Improvements relating to Filaments for Electric Lamps for Signalling and other purposes.
Year: 1890

page_text: Date of Application, 18th Mar., 1890
Complete Specification Left, 17th Dec., 1890-Accepted, 21st Feb., 1891
PROVISIONAL SPECIFICATION.
Improvements relating to Filaments for Electric Lamps for Signalling
and other purposes.
I, JOHN PRICE REES, of 1, Boundary Terrace, Camberwell, in the County of
Surrey, Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to filaments for electric incandescent or glow lamps, and is
chiefly designed to provide for concentrating the light in signal-lamps for military
and other purposes, or in lamps for dissolving views, or for photographic and
similar purposes, or in other lamps provided with lenses.
My improved filament is so formed that, when the electric current is passed
through it, the said filament will present the appearance of a spot or disc of
light, which can be so placed relatively to the lens that the focal axis of the said
lens will extend through the centre of the said disc of light. I thus provide
for greatly increasing the illuminating power of the lamp as compared with lamps
provided with the ordinary filaments, which are of elongated form, and a large
proportion of the rays from which do not impinge upon the lens in an advantageous
manner and are consequently not properly utilized.
I combine my improved filament with the other parts of a signalling lamp
constructed substantially as described in the Specification of former Letters Patent
In this manner I
granted to me and dated 19th January A.D. 1889 No. 1038.
produce a signal-lamp for military and other purposes, which, by reason of its high
illuminating power, can be used for the transmission of signals through distances
much greater than has heretofore been practicable with lamps of the same
dimensions as hitherto constructed.
I find it advantageous to make my filament in the form of a volute, so that,
when the current is passed through it, a disc of light is produced. The filament
is bent at the inner end of the volute and preferably extends outward to, or beyond
the periphery of the disc. The two ends of the filament are united to the
leading-in wires of, the lamp, preferably as near as practicable to the periphery of
the said disc.
Dated thi. 19th Joy of Mo 1800
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for, the Applicant..
COMPLETE SPECIFICATION.
Improvements relating to Filaments for Electric Lamps for Signalling
and other purposes.
1, JOHN PRICE REES, of I, Boundary Terrace, Camberwell, in the County of
Surrey, Electrical 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 filaments for electric incandescent or glow lamps, and is
chiefly designed to provide for concentrating the light in signal-lamps for military
and other purposes, or in lamps for dissolving views or for photographic and similar
purposes, or in other lamps provided with lenses.
My improved filament is so formed that, when the electric current is passed
through it, the said filament will present the appearance of a spot or disc of light,
which can be so placed relatively to the lens that the focal axis of the said lens

page_text: will extend to or through the centre of the said spot or disc of light, and the
light will be greatly intensified or concentrated. The illuminating power of a
signal or other lamp provided with my improved filament will, therefore, be greatly
increased as compared with lamps provided with the ordinary filaments, which
are of elongated form, and a large proportion of the rays from which do not
impinge upon the lens in an advantageous manner, and are consequently not
properly utilized.
I combine my improved filament with the other parts of a signalling lamp
constructed substantially as described in the Specification of former Letters Patent
granted to me and dated 19th January A.D. 1889, No. 1038. In this manner I
produce a signal-lamp for military and other purposes which, by reason of its high
illuminating power, can be used for the transmission of signals through distances
much greater than has heretofore been practicable with lamps of the same
dimensions, as hitherto constructed.
In the accompanying drawing,
Figure 1 is a plan, and
Figure 2 a side elevation, showing one form of an incandescent electric lamp
provided with my improved filament, a portion of the glass bulb or globe being
removed to show the filament more clearly.
a is the bulb or globe, is my improved filament.
Instead of using a long filament the ends of which are attached to the leading-in
wires near the point where the latter are scaled into the bulb or globe, either
arrange the said leading-in wires so that they extend a considerable distance within
the bulb or globe, and attach to the ends of the said wires my improved filament;
or I connect with the said leading-in wires suitable conductors c to which 1 attach
my improved filament.
The filament shown in the drawing is made in the shape of a short spiral so
placed that, when the lamp is properly arranged in combination with a lens, the
axis of the said spiral will be coincident with the axis of the said lens or with a
prolongation thereof.
The coils or convolutions of this spiral filament may, if desired, increase in
diameter successively from one to the other end of the said spiral, as shown or they
may be of uniform or approximately uniform diameter.
I sometimes make my filament in the form of a volute, so that, when the current
is passed through it, a disc of light is produced. The filament is bent at the
inner end of the volute and preferably extends outward to or beyond the periphery
of the disc. The two ends of the filament are united to the leading-in wires of
the lamp, preferably as near as practicable to the periphery of the said disc.
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
First. The improved filament formed substantially as hereinbefore described so
that, instead of a light of the usual elongated form, a spot or disc of light will be
produced and the light will be intensified, as, and for the purpose, above
specified.
Second. A signal or other lamp provided with a lens and having my improved
filament so arranged within it that the focal axis of the said lens will extend to or
through the centre of the spot or disc of light, substantially as, and for the
purpose, above specified.
י
Haseltine, Lake & Co.,
J. P. REES.
45, Southampton Buildings, London, W.C., Agents for the Applicant.