Improvements in and relating to Underground Main and Branch Conduits for Electrical Conductors, and to Feeding Devices therefor.
Year: 1890

page_text: Date of Application, 22nd Apr., 1890-Accepted, 5th July, 1890
COMPLETE SPECIFICATION.
Improvements in and relating to Underground Main and Branch
Conduits for Electrical Conductors, and to Feeding Devices
therefor.
I, JAMES FERGUSON MUNSIE, of 337 Broadway in the City of Brooklyn, County of
Kings, State of New York, United States of America, Electrician, do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
My invention relates to certain new and useful Improvements in and relating to
Underground Conduits for Electrical Conductors, and embodies novel features in the
construction of the main conduit and in the manner of feeding or introducing the
conductors therein and also in the manner of drawing the conductors into the branch
conduits.
The first part of my invention relates to improvements in the construction of
underground main conduits for electrical conductors, and has for its object to
provide a conduit which shall be simple in construction, readily accessible for the
insertion of the conducting wires or cables, economical in point of manufacture and
installation, and which shall maintain its efficiency during long continued use. In
the attainment of these ends I have devised the construction and arrangement of parts
illustrated in the accompanying drawings, wherein
Fig. 1, Sheet 1, represents in longitudinal section a portion of my improved main
conduit and the man holes used in connection therewith, the section being taken on a
plane indicated by the line 1-1 of Fig. 2;
Fig. 2, Sheet 1 represents a cross-sectional view taken on a plane indicated by the
line 2-2 of Fig. 1;
Fig. 3, Sheet 2, represents partly in clevation and partly in section, one of the
subdivisions of my improved conduit between adjacent man-holes;
Figs. 4 and 5 Sheet 2, represent detail views in longitudinal and transverse section,
respectively, of a portion of the enclosing casing or outside envelope of the main
conduit, illustrated more particularly the method of forming the joints therein;
and
Figs. 6 and 7 represent respectively an end elevation and a longitudinal section of
my preferred form of, wire duct.
Similar numerals of reference indicate similar parts throughout the several
views.
As represented more fully in Fig. 3, my improved conduit consists of a number of
sections, isolated from each other, cach section extending between adjacent man-holes,
as 1, 2, which for purposes of convenience may be located at the intersection of cross
streets. The conduit is located at a distance below the surface of the ground
beneath the ordinary frost limit, and is made up primarily between adjacent man-
holes of an outer jacket or casing of any suitable cross-section and consisting
of a series of subdivisions abutting end to end as shown in Figs. 3 and 4, the
point of juncture being protected by an exterior sleeve 3, as shown in said figures.
The subdivisions of the exterior casing are preferably made of wood, impregnated with
creosote, asphaltum or the like, so as to be waterproof and not liable to decay. The
abutting end surfaces are carefully fashioned off to fit accurately one against the
other, and are connected by means of dowel pins 4, of harder wood, so as to make a
ight joint. About the dividing line between the adjacent subdivisions is wrapped a
sheet of waterproof paper (tar paper or the like) and over the joint is slipped the
etaining sleeve or cover 3, provided with an internal circumferential groove 6 and a
illing aperture 7, through which aperture a liquid composition consisting of asphaltum,

page_text: tar or the like, may be inserted under pressure, so as to compress the paper closely
upon the pipe ends, the subsequent solidification of the liquid composition leaving the
joint entirely water and air proof.
is
Within the external casing and separated therefrom by an intervening space
located the wire conducting conduit proper, said conduit consisting of one or more
ducts adapted for the reception of wires and being held apart from the walls of the
surrounding envelope by bottom blocks 8, top blocks 9 and side blocks 10, 11, all of
said blocks being preferably perforated so as not to obstruct free communication
At each man-hole the
between all parts of the intervening space above referred to.
said intervening space is closed at each end by the closing partition 12, said entire
space between adjacent man-holes being therefore completely enclosed and isolated from
contact with the external air and from communication with the interior of the enclosed
duct or ducts.
In the form of my invention illustrated in the drawings, the wire ducts are com-
posed of a series of blocks of wood or the like provided with longitudinal
semi-circumferential grooves registering with each other as shown in Fig. 2, so as
to make up a series of circular ducts, the inner surface of which is coated with a
layer of fireproof paint, so as to resist the heating effect due to the formation of an
are in the duct on the accidental rupture of one of the conductors should such rupture
take place; while the exterior surface of the duct or ducts is coated with a layer
of waterproof material such as asphaltun, tar or the like, to act as an additional
reinforcement against the penetration of moisture from without.
The exterior casing of the conduit is continued beyond the inner walls of the
man-hole, as shown, the bottom and side partitions being carried across the man-
hole and a section of the top being hinged at 13, as shown, so as to enable access
from without to be had to the intermediate space 14 between the ends of the wire
ducts. Within the man-hole an additional casing 15 is built surrounding the
external casing of the conduit thereat, and said additional casing 15 is provided at
the top with a door 16 adapted to be secured in place by a lock 17, so that the under-
ground conduit shall, even at the man-hole be secure from interference by
meddlesome or malicious persons. The door 18 of the exterior envelope of the
conduit is provided with a short tube or nipple 19 having an outwardly opening
valve 20, said nipple. being adapted to be closed by a screw cap 21, which is
removable so as to permit the attachment of an air pump to the nipple 19), thereby
permitting the exhaustion of the air from the space 11 after the cover 18 is closed.
The space between the casing 15 and the outer walls of the exterior envelope of the
conduit is adapted to be filled up by a non-congealable liquid such as rosin oil, or the
like, after the cover 18 shall have been closed.
It will be noted that in the arrangement illustrated in the drawings the ends of
the ducts extend into the man-hole in a staggered position with respect to each
other, this arrangement permitting each duct to be provided at its upper surfaco
with a separate nipple and cap of the same character as that heretofore described
with reference to the cover 18 and for a similar purpose, namely, to permit the
exhaustion of the air from the ducts. A similar provision is made at 22 for the
exhaustion of air from the space between the exterior envelope of the conduit and
the exterior surface of the duct or ducts. I prefer in most instances to supplement
the ends of the several ducts with additional cap pieces, as illustrated in Figs. 6 and 7
of the drawings, these cap pieces corresponding to and fitting over the duct ends and
being provided with apertures closable by plugs 23, through which a body of paraffin
or other congealable waterproof substance may be forced so as to be compressed
tightly about the issuing wire or wires from the duct, thereby insuring the per-
manency of the vacuum in said duct while permitting the wires to issue from the
duct ends. It will be noted by reference to Fig. 6 that each of the cap pieces 24
is separately removable without disturbing its neighbour, so that any particular
duct may be operated upon by closing its end without interfering with its
neighbour.
The parts being constructed and arranged as described, the operation of my in

page_text: vention is as follows: the exterior envelope or casing of the underground conduit
having been located or installed in the ground in the manner described, and the
interior ducts inserted, the operator at the man-hole proceeds in any suitable manner
to insert within one or more of the ducts the conducting wires to be used for the two
adjacent sections of the conduit. These wires project from the ends of the ducts and
the caps are then placed in position, the wires led through them and the congealable
waterproof material, as paraffin or the like, is forced through the openings in said
caps by a suitable liquid force pump, so as to compact said material firmly around
the wires and hermetically seal the ends of the several ducts. The cap pieces are
then removed from the short tubes or nipples of the said ducts and from the short
tube or nipple 22, and by means of an air pump the air is withdrawn or exhausted
from all of the ducts and from the space surrounding them. The operator then closes
the door 18 and withdraws by means of the nipple the air from the space 14, where-
upon the cap piece 21 is screwed on and rosin oil, or the like, is poured into the
casing 15 so as to completely surround that portion of the underground conduit
which passes through the man-hole and cut off communication with the external
air. The cover 16 is then lowered and secured in place by the lock 17.
To gain access to the conduit at a subsequent time the operator unscrews the
plug 23, permitting the rosin oil to be drawn off, whereupon the doors 16 and 18 are
opened, thereby permitting any one of the ducts to be operated upon by the removal
of its appropriate cap piece, without disturbing any one of the other ducts in the
series and without admitting, air into said ducts or into the space surrounding them.
The appropriate manipulation having been gone through with in relation to any par-
ticular duct, its cap piece is again replaced and the duct exhausted and the man-hole
space closed as before. Should any accident happen whereby the integrity of the
external envelope of the conduit is destroyed, the opening 22 affords a means of
injecting into said space any appropriate liquid insulating material. I propose, how-
ever, to employ this expedient only in cases where some injury has happened to the
exterior envelope of the conduit, as I prefer for general practice to avail myself of a
vacuum within the annular space enclosed by said envelope.
Care must be taken during the installation of the conduit to tamp the surrounding
body of earth firmly and compactly about the external surface of the outer envelope,
so as to firmly and securely imbed the conduit within the ground in such mannor that
it shall not be liable to be forced out of aligninent by subsequent settling or by
excavation going on near it.
The second part of my invention relates to certain new and useful improvements in
devices for introducing electrical conductors into the conduits, and consists in the
novel construction and arrangement of parts illustrated on Sheet 3 of the accompanying
drawings, wherein,
Fig. S, Sheet 3, represents a plan view of my said improved device in the act of
introducing an electrical conductor into its duct or conduit, the latter being shown in
horizontal section.
Fig. 9, Sheet 3, represents a side elevation of the same, the conduit being shown in
vertical section; and
Fig. 10, Sheet 3, represents upon a reduced scale a longitudinal vertical section of
the feeding and straightening devices.
Similar numerals of reference indicate similar parts throughout the said three
views.
Referring to the drawings, 27 indicates a base plate upon which are erected stout
standards 28, 29, constituting the frame-work of the apparatus. Within this frame-
work is journaled the power wheel 30, adapted to be turned by the band crank 31 and
having upon its periphery cog teeth intermeshing with the cog teeth of the rollers 32, 33.
These rollers are likewise journaled in the frame-work so as to revolve freely therein,
and their cog teeth intermesh respectively with the cog teeth of the rollers 34, 35,
above them, said latter rollers being located in adjustable bearings consisting of the
slotted yoke 36, shoe 37 and adjusting screw 38.
The periphery or cylindrical surfaces of the rollers 32, 33, and 34, 35, are provided

page_text: with a coating of stout rubber, as indicated more clearly in Fig. 10. By means of
the adjusting screws 38 the upper rollers 34, 35, can be forced downwardly upon the
lower rollers 32, 33 so as to vary as desired the friction exerted upon the electrical
conductor they are adapted to feed, the amount of pressure varying to correspond
with the amount of friction which the conductor meets with in passing through the
particular conduit into which it is introduced.
At the forward end of the apparatus and proximate to the duct or conduit, as 39, to
be operated upon, is located a pair of straightening rolls 40, 41, having a groove of a
contour corresponding to the cylindrical surface of the conductor, and being provided
with pressure adjusting devices for the upper roll of like character to those described
with reference to the rollers 34, 35. Additional pairs of straightening rolls may be
provided for the wire and located at such points as experience shall demonstrate to be
desirable. One of such pairs of rolls 42, 43, I have illustrated as interposed between
the feed rollers.
The parts being constructed and arranged as described, the operation of this second
part of my invention is as follows:-
When it is desired to introduce an electrical conductor within its duct or conduit,
as 39, the apparatus is placed in front of said duct at the entrance thereof, for instance
at the man-hole into which the duct opens. The conductor, as 45, is introduced
between the rollers 32, 34, and by revolution of the hand winch 31 is fed forward by
said roliers through the straightening rolls 42, 43, the forward feed rollers 33, 35 and
the straightening rolls 40, 41 and into the duct 39. Before introduction into the duct
the electrical conductor is provided at its forward end with a guide shoe 44, preferably
screwed on the end of said conductor, as illustrated more fully in Fig. 9.
The guide
shoe is of an external diameter corresponding to the internal diameter of the duct,
and is conoidal at its forward end. The cylindrical sides of the shoe at its rear end
travel in contact with the inner surface at the duct and thereby prevent the wire or the
forward conoidal end of the shoe from striking against the duct and injuring it.
After the introduction of the electrical conductor into the duct, the pressure between
the feed rollers 32, 34, and 33, 35, is regulated to correspond to the amount of friction
necessary to project or propel the conductor entirely through the duct, and the
straightening rolls are likewise adjusted to straighten the wire and remove kinks and
irregularities therefrom before its entrance into the duct, care being taken however
that the pressure shall not be of such character as to injure the protective insulating
coating of the conductor. When the conductor reaches the opposite end of the duct
the shoe or cap 44 is removed and the conductor is then ready for use.
The third part of my invention relates to means for withdrawing an electrical con-
ductor or conductors from a inain conduit into a branch conduit. I have illustrated
this part of my invention as applied to a main conduit of the kind shown in Letters
Patent No. 1393 A.D. 1887 bearing date January 28, 1887 and consisting of a main
duct extending between man-holes and provided at its upper portion with a
supplemental duct for the reception of a hauling-through cable or rope adapted for
attachment to the electrical conductor, and having a trailing cable whereby, after being
drawn from one man-hole to another, it may be returned for attachment to a second
conductor.
The object of this third part of my present invention is to provide means for
drawing an electrical conductor or conductors from the main duct or conduit into and
through a branch duct or conduit leading to a house or other locality at either side of
the main conduit.
In the accompanying drawings, Sheet 4 illustrative of this part of my invention,
Fig. 11 represents in perspective the devices for manipulating the electrical conductors
in the main and branch conduits, and also in dotted lines in said figures illustrates a
sectional view of the main and branch conduits.
Fig. 12 represents a central longitudinal section of the branch conduit and a cross
section of the main conduit at their point of intersection, the hauling-through devices
of the branch conduit being shown in side elevation.
Similar numerals of reference indicate similar parts throughout the said two views.

page_text: or
Referring to the drawings, the main conduit consists of the main body portion or
duct proper 46, provided with the supplemental hauling-through conduit
chamber 47 with which it communicates by means of a longitudinal slot 48. Within
the supplemental chamber 47 is located the hauling-through cable 59, passing from
man-hole to man-hole, in the manner described in my patent above referred to. At 50
is represented a suitable means of attachment for one of the ends of an electrical
conductor as 51; and 52 indicates a trailing cable serving as a follower during the
progress of the electrical conductor from one man-liole to another, whereby the attach-
ment piece 50 and the cable 49 may be drawn back from the distant man-hole after
the electrical conductor has been drawn through the duct or conduit 46. As far as
described the arrangement and construction of parts and their mode of operation is
precisely similar to that set forth at length in my patent above referred to.
From point to point along the length of the main conduit 46 are located branch
conduits for serving buildings or other localities along the line. One of these branch
conduits is shown in the drawings, and consists of a main body portion 53 and a
supplemental hauling-through duct or chamber 9 communicating respectively with
the main body portion 46 and the hauling-through chamber 47 of the main conduit.
The supplemental duct or chamber 54 is of a size sufficient to receive a stout wire or
cable 55 having sufficient rigidity to remain straight while being passed into said duct
from the house end of the branch conduit. In practice I have found a No. + copper
wire well adapted to the purpose, although it will be evident that varying conditions
may require or permit greater or less size of wire for the purposes. At the end of
the wire 55, proximate to the main conduit, is connected in any suitable manner a
sliding piece 56, provided with a downwardly inclined dependent arm 57 having a
return bend 58 and preferably provided with a friction roller 59 for purposes herein-
after to be described. That portion of the depending arm 57 which projects within the
main body portion 46 of the main conduit is rounded off, as shown, upon its top and
sides, so as to avoid abrasion of the insulating covering of the electrical conductor
with which it comes in contact in the operation of the invention.
The operation is as follows: When it is desired to draw into the branch conduit 53
an electrical conductor said conductor is connected at one of the man-holes of the
main conduit line with the connection 50 preparatory to being drawn towards the next
man-hole, between which and the first is located the branch conduit to be served.
Before drawing the electrical conductor through the section of the main conduit
hetween the said man-holes, the sliding piece 56 is inserted at the house end of the
branch conduit and pushed inwardly by means of the rigid wire 55 or its equivalent
until the depending arm 57 is advanced to the position indicated in full lines in
Figs. 11 and 12, in which position the hooked portion 58 will be at the opposite side
of the longitudinal slot 48 connecting the main and supplemental ducts of the main
conduit. An electrical conductor, as 51 is now drawn through the main conduit in the
manner prescribed by my patent above referred to, until it passes the point of inter-
section of the branch and main conduits, as indicated in Fig. 11 of the drawings. In
passing the said point of intersection the electrical conductor drops upon the end of
the depending piece 57, and is protected from abrasion by the rounded surfaces of said
projecting piece upon which it rests. The sliding piece 56 and its depending arm 57
are thereupon withdrawn through the supplemental chamber 54 of the branch conduit and
the hooked portion 58 of the depending arm engages with the electrical conductor, thus
drawing it through the branch conduit in the manner indicated in dotted lines in Fig. 11,
the conductor being drawn through in the form of a loop, as indicated in said figure,
and during its progress through the branch conduit 53 being protected from abrasion
by means of the friction roller 59. When the loop has been drawn entirely through
the branch conduit it may either be severed at the house end of said branch conduit
and that portion which is connected with the piece 50 drawn back and out through the
main conduit by means of the hauling-through cable; or before severing the inner
end of the loop, said end may be retained in engagement with the hook 58 of the
depending arm, and by means of the hauling-through cable 49 the conductor may then
be drawn onward to the next man-hole; whereupon the loop may be severed as before

page_text: and the work inserted between the severed portions of the loop, both portions of the
loop in this instance remaining in the branch conduit.
I prefer before drawing the loop into the branch pipe to carry the electrical con-
ductor for some distance beyond the point of intersection of the branch and main
conduits, so as to leave a sufficient length of conductor beyond said point of intersec-
tion to readily form one side of said loop. In forming the loop the connecting piece 50
and the hauling-through cable 49 will be preferably drawn back, thereby lessening the
strain on the conductor and the arm 58. It is apparent that by fixing the hauling-
through cable rigidly this retrograde movement thereof might be prevented and the
loop formed entirely from that portion of the electrical conductor Between the mouth
of the branch conduit and the initial man-hole; but for most purposes the friction
occasioned by this mode of operation would be undesirable.
It is evident that instead of attaching the electrical conductor to the connecting
piece 50 an ordinary rope might be attached thereto of a length corresponding to the
length of the branch conduit. By this expedient should it be desired merely to leave
a single wire in the branch conduit without return the expense of the severed portion
.in those instances where the wire is connected directly to the piece 50 would be
avoided.
Having now particularly described and ascertained the nature of my said Inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :
1. An underground conduit consisting of a series of isolated sections, each section
extending from one man-hole to an adjacent man-holo in the system, and provided
with ducts containing electrical conductors extending through the opposite ends of
said ducts, said ducts being hermetically sealed at both ends and provided with taps for
the attachment of an exhaust pump; substantially as and for the purposes described.
2. An underground conduit consisting of an exterior casing and an interior duct or
ducts separated therefrom by an intervening space, said intervening space and the ducts
or ducts themselves being under exhaustion, substantially as described.
3. In an underground conduit, the combination with a man-hole, of an external
casing forming a part of said conduit and extending within the man-hole, and a duct
or ducts projecting beyond said casing, each duct or ducts being provided with an air
exhaust port, substantially as described.
4. In an
underground conduit, the combination with a man-hole, of ducts extending
within said man-hole in a staggard relation one to the other, cach duct being provided
with an air exhaust port, substantially as described.
5. In an underground conduit, a duct having an interior coating of mineral paint
and an exterior coating of asphaltum, substantially as described.
6. In an underground conduit, a duct having an interior coating of mineral paint,
substantially as described.
7. In an underground conduit, the combination with a duct having its end perforated
for the passage of a conducting wire, of a cap fitting said end, said cap being provided
with a filling aperture whereby a congealable waterproof liquid may be inserted,
substantially as described.
8. In an underground conduit, the combination with a duct, of an air exhaust port
therefore, consisting of a nipple, a valve within said nipple and a removable cap,
substantially as described.
9. In an underground conduit, an exterior casing consisting of a series of sub-
divisions having abutting ends connected by dowel pins, a coating of paper surround-
ing said ends, a sleeve having an internal circumferential groove and having a filling
aperture whereby a congealable waterproof material may be forced within said groove,
substantially as described.
10. In an underground conduit, the combination with a man-hole, of ducts leading
into said man-hole, an exterior casing having at the man-hole a hinged top and a
second casing adapted to contain a liquid, the ducts and the space about them being
under exhaustion, substantially as described.

page_text: 11. In an underground conduit, the combination with a man-hole, of ducts
extending within said man-hole each duct being provided with an air exhaust port, an
exterior casing for said ducts, separated therefrom by an intervening space and
extending within the man-holo said casing being provided with an air exhaust port, a
door for said casing, said door being provided with an air exhaust port, and a second
casing surrounding the first, within the man-hole, and adapted to contain a liquid,
substantially as described.
12. In an underground conduit, the combination with a man-hole, of ducts
extending within said man-hole, cach duct being provided with an air exhaust port,
an exterior casing for said ducis, separated therefrom by an intervening space and
extending within the man-hole, said casing being provided with an air exhaust port, a
door for said casing, said door being provided with an air exhaust port, and a second
casing surrounding the first, within the man-hole, and adapted to contain a liquid, said
second casing being provided with a closing door, and an outlet opening, substantially
as described.
13. In an underground conduit, the combination with a man-hole, of a series of
ducts extending within said man-hole, each duct being provided with an air exhaust
port and with a separate cap piece, said cap piece having an opening for the insertion
of a congealable liquid, substantially as described.
14. An apparatus for feeding electrical conductors into their ducts or conduits,
consisting of a suitable frame, feed rollers mounted in said frame and straightening
rolls, said straightening rolls being grooved for the reception of the electrical conductor,
substantially as described.
15. An apparatus for feeding electrical conductors into their ducts or conduits,
consisting of a suitable frame, two pairs of feed rollers mounted therein, one in
advance of the other, a cog wheel provided with an operating winch connecting said
pairs of feed rollers, and straightening rolls, said straightening rolls being grooved for
the reception of the electrical conductor, substantially as described.
16. An apparatus for feeding electrical conductors into their ducts or conduits,
consisting of a suitable frame, and feed rollers mounted in said frame, the said feed
rollers being provided with an outer layer of rubber and being adjustable with relation
to each other, substantially as described.
17. An apparatus for feeding electrical conductors into their ducts or conduits,
consisting of a suitable frame, feed rollers mounted in said frame, the said feed rollers
being provided with an outer layer of rubber and being adjustable with relation to
each other, and straightening rolls, said straightening rolls being grooved for the
reception of the electrical conductor and being adjustable with relation to each other,
substantially as described.
18. An apparatus for feeding electrical conductors into their ducts or conduits,
consisting of a suitable frame, two pairs of feed rollers mounted in said frame, one
located in advance of the other, provided with an outer layer of rubber, a cog wheel
provided with an operating winch connecting said pairs of feed rollers, straightening
rolls interposed between the feed roilers, and straightening rolls located in front of
both pairs of feed rollers, substantially as described.
19. An apparatus for feeding electrical conductors into their ducts or conduits,
consisting of a suitable frame, two pairs of feed rollers mounted in said frame, one
located in advance of the other, provided with an outer layer of rubber, a cog wheel
provided with an operating winch connecting said pairs of feed rollers, straightening
rolls interposed between the feed rollers, and straightening rolls located in front of
both pairs of feed rollers, the feed rollers and the straightening rolls being respectively
adjustable with relation to each other and the straightening rolls being grooved
for the reception of the electrical conductor, substantially as described.
20. The combination with the duct 13 and the electrical conductor, of a shoe for
said electrical conductor, said shoe being of larger diameter than the electrical con-
ductor and fitting the interior of the duct, substantially as described.
21. The combination with a main conduit for electrical conductors, of a branch
conduit and a travelling grapple or hook located within said branch conduit, and a

page_text: way for supporting said grapple or hook during its forward and backward movements,
substantially as described.
22. The combination with a main conduit, of a branch conduit extending therefrom,
said main and branch conduits being each provided with a supplemental duct or
chamber, a hauling-through cable located in the supplemental duct of the main conduit,
a hauling-through wire located in the supplemental duct of the branch conduit and a
hook or grapple connected to the end of said wire, substantially as described.
23. The combination with a main conduit, of a branch conduit extending therefrom,
said main and branch conduits being each provided with a supplemental duct or
chamber, a hauling-through cable located in the supplemental duct of the main
conduit, a hauling-through wire located in the supplemental duct of the branch
conduit and a hook or grapple connected to the end of said wire, said hook or grapple
having rounded surfaces so as to prevent abrasion of the insulating covering of the
electrical conductors, substantially as described.
24. The combination with a main conduit, of a branch conduit extending therefrom,
said main and branch conduits being each provided with a supplemental duct or
chamber, a hauling-through cable located in the supplemental duct of the main
conduit, a hauling-through wire located in the supplemental duct of the branch
conduit, a hook or grapple connected to the end of said wire, said hook or grapple
having rounded surfaces so as to prevent abrasion of the insulating covering of the
electrical conductors, and a friction roller at the outer end of said hook or grapple,
substantially as described.
25. The combination with the main conduit 46, having supplemental chamber 47,
of a branch conduit 53, having supplemental chamber 54, a hauling-through cable 49
located within the supplemental chamber 47, attachment piece 50 connected to said
hauling-through cable, trailing rope 52 connected with said attachment piece and
located within the supplemental chamber 47, and a wire 55 and sliding piece 56
located within the supplemental chamber 54, said sliding piece 56 having a depending
arm 57 terminating in a hook-shaped projection 58, substantially as described.
26. The combination with the main conduit 46, having supplemental chamber 47,
of a branch conduit 53, having supplemental chamber 54, a hauling-through cable 49,
its attachment piece 50, a trailing rope 52, wire 55 and sliding piece 56, having a
dependent arm 57 terminating in a hook-shaped projection 58, said hook-shaped
projection having rounded surfaces and being provided with a friction roller 59,
substantially as described.
Dated this 22nd day of April 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.