Improvements in Underground Conduit Systems Conductors
Year: 1889

page_text: Date of Application, 23rd Nov., 1889-Accepted, 25th Jan., 1890
COMPLETE SPECIFICATION.
Improvements in Underground Conduit Systems
Conductors."
"for Electric
I, SYDNEY PITT, of Sutton, in the County of Surrey, Gentleman, (a communica-
tion to me from abroad by William Hampden Johnstone, of Philadelphia, Pennsyl-
vania, U.S.A., Gentleman,) 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 a system of underground distribution of wires for
telegraphy, telephony, electric lighting and for all the purposes for which electricity
may be applied. The invention comprehends certain improvements in the construc-
tion of the conduit whereby proper ducts are provided in a practical and convenient
manner, and whereby at hand holes or distributing boxes a large number of exterior
ducts may readily be reached for the purpose of making lateral connection and
distribution for consumption circuits: Also certain improvements at the hand holes
or distributing boxes whereby all the cables may readily be reached, connections
made and the lateral wires conveniently carried out through the lateral spigot
openings. Subways constructed in accordance with these improvements may at the
intersection of streets or other suitable points connect with large man-holes, from.
which such subways may radiate in various directions. The system herein described
has the advantage of being capable of being manipulated so that all of the conductors
at any point in the length of the conduit may readily be reached for connection,
inspection, repair or testing. All the features of the invention will, however, be
plain from the following specification and accompanying drawings.
Figure 1 is a view partly in section, and partly in side elevation of a portion of
a subway built according to my invention.
Figure 2 is a plan view of the same.
Figure 3 a transverse section on a line 3, 3, of Figure 1;
Figure 4 a like section on the line 4, 4, of Figure 1; and
Figure 5 a detached view of a portion of one of the channel iron shelves which
form the interior ducts of the conduit.
In the organization shown in these figures the conduit is formed by upper and
lower half-sections A, B, which are laid one upon the other, so as to break joints as
indicated plainly in Figure 1. The upper and lower sections have interlocking
joints as indicated at a, and these joints are preferably leaded, puttied or cemented.
The sections are bolted together by means of lugs b, midway of the length of one
section which come opposite lugs 6 at the end of an opposite section, and to give
increased strength and to afford means for a proper joint, one end of a section either
upper or lower is formed with a flare or half bell mouth 62, and the opposite end with
a narrow bead or flange ³. The joint thus formed may be calked. In this way a
strong and durable structure is formed and as the sections are made in comparatively
short lengths, the top sections can readily be removed to afford access to the interior.
The interior ducts Cin which the cables lie are formed of channel iron c, of suitable
length, laid in as indicated in Figures 3 and 4, that is, the bottom layer is laid in
with the sides standing upwardly. A horizontal partition D of wood preferably
creosoted, is then laid across the edges of the channel iron thus forming the four
lower ducts; other channel irons are laid upon the partition with their sides extending
downward, thus forming the next four ducts; the third row is now laid directly on
top of the second the flanges projecting upwardly, and a partition D of wood, is
interposed between their edges and the edges of the channel irons forming the top
row of ducts. Channel iron of this description may be rolled from relatively light
metal and when placed in position in the manner describel, even continuous ducts
are formed into which the wires or cables may be threaded in ordinary ways.
At

page_text: such suitable intervals as may be desired handholes or distribution boxes are provided
in the following manner. An upper section A is formed with an opening surrounded
by a grooved flange A' and closed by a cover A² held in place by suitable bolts. On
either one or both sides the upper and lower sections are formed with openings
preferably of semi-circular or semi-elliptical shape. The openings in the upper and
lower sections coincide. These half openings are indicated by the letter E in the
drawing and are formed by a projecting flare or half bell-mouth e, having at its edge
a small flange or bead. Such an opening is normally (that is when no lateral
connections are carried out at this point) closed by two correspondingly shaped half
plates E¹ which embrace the beads on the edges of the part e and are bolted together
in the middle by means of their flanged edges e'. When provision is to be made
for lateral connections the plates E' are removed and replaced by a spigot F formed
in halves clamped together at f and embracing the parts e in the same manner that
the half plates E' do. At such band-holes or distribution boxes the wooden partitions D
instead of being continuous may be formed of slats which afford lateral passage ways d
for carrying the conductors out laterally through the spigot mouth F. Or instead
of leaving such openings d, the wooden partition may be grooved as indicated at d¹
in any desired places for the same purpose. With such an organization as I have
described by removing one or more of the top sections the channel iron shelves may
be so manipulated as to be removed and all the conductors within the conduit exposed
as is well understood by those skilled in the art. Those channel irons located just
at the openings E may have their sides cut out so that the cables lying therein
would be readily accessible from the opening. And those channel irons at the top
may have their backs cut out so that the conductors lying therein will be accessible
upon the removal of the cover A².
Figure 6 is a view partly in side elevation and partly in section of a similar
conduit baving a different arrangement of shelves and also varying in some details of
construction.
Figure 7 is a view partly in plan and partly in section of the same matter;
. Figure 8 a transverse section on the line 8, S, of Figure 6;
Figure 9 a transverse section on the line 9, 9, of Figure 6.
The upper and lower sections A B are laid to break joints and are secured
together at b, that is to say, opposite lugs have passed through them a bolt
through the slotted end of which a transverse key is driven. In this instance, an
eliptical hand hole closed by a suitable cover A2 is provided; spigot mouths or
lateral openings E which may be normally closed as before described, are also shown.
The ducts are however formed in a somewhat different manner, that is to say, the
interior sidewalls of the upper and lower sections are formed with projecting lugs or
ledges and the interior or the bottom of the lower section is preferably provided
with longitudinal grooves y. The shelves consist of horizontal partitions G supported
upon the ledges or lugs and having one, two or more parallel projections or flanges
standing out at right angles. Such flanges or vertical partitions g of one horizontal
partition are seated in longitudinal recesses in the face of an adjoining partition G.
And the flanges g of the bottom partition are seated in the longitudinal recesses y in
the bottom of the conduit. The flanges or vertical partitions g might be made
separate from the horizontal partitions G as indicated at the outer part of Figure 8
where they are shown as seated in longitudinal sockets in the top section of the
conduit and the upper partition G. Such vertical partitions may then readily be slid
into place endwise after the other parts are set up. In order to provide a means
whereby access may he had to all the conductors in the conduit through the hand
holes I adopt the following plan.
'
The shelves G on each side, of the hand hole are made of such length that they
terminate at z, just before reaching, the edge of the hand-hole. The horizontal
distance between the points is bridged by a series of shelves each divided into three
relatively short lengths G. G2, G3, the centre sections G2 are immediately under the
hand hole opening and are of such length that they may be disengaged from the
conductors in the ducts and lifted out through the hand hole. A section G' or G³
. "

page_text: may then be shifted endwise, until it is directly under the hand-hole, and similarly
disengaged from the conductors and lifted out. To permit of the withdrawal of
the shelves from the hand holes they are split longitudinally at G4, each short
length G1, G2, G3, being composed of two parts. They might be further divided both
longitudinally and transversely if desired. In order to permit of the distribution of
the wires from all the ducts at such a hand-hole 1 perforate the shelves-G at g¹, and
coincident with these perforations I form transverse recesses g² in the vertical
partitions g. Wires from cables lying in the ducts may be passed through such per-
forations and recesses up to the open space just under the hand hole cover and then
carried laterally to the lateral openings E, which may be provided on one or both
sides as before described. The openings gl might be elongated and the recesses g
made relatively wider to avoid any possibility of the conductor being sheared or cut
off by the "creeping" of the conduit. In this construction the side ducts are more
readily accessible from the band hole and openings E. The cables or conductors for
distribution may therefore be located in these ducts, while the through or trunk lines
may be located in the interior ducts.
In the organization shown in Figures 1 to 5 the channel irons forming the ducts
may be cut into short lengths in the same manner that the horizontal partitions are in
Figures 6 to 9, and the same results obtained that follow the use of the short shelves
shown in the latter figures. Of course it is to be understood that the number of ducts
may be either increased or decreased by changing the partitioning according to the
requirements of the system, and any suitable number of openings E normally closed
by half plates may be provided and opened for lateral connections when desired, in
the manner described.
Figure 10 is a view partly in elevation and partly in section of another form of
conduit constructed according to my invention:
-
Figure 11 a plan of the same; and
Figure 12 a transverse section on the line 12, 12, of Figure 10.
In this arrangement the upper and lower sections A B are laid so as to break joints
as before described, the sections being clamped together by hook bolts b, passing
through lugs b on the upper section the hooked end engaging a flange or lug on the
lower section and the parts being clamped together by a nut on the upper end of the
bolt. These sections A B as indicated by the drawing have in transverse section
fluted or scalloped exteriors produced by the conformation of the walls to provide
circular ducts. The upper sections are wider than the lower ones, there being four
ducts at the top and three at the bottom. Partitions H formed with three longitudinal
recesses on the under face to form the upper walls of the three lower ducts are seated
or supported upon the lower sections, as shown. The partition is similarly formed
with four curves or depressions in its upper face to complete the four upper ducts.
The partition H is cast and is preferably so shaped as to reduce the amount of metal
to a minimum. Side spigots for lateral connection are shown upon one side, but
they may be provided also for the opposite side of each hand hole. By the removal
of the cover A2 the entire upper row of ducts is fully exposed and connections may
readily be made and carried laterally through the spigot on either side. The two side
ducts adjoining a spigot are of course accessible from the spigot opening. With
such an arrangement as this it is obvious that all the ducts except the central bottom
duct may be used for distribution. By adopting the plan described in connection
with both of the modifications above referred to and shown especially in Figures 6
to 9, that is, of having short shelves longitudinally divided the bottom;ducts may also
be reached from the top if desired. In other words the partition H which is shown
in Figure 12 as solid transversely, may be divided longitudinally and may at the
handholes be divided into short-lengths.
In Figures 13, 14 and 15 I have shown an arrangement more especially intended
to be laid beneath sidewalks:
Figure 13 is a transverse section ;
Figure 14 a similar view; and

page_text: In this instance the conduit is formed of sides, top and bottom plates or sections I,
secured together at the corners by means of locking keys and a construction perfectly
obvious from the drawing. The side section upon one or both sides may be cast with
longitudinal recesses K which form ducts, in which conductors for distribution are to
be located. These deep corrugations which form the ducts serve to strengthen the
side walls of the conduit. In Figure 13 only one side is shown so constructed. In
Figure 14 both sides are formed with distribution ducts. The interior of the conduit
is divided in the manner described in connection with Figures 6 to 9 into ducts which
serve for trunk or through lines. The horizontal partitions G by being tilted side-
ways may be readily dropped into place. At points where lateral connections are to
be made the side wall of the conduit is formed with a small spigot opening K
opposite each duct. These openings are normally closed by screw caps as shown.
When lateral connections are to be made the wires are brought out through pipes K²
leading from the spigot openings and suitably secured therein. Of course instead of
providing the small spigots-one for each duct one large lateral spigot communi-
cating with all the distribution ducts upon that side may be used, but I prefer the
arrangement shown as it affords no opportunity for the displacement of the wires, and
the bringing of the lateral connections out through the small spigot openings will not
interfere with the threading of additional conductors into the ducts.
Figure 16 is a general view of a conduit system in which my improvements may be
embodied. Only a general reference to this Figure is required. It shows a man-
hole O, conduits 01, 02 running therefrom. At 0³ the conduit is broken away, the
cover of a hand hole is removed and connections are shown carried out laterally for a
street light. Similarly conductors could be carried laterally into buildings for power,
light telegraphy or telephony.
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. In a conduit system the arrangement of short shelves in connection with the
hand hole, substantially as described.
2. The arrangement of short shelves longitudinally divided so that two or more
shelves occupy the width of the conduit.
3. The arrangement of shelves or partitions at the hand holes whereby apertures or
passage ways are provided through which the conductors are led for lateral connections,
substantially as described.
4. The combination with the hand holes section, of the openings E E normally
closed by divided or half-plates and adapted to receive a spigot for lateral
connections.
5. The combination with the conduit sections of the channel iron ducts, substantially
as described.
6. The combination, with the conduit sections of the channel iron ducts and wooden
partitions between the same, substantially as and for the purpose set forth.
7. The underground conduit system, substantially as shown and described in
Figures 1 to 5.
8. The underground conduit system, substantially as shown and described in
Figures 6 to 9.
9. The underground conduit system, substantially as shown and described in
Figures 10 to 12.
10. The herein described conduit system shown in Figures 13 to 15 comprising
side plates formed with recesses or corrugations constituting distributing ducts and
having the interior ducts formed by suitable shelving.
Dated this 19th day of November 1889.
S. PITT.