Improvements in Conduits or Casings for Subterranean Electric Lines.
Year: 1889

page_text: Date of Application, 3rd Dec., 1889
Complete Specification Left, 3rd Sept., 1890-Accepted, 3rd Dec., 1890
PROVISIONAL SPECIFICATION.
Improvements in Conduits or Casings for Subterranean
Electric Lines.
I, FRANZ ZÖPKE, Electrician, of Berlin, Wilhelm Strasse 96, do hereby declare
the nature of this invention to be as follows:-
This invention relates to improvements in casings for subterranean electric lines
and has for its object to provide conduits or casings which shall protect the conductors
enclosed therein (particularly if they consist of bare bars of copper) against injury
"short
by water, and shall also prevent the line "making earth" or becoming
circuited."
The conduits or casings may be made either of clay or stoneware, or of
asphalte.
A clay or stoneware conduit or casing embodying this invention consists of a
lower part or base and a cover which when fitted together present in cross section
the shape of an oblong quadrangle with the corners rounded off or the outline may
be oval or nearly so.
There may be one or more channels each for enclosing one conductor and each
channel is approximately circular having two shoulders or ribs projecting into its
interior for a purpose presently to be set forth. The surfaces of the two parts of the
conduit are corrugated or grooved between the channels so that when placed
together they will produce a better joint and the ends of the parts or lengths of
which a conduit consists are also corrugated for the same purpose.
The shoulders ribs or projections at the bottom of each channel serve to hold
in position or clamp insulators preferably made of porcelain which support the
conductors.
In laying down such conduits the bottom part or base is first put in position,
the insulators are inserted and the conductor or conductors are placed thereon and
lengths forming the cover or top placed over these so as to "break joint" with the
lengths forming the bases. The surfaces of contact of the lengths of which the .
conduit consists and of the top and base are united by some waterproof cement, say
asphalt, or water glass. All the parts of the conduit are preferably glazed both
inside and out so that the whole is entirely waterproof.
Where branches or secondary circuits are to be connected with the line a cover is
provided which has on its upper surface channels similar to those in the base but
at a suitable angle to the latter and holes pass from the channels in the cover to
those in the base through which connection is made for the line. A cover or top
piece of suitable shape being provided to close the upper channels.
To facilitate examination of the line and for similar purposes manholes are
provided at suitable places. They are sunk in the ground to a suitable depth and
preferably lined with cast iron. The line is laid with a slight fall towards these
manholes and in the bottom of the latter receivers are placed which communicate
with the channels so that any water condensing in the conduit flows to these
receivers and is from time to time drawn off by pipes in the latter.
If the conduit is to be made of asphalt the parts may be moulded and when
laid united by heating the edges as will be readily understood I may however
produce an asphalt conduit embodying my invention as follows:-
The trench for the line is made and a layer of asphalt of suitable thickness and
width laid down thereon. Into the asphalt are introduced lengths of clay or
stoneware tubes or blocks forming the lower part of one or more channels such as
herein above described and after insertion of the conductor or conductors are
covered with suitable top pieces and the whole is then laid over with a suitable
I

page_text: thickness of asphalt which is then treated in the usual manner so that the channels
are enclosed in a solid thickness of asphalt.
It is preferable to ventilate the entire conduit by connecting one end thereof
with a fan or blower so that any noxious gases may be continuously exhausted
therefrom.
Dated this 2nd dose of Daromhan 1000
BERNHARD DUKES,
226, High Holborn, London, W.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Conduits or Casings for Subterranean
Electric Lines.
I, FRANZ ZÖPKE, Electrician, of Berlin, German Empire, 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 :-
This invention relates to conduits or casings for clectric lines which shall protect
the conductors enclosed therein (particularly if they consist of bare bars of copper)
against injury by water and shall also prevent the line making earth or becoming
short-circuited.
The accompanying drawings illustrate this invention and show in:
Fig. 1 a perspective view of a portion of this conduit or casing. They are made
of clay glazed within and without and therefore impervious to water. Two such
pieces laid one upon another form one, two or more channels a a¹ a² and to make a
better joint, grooves or corrugations b¹ are provided as shewn in Fig. 3, and filled,
when the conduit is laid down with a suitable waterproof binding material such for
instance as water glass, asphalte, and the like. The ends of the pieces or boxes are
similarly made with grooves or corrugations c and as will be seen in Fig. 1 they are
preferably so placed as to "break joint" for the sake of greater security against
pressure from above. The channels a a¹ a² have projections or flanges d d' d' extending
along their entire length which retain insulators of say porcelain shewn in Fig. 3.
Each of the insulators supports a conductor, copper bars K being shewn in the
drawings.
For branches the arrangement shewn in Fig. 2 is employed. A piece A of the
shape here shewn is substituted for the cover and has a channel or channels like the
other portions of the conduit but running at the desired angle to the main line. At
the point of intersection of two channels, holes m m' are provided where short
connecting bars or bead joints may be provided for connecting the upper portion of
the line with the lower or main line. A cover D similar in construction to that for
the main line is employed to cover the branch. Similar means serve to connect main
lines and loop lines or circuits. To allow inspection and to facilitate other operations
such as measurements" manholes" preferably of cast iron and made as illustrated in
Fig. 4 are provided where requisite. These may receive that portion of the lines
where two lines join or cross one another and into the manholes stoneware jars B B¹
are also placed. Short extensions e el connect the jars with the conduit and serve as
catch-basins for the water condensing in the conduits it being obviously requisite to
give a certain amount of fall towards the jars to the conduits. The water of
condensation can consequently neither produce an "earth" in the line nor short
circuit the conductors. System tubes f,fallow withdrawal of the water from the jars
when the lid and cover plate E are removed.
Instead of earthenware asphalte may be used in making the conduits. In this case
they are pressed from powdered asphalte in hot moulds and when laid the conduit is
closed at the edges by the application of hot irons.
Instead of making the conduit in pieces and laying the parts down the whole
conduit may be moulded and laid "in situ." In this case a trench is dug and a layer
of asphalte of suitable thickness and width laid on the bottom of the trench. Into

page_text: this layer of asphalte are laid suitable half tubes or simple bottom bars. When the
conductors have been placed into the half tubes or upon the bottom plates, corresponding
half tubes or cover pieces of inverted U-shape are laid over the same and asphalte
(or other such material) is poured over the whole and consolidated so as to form a
solid homogenous conduit which may contain any suitable number of channels. This
dispenses with the necessity for making the joints tight as the layer of asphalt
hermetically encloses all the conduits.
To prevent the accumulation of gases in the conduit a ventilator is applied, say at
the end in the engine house, and suitable vents are provided where required so that
the ventilator drives in fresh air and expels the foul gases.
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. Conduits or casings for electric lines of the form shewn in Figs. 1 to 3 and
constructed of earthenware or of asphaltum or the like as set for electric lines.
2. In conduits or casings for electric lines the insertion of the arrangements
described with reference to and shown in Fig. 4.
Dated this 2nd day of September 1890.
BERNHARD DUKES,
226, High Holborn, London, W.C., Agent for the Applicant.