Improvements in the Method of Lining Tubes and Cylinders.
Year: 1895

page_text: Date of Application, 24th Sept., 1895-Accepted, 26th Oct. 1895
COMPLETE SPECIFICATION.
Improvements in the Method of Lining Tubes and Cylinders.
We, CHARLES ANTHONY NOLL of 2024 Lexington Avenue, in the City and
State of New York, United States of America, Electrician, and JOHN HOWE
ROBINSON WARD of Canton Street, Stoughton in the County of Norfolk and
State of Massachusetts, 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 :-
This invention relates to a method of lining the interior of tubes or other
cylindrical bodies with an insulating material for electrical and other purposes.
A modern method of wiring buildings for electrical distribution is to use metallic
tubes through which the wires are strung. Such tubes should be thoroughly
insulated interiorly to prevent earthing and short circuits.
Our method of insulating these tubes in its entirety, consists in first filling a tube
with a liquid holding in nechanical suspension, the insulating material in a finely
divided state, with which it is desired to line the tube; then closing the ends of
the tube and rotating it for a short time axially at high speed. The rotation
causes the particles of solid matter held in suspension in the liquid to be thrown
against the wall of the tube by centrifugal force, and there it becomes firmly
embedded or attached. Afterwards, the tube is opened and the liquid, free of solid
matter, is drawn off, leaving a coating or lining upon the interior of the tube. This
is then dried and, if desirable, impregnated with a filling such as asphaltum, after
which it is ready for use.
In the accompanying drawing, Figure 1 shows a conventional form of apparatus
with which our invention may be carried out, and Figure 2 a cross section of a tube
with its insulating lining.
The apparatus is a kind of lathe consisting of a number of bearings a a etc.
placed in line and adapted to receive a tube or cylinder of any ordinary length.
In one of the bearings, a rotating bushing b is placed and this carries a pulley to
which motion is imparted by a belt d.
The tube is represented by e. Suitable arrangements are provided for connecting
one end of the tube with a hopper (shewn in dotted lines) which will contain a
liquid such as water, holding in solution materials such as plaster of Paris and fine
asbestos. This mixture should be agitated by a stirrer g to keep it uniform. The
tube is completely filled with this material and its ends are afterwards closed in
any desired manner, plugs being here shewn. The tube is then rotated at a high
speed for a period of about five minutes, after which it is taken out of the lathe and
the liquid removed. It will now be found that the tube is provided with an even
lining of plaster of Paris and asbestos.
If the speed at which the tube is driven is high, the lining will be firmly
packed and comparatively free from moisture and may therefore be quickly dried
either by the circulation of air or application of heat. When dry, the pores of the
lining may be filled with asphaltum or pitch by pouring some of that material into
the tube and removing the excess.
Our invention is not limited to the particular materials mentioned herein, nor to
any particular apparatus for carrying out the method and it will be understood that
the nature of the lining may be moisture proof or fire proof as well as an insulator
of electricity. We may observe however that to get the best results hitherto
obtained, the tube should be completely filled with the liquid, mixture as otherwise

page_text: the layer may vary in thickness. The average thickness will depend upon the
quantity of solid matter held in suspension and the time of rotation.
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 bereinbefore described method of lining tubes and cylinders, consisting
in placing in the tube or cylinder a liquid holding solid matter in suspension, then
rotating the tube, substantially as set forth.
2. The hereinbefore described method of lining tubes and cylinders consisting
in placing in the tube or cylinder a liquid holding solid matter in suspension, then
rotating the tube to deposit the lining, then removing the liquid and drying the
lining, substantially as set forth.
3. The hereinbefore described method of lining tubes and cylinders with
insulating material, consisting in placing in the tube or cylinder a liquid holding
solid matter in suspension, then rotating the tube to deposit the lining, then
removing the liquid and drying the lining, and finally filling the pores of the
lining with an insulating compound such as asphaltum, substantially as set forth.
Dated this 23rd day of September 1895.
W. E. HEYS & SON,
Agents for the Applicants.