U.S. patent application number 13/285437 was filed with the patent office on 2012-07-05 for portable electric cable support tower.
Invention is credited to Roger A. Smith.
Application Number | 20120168570 13/285437 |
Document ID | / |
Family ID | 46379898 |
Filed Date | 2012-07-05 |
United States Patent
Application |
20120168570 |
Kind Code |
A1 |
Smith; Roger A. |
July 5, 2012 |
PORTABLE ELECTRIC CABLE SUPPORT TOWER
Abstract
A support for electrical cables having a nonconductive
telescoping pole. A frictional locking collar couples sections of
the telescoping pole to one another. The bottom end of the pole
fits into a round conical base formed of recycled tires. The top
end of the pole is affixed to a nonconductive head that is shaped
to cradle electrical cables.
Inventors: |
Smith; Roger A.; (Apollo
Beach, FL) |
Family ID: |
46379898 |
Appl. No.: |
13/285437 |
Filed: |
October 31, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61428891 |
Dec 31, 2010 |
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Current U.S.
Class: |
248/51 ;
248/65 |
Current CPC
Class: |
F16L 3/00 20130101; H02G
3/30 20130101 |
Class at
Publication: |
248/51 ;
248/65 |
International
Class: |
F16L 3/08 20060101
F16L003/08 |
Claims
1. A portable support tower for temporarily supporting one or more
electrical cables above ground level at a construction site, the
support tower comprising: an elongated lightweight member having a
proximal end and a distal end, the elongated lightweight member
being formed of a nonconductive, rigid first material; a base
having a downwardly-extending cavity formed therein, the cavity
being sized to accept the proximal end of the elongated lightweight
member, the base being formed of a nonconductive second material
that provides the base with substantially more mass than the first
material provides the lightweight member; and a support head shaped
to cradle one or more cables, the support head being removably
affixed to the distal end of the elongated lightweight member.
2. The support tower of claim 1, wherein the first material is
selected from the group consisting of: plastic, fiberglass, and
carbon fiber composite.
3. The support tower of claim 1, wherein the elongated lightweight
member comprises: a hollow bottom portion; and a top portion sized
to move freely inside the hollow bottom portion; and wherein the
support tower further comprises a frictional locking collar
disposed to encompass both the hollow bottom portion and the top
portion and to selectably lock the hollow bottom portion and the
top portion in fixed relation to one another.
4. The support tower of claim 1, wherein the second material
comprises shredded, recycled tire rubber.
5. The support tower of claim 1, wherein the support head is
affixed to the distal end of the elongated lightweight member via
threaded engagement.
6. A support tower for supporting one or more cables above ground
level, the support tower comprising: an elongated, nonconductive,
telescoping pole having a proximal end and a distal end; a
nonconductive base having a vertical cavity sized to accept the
proximal end of the pole, the cavity being formed substantially
centrally in the base; and a nonconductive support head shaped to
cradle one or more cables, the support head being removably affixed
to the distal end of the pole.
7. The support tower of claim 6, wherein the telescoping pole is
formed substantially of a material selected from the group
consisting of: plastic, fiberglass, and carbon fiber composite.
8. The support tower of claim 6, wherein the base comprises
shredded, recycled tire rubber.
9. The support tower of claim 6, wherein the support head is
affixed to the distal end of the pole via threaded engagement.
10. The support tower of claim 6, wherein telescoping portions of
the pole are engaged to one another via a frictional locking
collar.
11. A portable support tower for temporarily supporting one or more
electrical cables above ground level at a construction site, the
support tower comprising: a non-conductive base having a bottom
that engages the ground and a top that extends upwardly therefrom,
the base having an opening therein extending downwardly from the
top toward the bottom, the base being formed of a material
comprising a shredded, recycled rubber tire material, the base
being sufficiently wide and heavy that it resists being tipped over
by a tipping force applied thereto, the base being sufficiently
light that a single person is permitted by law to move it; an
elongated, lightweight tubular pole member having a lower end and
an upper end, the pole member being formed of a nonconductive
material comprising a synthetic resin, the pole member fitting
closely in the opening in the base so as to be supported in an
upward position by the base, the pole being removable from the base
for disassembly and moving the tower; and a support head removably
affixed at the upper end of the pole, the support head including
means for engaging and supporting one or more electrical cables
above the ground, the support tower being constructed so as to
provide stable and non-conductive above ground support for
electrical cables but being capable of being easily disassembled
and moved and reused at different sites.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims domestic priority benefit of
provisional application number 61/428,891, filed Dec. 31, 2010. The
priority application is incorporated herein by reference, in its
entirety, for all purposes.
FIELD OF THE INVENTION
[0002] The present invention is directed generally to a support
structure, and more specifically to a support pole that securely
holds electrical cables a safe distance above ground level.
BACKGROUND INFORMATION
[0003] Workplace safety practices include the practice of keeping
electrical cables (welding cables, power cords, and so forth)
suspended so that they are not in contact with the ground and are
not likely to come into contact with a worker. This safety practice
is advisable because of the risk that some portion of a worker's
body may complete an electrical circuit if the worker is standing
on the ground and touches a cable, or if the ground itself is in
electrical contact with an electrical cable.
[0004] A traditional way to keep electrical cables off the ground
on a work site is to use lengths of lumber nominally 2 in. by 4 in.
in cross section (for example, common 8 foot long two-by-four
"studs") to prop the cables overhead. One disadvantage of using
lumber to prop up cables is that each tower is constructed onsite,
requiring time-consuming rough carpentry to add a base to each
vertical board. Hooks to suspend the cables are formed by nails
driven partially into the top of the tower, a less-than-ideal
situation since it would be preferable for all parts of the tower
to be nonconductive. These lumber towers are only marginally
effective because they are prone to falling over due to a high
center of gravity.
[0005] The lumber towers are awkward to move and are almost never
moved from one job site to another. They are so inconvenient to
move and/or store that construction companies routinely dispose of
them when a job is completed, and accept that new ones will need to
be constructed at future construction sites. This is a waste of
resources, a drag on productivity, and an economically inefficient
recurring cost.
[0006] What is needed is a support structure that will hold
electrical cables overhead safely, and that is inexpensive,
lightweight, reusable, and convenient to move and store.
SUMMARY OF THE INVENTION
[0007] One aspect of the present invention is cable support tower
that has a vertical nonconductive pole.
[0008] Another aspect of the present invention is the use of a
fiberglass, telescoping pole in a cable support tower.
[0009] Yet another aspect of the present invention is a cable
support tower that has a telescoping nonconductive pole with a
frictional locking collar between telescoping sections.
[0010] Still another aspect of the present invention is a cable
support tower having a dense base with a low center-of-gravity.
[0011] A further aspect of the present invention is a cable support
tower that has a base formed substantially of recycled tire
rubber.
[0012] Another aspect of the present invention is a cable support
tower that has a top shaped to cradle plural electrical cables.
[0013] One embodiment provides support for electrical cables using
a nonconductive telescoping pole. A frictional locking collar
couples sections of the telescoping pole to one another. The bottom
end of the pole fits into a round conical base formed of recycled
tires. The top end of the pole is affixed to a head that is shaped
to cradle electrical cables. Fiberglass, plastic, and carbon fiber
composite are examples of nonconductive material suitable for the
pole.
[0014] According to some embodiments of the portable support tower,
the tower has a non-conductive base, a tubular pole member, and a
support head. The non-conductive base has a bottom that engages the
ground and a top wherein an opening extends downwardly from the top
toward the bottom. The base is formed of a material derived from
shredded, recycled rubber tire material, and the base is
sufficiently wide and heavy that it resists being tipped over by
application of a tipping force. The base is also sufficiently light
that only one person can move it without exceeding permitted safe
practice.
[0015] The tubular pole member is elongated and lightweight, has a
lower end and an upper end, and is formed of a nonconductive
material comprising that includes synthetic resin. The pole member
fits closely in the opening in the base so that it is supported in
an upward position by the base, while the pole is removable from
the base for disassembly and moving.
[0016] The support head is removably mounted at the upper end of
the pole. The support head includes structure for engaging and
supporting one or more electrical cables above the ground. The
support tower is constructed so as to provide stable and
non-conductive above ground support for electrical cables and is
capable of being easily disassembled and moved and reused at
different work sites.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 shows a perspective view of a cable support according
to an embodiment of the present invention.
[0018] FIG. 2 shows an elevation view of a cable support according
to the embodiment shown in FIG. 1.
[0019] FIG. 3 shows an elevation view of a cable support according
to another embodiment of the present invention.
DETAILED DESCRIPTION
[0020] Referring to FIG. 1, a perspective view of one cable support
embodiment is shown. A nonconductive telescoping pole 110 is
oriented substantially vertically to provide vertical structural
support. The bottom end 112 of the pole 110 fits into a round,
conical base 130 that is substantially heaver than the pole 110.
The top end 116 of the pole 110 is affixed to a head 150 that is
shaped to cradle electrical cables. Together, the pole 110, base
130, and head 150 form a tower 100 that provides support for
electrical cables 180 to keep the cables suspended above the
ground.
[0021] Referring to FIG. 2, an elevation view of the tower 100
embodiment of FIG. 1 is shown. An inner, top section 118 of the
telescoping pole 110 is slidably engaged and disposed partially
inside an outer, bottom section 114. The slidable engagement of the
pole top section 118 with the pole bottom section 114 is subject to
selectable locking of the sections 114, 118 into fixed engagement
by a frictional locking collar 120. The relative position of the
pole sections 114, 118, when locked into fixed engagement, is
selectable across a broad range from fully collapsed to fully
extended. The pole 110 is fiberglass and the frictional locking
collar 120 is nonconductive hard plastic.
[0022] An advantageous way to affix the locking collar 120 to the
bottom pole section 114 is by threaded engagement of threads formed
on the outside surface of the locking collar 120 engaging with
threads formed on the interior surface of the bottom pole section
114. A Teflon.RTM. (polytetrafluoroethylene) taper collar is
compressed between the collar 120 and the pole section 114 to hold
the threaded engagement securely.
[0023] The base 130 provides stability for the tower 110 by being
substantially heavier than the pole 110, and by having a form
factor that gives the base 130 a low center-of-gravity. The
relative weight (or mass) of the pole 110 (minimized) and the base
130 (maximized) is selected by choice of material and form factor.
The pole 110 is chosen to be lightweight fiberglass (or
alternatively, polymer, carbon fiber composite) and to be hollow
through both the top and bottom sections 114, 118. The base 130 is
formed of recycled tire rubber (or another dense nonconductive
material) with internal vanes (not shown) of a thickness that may
not be strictly necessary for structural integrity but provide the
advantage of extra stabilizing mass. A practical limit to
increasing the mass of the base 130 is to stay beneath a single
worker carry limit, for example the 75-pound limit enforced by
Occupational Safety and Health Administration (OSHA) in the US. A
commercially available traffic sign base formed of recycled rubber
is suitable for use as the base for embodiments of a cable support
tower according to the present invention.
[0024] The base 130 is formed to have a low center-of-gravity by
having substantially more of the mass nearer the bottom 132 than
the top 134. The round, conical shape (or frustoconical shape, to
be precise) of the base 130 well suits this approach. Other shapes
may also be suitable, so that an alternative embodiment may have a
pyramidal base. The lower end of the base is wide enough to prevent
the pole from tipping over in normal usage, and the base is high
enough to hold the pole securely in a vertical position. In the
preferred embodiment, the base is about eighteen inches wide and
about fourteen inches tall. These dimensions can be varied.
[0025] The base 130 has a handle 136 for ease of carrying by a
worker. The handle is formed of nonconductive, flexible rope
material. So long as it is nonconductive, the rope used to form the
handle 136 can be made from polymer or fibers (e.g., manila, hemp,
sisal).
[0026] A channel 140 is formed in the base 130, and has a diameter
sufficiently large to accommodate the bottom end 112 of the pole
110. The channel 140 is closed at the bottom 132 of the base 130 to
prevent the pole 110 from sliding down through the base 130 in the
event the tower 100 is placed on soft ground.
[0027] The head 150 has a stem 152, a bottom 154, and sides 156,
158. The stem 152 extends downward from the bottom 154 and is
threadably engaged with the top end 116 of the pole 110. The bottom
154 has a width sufficient to accommodate plural cables, 10 inches.
The sides 156, 158 extend upwardly from opposing ends of the bottom
154, and have length of 8 inches, sufficient to prevent cables from
sliding off of the head 150.
[0028] Referring to FIG. 3, an elevation view of a cable support
according to another embodiment is shown. An inner, top section 318
of the telescoping pole 310 is slidably engaged and disposed
partially inside an outer, bottom section 314. The slidable
engagement of the pole top section 318 with the pole bottom section
314 is subject to selectable locking of the sections 314, 318 into
fixed engagement by a frictional locking collar 320. The relative
position of the pole sections 314, 318 when locked into fixed
engagement is selectable across a broad range from fully collapsed
to fully extended.
[0029] The pole 310 is made of polymer and the frictional locking
collar 320 is nonconductive hard plastic.
[0030] The embodiments described have shown two section telescoping
poles, however, practice of the invention is not limited to poles
with that number of sections. According to an alternate embodiment
the pole has a single, fixed length (i.e., non-telescoping)
section. In the case a single-section pole is used, the length of
the pole is selected so as to keep the supported cables seven to
eight feet above the ground. According to other alternative
embodiments, the telescoping pole may have three or more sections.
In the case of multiple-section poles, the fully collapsed pole
length should five feet or less, for ease of portability and
storage, and the fully extended pole length should be at least
seven feet to provide for a safe height of suspension for cables. A
suitable outer diameter of a two-section telescoping pole is about
two inches.
[0031] The base 330 provides stability for the tower 300 by being
substantially heavier than the pole 310, and by having a form
factor that gives the base 330 a low center-of-gravity. The ratio
of weight of the base 330 to that of the pole 310 is maximized by
choice of material and form factor. The pole 310 is formed of a
rigid, nonconducting, lightweight, material that (examples are:
fiberglass, polymer, carbon fiber composite) and is made to be
hollow through both the top and bottom sections 314, 318. The base
330 of this embodiment is similar in form and composition to the
base 130 of the embodiment of FIGS. 1 and 2, and has a
functional/structural relationship with its pole 310 similar to
that described regarding the base 130 and pole 110 of the
embodiment of FIGS. 1 and 2.
[0032] A handle 336 is provided by forming an oblong recess of
approximately 1 inch by 5 inch through a side surface of the base.
A channel 340 is formed in the base 330, and has a diameter
sufficiently large to accommodate the bottom end 312 of the pole
310. The channel 340 is closed at the bottom 332 of the base 330 to
prevent the pole 310 from sliding down through the base 330 in the
event the tower 300 is placed on soft ground.
[0033] The head 350 has a stem 352, a body 354, and recesses 356
formed in opposed edges of the body. The stem 352 extends downward
from the body 354 and is threadably engaged with the top end 316 of
the pole 310. Each of the recesses 356 has a width sufficient to
accommodate at least one cable. The depth of each recess 356 is
sufficient to prevent cables from sliding off of the head 350. In
this embodiment, four recesses 356 are shown, but the number is not
critical to practice of the invention. In general, two or more
recesses would be appropriate for alternative embodiments. The head
350 is formed of plastic or other suitable materials that include
(without limitation) plastic, carbon fiber, fiberglass, and
ceramic. The head 350 can also be formed using a metal (e.g., steel
or aluminum) that is entirely covered on all exposed surfaces with
a nonconductive coating (e.g., plastic or rubber) of substantial
thickness.
[0034] Suitable materials for the pole structure have been listed
above, the listed materials not be considered as limiting, except
to note that PVC (polyvinylchloride) pipe is not considered to be
suitable for the pole because under cold conditions PVC has a
tendency to become brittle, presenting a risk of failure due to
cracking and/or breaking.
[0035] According to an alternate embodiment, the base is formed of
a rigid walled plastic container partially filled with sand (or
another dense, flowable, nonconductive solid material, such as
gravel). A practical limit to how much sand or gravel to add to
increase the mass of the hollow plastic base is to stay beneath the
70-pound carry limit for a single worker.
* * * * *