Conductor holding device

A device to be mounted on a support member for holding a conductor in a substantially fixed position extending generally parallel to the support member. The device includes a bracket having an arm with at least one opening therein and a clamp having a head and at least one leg projecting from the head adapted for reception in the opening in the arm. The leg of the clamp is movable in the opening in a first axial direction with respect to the leg so that the head of the clamp can be pushed closer to the arm to move the clamp to a clamping position in which the head of the clamp is in clamping engagement with a conductor disposed between the head and the arm. The device further includes a retainer for retaining the clamp in its clamping position. The retainer includes structure on the arm for biting into the leg of the clamp when the clamp is pushed to its clamping position thereby to lock the clamp in its clamping position by inhibiting any movement of the head of the clamp away from the arm after the clamp has been moved to its clamping position.

BACKGROUND OF THE INVENTION 
This invention relates generally to the building construction industry, and 
more particularly to a device adapted for securely maintaining electrical 
conductors (e.g., ROMEX wiring) at a predetermined distance from a wall. 
In constructing or rehabbing buildings, homes, and the like, studs are 
secured vertically to define a frame for walls of the building. Electrical 
conductors, such as wiring, are secured to the studs to provide 
electricity and other utilities throughout the building. Plasterboard 
(drywall) is thereafter secured to the studs with screws, nails or other 
fasteners to form the walls of the building. Typically, nail or screw guns 
are used to rapidly and forcefully drive fasteners into the studs. Because 
the studs are behind the drywall, and because the fasteners are installed 
rapidly with a gun, it is not uncommon for a fastener to miss the stud 
during the installation process. This can damage an electrical conductor 
behind the wall. Electrical wiring for homes is typically 120 or 240 
volts, and for commercial buildings, the voltages can be significantly 
higher. Thus, an installer is exposed to the risk of a severe electrical 
shock. A damaged wire may also create a dangerous fire hazard. 
Further, to decorate a completed building, pictures, clocks, lighting 
fixtures and other items are typically hung on walls using fasteners such 
as nails and screws. Since the electrical conductors behind these walls 
are hidden from view, the person hanging these items is exposed to the 
same hazards described above. 
For these reasons, in 1990, the National Electrical Code (NEC) was amended 
to require that electrical conductors be secured at least 
one-and-one-quarter inches (11/4") behind the wall. Even in the absence of 
such regulation, it is, of course, prudent to secure electrical conductors 
a sufficient distance behind the wall to ensure that a nail or screw does 
not go through the wall into a conductor, thereby causing injury and/or 
creating a fire hazard. 
To address this problem and to conform with the NEC, devices were developed 
in an effort to securely and uniformly maintain electrical conductors a 
safe distance behind a wall. An example of such a device is shown in U.S. 
Pat. No. 5,141,185 (the '185 patent). The '185 patent discloses an 
L-shaped bracket, one arm of which is adapted to be bent back with respect 
to the other arm of the bracket to secure conductors therebetween. The 
bracket is made out of a bendable, substantially non-resilient metal which 
can be crimped, if necessary, to hold the conductors between the arms of 
the bracket. 
There are several disadvantages associated with the '185 patent. While the 
device disclosed therein maintains the conductors a desired distance from 
the wall, the device is not suited for tightly gripping or clamping the 
conductors. As a result, the conductors tend to slide or slip vertically 
within the bracket, which causes the conductors to buckle toward the wall 
in areas where the conductors are not held by the bracket. This problem is 
particularly acute when the device is holding several conductors of 
varying diameter and size, as shown in FIG. 12 of the '185 patent. In this 
situation, smaller diameter conductors adjacent larger diameter conductors 
are especially prone to slip, which can result in code violation. Another 
problem associated with the device of the '185 patent is that the device 
is made out of a bendable but substantially non-resilient metal. Thus, if 
the device is inadvertently bent out of position during the installation 
process, the conductors held by the device will not be properly positioned 
with respect to the wall according to NEC standards. Yet another problem 
is that the device sometimes requires crimping the arm of the bracket 
around individual conductors, which can be cumbersome and time consuming. 
Another type of device is made out of a stiff, plastic. The device has a 
plurality of individual slots of a predetermined width, formed by adjacent 
arms. The arms are resiliently biased to a closed position. A conductor 
can be inserted into a slot by pulling an arm to open a corresponding 
slot. After the conductor is inserted into the slot, the arm is released 
to return to its biased closed position, thereby holding the conductor 
within the slot. Such a device suffers from the slippage problem described 
above to an even greater extent than the '185 patent because the slots are 
of predetermined width and thus are not adapted for tightly gripping most 
conductors. Moreover, because the arms of the device are made out of 
plastic, the arms cannot be crimped to apply a compressive force to the 
conductor. 
SUMMARY OF THE INVENTION 
Among the several objects of this invention may be noted the provision of a 
conductor holding device which is adapted to securely maintain one or more 
conductors a desired distance from a wall; the provision of such a holding 
device which is designed for tightly clamping each conductor to hold it 
against vertical slippage; the provision of such a holding device which is 
easy to secure to a support member; the provision of such a holding device 
which can readily be manipulated to hold one or more conductors; the 
provision of a holding device which is adapted for handling conductors 
having a wide variety of diameters and shapes; the provision of such a 
device which can be readily modified to accommodate a support member 
having a relatively small front-to-rear dimension; the provision of a 
device which is assembled in a unitary fashion to prevent parts from being 
lost; and, the provision of holding device fabricated from parts which are 
economical to produce. 
In accordance with the above objects, a device is provided which is adapted 
to be mounted on a support member for holding a conductor in a 
substantially fixed position extending generally parallel to the support 
member. The device comprises a bracket having an arm with at least one 
opening therein. The bracket is adapted to be mounted on the support 
member so that the arm extends laterally from the support member 12 at one 
side of the stud. The device further comprises a clamp having a head and 
at least one leg projecting from the head adapted for reception in the 
opening in the arm. The leg of the clamp is movable in the opening in an 
axial direction with respect to the leg so that the head of the clamp can 
be pushed closer to the arm to move the clamp to a clamping position in 
which the head of the clamp is in clamping engagement with a conductor 
disposed between the head and the arm and extending generally parallel to 
the support member The device also comprises a retainer for retaining the 
clamp in the clamping position. 
Other objects and features will be in part apparent and in part pointed out 
hereinafter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring now to the drawings, and initially to FIG. 1, a device according 
to a preferred embodiment of the present invention is designated generally 
by the numeral 10. The device 10 is adapted to be mounted on a support 
member 12 for holding conductors 14 in a substantially fixed position 
extending generally parallel to the support member. The device 12 
comprises a bracket, generally indicated at 16, and a series of clamps, 
each generally designated 18, for clamping a plurality of conductors 14 in 
fixed position with respect to bracket 16. In the preferred embodiment, 
the clamps are secured together by an integral flexible connector, 
generally designated 20. Connector 20 includes a plug 22 adapted to be 
received within a hole 24 (shown in FIG. 2) in the bracket 16, and a 
series of flexible strips 23 interconnecting the plug 22 and the 
individual clamps 18. Connector 20 allows the device to be assembled and 
sold as a single unit to facilitate use of the device and to prevent 
misplacement and loss of the individual clamps. 
As shown in the drawings, the support member is a metal stud of 
conventional design having opposing front and back flanges 26 and 28, 
respectively, and an orthogonal interconnecting side 30. It will be 
understood, however, that a device of the present invention is also 
suitable for use with wood support members (e.g., wood "2.times.4's"). A 
plurality of such wall studs are installed to define a vertical frame for 
a wall W of a building (FIG. 3). The wall W is typically of plasterboard 
and is adapted to be secured to the front flange 26 of stud 12 with 
screws, nails or other fasteners. 
Referring to FIG. 2, bracket 16 has an arm 40 with paired openings 42 for 
receiving the clamps 18. Bracket 16 further comprises a side part 44 that 
extends generally at a right angle to the arm, and a front part 46 that 
extends generally at a right angle to side part 44. As shown best in FIGS. 
1 an 3, the length of side part 44 determines the distance that conductors 
14 are maintained from the front flange 26 of support member 12, and thus 
it should be sized to accommodate safety regulations and other safety 
considerations for maintaining the conductors a fixed distance from 
plasterboard that is subsequently secured to the support member. Referring 
to FIG. 2, side part 44 has a hole 48 which is adapted to receive a 
fastening device (not shown), such as a nail or screw, to secure bracket 
16 to support member 12. The front flange 46 of the bracket has a hole 50 
which is likewise adapted to receive a fastening device, such as screw 52, 
to secure the bracket to the support member, as shown in FIG. 1. As shown 
in FIG. 2, side part 44 can also optionally include a zone of weakness, 
such as scored line 54, which allows front flange 46 and a front portion 
of side part 44 to be separated from bracket 16. In most applications, 
particularly for standard metal studs and wood "2.times.4's," the bracket 
16 is secured to the front flange 26 of support member 12 via the front 
part 46 of the bracket, as shown in FIG. 1. However, for support member 
(e.g., furring strips) having a smaller dimension than the interconnecting 
side 30 of a conventional support member 12, the side part 44 of the 
bracket can be shortened by separating the bracket at score line 54. The 
bracket can thereafter be secured to the support member (e.g., furring 
strip) by driving a fastener into the member through hole 48 in side part 
44 of the bracket. 
When bracket 16 is secured to the support member 12, arm 40 extends 
generally laterally outwardly from the member, as shown in FIGS. 1 and 3. 
Thus, conductors 14 secured to the bracket are maintained equidistant from 
the wall W that is subsequently secured to front flange 26 of the support 
member Bracket 16 is preferably a one-piece part formed of flexible but 
resilient metal, such as spring steel, to ensure that the bracket returns 
to its FIG. 1 position even if it is inadvertently bent prior to or during 
installation of wall W. Bracket 16 could also be made out of other 
durable, resilient materials, as is well understood by those skilled in 
the art. 
As stated above, the series of clamps 18 are coupled together by the 
integral connector 20 which is secured to the arm 40 of bracket 16 by plug 
22. The flexible strips 23 of the connector are of sufficient length and 
flexibility to permit one clamp to be installed on the bracket independent 
of the other clamps. 
in the preferred embodiment, each clamp comprises a relatively thin flat 
elongate head 60 and two legs 62 projecting from adjacent opposite ends of 
the head. The legs of the clamp are adapted for reception in corresponding 
paired openings 42 in the arm 40 of the bracket, and are movable in the 
openings in an axial direction with respect to the legs so that the head 
60 of the clamp can be pushed closer to the arm to a position in which it 
is in clamping engagement with a conductor disposed between the head and 
the arm (see FIGS. 1 and 3). The legs 62 of each clamp 18 can be sized 
relatively long (e.g., 0.750 in.) so that the spacing between the head 60 
of the clamp 18 and the arm 40 of bracket 16 can be varied over a wide 
range to accommodate one or more conductors having thicknesses which vary 
over a wide range. 
Referring to FIG. 3, the head 60 of each clamp has a top side 64 and a 
bottom side 66. The top side 64 is sized and configured so that a thumb 
can be pressed against it to push the legs 62 of the clamp in openings 42 
to move the head 60 of the clamp into the aforesaid clamping position in 
which the bottom side 66 of the head forcefully clamps conductor 14 
against arm 40 of bracket 16. It will be understood that the size and 
shape of the head 60 of each clamp may vary without departing from the 
scope of this invention. The number of legs 62 on each clamp may also vary 
(from one to two or more). 
Referring to FIGS. 4 and 5, the bottom side 66 of the head 60 of each clamp 
is formed with a plurality of integral protrusions 68 (e.g., four 
protrusions). These protrusions are adapted to engage conductor 14 and to 
apply a localized compressive force thereto to assist in holding the 
conductor against slippage in the direction of the conductor's length (see 
FIG. 5). Similarly, arm 40 can include a rib 70 between each set of paired 
openings 42 (see FIGS. 2 and 5). This rib 70 is adapted to engage the 
other side of conductor 14 when the clamp is pushed into its clamping 
position, thereby to apply a generally opposing localized compressive 
force to the conductor to assist in holding the conductor against slippage 
in the direction of its length (a typically vertical direction). The 
protrusions 68 and ribs 70 are suitably shaped to avoid piercing the 
insulative covers on the conductors 14. 
Referring to FIGS. 5-8, device 10 also includes retainer means comprising a 
structure 80 associated with each opening 42 in the arm 40 for fixedly 
maintaining the clamps 18 in their clamping positions. The structure 80 
are located adjacent the openings 42 and are engageable with the legs 62 
of each clamp 18 to inhibit movement of head 60 of the clamp away from arm 
40 of bracket 16 after the clamp has been moved to its clamping position. 
Each structure 80 is preferably an annular projection surrounding a 
respective opening 42 in arm 40 on the rear face 82 of the arm. The 
annular projection extends angularly inwardly and rearwardly from the arm 
and is configured to bite into the leg 62 of a clamp to hold it in its 
stated clamping position. The annular projections 80 are preferably formed 
integrally with bracket 16. 
In the preferred embodiment, the annular projections 80 are generally 
circular and the legs 62 of the clamps 18 are generally square in 
transverse cross-section along at least a major portion of their length 
(see FIGS. 6-8). The legs are sized so that the corner portions of the 
legs are engageable with the annular projections 80 as the legs are pushed 
through the openings 42, and so that the flats of the legs are spaced from 
the annular projections to provide gaps into which displaced corner 
material can flow as the legs are pushed farther into the openings. By way 
of example, the diameter D1 of an opening 42 may be about 0.188 inches. A 
leg may have a dimension D2 of 0.145 inches and a dimension D3 of 0.223 
inches. This configuration reduces the forces required to push the legs 
through the openings while ensuring a good "bite" between the legs and the 
annular projections to maintain the clamp in its clamping position. It 
will be understood that the legs 62 and annular projections 80 can have 
other shapes, so long as there is a suitable interference fit between the 
legs and the projections to hold the legs against substantial movement of 
the head 60 of the clamp away from the arm 40 of the bracket after the 
head has been pushed in to its clamping position. 
Other means may be used to retain the clamps in their clamping positions. 
For example, the legs 62 of each clamp 18 may have flexibly resilient 
barbs or the like at closely spaced intervals along the legs, the 
arrangement being such that the barbs flex to permit passage of the leg 
through the opening and then spring out to engage the arm 40 for holding 
the clamp in its clamping position. Similarly, the barbs may be rigid but 
the legs may be split along their lengths so that they resiliently flex 
inwardly to permit passage through the openings and then snap back to lock 
the clamp in a clamping position. Another option is to form the arm 40 
with a series of spring fingers around each opening which flex to permit 
passage of a barbed or grooved leg through the opening, and then spring 
back for engagement with the leg to prevent retraction of the leg back 
through the opening. It is also contemplated that a retainer separate from 
the arm 40 and clamp 18 could be used to hold the clamp in its clamping 
position. 
Referring to FIG. 2, plug 22 has a head 90 and a stem 92. Stem 92 is 
adapted to be inserted in hole 24 for securing the series of clamps 18 to 
bracket 16. Stem 92 is sized slightly larger than hole 24 so that it 
frictionally engages the side edge of the hole 24 to effectively maintain 
the plug on arm 40, as shown in FIGS. 1 and 3. The plug can be inserted 
into hole 24 by aligning stem 92 with hole 24 and pressing the head 90 of 
plug 22 in the direction of the hole. Plug 22 thus allows the series of 
clamps to be secured to bracket 16 so that device 10 can be assembled and 
sold as a single pre-assembled unit to facilitate use of the device 10 and 
to prevent misplacement and loss of the individual clamps. Clamps 18, 
connector 20, and plug 22 are preferably formed integrally as a one-piece 
molded plastic part. The plastic can be polyethylene or other suitable 
material. 
In use, bracket 16 is secured to support member 12 by means of a fastener 
such as screw 52 (shown in FIGS. 1 and 3). A conductor or conductors are 
placed between a pair of openings 42 and held in place while the installer 
simultaneously aligns the legs 62 of clamp 18 with a pair of openings 42 
and pushes the top side 64 of the clamp until the bottom side 66 of the 
clamp forcefully engages the conductors to clamp them in fixed position. 
The clamps thereafter maintain the conductors in alignment with the 
support member a fixed distance from the front flange 26 of the support 
member and the wall W. The process is repeated until all conductors are 
secured to arm 40 by the clamps, as shown in FIGS. 1 and 3. 
From the foregoing, it will be seen that this invention is one well adapted 
to attain all the ends and objects hereinabove set forth together with 
other advantages which are obvious and which are inherent to the 
structure. 
It will be understood that certain features and subcombinations are of 
utility and may be employed without reference to other features and 
subcombinations. This is contemplated by and is within the scope of the 
claims. 
Since many possible embodiments may be made of the invention without 
departing from the scope thereof, it is to be understood that all matter 
herein set forth or shown in the accompanying drawings is to be 
interpreted as illustrative and not in a limiting sense.