Improvements in or connected with Incandescence Electric Lamps.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in or connected with Incandescence Electric Lamps.
We, LOUIS JOHN STEELE, of 14, Clarendon Road, Holland Park, Kensington,
Electrical Engineer, Sir JOHN BLUNDELL MAPLE, Bart. M.P., of 145, Tottenham
Court Road, and JOHN VERITY, of 31, King Street, Covent Garden, Manufacturer,
all in the County of London, do hereby declare the nature of this invention
to be as follows:-
This invention relates to incandescence electric lamps and chiefly to lamps of
the kind wherein a reflector or reflectors is or are arranged in combination with
the filament or filaments for augmenting or diffusing the light or producing
optical effects.
Hitherto considerable difficulties have been experienced in using such lamps
and chiefly we believe for the reason that the reflector has been made of glass or
other substance which contains in its composition more or less lead or other
materials which are decomposed or acted upon by heat in such a manner as to
cause a film to deposit or form upon the reflector or reflectors and thereby reduce
its or their efficiency.
The chief object of our invention is to provide lamps which do not possess the
defects before indicated and to this end we make use of glass which is not liable
to be acted upon as before set forth and in order further to ensure that the
reflector or reflectors shall be kept free from deposit due either to the quality
of the glass or the gradual destruction of the filanient we place upon the reflector
flector a sleeve or collar which can be caused to slide upon the said
rub off any deposit therefrom.
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refle
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filled
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order to in
that in our improved lamps the reflector should be made hollow and
substance or combination of substances capable of becoming phos-
having fluorescent qualities under the action of light or heat, in
e the quality of the light.
Improvements in or connected with Incandescence Electric Lamps.
We, LOUIS JOHN STEELE, of 14, Clarendon Road, Holland Park, Kensington,
Electrical Engineer, Sir Joux BLUNDELL MAPLE, Bart. M.P., of 145, Tottenham
P 871

page_text: Court Road, and JOHN VERITY, of 31, King Street, Covent Garden, Manufacturer,
all in the County of London, 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 incandescence electric lamps and chiefly to lamps of
the kind wherein a reflector or reflectors is or are arranged in the bend or bight
of the filament or filaments for augmenting or diffusing the light or producing
optical effects.
It is found in practice that the efficiency of such lamps rapidly deteriorates,
and we believe this deterioration is partly due to the fact that the reflectors are
made of glass or other substance which contains in its composition more or less
lead or other materials which are acted upon or decomposed by heat in such
a manner as to cause a film to deposit or form upon the reflectors,
and partly to the disintegration of the filaments under the action of
the current and the "bombardment” of the disintegrated particles against the
reflectors.
The chief object of our invention is to provide a lamp which does not possess
the defects before indicated and to this end we make use of crystal glass or other
substance which is not liable to be acted upon as before set forth and in order
further to ensure that the reflector or reflectors of lamps whether made of
ordinary or special glass shall be kept free from deposit due either to the quality
of the glass or the gradual destruction of the filament we place upon the reflector
or each reflector a sleeve or collar which can be caused to slide upon the said
reflector to rub off any deposit thereon.
We prefer that in our improved lamp the reflector should be made hollow and
filled with a substance or combination of substances capable of becoming phos-
phorescent or having fluorescent qualities under the action of light or heat, in
order to improve the quality of the light.
Our invention of the cleaning collar will be readily understood by reference
to the accompanying drawing, in which;-
Figure 1 is a sectional elevation of a lamp having our improved sleeve or
collar upon the reflector; and,
Figure 2 is a vertical section of the said lamp;
Figure 3 is a view similar to a portion of Figure 1 and illustrating a slight
modification.
In these figures a indicates the bulb of the lamp, the reflector and c the sleeve
or collar. This sleeve or collar (which is advantageously composed of a ring or
core c¹ of metal having twisted around it a cord of asbestos or other suitable
material and which will not be injured by the heat to which it is subjected
which will not throw off vapour injurious to the lamp) is adapted to slide freely
upon the said reflector in such a manner that when the lamp is shaken in the
longitudinal direction of the reflector or the collar is subjected to the action of
a suitable magnet the said collar will slide up and down upon t' same and so
rub off any carbon or other deposit upon the said reflector.
When the reflector is made hollow and filled with a phorescent or other
material which is in the form of a powder we prefer to forin in the reflector a
hole through which any air, which may be present in the said tubular reflector,
will be exhausted, and we do this notwithstanding that the said reflector may be
strong enough to withstand the pressure of such air when the bulb is exhausted
as we believe that any air which remains in the said reflector will in some cases
be imperfectly imprisoned, through the bad sealing of the reflector to the bulb or
through a crack or flaw in the glass of the reflector, and might find its way from
the interior of the reflector into the bulb and thus spoil the vacuum.
In order to prevent the powder from escaping through the said hole the latter
is closed by a wad e of asbestos or other fire-proof material which is sufficiently
porous to allow the air to escape whilst at the same time preventing the escape
of powder. In Figure 2 this wad is represented as being placed over a hole at

page_text: the bottom of the reflector, whilst in Figure 3 the hole is represented at the top
of the reflector and the wad in position to cover the hole.
When our invention is applied to a lamp of the kind described in the Specifi-
cation of our Application No. 23420 of 1898, wherein the reflector is arranged
within a transparent tube we sometimes arrange a collar between the reflector
and the inside of the tube in addition to a sleeve or collar outside the tube.
Although we have described only the reflectors of lamps as being made of
special glass it is to be understood that we may with advantage make the bulbs
of such lamps of special glass.
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. An incandescence electric lamp provided with a reflector within the
filament, which reflector (and advantageously also the bulb of the said lamp) is
constructed of glass not liable to change under the action of the heat to which
it is subjected by the filament, in combination with a sleeve or collar adapted to
slide upon the said reflector, substantially as, and for the purpose, described.
2. In an incandescence electric lamp having a reflector within it, the com-
bination with the said reflector of a sleeve or collar adapted to slide upon the
reflector and remove any deposit thereon, substantially as described.
Dated this 29th day of July 1899.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.