Improvements in Conduits for Cables for Carrying Electric Currents.
Year: 1899

page_text: Date of Application, 14th Feb., 1899-Accepted, 20th May, 1899
COMPLETE SPECIFICATION.
Improvements in Conduits for Cables for Carrying Electric Currents.
We, LYNDS BELKNAP, of Fulton Street, Jamaica, Borough of Queens, New
York City, Manufacturer, and AUGUST SUNDH, of 116, Oak Street, Yonkers,
Westchester County, State of New York, Electrician, both in the United States
of America, 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:-
Our invention relates to the protective enclosing case employed for protecting
the cable from fire, water, and wear or abrasion when laid in the walls, floors,
partitions and other parts of buildings, and also when used in connection with
elevator cars, as hereinafter described reference being made to the accompanying
drawings in which:-
Fig. 1, represents an example of the arrangement of such cables at an angle
in a building.
Fig. 2 is a transverse section of our improved protective case, and an electric
cable therein.
Fig. 3, is a side view of a short section of the case and projecting portions of
an electric cable therein.
Fig. 4, is a side view of a short section of the cable without the exterior
metallic armor, and a part of the case being in longitudinal section, and also
showing projecting portions of an electric cable, and.
Fig. 5, is a side view of a short section of the case with a modified form of the
exterior metallic armor.
Iron pipes or tubes are now commonly used for the protective cases of electric
cables laid in the walls and other parts of buildings, but they are not satisfactory
because of the difficulty of removing and again inserting the cables, owing to
the short turns and obstructive nature of the elbows which cause too much
friction in pulling the cables out, and make it very difficult to insert the steel
tapes used for pulling the cables in again, and it is also difficult to arrange the
iron tubing in the sinuous courses often required in placing them in position,
and the iron tubing cannot be used with cables connected with elevator cars,
in which use the cables are often subject to abrasion by rubbing against the sides
and on the bottom of the elevator way.
We therefore propose to employ flexible rubber tubing for such casings, which
instead of being applied as a close fitting and permanent element of the cable
we arrange in such relation to the cable as enables the cable to be drawn in and
out lengthwise readily for inspection and repairs of the cable without disturbance
of the case.
We also propose to employ such rubber cases in which asbestos fibre is incor-
porated with the rubber web in lieu of or together with the canvas fabric com-
monly used in the construction of tubing to resist bursting pressure, for fire proof
protection of the cable, and we also propose to construct the case with metallic
armor of wire or thin metallic strips wound on the exterior in any approved way
LD017

page_text: for protection against wear in handling and in use, such armor being alike
applicable for cases to be laid in the walls &c., and for application to cables con-
nected with elevator cars.
In the drawings a represents the electric cable of common use for which we
seek to provide a better protective case as follows:-We make a rubber tube b
of suitably larger size than the cable to permit the cable to be drawn in and out,
said tube having a suitable quantity of asbestos fibre e for protection of the cable
against fibre incorporated in its structure either in mats or woven or braided
fabric, and when desired for greater resistance to collapsing pressure, coiled
wire d, or thin metal strips likewise incorporated in the structure, and we apply
an exterior metallic armor of wire e or thin strip f Fig. 5 for protection against
wear or abrasion of the outside of the rubber case.
It will be seen that the case constructed is practically as flexible as an ordinary
rubber tube, and may be laid in the walls of buildings to much better advantage
than iron tubing, it is equally or more protective against fire and may be used
with cables connected with elevator cars. It is especially advantageous for
arranging in angles in walls g of buildings, as represented in Fig. 1, in which
case it is shown without the protective armor as it may be used but the armor will
generally be preferred in such use.
It will be also seen that the rubber tube being itself an insulator for the
electric wires the insulating properties of the cable will be greatly reinforced,
and if desired may be of less effective character except for insulation from each
other.
While the fire proof element will generally be used in cases where there is
possible danger from the heat of the electric current, it will not necessarily be
used in all cases, and the exterior metallic armor may in some cases be omitted,
but it will generally be used to protect the tube in handling and especially in
drawing it into positions through floors, walls and places when arranging and
locating it for use.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is-
1. The combination with an electric cable, of a protective case adapted with
relation to the cable for the cable to be drawn in and out, and consisting of a
flexible rubber tube, substantially as described.
2. The combination with an electric cable, of a protective case adapted for
the cable to be drawn in and out, and consisting of a flexible rubber tube having
a fire proof element incorporated in its structure substantially as described.
3. The combination with an electric cable, of a protective case adapted for the
cable to be drawn in and out, and consisting of a rubber pipe having a fire proof
element, and a flexible metallic supporter of the web incorporated in its structure
substantially as described.
4. The combination with an electric cable, of a protective case adapted for the
cable to be drawn in and out, and consisting of a rubber tube having a fire proof
element incorporated in the structure, and an exterior flexible metallic armor
substantially as described.
5. The combination with an electric cable, of a protective case adapted for the
cable to be drawn in and out, and consisting of a rubber tube having a fire proof
element, and a flexible metallic supporter of the web incorporated in the struc-
ture, and an exterior flexible armor substantially as described.
6. The combination with an electric cable, of a protective case consisting of a
flexible tube, insulating material incorporated with the tube, and flexible
metallic protective armor for the case substantially as described.
7. The combination with an electric cable, of a protective case consisting of a
flexible tube, and a flexible protective metallic armor for the case substantially
as described.

page_text: 8. The combination with an electric cable, of a protective case consisting of a
flexible tube, and flexible metallic armor in the case substantially as described.
Dated the 14th day of February 1899.
PHILIP M. JUSTICE,
Chartered Patent Agent, London,
For the Applicants.