CA1100217A - Electrical outlet box and wall mounting clamp therefor - Google Patents
Electrical outlet box and wall mounting clamp thereforInfo
- Publication number
- CA1100217A CA1100217A CA295,377A CA295377A CA1100217A CA 1100217 A CA1100217 A CA 1100217A CA 295377 A CA295377 A CA 295377A CA 1100217 A CA1100217 A CA 1100217A
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- CA
- Canada
- Prior art keywords
- outlet box
- leg
- clamp
- wall
- pair
- 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
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Abstract
ELECTRICAL OUTLET BOX AND WALL
MOUNTING CLAMP THEREFOR
Abstract of the Disclosure An electrical outlet box and wall mounting clamps therefor for connection to a wall panel by the manual effort of a workman without the use of a tool or other mechanical device, in which the clamps comprise a pair of L-shaped members each having a first leg which forms a clamping wall and second leg extending from the first leg at slightly more than a 90° angle. The second leg includes a pair of spaced apart fingers defining an elongated clearance gap therebetween. The L-shaped clamps are mounted in the top and bottom wall of the outlet box by inserting the first leg through an elongated tranverse slot in such top and bottom walls, whereby the clamps may pivot between a retracted position and a clamping position at the junction joining the two legs of the L. When the clamps are in the retracted position, they are held in that position by a over-center spring lock, the box may be inserted through a corresponding aperture in a wall panel after which the clamps are pivoted to the clamping position to sandwich the adjacent sides of the wall panel between the clamp and a corresponding mounting ear, or front flange, of the outlet box. In the clamping position, snap buttons on the second leg are connected to respective apertures in the top and bottom wall of the electrical outlet box, and as the clamp is pivoted to the clamping position, bending forces occur at the contact between the clamp and front flange, and in the locked position the obtuse angle between the first and second legs is reduced to a sub-stantially 90° angle causing the bending forces to be translated to shear forces where the first leg contacts the slot. A screw, which holds the receptacle in the outlet box, extends through the first leg when it is in the clamping position and accordingly provides a safety lock in the event of disengagement of the second leg with the outlet box.
MOUNTING CLAMP THEREFOR
Abstract of the Disclosure An electrical outlet box and wall mounting clamps therefor for connection to a wall panel by the manual effort of a workman without the use of a tool or other mechanical device, in which the clamps comprise a pair of L-shaped members each having a first leg which forms a clamping wall and second leg extending from the first leg at slightly more than a 90° angle. The second leg includes a pair of spaced apart fingers defining an elongated clearance gap therebetween. The L-shaped clamps are mounted in the top and bottom wall of the outlet box by inserting the first leg through an elongated tranverse slot in such top and bottom walls, whereby the clamps may pivot between a retracted position and a clamping position at the junction joining the two legs of the L. When the clamps are in the retracted position, they are held in that position by a over-center spring lock, the box may be inserted through a corresponding aperture in a wall panel after which the clamps are pivoted to the clamping position to sandwich the adjacent sides of the wall panel between the clamp and a corresponding mounting ear, or front flange, of the outlet box. In the clamping position, snap buttons on the second leg are connected to respective apertures in the top and bottom wall of the electrical outlet box, and as the clamp is pivoted to the clamping position, bending forces occur at the contact between the clamp and front flange, and in the locked position the obtuse angle between the first and second legs is reduced to a sub-stantially 90° angle causing the bending forces to be translated to shear forces where the first leg contacts the slot. A screw, which holds the receptacle in the outlet box, extends through the first leg when it is in the clamping position and accordingly provides a safety lock in the event of disengagement of the second leg with the outlet box.
Description
~ 110~?217 1 Background of the Invention
2 This invention relates to the field of electrical outlet
3 boxes having self-contained clamping means to mount and secure
4 the boxes in corresponding apertures provided in a wall panel of a structure (such as a house or mobile home) in preparation for 6 wiring for electrical service.
7 For many years, outlet boxes were secured to studs and other 8 portions of a building wall by nails or screws, and many are 9 still secured by this method. In certain types of building con-struction such as pre-fabricated housing, manufacture of mobile 11 homes and the like, assembly line techniques are employed which 12 lend themselves to time and labor saving techniques. Thus, 13 various self-contained clamping devices have been incorporated 14 into electrical outlet boxes to enable securing the box in place in an aperture in a wall panel without the need for using screws 16 or nails driven into the studding framework. Among such self-17 contained clamping devices are winglike members mounted on a-18 frontal access screw to rotate upon rotation of the screw from a 19 folded position along a side of the box after the box has been inserted in a receiving aperture in a wall panel to an extended 21 position wherein the winglike member extends outwardly from the 22 side of the box to sandwich an edge of the wall panel between 23 such member and a frontal flange of the box. Such clamping 24 devices rotate on an axis which is normal to the open front wall 25; f the outlet box and normal to the wall panel in which the 26 outlet box is being secured. The bearing surface of such devices 27 which faces the front of the box remains the same both in the 28 folded position against the side of the box and in the extended 230 position when rotated outwardly to bear against the rear surface --- I ~ ~
1 of the wall panel after the box has been inserted in the aperture 2 in the wall panel. If this front facing bearing surface is made 3 relatively broad for good clamping contact when in the extended 4 position, the device will not clear when the box is inserted into the receiving aperture. If the front facing bearing surface is 6 made narrow enough to clear when inserting the box in the 7 receiving aperture in the wall panel opening, it provides only 8 minimal clamping contact when rotated outwardly from the side of 9 the box to its extended position. Accordingly, when using this type of device it is customary to provide one such device in each 11 corner of a rectangular outlet box in order to provide some degree 12 of stability to the box when installed.
13 Other attempts to provide self-contained clamping devices 14 for electrical outlet boxes have included forming integral ears or clamping surfaces as outward projections from wall portions 16 of the outlet box, with a cam surface positioned to contact a 17 corresponding wall panel edge bounding the aperture in the wall 18 panel as the box is pushed into such aperture to flex the integral 19 ears or clamping surfaces inwardly until they are pushed beyond the rear surface of the aperture of the wall panel whereupon they 21 are supposed to spring back to bear against such rear surface 22 and clamp the box in place with the wall edges held between such 23 ¦clamping surfaces and frontal flanges of the box. This type of 24 self contained device requires the use of materials capable of 25; flexing the clamping surfaces inwardly when the box is being 26 inserted and springing back when fully inserted. When used with 27 metal boxes, the cammed ears must be relatively thin to enable 28 them to flex inwardly when the box is pushedin the aperture in 29 the wall panel, thus limiting the area of bearing surface availabl~
.. ____._ . _ ~1~S?217 to clamp against the rear surface of the wall panel. ~hen this type of device is used with various types of plastic outlet boxes, the cammed ears do not always return to the fully extended position and hence do not provide a satisfactory clamping surface.
The present invention overcomes the problems associated with such prior art self-contained clamping devices. The L-shaped clamp members described herein pivot between retracted and clamping position on an axis which is parallel to the open front wall of the box and to the surface of the wall panel in which the box is mounted. This enables the use of a clamp which has a relatively broader bearing surface than devices which rotate on an axis normal to the surface of the wall in which the box is mounted. A more secure clamp of the box to the wall panel can thus be achieved, and with fewer clamp devices thus reducing cost.
According to one aspect of the present invention, there is provided a clamp for use with an electrical outlet box, said clamp receivably located in an elongated slot in a wall of said outlet box, said clamp comprises a first leg outside of said outlet box and a second leg inside of said outlet box, said second leg consisting of a pair of spaced apart projections, said first and second legs being connected at a juncture and forming an initial predetermined angle slightly greater than 90 degrees, said clamp being in a first position before said outlet box is installed in a predetermined opening in a house wall, said first leg being substantially parallel and adjacent to said outlet box wall and extending toward said rear wall of said outlet box, said second leg extending into said outlet box, a central appendage connected to said first leg of said clamp near said juncture, said central appendage having a step- dcwn end portion with a central apertureJ
a pair of snap buttons located on the end of said second leg opposite said juncture of said first and second legs, a snap button being located on each of said pair of spaced apart projections, for mating with a pair of apertures in said outlet box wall, such that after said outlet box is positioned in the predetermined opening in the house wall, said clamp is manually moved to a sesond position by pivoting said first and second legs about said juncture in said elongated slot until said snap buttons on said second leg are located in said corres-ponding apertures in said outlet box wall, said first leg effectively sandwiching the house wall between said second leg and a frontal flange, extending laterally away from a front edge of said outlet box wall, thereby securing said outlet box in the house wall, and an internally threaded bore in a center post extending inwardly from said front edge of said outlet box wall and a mounting screw, such that when said clamp is in said second position, said central aperture and said threaded bore are in registration, and when said mounting screw is inserted in said threaded bore, said mounting screw extends through said central aperture of said step-down portion of said central appendage thereby substantially retaining said clamp in said second position.
The wall mounting clamp provided for the electrical outlet box of this invention is disposed in a slot which is parallel to the front wall of the outlet box. The clamp is pivotable from a retracted position to a clamping position through the slot. In the retracted position, an over-center snap lock with a stop is provided to insure that the clamp does not move away and become detached from the outlet box during the process of shipping and installation. The clamp has two legs which are disposed obtuse angle, and in the clamping position the legs are resolved to a substantially 90 relationship whereby the bending forces B
:llO(~Z17 1 applied to a first leg of the clamp as it is pushed up against 2 the mounting wall are translated into shear forces at the point 3 of contact between the clamp and the slot. In the clamping 4 position, snap plugs on the other leg of the clamp hold a second leg to an inner wall of the outlet box. A secondary locking means 6 is provided by a screw which connects the receptacle to the out-let box. The screw also extends through the leg which abuts the 8 wall panel,and,in the event that the leg connected to the wall of the leg ~ panel of the outlet box becomesdetached,rotation/would be re-stricted over a limited distance, and the box would not become 11 detached from the wall panel.
12 These and other objects, features and advantages of this 13 invention will become apparent from the following description 14 and drawings.
Brief Description of the Drawings 16 Fig. 1 is a front elevation of an electrical outlet box in 17 accordance with this invention in partial cross section with a 18 receptacle in phantom having wall mounting clamps pivotally mounted 19 in the top and bottom walls shown in their clamping position;
Fig. 2a is a perspective view of the mounting clamp;
21 Fig. 2b is a side view of the mounting clamp;
22 Fig. 3 is a front elevation of an electrical outlet box in 23 accordance with this invention in partial cross section having 24 wall mounting clamps pivotally mounted in the top and bottom 25 ; walls shown in their retracted position;
26 Fig. 4 is a section view taken along lines 4-4 of Fig. 3;
27 Fig. 5 is a section view taken along lines 5-5 of Fig. 3;
28 ¦ Fig. 6 is a section view taken along line 6-6 of Fig. l;
29 ¦ Fig. 7 is an inverted section view taken along lines 7-7 of 3 ~ig. 6;
111~{P217 Fig. 8 is a section view taken alon~ lines 8-8 of Fig. l;
and Fig. 9 is a section view taken alon~ lines 9-9 of Fig. 1.
Detailed Description of the Invention Referring to the drawings, an electrical outlet box 1 includes a top wall 2 and a bottom wall 3 in which a pair of wall mounting - clamps 4 and 4 ! are mounted respectively through elongated slots
7 For many years, outlet boxes were secured to studs and other 8 portions of a building wall by nails or screws, and many are 9 still secured by this method. In certain types of building con-struction such as pre-fabricated housing, manufacture of mobile 11 homes and the like, assembly line techniques are employed which 12 lend themselves to time and labor saving techniques. Thus, 13 various self-contained clamping devices have been incorporated 14 into electrical outlet boxes to enable securing the box in place in an aperture in a wall panel without the need for using screws 16 or nails driven into the studding framework. Among such self-17 contained clamping devices are winglike members mounted on a-18 frontal access screw to rotate upon rotation of the screw from a 19 folded position along a side of the box after the box has been inserted in a receiving aperture in a wall panel to an extended 21 position wherein the winglike member extends outwardly from the 22 side of the box to sandwich an edge of the wall panel between 23 such member and a frontal flange of the box. Such clamping 24 devices rotate on an axis which is normal to the open front wall 25; f the outlet box and normal to the wall panel in which the 26 outlet box is being secured. The bearing surface of such devices 27 which faces the front of the box remains the same both in the 28 folded position against the side of the box and in the extended 230 position when rotated outwardly to bear against the rear surface --- I ~ ~
1 of the wall panel after the box has been inserted in the aperture 2 in the wall panel. If this front facing bearing surface is made 3 relatively broad for good clamping contact when in the extended 4 position, the device will not clear when the box is inserted into the receiving aperture. If the front facing bearing surface is 6 made narrow enough to clear when inserting the box in the 7 receiving aperture in the wall panel opening, it provides only 8 minimal clamping contact when rotated outwardly from the side of 9 the box to its extended position. Accordingly, when using this type of device it is customary to provide one such device in each 11 corner of a rectangular outlet box in order to provide some degree 12 of stability to the box when installed.
13 Other attempts to provide self-contained clamping devices 14 for electrical outlet boxes have included forming integral ears or clamping surfaces as outward projections from wall portions 16 of the outlet box, with a cam surface positioned to contact a 17 corresponding wall panel edge bounding the aperture in the wall 18 panel as the box is pushed into such aperture to flex the integral 19 ears or clamping surfaces inwardly until they are pushed beyond the rear surface of the aperture of the wall panel whereupon they 21 are supposed to spring back to bear against such rear surface 22 and clamp the box in place with the wall edges held between such 23 ¦clamping surfaces and frontal flanges of the box. This type of 24 self contained device requires the use of materials capable of 25; flexing the clamping surfaces inwardly when the box is being 26 inserted and springing back when fully inserted. When used with 27 metal boxes, the cammed ears must be relatively thin to enable 28 them to flex inwardly when the box is pushedin the aperture in 29 the wall panel, thus limiting the area of bearing surface availabl~
.. ____._ . _ ~1~S?217 to clamp against the rear surface of the wall panel. ~hen this type of device is used with various types of plastic outlet boxes, the cammed ears do not always return to the fully extended position and hence do not provide a satisfactory clamping surface.
The present invention overcomes the problems associated with such prior art self-contained clamping devices. The L-shaped clamp members described herein pivot between retracted and clamping position on an axis which is parallel to the open front wall of the box and to the surface of the wall panel in which the box is mounted. This enables the use of a clamp which has a relatively broader bearing surface than devices which rotate on an axis normal to the surface of the wall in which the box is mounted. A more secure clamp of the box to the wall panel can thus be achieved, and with fewer clamp devices thus reducing cost.
According to one aspect of the present invention, there is provided a clamp for use with an electrical outlet box, said clamp receivably located in an elongated slot in a wall of said outlet box, said clamp comprises a first leg outside of said outlet box and a second leg inside of said outlet box, said second leg consisting of a pair of spaced apart projections, said first and second legs being connected at a juncture and forming an initial predetermined angle slightly greater than 90 degrees, said clamp being in a first position before said outlet box is installed in a predetermined opening in a house wall, said first leg being substantially parallel and adjacent to said outlet box wall and extending toward said rear wall of said outlet box, said second leg extending into said outlet box, a central appendage connected to said first leg of said clamp near said juncture, said central appendage having a step- dcwn end portion with a central apertureJ
a pair of snap buttons located on the end of said second leg opposite said juncture of said first and second legs, a snap button being located on each of said pair of spaced apart projections, for mating with a pair of apertures in said outlet box wall, such that after said outlet box is positioned in the predetermined opening in the house wall, said clamp is manually moved to a sesond position by pivoting said first and second legs about said juncture in said elongated slot until said snap buttons on said second leg are located in said corres-ponding apertures in said outlet box wall, said first leg effectively sandwiching the house wall between said second leg and a frontal flange, extending laterally away from a front edge of said outlet box wall, thereby securing said outlet box in the house wall, and an internally threaded bore in a center post extending inwardly from said front edge of said outlet box wall and a mounting screw, such that when said clamp is in said second position, said central aperture and said threaded bore are in registration, and when said mounting screw is inserted in said threaded bore, said mounting screw extends through said central aperture of said step-down portion of said central appendage thereby substantially retaining said clamp in said second position.
The wall mounting clamp provided for the electrical outlet box of this invention is disposed in a slot which is parallel to the front wall of the outlet box. The clamp is pivotable from a retracted position to a clamping position through the slot. In the retracted position, an over-center snap lock with a stop is provided to insure that the clamp does not move away and become detached from the outlet box during the process of shipping and installation. The clamp has two legs which are disposed obtuse angle, and in the clamping position the legs are resolved to a substantially 90 relationship whereby the bending forces B
:llO(~Z17 1 applied to a first leg of the clamp as it is pushed up against 2 the mounting wall are translated into shear forces at the point 3 of contact between the clamp and the slot. In the clamping 4 position, snap plugs on the other leg of the clamp hold a second leg to an inner wall of the outlet box. A secondary locking means 6 is provided by a screw which connects the receptacle to the out-let box. The screw also extends through the leg which abuts the 8 wall panel,and,in the event that the leg connected to the wall of the leg ~ panel of the outlet box becomesdetached,rotation/would be re-stricted over a limited distance, and the box would not become 11 detached from the wall panel.
12 These and other objects, features and advantages of this 13 invention will become apparent from the following description 14 and drawings.
Brief Description of the Drawings 16 Fig. 1 is a front elevation of an electrical outlet box in 17 accordance with this invention in partial cross section with a 18 receptacle in phantom having wall mounting clamps pivotally mounted 19 in the top and bottom walls shown in their clamping position;
Fig. 2a is a perspective view of the mounting clamp;
21 Fig. 2b is a side view of the mounting clamp;
22 Fig. 3 is a front elevation of an electrical outlet box in 23 accordance with this invention in partial cross section having 24 wall mounting clamps pivotally mounted in the top and bottom 25 ; walls shown in their retracted position;
26 Fig. 4 is a section view taken along lines 4-4 of Fig. 3;
27 Fig. 5 is a section view taken along lines 5-5 of Fig. 3;
28 ¦ Fig. 6 is a section view taken along line 6-6 of Fig. l;
29 ¦ Fig. 7 is an inverted section view taken along lines 7-7 of 3 ~ig. 6;
111~{P217 Fig. 8 is a section view taken alon~ lines 8-8 of Fig. l;
and Fig. 9 is a section view taken alon~ lines 9-9 of Fig. 1.
Detailed Description of the Invention Referring to the drawings, an electrical outlet box 1 includes a top wall 2 and a bottom wall 3 in which a pair of wall mounting - clamps 4 and 4 ! are mounted respectively through elongated slots
5 extending transyersely through each of the walls 2 and 3.
A$ best seen in Figs. 2a and 2b, the wall mounting clamps 4 and 4' are L~shaped members. They are identical, as are the walls 2 and 3~ so only one clamp and wall will be described in detail, me clamp 4 includes a clamping wall 6 as a first leg 7 of the L-shaped member, and a pair of spaced apart projections 8 and 8 ! comprise a second leg 9 of the L. The first leg 7 is at a slightly greater than 90 an~le, preferably 101, to the second leg 9! whichr as best seen in Figs. 8 and 9, stresses the clamping wall 6 against the inner surface of a receiving wall panel lOa when the outlet box 1 is inserted therein and the clamp members 4 and 4' are moved to their clamping position.
As best seen in Figs. 8 and 9, the legs are resolved to a sub-stantially 9Q relationship to each other in the clamped position.
As shown in Fig. 2a, a clearance gap 10 is provided between the spaced apart projections 8 and 8' of the second leg 9. A
center post 11 of the top wall 2 and the center post of the bot-tom wall 3 (not shown) lie in the gap 10 between projections 8 and 8~ when the clamp member 4 is moved to its clamping position.
Each projection 8 and 8 ! has a primary locking means which includes near the free ends thereof a snap button comprising a short lug 12 having an enlarged head 13.
11~217 1 When the clamp member 4 is moved to its clamping position, the 2 enlarged head 13 of each lug 12 is received in a corresponding 3 locking aperture 14 positioned in the top wall 2 for registration 4 with lugs 12 when said clamp is moved to said clamping position.
The enlarged head 13 is compressed when it enters its respective
A$ best seen in Figs. 2a and 2b, the wall mounting clamps 4 and 4' are L~shaped members. They are identical, as are the walls 2 and 3~ so only one clamp and wall will be described in detail, me clamp 4 includes a clamping wall 6 as a first leg 7 of the L-shaped member, and a pair of spaced apart projections 8 and 8 ! comprise a second leg 9 of the L. The first leg 7 is at a slightly greater than 90 an~le, preferably 101, to the second leg 9! whichr as best seen in Figs. 8 and 9, stresses the clamping wall 6 against the inner surface of a receiving wall panel lOa when the outlet box 1 is inserted therein and the clamp members 4 and 4' are moved to their clamping position.
As best seen in Figs. 8 and 9, the legs are resolved to a sub-stantially 9Q relationship to each other in the clamped position.
As shown in Fig. 2a, a clearance gap 10 is provided between the spaced apart projections 8 and 8' of the second leg 9. A
center post 11 of the top wall 2 and the center post of the bot-tom wall 3 (not shown) lie in the gap 10 between projections 8 and 8~ when the clamp member 4 is moved to its clamping position.
Each projection 8 and 8 ! has a primary locking means which includes near the free ends thereof a snap button comprising a short lug 12 having an enlarged head 13.
11~217 1 When the clamp member 4 is moved to its clamping position, the 2 enlarged head 13 of each lug 12 is received in a corresponding 3 locking aperture 14 positioned in the top wall 2 for registration 4 with lugs 12 when said clamp is moved to said clamping position.
The enlarged head 13 is compressed when it enters its respective
6 aperture 14 and when pushed through aperture 14 the enlarged
7 head 13 expands to its original dimension thus locking the clamp
8 member in the clamping position.
9 The first leg 7 of the clamp members 4 and 4' includes a central appendage 15 having a step-down end portion 15a and a 11 central aperture 16 therethrough. The appendage 14 has a step-12 down end portion 15a which is received in the rearward extension 13 15b of the slot 5, as shown in Figs. 4 and 6. The central 14 aperture 16 of each clamp is in registration with internally threaded bore 17 through center post 11 when clamp 4 is moved to 16 its clamping position.
17 Mounting screws 18 which secure a wiring device in place, 18 such as duplex receptacle 19 as shown in Figs. 1 and 8, are 19 threaded through bore 17 and extend through the central apertures 16 of the clamp member 4 when it is in the clamping position.
21 The aperture 16 is not threaded and is slightly larger than the 22 diameter of the mounting screw 18. When the mounting screw 18 23 is extended through the aperture 16, it is received by a channel 24 l9a disposed in wall 2 and extending rearwardly from the extension 15b. When the clamp member is positively locked in 26 place in the clamping position to securely mount the outlet box 1 27 in the receiving aperture of the wall panel lOa, the wall panel 28 lOa is sandwiched between the clamping wall 6 of clamp members 4 29 and frontal flange 22,which extends laterally from a front edge 31 23 of the t wall 2.
~ ~ 110~217 1 In operation, the outlet boxes 1 are installed as follows.
2 Clamp 4 and top wall 2 are described below, but the operation for 3 clamp 4' and bottom wall 3 is identical.
4 The clamp 4 is connected through the elongated slot 5 in the top wall 2 of the outlet box 1 and positioned in the retracted 6 position, preferably by the manufacturer before shipment.
7 The slot 5 is parallel to the open front wall 25 of the outle :
8 box 1. The slot 5 is selectively spaced inwardly from the front ~ edge 23 a distance which is equal to or slightly greater than the width of the wall panel lOa in which the outlet box is to be 11 mounted. Dimensions of 1/4", 3/8" and 1/2" from the front wall 12 are used for wall panels having a thickness of 1/4" to 3/16", 5/16 13 to 3/8" and 7/16" to 1/2", respectively. A dimension of 1/4" is 14 shown in Fig. 5.
More specifically the connection between the clamp 4 and the 16 wall 2 is accomplished by inserting the first leg 7 through the 17 slot 5 from the bottom side until a pivot junction or junction 18 line 24, which joins the first leg 7 and second leg 9 of the L-B 19 shaped clamp 4, reaches the slot 5. The bosses i~a extend laterally from a forward side of the first leg portion 7 near the junction 21 line 24. The bosses ~ are selectively sized to allow the leg 22 portion 7 to be pushed through the slot 5 and then prevent the leg 23 portion 7 from moving back through the slot 5 in the event the 24 clamp 4 is jarred or shaken loose during shipment or installation.
When the junction line 24 of the clamp 4 is near the lower 26 edge of slot 5, the clamp 4 is then pivoted to the retracted 27 position so that the junction line 24 is above the top edge of 28 the slot 5 and leg 7 lies against an outer surface 26 of top 29 wall 2, as best seen in Figs. 4 and 5.
3o In the retracted position, as shown in Fig. 4, a free edge 31 27 of the step-down portion 15a of the central appendage 15 bears 32 against a corresponding edge 28 at point A of slot 5. The contact 33 ~f the free ge 27 against the corresponding edge 28 is slightly .
~^~ 11~2~7 1 above a contact point B of the inner side of the second leg to the 2 inner side of the slot 5, as shown in Fig. 4, creating a over-3 center switch action with the bearing at point A exerting a force 4 on the corresponding edge 28, thus providing a clockwise movement about a fulcrum at point B, thus holding the clamp 4 in its re-6 tracted position.
7 As best seen in Fig. 4, a boss 29a on the second leg also 8 acts as a stop means to prevent movement of the clamp outwardly 9 from the wall 2 when the clamp 4 is in the retracted position.
The respective corresponding edges 37 of central appendage 15 11 is preferably rounded slightly forming a cam surface to enable 12 free edge 27 of central appendage 15 to cam against corresponding 13 edge 28 of the slot ~ when the clamp 4 is pivoted from the re-14 tracted position to the clamping position. When cammed against the edge 28 the clamp may pivot to its clamping position. In 16 such clamping position, the clamping wall 6 of leg 7 extends 17 upright from the top wall 2. The projections 8 and 8' of the 18 second leg 9 of the L-shaped clamp member then lie against the 19 inner surface 29 of top wall 2 with the respective lugs 12 of projections 8 and 8' being lockingly received in their corres-21 ponding apertures 14. If the clamp 4 is moved to the clamping 22 position without a wall panel present, the clamping wall 6 will 23 be oblique to the rear surface of frontal flange 22.
24 In the retracted position of clamp 4, as seen in Figs. 4 and 5' the first leg 7 lies against the outer surfaces 26 of the wall 26 2, and the projections 8 and 8' of the second leg 9 of the L-shape 27 clamp member 4 at such time extend inwardly into the cavity 30 28 of the outlet box 1.
29 The outlet boxes are preferably furnished to the job site 3o with the clamps 4 and 4' mounted therein in their retracted 31 position. The boxes may then be inserted in a pre-cut receiving 32 aperture 20 of a wall panel lOa from the front side 31 of said 33~wall panel. he first leg 7 D~ the clamp 4 lying flat against 110~2i7 1 the top wall 2 of the outlet box 1 is able to clear the edges of 2 the aperture 20 as the box is pushed therein until the front side 3 31 of the wall panel lOa abuts against the fontral flanges 22 of 4 the outlet box 1. At such point, pressure is applied from the front against the projections 8 and 8' of clamp member 4 which 6 in the retracted position are extending inwardly of the box 7 cavity 30, thus causing the clamp member 4 to pivot until it 8 reaches the clamping position. As the clamp is pivoted through 9 the slot the clamping wall 6 of the first leg 7 contacts the inner side of the wall panel lOa commencing at a point near the 11 surface 26, and, as the rotation of the clamp is continued, the 12 area of surface contact increases between the clamping wall 6 13 and frontal flange 22 until the entire surface of wall 6 abuts 14 the flange 22, as best seen in Figs. 8 and 9. As the clamp is rotated to the clamped position, the clamp is subjected to bend Lng 16 forces. However, when the locking is completed,the clamp is 17 resolved into substantially a 90 relationship between the legs 18 and the bending forces are at least partially translated into 19 shear forces which occur at the point of contact C between the rear side of leg 7 and the rear edge of slot as shown in Fig. 9.
21 In the clamping position, additional manual pressure is appli~ d 22 agalnst the projections 8 and 8' of the second leg 9 until their 23 respective lugs 12 are lockingly seated in their respective 24 aperture 14.
The projections 8 and 8' of the second leg 9 are at such 26 time parallel with the respective wall of the outlet box in which 27 the clamp 4 is mounted, and the clamping wall 6 is in bearing 28 engagement against the inner surface 32 of the wall panel lOa.
11 S ce the clamping wall 6 of first leg 7 is at a slightly greater ~ 110~217 1 than 90 angle to the second leg 9, the clamping wall 6 becomes 2 stressed and flexes slightly when forced against the inner surface 3 32 of wall panel 21 when the clamp 4 is locked in its fully 4 clamped position. Such angle is perferably 101 as shown in Fig. 2b.
To further secure the clamp 4 in place, the central aperture 7 16 of central appendage 15 of the first leg 7 is in registration 8 with the internally threaded bore 17 of center post 11 of the 9 outlet box when in the fully clamped position, to receive the shank of mounting screw 18 therethrough when a wiring device is 11 secured to the outlet box 1. In the event the clamps are dis-12 engaged from the clamping position,the apertures will rotate 13 about the pivotal axis and the screw 18 will permit 14 only a limited amount of rotation inasmuch as the screws will become engaged with the wall of the channel l9a. This relation-16 ship provides a secondary clamp and prevents the outlet box from 17 becoming detached from the wall panel lOa.
18 In like manner clamp 4' in bottom wall 3 is then moved from 19 its retracted position to the fully clamped position to clamp and lock the opposite end of the outlet box 1 to the corresponding 21 edge of wall panel lOa.
22 The outlet box shown and described herein has the clamp 4 23 and 4' in the top wall 2 and bottom wall 3. It is understood 24 that the clamp members can be mounted at other positions of the peripheral walls of the outlet box, such as in the side walls 26 of the box if desired. The application is not to be limited 27 to the particular locations illustrated and described herein.
28 The lugs 12 are press-fitted in corresponding apertures in 230 the projections 8 and 8' of the second leg 9 of the L-shaped 11~217 1 clamp 4, in such a way that an end portion 33, as shown in Figs.
2 4 and 5, of the lug 12 extends through the projections 8 and 8' 3 to the opposite side as shown in Fig. 6. Such extending end 4 portion serves as a stop for a workman's thumb-nail, for example, when pushing the L-clamp 4 from a retracted position to a clamping 6 position.
7 The outlet boxes and self-contained wall mounting clamps 8 in accordance with this invention may be either metallic or non-~ metallic.
As shown by the description of the invention above, a novel 11 feature of the structure of the invention is that it allows the 12 electrical outlet box to be connected to a wall panel using 13 solely the manual efforts of a workman without resorting to tools 1 or other me anical d~vices ror assistance.
Y
23~
17 Mounting screws 18 which secure a wiring device in place, 18 such as duplex receptacle 19 as shown in Figs. 1 and 8, are 19 threaded through bore 17 and extend through the central apertures 16 of the clamp member 4 when it is in the clamping position.
21 The aperture 16 is not threaded and is slightly larger than the 22 diameter of the mounting screw 18. When the mounting screw 18 23 is extended through the aperture 16, it is received by a channel 24 l9a disposed in wall 2 and extending rearwardly from the extension 15b. When the clamp member is positively locked in 26 place in the clamping position to securely mount the outlet box 1 27 in the receiving aperture of the wall panel lOa, the wall panel 28 lOa is sandwiched between the clamping wall 6 of clamp members 4 29 and frontal flange 22,which extends laterally from a front edge 31 23 of the t wall 2.
~ ~ 110~217 1 In operation, the outlet boxes 1 are installed as follows.
2 Clamp 4 and top wall 2 are described below, but the operation for 3 clamp 4' and bottom wall 3 is identical.
4 The clamp 4 is connected through the elongated slot 5 in the top wall 2 of the outlet box 1 and positioned in the retracted 6 position, preferably by the manufacturer before shipment.
7 The slot 5 is parallel to the open front wall 25 of the outle :
8 box 1. The slot 5 is selectively spaced inwardly from the front ~ edge 23 a distance which is equal to or slightly greater than the width of the wall panel lOa in which the outlet box is to be 11 mounted. Dimensions of 1/4", 3/8" and 1/2" from the front wall 12 are used for wall panels having a thickness of 1/4" to 3/16", 5/16 13 to 3/8" and 7/16" to 1/2", respectively. A dimension of 1/4" is 14 shown in Fig. 5.
More specifically the connection between the clamp 4 and the 16 wall 2 is accomplished by inserting the first leg 7 through the 17 slot 5 from the bottom side until a pivot junction or junction 18 line 24, which joins the first leg 7 and second leg 9 of the L-B 19 shaped clamp 4, reaches the slot 5. The bosses i~a extend laterally from a forward side of the first leg portion 7 near the junction 21 line 24. The bosses ~ are selectively sized to allow the leg 22 portion 7 to be pushed through the slot 5 and then prevent the leg 23 portion 7 from moving back through the slot 5 in the event the 24 clamp 4 is jarred or shaken loose during shipment or installation.
When the junction line 24 of the clamp 4 is near the lower 26 edge of slot 5, the clamp 4 is then pivoted to the retracted 27 position so that the junction line 24 is above the top edge of 28 the slot 5 and leg 7 lies against an outer surface 26 of top 29 wall 2, as best seen in Figs. 4 and 5.
3o In the retracted position, as shown in Fig. 4, a free edge 31 27 of the step-down portion 15a of the central appendage 15 bears 32 against a corresponding edge 28 at point A of slot 5. The contact 33 ~f the free ge 27 against the corresponding edge 28 is slightly .
~^~ 11~2~7 1 above a contact point B of the inner side of the second leg to the 2 inner side of the slot 5, as shown in Fig. 4, creating a over-3 center switch action with the bearing at point A exerting a force 4 on the corresponding edge 28, thus providing a clockwise movement about a fulcrum at point B, thus holding the clamp 4 in its re-6 tracted position.
7 As best seen in Fig. 4, a boss 29a on the second leg also 8 acts as a stop means to prevent movement of the clamp outwardly 9 from the wall 2 when the clamp 4 is in the retracted position.
The respective corresponding edges 37 of central appendage 15 11 is preferably rounded slightly forming a cam surface to enable 12 free edge 27 of central appendage 15 to cam against corresponding 13 edge 28 of the slot ~ when the clamp 4 is pivoted from the re-14 tracted position to the clamping position. When cammed against the edge 28 the clamp may pivot to its clamping position. In 16 such clamping position, the clamping wall 6 of leg 7 extends 17 upright from the top wall 2. The projections 8 and 8' of the 18 second leg 9 of the L-shaped clamp member then lie against the 19 inner surface 29 of top wall 2 with the respective lugs 12 of projections 8 and 8' being lockingly received in their corres-21 ponding apertures 14. If the clamp 4 is moved to the clamping 22 position without a wall panel present, the clamping wall 6 will 23 be oblique to the rear surface of frontal flange 22.
24 In the retracted position of clamp 4, as seen in Figs. 4 and 5' the first leg 7 lies against the outer surfaces 26 of the wall 26 2, and the projections 8 and 8' of the second leg 9 of the L-shape 27 clamp member 4 at such time extend inwardly into the cavity 30 28 of the outlet box 1.
29 The outlet boxes are preferably furnished to the job site 3o with the clamps 4 and 4' mounted therein in their retracted 31 position. The boxes may then be inserted in a pre-cut receiving 32 aperture 20 of a wall panel lOa from the front side 31 of said 33~wall panel. he first leg 7 D~ the clamp 4 lying flat against 110~2i7 1 the top wall 2 of the outlet box 1 is able to clear the edges of 2 the aperture 20 as the box is pushed therein until the front side 3 31 of the wall panel lOa abuts against the fontral flanges 22 of 4 the outlet box 1. At such point, pressure is applied from the front against the projections 8 and 8' of clamp member 4 which 6 in the retracted position are extending inwardly of the box 7 cavity 30, thus causing the clamp member 4 to pivot until it 8 reaches the clamping position. As the clamp is pivoted through 9 the slot the clamping wall 6 of the first leg 7 contacts the inner side of the wall panel lOa commencing at a point near the 11 surface 26, and, as the rotation of the clamp is continued, the 12 area of surface contact increases between the clamping wall 6 13 and frontal flange 22 until the entire surface of wall 6 abuts 14 the flange 22, as best seen in Figs. 8 and 9. As the clamp is rotated to the clamped position, the clamp is subjected to bend Lng 16 forces. However, when the locking is completed,the clamp is 17 resolved into substantially a 90 relationship between the legs 18 and the bending forces are at least partially translated into 19 shear forces which occur at the point of contact C between the rear side of leg 7 and the rear edge of slot as shown in Fig. 9.
21 In the clamping position, additional manual pressure is appli~ d 22 agalnst the projections 8 and 8' of the second leg 9 until their 23 respective lugs 12 are lockingly seated in their respective 24 aperture 14.
The projections 8 and 8' of the second leg 9 are at such 26 time parallel with the respective wall of the outlet box in which 27 the clamp 4 is mounted, and the clamping wall 6 is in bearing 28 engagement against the inner surface 32 of the wall panel lOa.
11 S ce the clamping wall 6 of first leg 7 is at a slightly greater ~ 110~217 1 than 90 angle to the second leg 9, the clamping wall 6 becomes 2 stressed and flexes slightly when forced against the inner surface 3 32 of wall panel 21 when the clamp 4 is locked in its fully 4 clamped position. Such angle is perferably 101 as shown in Fig. 2b.
To further secure the clamp 4 in place, the central aperture 7 16 of central appendage 15 of the first leg 7 is in registration 8 with the internally threaded bore 17 of center post 11 of the 9 outlet box when in the fully clamped position, to receive the shank of mounting screw 18 therethrough when a wiring device is 11 secured to the outlet box 1. In the event the clamps are dis-12 engaged from the clamping position,the apertures will rotate 13 about the pivotal axis and the screw 18 will permit 14 only a limited amount of rotation inasmuch as the screws will become engaged with the wall of the channel l9a. This relation-16 ship provides a secondary clamp and prevents the outlet box from 17 becoming detached from the wall panel lOa.
18 In like manner clamp 4' in bottom wall 3 is then moved from 19 its retracted position to the fully clamped position to clamp and lock the opposite end of the outlet box 1 to the corresponding 21 edge of wall panel lOa.
22 The outlet box shown and described herein has the clamp 4 23 and 4' in the top wall 2 and bottom wall 3. It is understood 24 that the clamp members can be mounted at other positions of the peripheral walls of the outlet box, such as in the side walls 26 of the box if desired. The application is not to be limited 27 to the particular locations illustrated and described herein.
28 The lugs 12 are press-fitted in corresponding apertures in 230 the projections 8 and 8' of the second leg 9 of the L-shaped 11~217 1 clamp 4, in such a way that an end portion 33, as shown in Figs.
2 4 and 5, of the lug 12 extends through the projections 8 and 8' 3 to the opposite side as shown in Fig. 6. Such extending end 4 portion serves as a stop for a workman's thumb-nail, for example, when pushing the L-clamp 4 from a retracted position to a clamping 6 position.
7 The outlet boxes and self-contained wall mounting clamps 8 in accordance with this invention may be either metallic or non-~ metallic.
As shown by the description of the invention above, a novel 11 feature of the structure of the invention is that it allows the 12 electrical outlet box to be connected to a wall panel using 13 solely the manual efforts of a workman without resorting to tools 1 or other me anical d~vices ror assistance.
Y
23~
Claims (2)
1. A clamp for use with an electrical outlet box, said clamp receivably located in an elongated slot in a wall of said outlet box, said clamp comprising:
a first leg outside of said outlet box and a second leg inside of said outlet box, said second leg consisting of a pair of spaced apart projections, said first and second legs being connected at a juncture and forming an initial pre-determined angle slightly greater than 90 degrees, said clamp being in a first position before said outlet box is installed in a predetermined opening in a house wall, said first leg being substantially parallel and adjacent to said outlet box wall and extending toward said rear wall of said outlet box, said second leg extending into said outlet box, a central appendage connected to said first leg of said clamp near said juncture, said central appendage having a step-down end portion with a central aperture, a pair of snap buttons located on the end of said second leg opposite said juncture of said first and second legs, a snap button being located on each of said pair of spaced apart pro-jections, for mating with a pair of apertures in said outlet box wall, such that after said outlet box is positioned in the predetermined opening in the house wall, said clamp is manually moved to a second position by pivoting said first and second legs about said juncture in said elongated slot until said snap buttons on said second leg are located in said corresponding apertures in said outlet box wall, said first leg effectively sandwiching the house wall between said second leg and a frontal flange, extending laterally away from a front edge of said outlet box wall, thereby securing said outlet box in the house wall, and an internally threaded bore in a center post extending inwardly from said front edge of said outlet box wall and a mounting screw, such that when said clamp is in said second position, said central aperture and said threaded bore are in registration, and when said mounting screw is inserted in said threaded bore, said mounting screw extends through said central aperture of said step-down portion of said central appendage thereby substantially retaining said clamp in said second position.
a first leg outside of said outlet box and a second leg inside of said outlet box, said second leg consisting of a pair of spaced apart projections, said first and second legs being connected at a juncture and forming an initial pre-determined angle slightly greater than 90 degrees, said clamp being in a first position before said outlet box is installed in a predetermined opening in a house wall, said first leg being substantially parallel and adjacent to said outlet box wall and extending toward said rear wall of said outlet box, said second leg extending into said outlet box, a central appendage connected to said first leg of said clamp near said juncture, said central appendage having a step-down end portion with a central aperture, a pair of snap buttons located on the end of said second leg opposite said juncture of said first and second legs, a snap button being located on each of said pair of spaced apart pro-jections, for mating with a pair of apertures in said outlet box wall, such that after said outlet box is positioned in the predetermined opening in the house wall, said clamp is manually moved to a second position by pivoting said first and second legs about said juncture in said elongated slot until said snap buttons on said second leg are located in said corresponding apertures in said outlet box wall, said first leg effectively sandwiching the house wall between said second leg and a frontal flange, extending laterally away from a front edge of said outlet box wall, thereby securing said outlet box in the house wall, and an internally threaded bore in a center post extending inwardly from said front edge of said outlet box wall and a mounting screw, such that when said clamp is in said second position, said central aperture and said threaded bore are in registration, and when said mounting screw is inserted in said threaded bore, said mounting screw extends through said central aperture of said step-down portion of said central appendage thereby substantially retaining said clamp in said second position.
2. An improved electrical outlet box having top and bottom outlet box walls, side walls, and a rear wall, said top and bottom outlet box walls each having a frontal flange extending laterally away from a front edge thereof, the improvement for each of said top and bottom outlet box walls of said electrical outlet box comprising:
an elongated slot in said outlet box wall spaced inwardly a predetermined distance from said front edge and located parallel to said front edge, a clamp receivably located in said elongated slot, said clamp having a first leg outside of said outlet box and a second leg inside of said outlet box, said second leg consisting of a pair of spaced apart projections, said first and second legs being connected at a juncture and forming an initial predetermined angle, said clamp also having a central appendage connected to said first leg of said clamp near said juncture, said central appendage having a step-down end portion with a central aperture, said clamp being in a first position before said outlet box is installed in a predetermined opening in a house wall, said first leg being substantially parallel and adjacent to said outlet box wall and extending toward said rear wall of said outlet box, said second leg extending into said outlet box, a primary locking means consisting of a pair of snap buttons located on the end of said second leg opposite said juncture of said first and second legs, a snap button being located on each of said pair of spaced apart projections, and a pair of apertures in said outlet box wall for receiving said snap buttons, such that after said outlet box is positioned in the predetermined opening in the house wall, said clamp is manually moved to a second position by pivoting said first and second legs about said juncture in said elongated slot until said snap buttons on said second leg are located in said corres-ponding apertures in said outlet box wall, said first leg effectively sandwiching the house wall between said second leg and said frontal flange, thereby securing said outlet box in the house wall, and a secondary locking means consisting of an internally threaded bore in a center post extending inwardly from said front edge of said outlet box wall, a mounting screw, and said central appendage on said clamp, such that when said clamp is in said second position, said central aperture and said threaded bore are in registration, and when said mounting screw is inserted in said threaded bore, said mounting screw extends through said central aperture thereby substantially retaining said clamp in said second position even if said first locking means becomes defective.
an elongated slot in said outlet box wall spaced inwardly a predetermined distance from said front edge and located parallel to said front edge, a clamp receivably located in said elongated slot, said clamp having a first leg outside of said outlet box and a second leg inside of said outlet box, said second leg consisting of a pair of spaced apart projections, said first and second legs being connected at a juncture and forming an initial predetermined angle, said clamp also having a central appendage connected to said first leg of said clamp near said juncture, said central appendage having a step-down end portion with a central aperture, said clamp being in a first position before said outlet box is installed in a predetermined opening in a house wall, said first leg being substantially parallel and adjacent to said outlet box wall and extending toward said rear wall of said outlet box, said second leg extending into said outlet box, a primary locking means consisting of a pair of snap buttons located on the end of said second leg opposite said juncture of said first and second legs, a snap button being located on each of said pair of spaced apart projections, and a pair of apertures in said outlet box wall for receiving said snap buttons, such that after said outlet box is positioned in the predetermined opening in the house wall, said clamp is manually moved to a second position by pivoting said first and second legs about said juncture in said elongated slot until said snap buttons on said second leg are located in said corres-ponding apertures in said outlet box wall, said first leg effectively sandwiching the house wall between said second leg and said frontal flange, thereby securing said outlet box in the house wall, and a secondary locking means consisting of an internally threaded bore in a center post extending inwardly from said front edge of said outlet box wall, a mounting screw, and said central appendage on said clamp, such that when said clamp is in said second position, said central aperture and said threaded bore are in registration, and when said mounting screw is inserted in said threaded bore, said mounting screw extends through said central aperture thereby substantially retaining said clamp in said second position even if said first locking means becomes defective.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US76109977A | 1977-01-21 | 1977-01-21 | |
| US761,099 | 1977-01-21 | ||
| US83795577A | 1977-09-29 | 1977-09-29 | |
| US837,955 | 1977-09-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1100217A true CA1100217A (en) | 1981-04-28 |
Family
ID=27116924
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA295,377A Expired CA1100217A (en) | 1977-01-21 | 1978-01-20 | Electrical outlet box and wall mounting clamp therefor |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1100217A (en) |
| MX (1) | MX145169A (en) |
-
1978
- 1978-01-20 CA CA295,377A patent/CA1100217A/en not_active Expired
- 1978-01-23 MX MX17214078A patent/MX145169A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| MX145169A (en) | 1982-01-12 |
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| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |