Improvements in Incandescent Mantles for Lamps.
Year: 1895

page_text: Date of Application, 13th Aug., 1895-Accepted, 12th Oct., 1895?
Improvements in Incandescent Mantles for Lamps.
I, SAMUEL HENRY CROCKER of 31 Furnival Street Holborn London 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:-
My invention relates to improvements in the manufacture of incandescent
mantles for lamps the object being to provide for such manufacture in an efficient
and economical manner from a single piece of material consisting of a thin sheet or
support having applied thereto a layer or layers of the compound for forming the
radiant matter of the mantle.
To this end I take a suitable thin sheet or support such for example as a thin
sheet of paper which if desired may be rendered non absorbent and upon this I
apply a layer or film of suitable thickness consisting of the compound above
referred to. This layer or film may be formed by repeatedly coating the support
with a solution of the compounds and allowing it to dry between each such coating,
suitable adhesive or cementing bodies such as dextrin for example being added to
the solution if necessary to increase the adherence.
After a layer of sufficient thickness has accumulated on the paper or other
support the whole is then perforated by any suitable means so as to impart a
gridlike structure thereto, through which the flame can play freely as in ordinary
luminous mantles. After perforation the coated sheet is corrugated or rubbed
longitudinally or otherwise and its edges are then fastened together by any
suitable cement so as to bring it into the general form of the finished mantle.
The whole is then very slowly baked and carbonized in an oven so as to remove
the support or base very gradually and evenly without distorting the mantle.
In order to further assist in preserving the true conical form of the mantle I may
provide in the oven a truncated conical piece which during the baking is situated
inside the mantle & over which the said mantle is adapted to fit easily. This
piece is not designed to serve as a support for the mantle during the burning but
is only intended to allow of the mantle being very gently lowered upon it from
time to time in order to keep the mantle in its true shape or to bring it back to such
shape should it have become slightly distorted.
By means of the corrugations above referred to, I am able to considerably extend
the luminous area of the mantle and to moreover ensure the utilisation of the full
thickness of the outermost and hottest zone of the flame and as far as possible 1
arrange that the corrugations shall correspond in depth to the depth of such outer
zone or mantle of the flame.
It will be observed that the sheet or support upon which the layer of luminous
material is formed does not become incorporated with such layer but remains separate
therefrom, and indeed may be removed altogether after the perforating operation,
if its nature will permit without affecting the character of the finished mantle.
In carrying out my invention when using a sheet of paper as the support, I may
advantageously apply to one or both sides thereof a film of collodiou drying oil or
other like substance to render it impervious. I then coat the impervious surface thus
obtained with a solution of the compound to yield on ignition the luminous matter of
the mantle. The solution I prefer to use is one containing a salt of erbium which on
ignition will become decomposed and leave behind oxide of erbium. If the compound
is applied to both sides of the paper the two layers will after ignition remain adhering
together thus giving a somewhat thicker but rather more porous product.

page_text: In order to apply the coats of luminous compound to the support I may employ
rollers covered with such compound or may paint on or apply the same to the
support by means of a brush. I may moreover dip the support into the solution in
order to coat it and allow it to dry after dipping.
In some cases I may form the film or skin of collodion or other suitable material
upon a paper or other sheet which has been previously gammed or sized, and after
coating the collodion-with the compounds referred to, I may gently immerse the
whole in water, so as to loosen or dissolve the gum or size and allow the collodion
with the coating of compound to float off.
The collodion skin with the adhesive coating may then be perforated, corrugated,
& baked to produce the finished mantle. By this means I am enabled to materially
diminish the quantity of supporting material requiring to be burnt away.
The perforation of the support with the layer or layers thereon is effected in any
convenient manner such as by a perforating machine having suitably shaped punches.
I prefer to make the perforations as shown in Figs. 3 and 4 that is to say arranged
in lines or rows made up of a number of short slots a the slots of one line or row
breaking joint with those of the next. These slots a may either extend vertically
as shown in Fig. 3 or horizontally as in Fig. 4. I do not however limit myself to
this kind of perforations as I may sometimes employ round perforations 6 Fig. 5,
or any other form that may be convenient.
The coated sheet having been perforated its corrugation is next effected in
performing which I take care to make the corrugations deeper or more prominent
at the upper edge of the mantle than at the lower edge as will be more clearly
seen in Fig. 2 which is a plan of a mantle made according to my invention. By
this means the material of the mantle is drawn in more at the top than at the
bottom so imparting to it a regular tapered or truncated conical form..
After corrugation it only remains to cement the upper edges of the coated sheet
together by a cement composed mainly of the luminous compound and some adhesive
substance and then to cement to the upper edge thereof a strip or thread of
asbestos in Fig. 1 for supporting the mantle over the lamp Hame, and also
during the burning or baking operation.
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 the manufacture of incandescent mantles for lamps applying the compound
in a layer upon a suitable support and perforating it upon and together with its said
support substantially as described and for the purposes set forth.
(2.) In the manufacture of the incandescent inantles for lamps, applying the
compound in the form of a layer upon a non-absorbent support and subsequently
perforating it as and for the purposes described.
(3.) An incandescent mantle for lamps having corrugations from its upper to its
lower edge substantially for the purposes specified.
(4.) A corrugated incandescent mantle having its corrugations deeper or more
pronounced towards its upper edge than towards its lower edge substantially as
described and as shown in Figs. 1 and 2 of the accompanying drawings.
(5.) The manufacture of incandescent mantles for lamps by coating a suitable
support with a compound such as described and perforating corrugating and
baking it substantially as set forth.
Dated this 13th day of August 1895.
GEO. H. RAYNER,
37 Chancery Lane, W.C., Agent for the Applicant.

page_text: Fig.3.
HHHHHI