Improvements in Non-conducting Coverings.
Year: 1893

page_text: Date of Application, 5th Dec., 1893-Accepted, 3rd Mar., 1894
COMPLETE SPECIFICATION.
Improvements in Non-conducting Coverings.
I, HENRY WARD JOHNS, a resident at the Dakota Apartment House, Seventy-
second Street and Eighth Avenue, in the City of New York, County and State of
New York, United States of America, Manufacturer and Merchant, 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 an improvements in non-conducting coverings, fire-proof
linings and the like manufactures, of the class in which a sheet or layer of fibrous
material is used in conjunction with interposed layers of plastic or plaster-like
material. As these manufactures have heretofore been made, a difficulty has been
experienced; that the heat of the hot surfaces acts injuriously upon the fibrous
sheet, gradually reducing its strength, so that after a time, the plastic material or
layer, having nothing sufficiently strong to support it, crumbles and falls away,
especially when arranged on vertical pipes, and this has necessitated the previous
coating or covering of the hot surfaces, usually with a layer of some plastic cement
mixture, which has been applied by hand, and is a laborious and expensive
process.
By my invention, 1 overcome these difficulties and I make the covering in such
manner that there is formed integrally with it, an interior lining of asbestos or
other fire-proof material, which comes immediately in contact with the hot surface
and outside of it, I arrange the alternating layers of fibrous material and plastic
material, and the plastic material is so combined, that it will adhere to the sheet of
fabric, during the rolling up process, and will alternate with it in the completed
covering.
The process of manufacture is as follows: A suitable mandrel is arranged in a
machine, so that it may be rotated. I then first wind upon the, mandrel, one or
more layers, preferably a number of them, of asbestos paper or fire-felt, so-called,
preferably using that which has considerable thickness. The surface of this
asbestos material or fire-proof material, it .not being essential to use asbestos, is
sufficiently coated with adhesive material to cause the several layers of it, if more
than one layer be wrapped about the mandrel, to adhere together, so that, when the
completed covering is cut across, the sections of this fire-proof interlining will not
be separated from the rest of the covering. Then after a sufficient quantity of the
asbestos material has been wound upon the mandrel, I wind outside of it a sheet of
fibrous material, which, for very hot surfaces should preferably be asbestos, but for
certain uses, where heat is not so great, a paper or cloth not of asbestos, may be
employed. This sheet of material, whatever its character may be, is coated with a
layer from one-sixteenth to one-quarter of an inch thick, more or less, as desired, of
plastic material, such as asbestos cement or any compound of clay, lime or other
like incombustible substance, mixed to the proper consistency, so that the layer of
plastic material will wind up upon the mandrel, together with the layer of fibrous
material. These alternating layers are wound upon the mandrel until the desired
thickness is attained, thereupon the fabric and plastic material will be cut across,
and then the tubular covering will be stripped off from the mandrel in a manner
now well understood.
After the material has become sufficiently hard, the tubular covering is. sawed in
half longitudinally, so that the two sections may be readily applied to the pipe, and
they may be held in place upon the pipe by suitable bands or other appliances, or a
canvas or other covering may be employed, which will form a hinge, connecting the

page_text: two halves of the covering. If preferred, the longitudinal sawing of the tube may
be done so as not to cut the last or outside layer of the fabric sheet which will then
act as a hinge.
In the drawings hereof, I show a transverse sectional view of a piece of pipe
covering made on my plan. A is the plastic material. B is the fabric.
C, C' illustrate the two ends of the fabric material; the inner one C is
wrapped about the interior fire-proof lining for a little distance, and the tension
with which it is wound on the mandrel G is preferably such that the
plastic material is squeezed back so that it presents no abrupt edge, and
the same is true at the outer end, where the fabric extends beyond the
plastic material to form a lap C'. D is the line on which it may be sawed' or
cut. This cut is preferably located under the lap C', and as shown it may not
extend quite through the covering, but only to the outer layer of the fabric B, so
that it will act as a hinge, when applying the covering to the pipes. It may, how-
ever, be cut entirely through, if preferred. F shows the interior layers of asbestos
paper or other incombustible material. If the lap C¹ is not employed, the meeting
edges of the covering, after being put upon the pipe may be covered with paper,
canvas, or other suitable material, cemented or otherwise held in place, and the
.. entire exterior surface of the covering may be coated or ornamented with paint or
in any other desired manner. As before stated, any suitable material may be used
as the fabric upon which the plastic material is spread, preferably an asbestos
fabric, because of its incombustibility, but for many uses, felt, paper, burlaps,
canvas and the like materials may be employed, and in addition to the cement-like
or plaster-like material mentioned by me, a compound embodying asbestos and
sponge, which has been heretofore patented to me, (see the Specification to my
Patent No. 9303 of 1888) may be used, and to increase the porosity, strength and
non-conductivity of the plaster-like layer, it may have any fibrous or porous
material mixed with it, such as fibrous asbestos, hemp, wool, hair, ground sponge,
saw-dust, chopped hay or straw, and any suitable adhesive inaterial may be used
to additionally bind or cement the layers of fabric and plastic material together,
preferably, but not necessarily a fire-proof substance, such as silicate of soda.
When the non-conductor is to be used on surfaces other than tubular ones, I
make the covering in flat or other suitable form, to be properly applied to the
surface to be. protected.
:.
It will be seen, that by my invention, I make in a single structure, a covering
adapted to withstand great heat, and that it is clean in application, and that it may
be applied quickly and inexpensively. The asbestos paper on the interior of the
: covering prevents injurious action of the heat upon the fibrous material and upon
the plastic material outside of the fire-proof lining.
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 :
As a
new article of manufacture, a non-conducting covering, comprising
alternating layers of fabric and plastic material, and an inner lining of incom-
bustible fibrous material, said lining and the fabric and the plastic material all
being permanently attached together, forming an integral structure.
Dated this 5th day of December 1802
HENRY WARD JOHNS,
By E. P. Alexander & Son, F.C.I.P.A.,
19, Southampton Buildings, W.C., Agents.