Improvements in Incandescent Mantles and in Fabrics for Use in the Manufacture thereof.
Year: 1899

page_text: Date of Application, 3rd Feb., 1899-Accepted, 25th Mar., 1899
COMPLETE SPECIFICATION.
Improvements in Incandescent Mantles and in Fabrics for Use in the
Manufacture thereof.
We, NICODEM CARO, Ph. D., of 71, Koenigin Augusta Strasse, and WILLY
SAULMANN, Ph.D., of 7, Dornberg Strasse, both in Berlin, in the German Empire,
Chemists, 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, reference being had to the accompanying drawings and
to the letters and figures marked thereon, that is to say; -
Incandescent mantles are made of a net-like cotton fabric impregnated with
certain salt solutions, and after their upper ends are sewn together, by means of
asbestos, the entire mantle is burned. By this operation a skeleton is formed
having an asbestos loop at its upper end.
In order to impart. greater solidity to that portion of the incandescent body
to which the asbestos loop is attached, it is usual to turn down the upper end of
the mantle, or to reinforce the latter by applying a strip of gauze (so that this
part which forms the so-called head" consists of a double layer of fabric) after
which the head is impregnated with a suitable fixing or strengthening solution.
Now, in incandescent mantles thus manufactured, the defect is that they are very
fragile in as much as they were subject to be easily ruptured by concussion at
the part between the head and the body. This rupture was still more liable to
occur owing to the fact that the mantle being expanded below the place where the
head was tied, was, at this place, exposed to tangential strain.
Now, in order to obviate this defect, we manufacture our mantles with the
meshes of the fabric narrower at the top than in the body thereof, and the top
portion of the mantle which is provided with the narrow meshes is either turned
down, in any known manner, or a strip of gauze is sewn on between the body
and the head. This reinforcement is effected in such a way that an intermediate
portion of narrow mesh fabric is left between the head and the body.
In the accompanying drawings:
Fig. 1 represents the mantle prior to the head portion being turned down at a, b,
as far as the line c d, and prior to being sewn together.
C
Fig. 2 represents a finished mantle.
In both these figures the difference in the width of the meshes of the head and
body portion is clearly perceptible.
If a mantle thus manufactured be impregnated, sewn, and burned, then the
portion lying between the head and the body which, as already stated, is exposed
to greater strain, will offer a sufficient resistance, seeing that the narrow meshes
will absorb a larger amount of salt than the wide meshes. Thus, rupture of the
head under a shaking or concussive action is effectively prevented. Moreover,
the fixing solution which was hitherto solely employed for increasing the resist-
ance of the head, may now also be employed for impregnating the intermediate
portion between the head and body as, owing to the narrowness of the mesh of this
portion, the solution is readily retained in the fabric.

page_text: 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. A fabric for incandescent mantles in which the mesh is made narrower at
the portion between the head and the body of the mantle (such fabric being either
turned down on itself, or having a strip of gauze sewn on it) so as to impart to
the said portion a greater resistance by reason of the greater accumulation of
impregnating material, and to enable the strengthening liquid, which could only
be used for the head, to be applied to the portion in question, substantially as
set forth.
2. A mantle for incandescent lighting having narrower meshes at its upper
part than at its lower part, substantially as and for the purposes set forth.
ERNEST DE PASS,
Chartered Patent Agent 78, Fleet Street, London, E.C., and
5A, Market Street, Nottingham, Agent for the Applicants.