Note: Descriptions are shown in the official language in which they were submitted.
5ddp761 ~LN 3158
CANADIAN PATENT
2~86~
SUPPORT FOR AN ELECTRICAL BOX
Backqround of the Invention
This invention relates generally to devices for
supporting electrical boxes and, more particularly, to an
improved device for mounting electrical boxes in a selected
position between two generally parallel wall studs or the
like.
In the building construction industry, various
devices have been used to mount electrical boxes in fixed
position relative to structural members, including such
devices as shown in U.S. patents 1,056,759, 1,156,885,
1,550,327, 1,800,813, 2,963,253, 3,425,655, 3,518,421,
3,528,636 and 4,757,967. However, these devices have
drawbacks. For example, some are overly complicated and
thus difficult to handle and use. Others require the use
of power tools to attach an electrical box to the device.
Still others cannot accommodate electrical boxes of
different depths. Accordingly, there is a need in the
`~ industry for an improved support for an electrical box.
Summary of the Invention
Generally, an electrical box support of this
invention comprises a bar adapted to be mounted between two
spaced-apart wall studs or the like. The bar comprises an
elongate web of sheet metal forming a front face of the bar
and having side edges extending lengthwise of the bar, a
pair of flanges extending rearwardly from the side edges of
the web, and a forwardly-opening, generally U-shaped
chsnnel formed in the web running substantially the full
length of the web between the side edges of the web. The
channel has spaced apart side walls extending rearwardly
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CANADIAN PATENT
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from the front face of the web, a bottom wall connecting
the side walls and forming the bottom of the channel, and a
plurality of preformed pilot holes spaced along the bottom
wall of the channel at relatively closely spaced and
regular intervals whereby an electrical box may be attached
to the bar in a selected position lengthwise of the bar by
placing the back wall of the box flush against the front
face of the web over the channel and then fastening the box
to the bar by using fasteners threaded through selected
pilot holes in the bottom wall of the channel.
In a second aspect of this invention, the support
comprises a bar adapted to be mounted between two
spaced-apart wall studs or the like. The bar comprises an
elongate web of sheet metal forming the front face of the
bar and having opposite side edges extending lengthwise of
the bar, a forwardly-opening, generally U-shaped channel
formed in the web running substantially the full length of
the web between the side edges of the web, and elongate
extensions of the bar projecting generally forwardly from
the web at opposite ends of the bar and having free outer
end portions bent to form fastening flaps extending
laterally outwardly away from one another and generally
parallel to the web of the bar. The flaps are adapted for
engagement with the vertical studs and securement thereto
by fasteners, each extension having means spaced inwardly
from its free outer end defining a first fold line
extending generally transversely of the extension and means
spaced inwardly from the first fold line defining a second
fold line extending generally transversely of the
extension. If a relatively deep electrical box is to be
attached to the bar, the extensions are adapted to be bent
at the first fold lines to form the fastening flaps, and if
a shallower electrical box is to be attached to the bar,
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64725-512
the extensions are adapted to be bent at the second fold lines to
form said fastenlng flaps. The electrical box is adapted to be
attached to the bar in a selected position lengthwise of the bar
by placing the back wall of the box flush against the front face
of the web over the channel and then fastening the box to the bar
by using fas~eners threaded into said channel.
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C~NADIAN PATENT
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Other objects and features will be in part
apparent and in part pointed out hereinafter.
Brief Description of the Drawinas
Fig. 1 is an elevational view of a support of
this invention fastened to two wall studs, and an
electrical box mounted on the support;
Fig. 2 is a plan view of Fig. l;
Fig. 3 is an enlarged view of Fig. 1 showing an
end extension of the support with two pairs of slots
defining a pair of parallel fold lines;
Fig. 4 is a vertical section taken on line 4--4
of Fig. 1 showing the support as used to mount a relatively
deep electrical box;
Fig. 5 is a view similar to Fig. 4 showing the
support as used to mount a shallower electrical bo~;
Fig. 6 is a view of a support comprising
telescoping bars to enable lengthwise adjustment of the
support; and
Fig. 7 is an enlarged vertical section taken on
line 7--7 of Fig. 6.
Corresponding parts are designated by
corresponding numerals throughout the several views of the
drawings.
Descri~tion of the Preferred Embodiment
Referring now to the drawings, and first more
particularly to Figs. 1 and 2, there is generally indicated
at 1 a support of the present invention for mounting an
electrical bo~ generally indicated at B between two
spaced-apart generally vertical wall studs, each designated
S, which may conventional wood or metal studs. The
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electrical box is of traditional design, having a back wall
Bl, side walls B3, and top and bottom walls B5 and B7,
respectively. The back wall Bl iS formed with a serieæ of
circular knockout portions H9 which may be removed to
permit passage of electrical conduit in conventional
fashion. The back wall of the box also has a series of
openings (not shown) therein for enabling the box to be
secured in position by suitable fasteners 13, as will
become apparent.
The hanger 1 comprises a bar generally indicated
at 21 adapted to be mounted in generally a horizontal
position between the two wall studs S. The bar comprises
an elongate web 23 of sheet metal (20-ga. galvanized sheet
steel, for example) forming the front face 25 of the bar
lying in a generally vertical plane when the bar is mounted
in its usual orientation, as shown in Fig. 1. The web 23
has a pair of generally parallel side edges, one of which
constitutes the upper edge 27 of thé web and the other of
which constitutes the lower edge 29 of the web. A pair of
integral flanges 31 extend generally horizontally
rearwardly Sto the right as viewed in Fig. 4) from
respective upper and lower edges 27, 29 of the web. These
flanges 31 have rearward end portions bent to form a pair
of relatively short lips, each designated 33, extending
; 25 generally at right angles to the flanges inwardly toward
one another. These lips increase the beam strength of the
bar in front-to-rear direction, which is the direction of
greatest force applied to the bar during and after
attachment of an electrical box B to the bar. It is
j 30 understood that the lips 33 can be eliminated from the bar
without departing from the scope of this invention.
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The web 23 is fabricated to have a forwardly-
opening generally horizontal channel, generally designated
37, running substantially the full length of the web
approximately midway between its upper and lower edges 27,
29. The channel 37 is a relatively narrow flat-bottom
generally U-shaped channel, comprising a pair æpaced apart
side walls 39 extending generally rearwardly from the front
face 25 of the web, and a generally planar vertical bottom
wall 41 connecting the side walls and forming the bottom of
the channel. The side walls 39, which also increase the
strength of the bar in front-to-rear direction, taper
inwardly (at about a 5 angle) toward one another in the
rearward direction to provide the necessary clearance for
screw fansteners 13.
In accordance with this invention, pilot holes 45
are spaced along the bottom wall 41 of the channel 37 at
closely spaced and regular intervals (e.g., every 1/4 in.
whereby an electrical box (such as the one indicated at B
in the drawings) can be attached to the bar 21 in a
selected position lengthwise of the bar by placing the back
wall Bl of the box flush against the front face 25 of the
web 23 of the bar over the channel 37 and then fastening
the box to the bar by using screw fasteners 13 threaded
through selected pilot holes 45 in the bottom wall of the
channel, as shown in Figs~ 2 and 4. Because the row of
pilot holes 45 is centered between and parallel with the
upper edge 27 and lower edge 29 it insures that all
fasteners 13 are inserted on the centerline of the bar.
This further insures that all electrical boxes B are
quickly and effortlessly affixed to the bar in proper
orientation and alignment. When the fastener openings in
the electrical box B are substantially larger in diameter
than the shank of the f asteners 13, the screw fasteners 13
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are preferably "bugle-head" screw fasteners, meaning that
the screw heads are generally conical in shape, so that the
screws are self-centering with respect to the fastener
openings in the back wall of the electrical box to ensure
that the box is mounted square on the bar. It will be
noted that the bar 21 is sufficiently narrow (no greater
than about 3/4 inches) that it does not block any of the
four knockout portions B9 in the back wall of the box (see
Fig. l), the result being that the bar does not interfere
with the useage of these knockout portions.
As best illustrated in Fig. l, the front face 25
of the web 23 of the bar 21 has two sets of graduations
thereon at spacings preferably corresponding to inches and
fractions thereof, so that an electrical box may be mounted
in a precise position relative to the bar, or so that a
series of boxes may be mounted in the same location on
different bars. A first set of graduations, designated Gl,
is provided between the channel 37 and the upper edge 27 of
the web and is oriented to be read when the bar is mounted
as shown in Fig. 1. A second set, designated G2, is
provided between the channel and the lower edge 29 of the
web and is oriented to be read when the bar is mounted with
side edge 29 facing upwardly. Thus, the appropriate set of
graduations may be conveniently used regardless of which
side edge 27, 29 is facing up when the bar 21 is mounted on
the studs S. Preferably, the graduations Gl, G2 on the bar
are so positioned relative to the pilot holes 45 in the
channel bottom 41 that when a side wall B3 of the
electrical box is aligned with a graduation, at least two
pilot holes are in register with two of the fastener
openings in the back wall of the box to ensure ease of
installation of the box on the bar.
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CANADIAN PATENT
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The bar is attached to studs S by a pair of
integral elongate extensions 51 of the bar 21 projecting
generally forwardly from the web at opposite ends of the
bar (see Fig. 2). The extensions have free outer end
portions bent to form fastening flaps, each designated 53,
extending laterally outwardly away from one another and
generally parallel to the web of the bar for engagement
with faces of the vertical wall studs S. Each flap has
openings 55 therein for receiving fasteners 57 to fasten
the support to the studs.
As shown best in Fig. 3, each extension 51 has a
pair of side edges and an outer end edge. Each extension
also has means comprising a first pair of spaced-apart
slots 61 (constituting first slot means) spaced inwardly
from its free outer end edge and defining a first fold line
FLl extending generally transversely of the extension, and
means comprising a second pair of spaced-apart slots 63
(constituting second slot means) spaced inwardly from the
first fold line FLl and defining a second fold line FL2
extending generally transversly of the extension and
generally parallel to the first fold line FLl. The slots
61, 63 are spaced from the side edges of the extension so
that each slot is closed at each of its two ends. The
arrangement is such that the support 1 of the present
invention may accommodate electrical bo~es of two different
depths (e.g., 1-1/2 in. deep and 2-1/8 in. deep boxes).
Thus, if a relatively deep box B is to be attached to the
bar, as shown in Fig. 4, the extensions 51 are bent at the
first fold lines FLl to form the fastening flaps 53. If,
on the other hand, a shallower box is to be attached to the
bar, as shown in Fig. 5, the extensions 51 are bent at the
second fold lines FL2 to form the fastening flaps 53. It
will be noted in this regard that the fold lines are so
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5ddp761 BLN 3158
CANADIAN PATENT
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20286~2
located that when the fastening flaps 53 are formed
according to the depth of electrical box to be attached to
the bar, the distance between the front face 25 of the bar
and the plane of the fastening flaps generally corresponds
to the depth of the box so that, when the box is attached
to the bar, the front of the box lies generally in the
plane of the flaps for mounting of the box in proper
front-to-rear direction with respect to the wall studs S.
It will be observed that a slot 71 extends from
the bottom 41 of channel 37 up to approximately the first
fold line FLl of each extension 51. This slot 71 is the
result of the process (e.g., a progressive die stamping
operation) by which the support is formed and has no
functional purpose in the use of the support. The
fastening flaps 53 have V-notches 73 therein extending
inwardly from their outer end edges in line with the
central longitudinal a~is of the bar 21. These notches 73
enable the bar to be lined up with markings on the studs S
indicating the height at which the support 1 is to be
mounted.
Figs. 6 and 7 illustrate a support 101 of the
present invention modified to provide lengthwise of
adjustment of the support for accommodating different stud
spacings (e.g., 14-24 in. spacing). As shown, this support
comprises two telescoping bars designated 103A and 103B,
each bar being identical in shape to the bar 21 previously
described except that each has an extension 105 only at one
end so that when the bars are telescopically interfitted
they combine to form a complete support which is adjustable
in length. One of the bars (103B) is slightly smaller in
cross section than the other bar (103A) so as to
telescopically fit inside the other bar with the web 107,
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202~6~2
flanges 109 and lips 111 of one bar being in engagement
with the web 113, flanges 115 and lips 117, respectively,
of the other bar, as shown in Fig. 7. It will be noted in
this regard that the engagement of the lips 111, 117 of the
two bars maintains the two bars together and makes them
self-supporting without the need for fasteners.
In use, the support 1 or 101 of the present
invention is ~uickly and easily installed by bending the
extensions 51, 105 of the bar along the appropriate fold
lines FLl or FL2 according to the depth of electriaal box
to be mounted. The fastening flaps 53 thus formed are then
fastened by suitable fasteners 57 to the wall studs to
secure the bar in a generally horizontal position extending
between the studs. Using the upper set of graduations
(e.g., Gl), the electrical box is then placed in precise
position on the bar with the back wall Bl of the box flush
against the front face 25 of the bar. The box is attached
to the bar by inserting suitable screw fasteners 13
(preferably "bugle-head" s~rews) through fastener openings
in the back wall of the box and then threading the
fasteners through pilot holes 45 in register with the
fastener openings. This may be done manually by using a
screw driver or automatically by using a power tool. In
either case~ the pilot holes facilitate and expedite
driving the screws. Moreoever, because the channel is
U-shaped (rather than V-shaped), the threads of the screw
fasteners are able engage the full thickness of the channel
bottom 41 to prevent stripping of the metal. The taper of
the channel side walls 39 provides clearance for the screws
as they are threaded through the channel bottom.
It will be understood that more than one
electrical box can be mounted on a support of the present
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invention, in which case the graduations (Gl or G2) allow
the boxes to be located at precise spacings without the use
of a ruler or tape measure.
In view of the above, it will be seen that the
several objects of the invention are achieved and other
advantageous results attained.
As various changes could be made in the above
constructions without departing from the scope of the
invention, it is intended that all matter contained in the
above description or shown in the accompanying drawings
shall be interpreted as illustrative and not in a limiting
sense.
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