to the rear of the box.
A molded electrical box is provided with attach-ment housings at opposite ends thereof. The attachment housing include a fixed arcuate surface and a movable partial threaded cam member to engage a screw inserted therein. The housing are positioned between knockouts formed in the end walls to avoid interference during the molding production thereof. A channel extends from the rear of each attachment housing along the outer surface of the and wall to the rear of the box.
Description
TIT~: SCREW ATTACHMENT FOR ELECTRICAL BOX
SPECIFIÇAIION
This invention relates to an electrical box having an improved camming thread engagement structure.
Backqround o~ the Invention In U.S. Patent 4,315,100, Haslbeck, there is shown an electrical box with an electrical device attachment structure having a wedging thread engagement means of the yeneral type to which the present invention relates. As shown in that patent, the electrical box is molded of a thermoplastic or the~mosetting plastic and a rectangular protrusion is formed ~t each end on the outside of the box. A downwardly opening~ general-. .~
~ 7 4()'~
ly triangular c~ity wlthin the protru~ion ha~ partial threads along on~ wall. A triangular cam member fits within the cavity and has partial threads along the ~ide facing the threaded wall. A ~crew of suitable ~ize can easily be inserted by pushing the ficrew between the partially threaded regions and then, as th~
screw is rotated, the threads on the screw engage the threads on the cam memb~r and the wall, forming a secure mechanical engagement. ~he axial force tending to extract the 6crew pull~ the sloping surface of the cam member against the similarly 610ping ~urface of the cavity, increasing the compressive force of the partial threads against the 6crew and preventing its removal.
Wh$1e this structure functions quite well, there are ~ome practical problems with the arrangement as shown in the ~a~lb~ck patent and as origlnally pro-duced. The problsms are based partly on the fact that the box must have molded knockouts to provide entry openings for cables, and that the inner surface of the box mu6t be clear betwQen the knockouts and the open side of the box 80 that the molded box can be e~ected from the ~old during production.
Thus, the original box was made with the cam-receiving cavity formed ln a protru~ion on the outside of the box. If the attachment structure were formed inside the box it would extend across the area above the knockouts And could not be molded in any com~er-cially acceptable manner. However, the center-to-center distance betwQen ~crew~ i8 a ~tandard d~tance(3.281~), which means that the Qrf~cti~e, usable interior volu~e o~ th~ box was reduced by about 13% or more, dependent upon box depth, a serious lo ~ o~ wire fill capacity ln a box which ~u6t receive a 6witch, ~ ~ 7740~3 outlet or other electrical device and then accommodate wlres as well. The 10B8 of wire capacity d~trimentally a~5t8 the box rating ~incQ the Nat~onal Electrical Code raquires that the box have a certain cublc inch capacity ln order to receive wire~ of ~peci~ic ~izes.
Simply rotating the or~ginal design 90 would create an unacceptable protrusion on each end o~ the box. The or~ginal box thu~ had lim~ted utllity.
Summary o~ the I~vention The presen-t invention seeks to provide ~n ~lectrical box having improv~d cam action screw engaging means arr~nged 80 that the interior volume of the box is maximized but ~o that the box can be molded with cable kn~ckouts ln the desired locations.
Further the invention seeks to provide such a box with improved attachment means wherein the mo~able cam components are loosely held and easily assembled.-Briefly descr$bed, the invention comprises a molded electrical box having ~ir~t and second generallyparallel side walls, ~irst and sQcond generally parallel end walls perpend~cular to thQ side wall~, and a back wall forming a box with an open front ~or receiving wires ~nd an electrical fixture or device. A
plurallty of cabla entry Xnockouts are formed in each of thQ end walls ad~acent the back wall. Fir~t and sQcond 6crew ~ttachment housings are formed ~t the ~ront edges o~ ths ond wall~, each attachmQnt housing lncluding a cavity having an openi~g ~aclng in the same direotion as the box ~or r~ceiving ~ scrQw, ~ean~ in th4 cavl~y def$ning an ~rcuat~ ~ur~ce facing outwardly ~rom the box, and a flrst sloping sur~a~2 ln the cavity ~cing toward the æxcuatQ sur~acQ ~nd al80 toward the bacX wall, A gener~lly trlangular cam ~ember having a ~a ~ ~'7~409 second ~loping surface and a set of partial threads is ~n~ertable into th~ cavity wlth thQ first and ~econd 610ping 6urface~ facing Qach other and the partial threads of ~he cam member ~acing the arcuate surface in the cavity so that the sloping surfaces are intersected by a longitudinal plane which bisects the box. A concave channel i~ formed ln the outer ~ur~ace o~ each of the end wall~ and extend~ from ~ach ~ttachment housing to the rear o~ thQ box, the housing and the channel being between th~ knockouts in each end wall.
Br~e~ De~cription of ~he ~rawin~
In order to impart full understanding of the ~anner in which thQ6Q and other ob~ectives are attained in accordancQ with thQ invention, a particularly ~dvantageous embodimQnt thereof will be described with reference to the accompanying drawings, which form a part of thi~ specification, and wherein:
Fig. 1 i~ ~ per~pective view of a box constructed in ~ccordance with the present invention;
Fig. 2 i8 a partial bottom plan ViQW of one end of the box o~ Fig. ls Flg. 3 18 an enlargQd partial top plan view of an end of the box of Flg. l 6howing a ~crew attachment housing;
Flg. 4 is ~ transverse sectional vi~w along longitudinal lin~ 4-4 o~ Fig. 3:
Fig. 5 i8 ~ partl~l sactional elQvation along line 5-5 o~ F$g. 4s Fig. 6 1~ a ~lde elavati~n of a cam member u~able in the box o~ Fig l ~nd 2;
Figs. 7 and 8 ars top plan ~nd side el~vatio~
vi~ws, re~pectively, o~ th2 c~m member of Fig. 6; and A
7~ 3 Flg. 9 18 a side elevation :Ln section of the end ~ember of Fig. 6.
pe~crlption of the Prç~Fred Embodlment ~eferring flrst to Fig~. 1 and 2, an electrical box indicated generally ~t lO constructed ln accordance with the invention includes parallel ~ide walls ll and 12, parallel end walls 14 and 15, ~nd a back wall 16, the walls belng mutually perpendicular to form a box having an open front. Tha box iB preferably molded as a unitary component u~ing a polymeric material which can be a thermoplastic 6uch as PVC, Noryl or the like, or a thermosetting material such as a phenolic.
Sloping nail guides 18 ars pro~ided in pairs at opposite ends of the box to perm~t attaching the box to a wooden ~tud or ~oist, these nail guides being integrally form~d on the outer surfaces of the end wall~. ~nockout~ 20 are formed ln the end walls near the rear wall to provide easily removable panels through which cable6 can be inserted. In the specific embodiment shown, the knockouts are L-shaped and extend around the ~orners ~oining the end 2nd rear walls, but v~rious forms of knockouts can be u6ed without affecting the construction or utility of the other a6perts of the box insofar as the invention is concerned.
At the upper or front edge of end wall 15 an attachment hou~ing 22 is for~ed, the attachment housing itself being somewhat D-~haped as viewed from the front. An identical attachment hou~i~g 24 is for~ed ~t the ~ront o~ end wall 14. The lnner ~urface of each attachment hGusing 1~ ~omewhat cylindrical in shape and extends all the way down the in~de of the box to the inner ~ur~ace o~ rear wall 16. On the 7~(.39 outs~de of the box the attachment housing extend~
downwardly ~or a distance of approxlmately 3/8".
Below the housing 22, the outer surface of end wall 15 i 6 for~ed with a cDnca~e channel 26 which extends ~or the full depth of the ~ox and ends at a U shaped reces~ in back wall 16. Thu~, as seen in Flg. 2, ther~ 1~ clear, unub~tructed acce~6 from the back of the box to the lower Qr back ~ide of housing 22n The attachment ho~sing it~elf i6 more clearly shown in the enlarged partial and 6ection~1 views in Figs. 3, 4 and .5. Within housinq 22 i~ a cavity indicated generally at 28, the top part of which is generally rectangular snd the lower part of which includes an upwardly and inwardly sloping 6urface 30 which make6 an angle of about 70 with the horizontal and which faces inwardly toward the oppo6ite side of the cav~ty and downwardly toward the rear wall of the housing. Opposite ~ur~ace 30 wlthin the cavlty is an ~rcuate surf~c~ 32 which 15 formed smooth but which wlll be impressed with a ~et of partial thread~ by ~n attachment screw, as wlll be described. A~ will be seen in Fig. 5, the upper rectangul~r portion of cavity 28 i8 ~lightly wider than the lower portion, ~orming 6houlders 34 within the cavity. Surface 32 can be smoothly arcuate, a~ Ghown, or can have the shape of a portion of h polygon~l cylinder.
A gener~lly tri~ngular cam member which fits within cavity 28 i8 shDwn in Figs. 6-9. The cam member 35 lnclude~ a ~lo~ing surface 36 as the hypote-nuse of the trlnngle and ha~ an arcuate fac~ 38 whichiB formed with a ~et o~ partial threads. Th2~e threads ar~ partial thre~d~ in t~e ~ense that they occupy a portion of an nrc ~ual to ~r 1~88 ~han 180. The ~ldes 39 of member 35 ~re generally smooth but a~ the ~7~
upper ends thereof ears 40 protrude outwardly, the ears having downwardly and outwardly F,loping upper ~urfa~es ~nd horizontal lower surface6.
The width o~ cam member 35 between sur~aces 39 is ~pproximately e~u~l to the width of the lower portion ~f cavity 28, i.e., the dimension visible in Fig. 5.
T~us, a cam member 35 can be inserted upwardly in the direct~on of arrow 42 in Fig. 4, unt~l ear~ 40 pass through the lower portion of cavity 28 and snap outwardly ~bove shoulder~ 34 BO that the lower 6urfaces of the ears can rest on those ~houlders. The ears and ~houlders thu~ lnhibit downward movement of the cam member ~nd upward movement iR limited by the widest dimen~ion of the lower portion of the cam member. As will be recognized, the c~m ~ember is inserted with itB parti~l threade 38 racing arcu~te ~urface 32 ~nd ~o th~t ~urface 36 ie ~acing ~loping surface 30.
The operation of th~ ~pparatus can be very briefly described. With c~m member 35 in cavity 28, a conven-tional No. 6 or No. 8 ~crew can be inserted ~romabove between ~rcuate surface 32 and parti~l thread set 38 by direct nxial movement. Following axial insertion, the ficrew can be rotated in the tightening direction, the threads o~ the screw engaging partial thre~ds 38 and c~using upward movement oP cam member 35 until surface 3~ contact~ sur~ace 30. At this time, the ~crew begin~ to impress ~ set o~ partial threads in 6urface 32. Any further rotation o~ the 6crew causes cam member 35 to move upwArdly and lnwardly toward the screw, further ~orming threads 32, compres-sing the screw and tightening ~he engageme~t between the ~crew thr~ads And the threads on member 35 2~ well as newly formed threads in surface 32. Fi~m engagement o~ the ~crew i8 thereby achievQd. The screw can ~'~'774~9 readily be removed by ~imply rotating it in the opposite direction. The newly formPd threads, however, remain.
While one advantagPou~ embodiment has been chosen to illustrate the lnvention, it will be understood by those skilled in the art that var~ous changes and modifications can be made therein without departing frc~m the scope of the invention as deflned in the appended claims.
SPECIFIÇAIION
This invention relates to an electrical box having an improved camming thread engagement structure.
Backqround o~ the Invention In U.S. Patent 4,315,100, Haslbeck, there is shown an electrical box with an electrical device attachment structure having a wedging thread engagement means of the yeneral type to which the present invention relates. As shown in that patent, the electrical box is molded of a thermoplastic or the~mosetting plastic and a rectangular protrusion is formed ~t each end on the outside of the box. A downwardly opening~ general-. .~
~ 7 4()'~
ly triangular c~ity wlthin the protru~ion ha~ partial threads along on~ wall. A triangular cam member fits within the cavity and has partial threads along the ~ide facing the threaded wall. A ~crew of suitable ~ize can easily be inserted by pushing the ficrew between the partially threaded regions and then, as th~
screw is rotated, the threads on the screw engage the threads on the cam memb~r and the wall, forming a secure mechanical engagement. ~he axial force tending to extract the 6crew pull~ the sloping surface of the cam member against the similarly 610ping ~urface of the cavity, increasing the compressive force of the partial threads against the 6crew and preventing its removal.
Wh$1e this structure functions quite well, there are ~ome practical problems with the arrangement as shown in the ~a~lb~ck patent and as origlnally pro-duced. The problsms are based partly on the fact that the box must have molded knockouts to provide entry openings for cables, and that the inner surface of the box mu6t be clear betwQen the knockouts and the open side of the box 80 that the molded box can be e~ected from the ~old during production.
Thus, the original box was made with the cam-receiving cavity formed ln a protru~ion on the outside of the box. If the attachment structure were formed inside the box it would extend across the area above the knockouts And could not be molded in any com~er-cially acceptable manner. However, the center-to-center distance betwQen ~crew~ i8 a ~tandard d~tance(3.281~), which means that the Qrf~cti~e, usable interior volu~e o~ th~ box was reduced by about 13% or more, dependent upon box depth, a serious lo ~ o~ wire fill capacity ln a box which ~u6t receive a 6witch, ~ ~ 7740~3 outlet or other electrical device and then accommodate wlres as well. The 10B8 of wire capacity d~trimentally a~5t8 the box rating ~incQ the Nat~onal Electrical Code raquires that the box have a certain cublc inch capacity ln order to receive wire~ of ~peci~ic ~izes.
Simply rotating the or~ginal design 90 would create an unacceptable protrusion on each end o~ the box. The or~ginal box thu~ had lim~ted utllity.
Summary o~ the I~vention The presen-t invention seeks to provide ~n ~lectrical box having improv~d cam action screw engaging means arr~nged 80 that the interior volume of the box is maximized but ~o that the box can be molded with cable kn~ckouts ln the desired locations.
Further the invention seeks to provide such a box with improved attachment means wherein the mo~able cam components are loosely held and easily assembled.-Briefly descr$bed, the invention comprises a molded electrical box having ~ir~t and second generallyparallel side walls, ~irst and sQcond generally parallel end walls perpend~cular to thQ side wall~, and a back wall forming a box with an open front ~or receiving wires ~nd an electrical fixture or device. A
plurallty of cabla entry Xnockouts are formed in each of thQ end walls ad~acent the back wall. Fir~t and sQcond 6crew ~ttachment housings are formed ~t the ~ront edges o~ ths ond wall~, each attachmQnt housing lncluding a cavity having an openi~g ~aclng in the same direotion as the box ~or r~ceiving ~ scrQw, ~ean~ in th4 cavl~y def$ning an ~rcuat~ ~ur~ce facing outwardly ~rom the box, and a flrst sloping sur~a~2 ln the cavity ~cing toward the æxcuatQ sur~acQ ~nd al80 toward the bacX wall, A gener~lly trlangular cam ~ember having a ~a ~ ~'7~409 second ~loping surface and a set of partial threads is ~n~ertable into th~ cavity wlth thQ first and ~econd 610ping 6urface~ facing Qach other and the partial threads of ~he cam member ~acing the arcuate surface in the cavity so that the sloping surfaces are intersected by a longitudinal plane which bisects the box. A concave channel i~ formed ln the outer ~ur~ace o~ each of the end wall~ and extend~ from ~ach ~ttachment housing to the rear o~ thQ box, the housing and the channel being between th~ knockouts in each end wall.
Br~e~ De~cription of ~he ~rawin~
In order to impart full understanding of the ~anner in which thQ6Q and other ob~ectives are attained in accordancQ with thQ invention, a particularly ~dvantageous embodimQnt thereof will be described with reference to the accompanying drawings, which form a part of thi~ specification, and wherein:
Fig. 1 i~ ~ per~pective view of a box constructed in ~ccordance with the present invention;
Fig. 2 i8 a partial bottom plan ViQW of one end of the box o~ Fig. ls Flg. 3 18 an enlargQd partial top plan view of an end of the box of Flg. l 6howing a ~crew attachment housing;
Flg. 4 is ~ transverse sectional vi~w along longitudinal lin~ 4-4 o~ Fig. 3:
Fig. 5 i8 ~ partl~l sactional elQvation along line 5-5 o~ F$g. 4s Fig. 6 1~ a ~lde elavati~n of a cam member u~able in the box o~ Fig l ~nd 2;
Figs. 7 and 8 ars top plan ~nd side el~vatio~
vi~ws, re~pectively, o~ th2 c~m member of Fig. 6; and A
7~ 3 Flg. 9 18 a side elevation :Ln section of the end ~ember of Fig. 6.
pe~crlption of the Prç~Fred Embodlment ~eferring flrst to Fig~. 1 and 2, an electrical box indicated generally ~t lO constructed ln accordance with the invention includes parallel ~ide walls ll and 12, parallel end walls 14 and 15, ~nd a back wall 16, the walls belng mutually perpendicular to form a box having an open front. Tha box iB preferably molded as a unitary component u~ing a polymeric material which can be a thermoplastic 6uch as PVC, Noryl or the like, or a thermosetting material such as a phenolic.
Sloping nail guides 18 ars pro~ided in pairs at opposite ends of the box to perm~t attaching the box to a wooden ~tud or ~oist, these nail guides being integrally form~d on the outer surfaces of the end wall~. ~nockout~ 20 are formed ln the end walls near the rear wall to provide easily removable panels through which cable6 can be inserted. In the specific embodiment shown, the knockouts are L-shaped and extend around the ~orners ~oining the end 2nd rear walls, but v~rious forms of knockouts can be u6ed without affecting the construction or utility of the other a6perts of the box insofar as the invention is concerned.
At the upper or front edge of end wall 15 an attachment hou~ing 22 is for~ed, the attachment housing itself being somewhat D-~haped as viewed from the front. An identical attachment hou~i~g 24 is for~ed ~t the ~ront o~ end wall 14. The lnner ~urface of each attachment hGusing 1~ ~omewhat cylindrical in shape and extends all the way down the in~de of the box to the inner ~ur~ace o~ rear wall 16. On the 7~(.39 outs~de of the box the attachment housing extend~
downwardly ~or a distance of approxlmately 3/8".
Below the housing 22, the outer surface of end wall 15 i 6 for~ed with a cDnca~e channel 26 which extends ~or the full depth of the ~ox and ends at a U shaped reces~ in back wall 16. Thu~, as seen in Flg. 2, ther~ 1~ clear, unub~tructed acce~6 from the back of the box to the lower Qr back ~ide of housing 22n The attachment ho~sing it~elf i6 more clearly shown in the enlarged partial and 6ection~1 views in Figs. 3, 4 and .5. Within housinq 22 i~ a cavity indicated generally at 28, the top part of which is generally rectangular snd the lower part of which includes an upwardly and inwardly sloping 6urface 30 which make6 an angle of about 70 with the horizontal and which faces inwardly toward the oppo6ite side of the cav~ty and downwardly toward the rear wall of the housing. Opposite ~ur~ace 30 wlthin the cavlty is an ~rcuate surf~c~ 32 which 15 formed smooth but which wlll be impressed with a ~et of partial thread~ by ~n attachment screw, as wlll be described. A~ will be seen in Fig. 5, the upper rectangul~r portion of cavity 28 i8 ~lightly wider than the lower portion, ~orming 6houlders 34 within the cavity. Surface 32 can be smoothly arcuate, a~ Ghown, or can have the shape of a portion of h polygon~l cylinder.
A gener~lly tri~ngular cam member which fits within cavity 28 i8 shDwn in Figs. 6-9. The cam member 35 lnclude~ a ~lo~ing surface 36 as the hypote-nuse of the trlnngle and ha~ an arcuate fac~ 38 whichiB formed with a ~et o~ partial threads. Th2~e threads ar~ partial thre~d~ in t~e ~ense that they occupy a portion of an nrc ~ual to ~r 1~88 ~han 180. The ~ldes 39 of member 35 ~re generally smooth but a~ the ~7~
upper ends thereof ears 40 protrude outwardly, the ears having downwardly and outwardly F,loping upper ~urfa~es ~nd horizontal lower surface6.
The width o~ cam member 35 between sur~aces 39 is ~pproximately e~u~l to the width of the lower portion ~f cavity 28, i.e., the dimension visible in Fig. 5.
T~us, a cam member 35 can be inserted upwardly in the direct~on of arrow 42 in Fig. 4, unt~l ear~ 40 pass through the lower portion of cavity 28 and snap outwardly ~bove shoulder~ 34 BO that the lower 6urfaces of the ears can rest on those ~houlders. The ears and ~houlders thu~ lnhibit downward movement of the cam member ~nd upward movement iR limited by the widest dimen~ion of the lower portion of the cam member. As will be recognized, the c~m ~ember is inserted with itB parti~l threade 38 racing arcu~te ~urface 32 ~nd ~o th~t ~urface 36 ie ~acing ~loping surface 30.
The operation of th~ ~pparatus can be very briefly described. With c~m member 35 in cavity 28, a conven-tional No. 6 or No. 8 ~crew can be inserted ~romabove between ~rcuate surface 32 and parti~l thread set 38 by direct nxial movement. Following axial insertion, the ficrew can be rotated in the tightening direction, the threads o~ the screw engaging partial thre~ds 38 and c~using upward movement oP cam member 35 until surface 3~ contact~ sur~ace 30. At this time, the ~crew begin~ to impress ~ set o~ partial threads in 6urface 32. Any further rotation o~ the 6crew causes cam member 35 to move upwArdly and lnwardly toward the screw, further ~orming threads 32, compres-sing the screw and tightening ~he engageme~t between the ~crew thr~ads And the threads on member 35 2~ well as newly formed threads in surface 32. Fi~m engagement o~ the ~crew i8 thereby achievQd. The screw can ~'~'774~9 readily be removed by ~imply rotating it in the opposite direction. The newly formPd threads, however, remain.
While one advantagPou~ embodiment has been chosen to illustrate the lnvention, it will be understood by those skilled in the art that var~ous changes and modifications can be made therein without departing frc~m the scope of the invention as deflned in the appended claims.
Claims (2)
1. A molded electrical box comprising first and second generally parallel side walls, first and second generally parallel end walls perpendicular to said side walls and a back wall forming a box with an open front for receiving wires and an electrical device;
a plurality of cable entry knockouts formed in said end walls adjacent said back wall;
first and second screw attachment housings, one in each of said end walls at said open front, each said attachment housing including a cavity having an opening facing in the same direction as said box into which a screw can be inserted, means in said cavity defining an arcuate surface facing away from the other end wall, and a first sloping surface in said cavity facing toward said arcuate surface and toward said back wall;
a generally triangular cam member having a second sloping surface and means on another surface defining a set of partial threads, said cam member being insertable into said cavity with said first and second sloping surfaces facing each other and said arcuate surface facing said set of partial threads and said sloping surfaces being intersected by a longitudinal plane bisecting said box; and means defining a concave channel in the outer surface of each of said end walls extending from said attach-ment housing to the rear of said box, said housing and said channel being between said knockouts in each end wall, said cam member being operative to engage and press a screw into said arcuate surface to form threads therein when the screw is inserted and rotated between said arcuate surface and said set of partial threads.
a plurality of cable entry knockouts formed in said end walls adjacent said back wall;
first and second screw attachment housings, one in each of said end walls at said open front, each said attachment housing including a cavity having an opening facing in the same direction as said box into which a screw can be inserted, means in said cavity defining an arcuate surface facing away from the other end wall, and a first sloping surface in said cavity facing toward said arcuate surface and toward said back wall;
a generally triangular cam member having a second sloping surface and means on another surface defining a set of partial threads, said cam member being insertable into said cavity with said first and second sloping surfaces facing each other and said arcuate surface facing said set of partial threads and said sloping surfaces being intersected by a longitudinal plane bisecting said box; and means defining a concave channel in the outer surface of each of said end walls extending from said attach-ment housing to the rear of said box, said housing and said channel being between said knockouts in each end wall, said cam member being operative to engage and press a screw into said arcuate surface to form threads therein when the screw is inserted and rotated between said arcuate surface and said set of partial threads.
2. A box according to claim 1 wherein said cam member includes laterally protruding retention ears to loosely hold said member in said cavity.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US83129486A | 1986-02-20 | 1986-02-20 | |
| US831,294 | 1986-02-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1277409C true CA1277409C (en) | 1990-12-04 |
Family
ID=25258746
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000529281A Expired - Lifetime CA1277409C (en) | 1986-02-20 | 1987-02-09 | Screw attachment for electrical box |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1277409C (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7306482B1 (en) | 2001-03-06 | 2007-12-11 | Cheetah Usa Corp. | Electrical connection box |
| US7395598B2 (en) | 2001-03-06 | 2008-07-08 | Cheetah Usa Corp. | Face plate securement method |
| US8029301B2 (en) | 2005-01-11 | 2011-10-04 | Cheetah Usa Corp. | Wide safety strap for electrical fixtures |
| US8299359B2 (en) | 2006-07-18 | 2012-10-30 | Leviton Manufacturing Company, Inc. | Wiring device and cover plate snap-on assembly |
-
1987
- 1987-02-09 CA CA000529281A patent/CA1277409C/en not_active Expired - Lifetime
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7306482B1 (en) | 2001-03-06 | 2007-12-11 | Cheetah Usa Corp. | Electrical connection box |
| US7395598B2 (en) | 2001-03-06 | 2008-07-08 | Cheetah Usa Corp. | Face plate securement method |
| US7494371B2 (en) | 2001-03-06 | 2009-02-24 | Cheetah Usa Corp. | Pronged, screwless face plate |
| US8109785B2 (en) | 2001-03-06 | 2012-02-07 | Cheetah Usa Corp. | Connection box assembly method |
| US8029301B2 (en) | 2005-01-11 | 2011-10-04 | Cheetah Usa Corp. | Wide safety strap for electrical fixtures |
| US8299359B2 (en) | 2006-07-18 | 2012-10-30 | Leviton Manufacturing Company, Inc. | Wiring device and cover plate snap-on assembly |
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