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Патент USA US3028159

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April 3, 1962
_w. SPARKS
3,028,146
FISH TAPE
Filed 001;. e, 1959
2868
WL.
%f’ 22
W/ ///0/77
Jp ar/w
IN VEN TOR.
ATTORNEY)‘
21";
atet iii
3,928,1d?
Patented Apr. 3, 1962
2
1
as a result a large portion of the outer face of the housing
3,028,146
FISH TAPE
drags on the conduit along its entire length. This friction
between the housing and conduit makes it dii?cult to
.
William Sparks, Costa Mesa, Calif.
(P.0. Box 2374, Anaheim, Calif.)
insert the ?sh tape through the conduit and substantially
increases the pulling force required to pull the cable
through the conduit.
Filed Oct. 9, 15959, Ser. No. 845,353
7 Claims. ((11. 254-1343)
An object of this invention is to provide a ?sh tape
that will obviate the above di?iculties and disadvantages.
Another object of this invention is to provide a ?sh tape
relates to a ?sh tape which is so constructed to be ?exible 10 that is ?exible in different planes.
Another object of this invention is to provide a ?sh
in different planes. In another of its novel aspects, it
tape having a low degree of friction during the insertion
relates to a ?sh tape that is guided and supported win a
and pulling of the ?sh tape through a conduit.
conduit on spaced sleds or runners to provide for easy
Another object of this invention is to provide a ?sh
insertion and pulling of the tape through the conduit.
tape for pulling cable or similar material through a con
In the electrical industry and other industries, it is fre
duit that is so constructed so as to be easily inserted and
quently necessary to pass cable or similar material through
pulled through a conduit which may be of substantial
a conduit which may be laid in the walls, ?oors and ceil
length and which may have a number of bends in dif
ings of buildings or buried in the ground. The conduit
ferent planes along this length.
may be of substantial length and may be bent or curved
Another object of this invention is to provide a ?sh
in different planes over its length. Usually it is not pos 20
tape for pulling cable through a conduit, the ?sh tape
sible to push the cable itself through the conduit because
being constructed of a plurality of elements, each element
of limited space, lack of rigidity in the cable or other
contributing in a substantial degree to the compressive
reasons; therefore, it is common practice to pull the cable
strength or stiffness required to push the tape through the
through the conduit by use of a pulling member, previ
ously threaded through the conduit. Members used for 25 conduit and also contributing in a substantial degree to
the tensile strength required to pull a tape and cable
this purpose are known in the electric wiring art as “?sh
This invention relates to a tool for pulling cable or the
like through a conduit. In one of its novel aspects, it
throughthe conduit.
ta es.”
pOne type of ?sh tape known in the art comprises a
metallic shaft of substantially rectangular cross-section.
While this rectangular ?sh tape is ?exible about its major
axis, it is virtually in?exible about its minor axis. Being
flexible about a single axis, this ?sh tape is dif?cult to
Another object of this invention is to provide a ?sh
tape of the type described in the above object which is so
Ci: 0 constructed that the individual elements alternatively form
sleds or runners at spaced intervals along the length of
the tape for guiding and supporting the ?sh tape with a
Eninixnum of friction during its passage through the con
insert and pull through a conduit that may bend in more
than one plane, particularly if the bends are relatively 35 uit.
These and other objects and advantages are realized by
close together, since the tape must be twisted to expose
the practice of this invention in the forms illustrated in
its flexible axis to the new bending plane. In addition,
the drawings wherein at least two opposing pairs of elas
a rectangular ?sh tape tends to ride along the conduit on
tically ?exible elements are braided together to form a
its face or larger surface rather than its edge or smaller
surface. This situation can cause a great amount of fric 40 ?sh tape by crossing a ?rst opposing pair of elements
between a second opposing pair of elements and then
tion between the tape and conduit making it extremely
difficult to insert and pull the tape through the conduit.
The twisting action necessary to negotiate bends in dif
ferent planes further increases the friction and resistance
to movement of the tape through the conduit.
7
Another type of ?sh tape known to the art comprises
a two-piece ?sh tape having an inner pulling element and
an outer housing, for example, a steel spring, for guiding
and supporting the inner pulling element. Neither of
these elements contributes substantially to the function of 0
the other, that is, the housing does, not have suf?cient
stiffness or tensile strength to contribute sign?cantly to
threading through the conduit or to the pulling function
crossing the second opposing pair of elements between the
?rst opposing pair of elements before re-crossing the ?rst
opposing pair of elements. The ends of the elements at
each end of the ?sh tape may then be secured, as by
welding or crimping to a suitable eye or hook to provide
a connection for attaching the ?sh tape to the cable on
one end and to provide a coupling for a pulling device
at the other end.
.
Such a fish tape has a series of spaced skids or run
ners approximately parallel to its longitudinal axis lo
cated at intervals around the face of the tape and along
its length. These provide points of contact between the
?sh tape and conduit at spaced intervals along the con
of the inner element, and the inner element does not con
tribute substantially to the guiding and supporting func-' 55 duit to guide and support the ?sh tape when it is passed
through the conduit. Inasmuch as the ?sh tape contacts
tion of the housing during insertion of the tape through
the conduit only at spaced intervals along its length, the
the conduit. This two-piece ?sh tape has other disad
friction or resistance to movement of the ?sh tape through
vantages and undesirable features. It is expensive to
the conduit is greatly reduced. This reduction in fric
manufacture and di?‘icult to anchor the two elements
together so that they will move as a unit through the con 60 tion provides for easy insertion of the ?sh tape through
the conduit and also provides for easy pull of the cable
duit during the insertion operation and the pulling opera
and tape through the conduit. This arrangement also
tion. Since the pull on this type of ?sh tape is exerted
reduces the tendency of the ?sh tape to spiral or twist
primarily on the inner element and the drag or friction
as it is passed through the conduit.
is exerted primarily between the outer element and con
‘It is intended that the term “elastically ?exible” as
duit, a high shearing force is created between the inner
used in the speci?cation and claims be taken to include
and outer elements during the pulling operation. This
all elements known to the art as being suitably ?exible
shearing force in some cases may shear the anchor con
and elastic for the construction of a ?sh tape according
nection between the inner pulling element and outer hous
to this invention. For example, the elements may be of
ing thereby separating the tape into two parts. In addi
tion, the friction between the housing and conduit is 70 steel or plastic wire or ?laments. In other applications,
it may be desirable to use insulated wire to protect the
relatively high since the housing is usually of substantially
operator from “hot” circuits in a fuse panel. In any
the same con?guration in cross section as the conduit, and
3
4
event, the elastically ?exible elements used in the con
structicn of the ?sh tape of this invention should be suf
?ciently ?exible to negotiate the bends which may be
18a in the other direction. This sequential twisting of one
opposing pair of elements in one direction intermediate
the twisting of the other opposing pair of elements in
encountered in the conduit, yet have suf?cient compres
another direction is continued until a ?sh tape of the
sive strength and sti?ness to feed through the conduit
without buckling or doubling back when inserted therein
by an operator. In addition, the elements should have
sufficient tensile strength to pull a cable through the con—
dnit, even though a substantial force may be required to
10
accomplish such a pull.
The elements making up the opposing pairs may com
desired length is obtained. The ends of the elements at
each end of the tape may then be secured, as by welding,
to a coupling 19 to provide a means of connecting the
?sh tape at one end to the cable to be pulled through a
conduit, and to provide a means at the outer end for
pulling the ?sh tape and cable through the conduit.
Although the elements in this embodiment are braided
prise a plurality of strands, the strands comprising each
together by twisting the opposing pairs of elements in
element preferably being taken as a unit and braided with
other elements as above described to provide the ?sh tape
opposite directions, it will be understood that it is with-in
the scope of this invention to braid the elements together
The number of strands comprising 15 by crossing opposing pairs of elements intermediate the
crossing of other opposing pairs of elements without twist
ing‘ the elements of opposing pairs together.
plication involved. For example, for a given total tensile
One important feature of this invention is the provi
strength to be provided by the ?sh tape, greater ?exibility
sion of spaced skids or runners along the face of the
for negotiating bends in a conduit is generally provided
braided body member for guiding and supporting the
by utilizing a plurality of relatively small strands for each
body member when it is passed through a conduit. This
element rather than a fewer number of larger strands for
feature of the invention can be seen in FIG. 2 wherein
each element. On the other hand, because of the pres
the segmental portions of elements 17 and 17a between
ence of other cable in the conduit or other reasons, it
their crossings 20 de?ne such skids or runners alterna
may be desirable to provide a ?sh tape of relatively high
compressive strength or stiffness to permit the ?sh tape 25 tively along the length of body member 16. Elements
18 and 18a de?ne like skids or runners intermediate
to be inserted through the crowded conduit. In this
their crossings 22, the skids or runners formed by ele
case, a smaller number of relatively large strands in each
of this invention.
each element can vary, depending upon the particular ap
element would be preferred. Other considerations can
in?uence the number and size of strands to be used in a
particular application.
In this connection, it will be understood that it is gen
erally preferable that the elements of opposing pairs
ments 18 and 18a being disposed between the skids or
runners of elements 17 and 17a and in a plane at an an
30 gle thereto. These skids or runners de?ned by the ele
ments intermediate their crossings provide points of con—
tact between the braided body member and the conduit
at spaced intervals along the length of the conduit (FIG.
1) when the ?sh tape is passed through the conduit.
instances, it is desirable that the di?erent opposing pairs
comprising the ?sh tape of this invention include elements 35 Thus, as distinguished from ?sh tapes presently known
comprise an equal number of strands. Further, in some
having an equal number of strands.
Referring now to the drawings wherein like charac
ters are used to designate like parts:
FIG. 1 is a perspective view of one embodiment of the
in the art, the ?sh tape of this invention is guided and
accomplished by sequentially twisting one opposing pair
together with opposing pairs of elements 25 and 25a,
supported in the conduit by relatively widely spaced skids
or runners along the length of the ?sh tape. This reduc
tion in overall area of contact between the ?sh tape and
?sh tape of this invention being passed through a conduit, 40 conduit substantially reduces the friction or resistance to
movement of the ?sh tape when it is passed through the
the conduit being shown as bent in di?erent planes and
conduit, thereby reducing the force required to insert the
the conduit broken away to show the spaced points of
?sh tape through the conduit and to subsequently pull
contact between the tape and conduit;
the ?sh tape and attached cable through the conduit.
FIGS. 2 and 3 are plan views of the ?sh tape of
In addition, it will be observed that the skids or runners
FIG. 1;
de?ned by the elements lie in planes substantially parallel
FIG. 4 is a section taken along the ?sh tape of FIG. 2
to the longitudinal axis of the braided body member, and
at the line 4-4;
ence are directed toward, rather than across, the direc
FIG. 5 is a section of the ?sh tape of FIG. 2 taken
tion of movement of the ?sh tape when it is passed
along line 5—5;
FIG. 6 is a section of the ?sh tape of FIG. 2 taken 50 through a conduit. This arrangement further reduces
the friction between the ?sh tape and conduit and also
along line 6-6;
reduces the tendency of the ?sh tape to twist or spiral as
FIG. 7 is a section of the ?sh tape of FIG. 2 taken
it is moved through the conduit.
along line 7—7; and
In the embodiment of FIG. 8, one opposing pair of
FIG. 8 is a section of another embodiment of this in
elements, 23 and 24, comprise a plurality of strands,
vention wherein each element of one opposing pair in
element 23 including strands 23a and 23b, and element
cludes two elastically ?exible strands.
24 including strands 24a and 24b. In this embodiment,
In a preferred embodiment of this invention, the cross
opposing pairs of elements 23 and and 24 are braided
ing of elements of opposing pairs, above referred to, is
of elements in one direction intermediate the twisting of 60 as above described, the strands making up each element
being taken as a unit in the braiding operation.
another opposing pair of elements in the opposite direc
The operation and use of the ?sh tape of this invention
tion, each element comprising an equal number of elas
is as follows. A ?sh tape of desired length, constructed,
tically ?exible strands.
for example, according to the foregoing embodiment, is
Referring now to the drawings wherein the above em
bodiment is shown, and for reason of simplicity of illus 65 threaded by pushing it through a conduit 21 (FIG. 1)
and a cable is attached to the coupling at the end of the
tration, each element is shown as comprising a single
?sh tape. The ?sh tape and cable are then pulled through
elastically ?exible strand, for example, steel wire such
the conduit by pulling on the coupling at the other end
as piano wire, the ?sh tape indicated generally at 15 com
of the ?sh tape. Inasmuch as the braided body member
prises a braided body member 16 fashioned by braiding
together opposing pairs of elements, one opposing pair 70 of the ?sh tape of this invention is approximately equally
flexible in all different planes, the ?sh tape‘ may be in
being designated 17 and 17a, and the other opposing
serted through the conduit without the necessary of twist
ing the ?sh tape to expose a ?exible axis to bends in the
FIGS. 2 through 7, the elements are braided together by
conduit, even though such bends may be in dilferent
twisting opposing elements 17 and 17a in one direction
intermediate the twisting of opposing elements 18 and 75 planes and relatively close together. Further, each ele
pair being designated 18 and 1811. As can be seen from
3,028,148
6
5
ment comprising the ?sh tape of this invention not only
forms skids for guiding and supporting the ?sh tape when
it is passed through a conduit, but also contributes in a
substantial degree to the required compressive strength
or stiffness for inserting the ?sh tape through the con
duit, and to the required tensile strength for pulling the
?sh tape and cable through the conduit.
From the foregoing it will be seen that this invention
is one well adapted to attain all of the ends and objects
hereinabove set forth, together with other advantages
which are obvious and which are inherent to the ap
paratus.
.
gether, one opposing pair of elements being twisted in
one direction intermediate the twisting of the other op~
posing pair of elements in the other direction whereby
the segments of each opposing pair of elements between
the crossings thereof de?ne skids alternatively spaced
along the face of the body member for guiding and sup
porting the body member when it is passed through a
conduit, said skids having smooth longitudinally extend
ing skid surfaces and being substantially parallel to the
10 longitudinal axis of said body member, and connecting
means mounted on said body member for connected
- the body member to the cable to be pulled through the
conduit.
It will be understood that certain features and sub
4. A ?sh tape according to claim 3 wherein at least
combinations are of utility and may be employed with
out reference to other features and subcombinations. 15 one of said elements comprises a plurality of elastically
?exible strands.
This iscontemplated by and is Within the scope of the
5. A ?sh tape according to claim 3 wherein each ele
claims.
ment of at least one of said opposing pair of elements
As many possible embodiments may be made of the
comprises a plurality of elastically ?exible strands, each
invention without departing from the scope thereof, it
is to be understood that all matter herein set forth or 20 element of said opposing pair of elements having an equal
number of said elastically ?exible strands.
shown in the accompanying drawings is to be interpreted
6. A'?sh tape according to claim 3 wherein each of
as illustrative and not in a limiting sense.
said elements comprises at least one elastically ?exible
The invention having been described, what is claimed is:
strand, each of the elements having an equal number of
l. A ?sh tape for pulling cable or the like through a
conduit, comprising, a plurality of opposing pairs of 25 said elastically ?exible strands.
7. A ?sh tape for pulling cable or the like through a
elastically ?exible elements braided together, the braided
elements being ?exible in different planes and de?ning
conduit, comprising, in combination, a braided body
member, a coupling mounted on each end of the body
alternate skids spaced along the length of the tape to
member, said braided body member including elastically
provide spaced points of contact between the ?sh tape
and conduit for guiding and supporting the ?sh tape when 30 ?exible means bendable in different planes for guiding
and supporting the braided body member when it is
it is passed through a conduit, said braided elastically
passed through a conduit, said elastically ?exible means
?exible elements being contiguous along the length of
having su?icient strength in compression to avoid buck
said tape and having su?icient strength in compression
ling while being inserted longitudinally through the con
to avoid buckling While being pushed through a conduit
and sufficient strength in tension to pull a cable there 35 duit from one end thereof and sut?cient strength in
tension to pull a cable through the conduit, said elasti
through without substantial change in cross-sectional area
cally ?exible means including at least two pairs of
of the tape and connecting means mounted on said elasti
mutually twisted opposing elastically ?exible Wires con
cally ?exible elements for connecting said cable to said
nected at the ends thereof to, said couplings and being
elements.
2. A ?sh tape for pulling a cable or the like through a 40 braided together intermediate said couplings, one pair
of wires being twisted about each other in one direction
conduit, comprising, a body member, said body member
intermediate the twisting of another pair of wires about
including at least two pairs of crossed opposing elements
each other in the other direction whereby the segmental
braided together, one pair of opposing elements being
portions of each pair of wires intermediate the crossings
crossed intermediate the crossing of the other pair of
opposing elements whereby the elements in each oppos 45 of such pair of wires de?ne alternate skids along the
face of the braided body member for contacting the con
ing pair of elements de?ned skids, each skid having a
duit at spaced points along the conduit to provide said
smooth continuous surface extending approximately longi
guiding and supporting of the braided body member when
tudinally along the face of said body member intermedi
it is passed through the conduit, said skids having smooth
ate the crossings of said opposing elements for contacting
a conduit at spaced intervals along the conduit to guide 50 longitudinally extending skid surfaces and being sub
stantially parallel to the longitudinal axis of said braided
and support the body member when it is inserted through
body member.
the conduit, said elements being of an elastically ?exible
nature and having sufficient strength in compression to
avoid buckling while being inserted through a conduit and
References Cited in the ?le of this patent
su?icient strength ‘in tension to pull a cable through the 55
UNITED STATES PATENTS
conduit, and connecting means mounted on said body
member for connecting the body member to the cable to
832,343
Scott ________________ __ Oct. 2, 1906
be pulled through the conduit.
1,020,672
Wilson ______________ __ Mar. 19, 1912
3. A ?sh tape for pulling cable or the like through a
1,475,859
Nyman ______________ __ Nov. 27, 1923
conduit comprising, a body member bendable in ditfer 60 2,142,641
Garris _______________ __ Ian. 3, 1939
ent planes, said body member including at least two op
2,750,152
Schinske _.,_, __________ __ June 12, 1956
posing pairs of elastically ?exible elements braided to
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