Improvements connected with Tubular Electric Conductors.
Year: 1892

page_text: Date of Application, 27th May, 1892
Complete Specification Left, 27th Feb., 1893-Accepted, 6th May. 1893
PROVISIONAL SPECIFICATION.
Improvements connected with Tubular Electric Conductors.
ERNEST PAYNE Albany Buildings, 39 Victoria Street Westminster, London,
S.W. Electrical Engineer do hereby declare the nature of this invention to be
as follows:-
This invention relates to improvements in a system of tubular electric conductors
and fittings of which I was part inventor and for which a Patent was granted
No. 17402 1890 entitled "Improvements in and connected with Electrical
Conductors and Fittings combined therewith." The conductors in this system are
arranged on the concentric principle and kept apart by rings or by studs of non-
inflammable insulating material. The inner conductor may be tubular or solid
and is prevented, from touching the outer conductor which surrounds it by means
of insulating rings or studs, which I will call the inner rings or inner studs, these
may be enclosed in a third tube, forming a guard or mechanical protection, carrying
no current and prevented from touching the outer conductor by means of rings or of
studs which I will call the outer rings or the outer studs. When rings are employed
they are placed at suitable intervals along the conductors, when studs are employed
they are fitted into small holes made in the conductors. When I employ tubular
conductors composed of metal strips drawn through dies and not brazed or other-
wise joined at their edges, I make use of the following method of fixing the rings
to the outer conductor, so that the inner conductor may be drawn freely in and out
without disturbing either the inner or the outer rings. I make the inner rings with
their outside diameter either equal to or slightly larger than the inside diameter of
the outer rings; and I sometimes make the inner rings with one end slightly
larger than the other. I proceed thus to fix the rings to the conductor. I first
push in an inner ring, the larger end first, next I slide on an outer ring until it fits
tightly close to the first, lastly I push a second inner ring into the conductor, the
small end first. Thus the inner rings force the metal outwards and hold the outer
ring firmly in position between them. I sometimes employ another method of
fixing the rings. I make the inner ring with a projecting portion or rib on the
outside which projects through a gap between the adjacent edges of the strip
forming the tubular conductor. Then in the case where the inner rings are fixed
to the inner conductor the projection prevents the outer ring from slipping along or
down as the case may be and when the outer ring is fixed to the onter conductor the
projection rests against it and keeps the inner ring in position. This projection
may be on the inside of the outer ring and project inwards through the gap between
the adjacent edges of the conductor and thus fulfil the same purpose.
To prevent a general earthing of the system if an accidental contact occurs
between the conductors and the guard or protecting tube I employ flanges or rings
of insulating material at the points where the conductors are fixed into the junction-
supports. And to prevent the tubes from turning round or coming out of the
junction support or box I make these flanges with slots or grooves on the inside and
I make the tubes with small projections at the ends which fit into and slide in these
grooves or slots. This allows the tubes to contract or expand without breaking
the flanges.
In order to avoid the use of set screws and screwed flanges at the points where
the tubes enter the junction-boxes I make these boxes with small projecting pins
or tongues which may project from the top bottom or sides of the boxes inwards,
and fit into holes or slots at the ends of the tubes.
I also make the junction-supports or junction-boxes with a base plate and two or
more projecting legs fixed to the base for supporting the sides and cover of the

page_text: box and I make these legs separately so that any number can be fixed to the base
plate. And I sometimes cast these legs with zinc or other suitable metal and with
holes in them to receive the screws for supporting the sides and cover above
mentioned. The screwthreads may be cast in the holes by means of screwed
pieces of metal fixed into the mould before the melted metal is poured in or small
blocks of suitable metal may be first drilled and tapped and then placed into the
mould before the melted metal is poured in.
When making joints in the conductors the are sometimes fitted into holes made
in flat pieces of metal after the manner of a flange. And for preparing the ends
of the tubes for fitting into these pieces I sometimes use a special tool. This tool
is composed of one or more cutting levers fitted round a mandril that can be
inserted into the end of a tube so that small slits can be made at the end of the
tube about one eighth of an inch deep and alternate portions of metal set up and
set down; the end of the tube, thus prepared, is inserted into the hole in the flat
strip, above mentioned, the projecting parts, set down by the tool are then turned
up on the outer face of the strip thus holding it firmly in position.
I also make this tool with a hollow or tubular mandril arranging the cutting
parts on the inside. The conductor, the ends of which are to be prepared for
fitting into the flange, is inserted inside the mandril, the levers cutting outwards,
thus effecting the same result as above described.
When a tube that has been brazed or otherwise joined up, is used for the outer
conductor the inner rings cannot always be conveniently fixed to it; I then keep
the inner rings in position by slightly Hattening the inner conductor on either side
of the rings. Or with tubular conductors I keep the rings in position by pushing in
small plugs of cylindrical form and of any suitable material on either side of the rings
the plugs force the tube outwards slightly increasing the diameter and preventing
the rings from slipping out of position in a manner similar to that already described
for fixing the inner and outer rings to the outer conductor.
For subdividing the current I sometimes make the outer conductor of two or
more strips of metal using rings with ribs as above described to keep the strips
apart the ribs being two or more in number on each ring. I then fix the inner
and outer rings to these strips in the manner already described for fixing the
inner and outer rings both to the outer conductor.
Dated this 26th day of May 1892.
COMPLETE SPECIFICATION.
Improvements connected with Tubular Electric Conductors.
ERNEST PAYNE Albany Buildings 39 Victoria Street Westminster, London
S.W. Electrical Engineer, 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 improvements connected with electric conductors when
they are enclosed in tubes or hollow casings especially as to the methods of
insulating, subdividing and jointing such conductors.
When I employ a metal strip, as a conductor, drawn into tubular form but not
brazed or soldered at the edges I fix insulators to this strip at intervals; and these
insulators which are made preferably of non-inflammable material, may be provided
with grooves or holes into which or through which other conductors of any suitable
form may
be placed or drawn without disturbing the insulators from their positions.
I employ two forms of insulators in combination, one in the shape of a ring pushed
on outside the tubular conductor and the second in the form of a disc pushed inside
the tubular conductor. The outside diameter of a disc is of such a size that when
it is pushed into the tubular strip the outer ring-shaped insulator cannot be pushed

page_text: along the strip over the place where the disc has been pushed inside. By pushing
in first a disc inside, next a ring outside and lastly another disc inside, the three
insulators are held firmly in position by their mutual inward and outward pressure
against the metal strip. In this manner any number of insulators can be fixed to a
tubular strip at suitable intervals after which the strip may be pushed into a tube
or placed in a hollow casing.
This method of fixing the insulators to tubular strips is illustrated in Figures 1, 2, 5
and 6.
In Figure 1 the tubular strip B has inner discs D, D, and outer rings E attached
to it at intervals in the manner above described; an additional conductor A being
afterwards passed through holes in the discs as above mentioned, and the whole
enclosed in a tube C.
Two curved strips B, B, are shown in Figure 5 with discs D and rings E
attached to them. The inner insulator or disc D has projections, P Figure 6, to
prevent the strips from coming in contact.
For subdividing the current I use a number of separate wires, rods or strips of
any suitable section and place two or more round the periphery of a disc fixing the
insulators in the manner already described.
The discs or rings may be provided with projections on the outside or inside
surfaces respectively to keep the conductors apart.
In Figures 3 and 4, four wires B, B, are shown with inner and outer insulators D
and E fixed along them at intervals. The wires and insulators together are then
pushed into the outside tube C, through which the rings E will slide freely.
In the case of large conductors as for instance those employed as vertical mains
in large buildings, I sometimes employ a disc with projections round the periphery
and fix them first to a conductor by any suitable method the projections prevent the
outer rings from passing along or slipping down, which are placed outside the
conductors to prevent them from coming in contact with the outer protecting tube
or hollow casing. The projections may be on the inner surface of the outer rings
in which case they will project inwards between the conductors and rest on the
discs. If the outer rings are first fixed in position then the discs will rest upon the
rings.
This arrangement is shown in Figures 7 and 8.
The insulators D and E are first threaded on to the conductor B, the inner
conductor A is then passed through the holes in the inner discs D.
A small pin, O, is shown in the Figures 7 and 8 to prevent the inner discs from
slipping along or down as above mentioned. The outer rings E rest against or
upon the projecting part P on the disc. The whole is enclosed in the outer
tube C.
To prevent a general earthing of the system if an accidental contact occurs
between the conductors and the outside protecting tube or casing I employ flanges,
Figures 11 and 12 F, of non-conducting material at the points where the conductors
are fitted into the junction-supports as in Fig. 11. G and to prevent the tubes C
from turning round or coming out of the junction-support I make these flanges with
slots on the inner surfaces S Figs. 12 and 13; and make the tubes with small
projections near the ends which fit into and slide in these slots. This allows the
tubes to contract or expand or move slightly without fear of breaking the insulating
flanges especially when the the latter are made of slate or porcelain.
I also make the junction-supports, Figs. 14 and 15, with a baseplate H, and two
or more projecting legs, L L, to support the sides and cover I of the junction-
support or junction box. I make these legs, L L separately so that any number
may be fixed to the base-plate where required. And I sometimes cast these
supports and legs of zinc or other suitable metal. The holes required for fixing
the parts together may be cast with screwthreads in them by employing screwed
pieces of metal fixed into the mould before the melted metal is poured in. Or
small blocks of suitable metal may be first drilled and tapped and then placed in
position in the mould before the melted metal is poured in. An example of this

page_text: box is shown Fig. 16 with sides removed. L1 and L2 Fig. 17. showing two views
of the legs alone.
When only one conductor is required or when several conductors form one
circuit the inner disc above mentioned need not be of insulating material.
For convenience in fixing and removing the outside insulators I sometimes make
them in the form of a double T, as shown at E Figs. 9 and 10, having a central
rib with a cross-piece at each end, the cross-pieces then serve to hold the conductors
against the outward pressure of the inner insulators. The inner or outer insulators
or both may be provided as before with grooves to prevent the conductors from
slipping out. This method may be employed in connection with wires and strips.
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 electric conductors the combination of tubes or hollow casings enclosing
conductors with inner insulators and outer insulators held in position at intervals
along these conductors by their mutual inward and outward pressure against the
conductors substantially as described.
2. In electric conductors the combination of tubes or hollow casings enclosing
conductors with inner and outer insulators provided with projecting portions to
keep the insulators in position substantially as described.
3. In tubular electric conductors the combination of junction-supports with
insulating flanges provided with slots to prevent the tubes from moving from their
fixed positions substantially as described.
4. In tubular electric conductors the combination of junction-supports with
interchangeable baseplates and legs provided with screwholes substantially as
described.
Dated this 25th day of February 1893
ERNEST PAYNE.