Improvements in Electric Incandescent Lamps with Interior Reflectors.
Year: 1888

page_text: Improvements in Electric Incandescent Lamps with Interior
Reflectors.
I, JOHN WILLIAM OLDROYD, of No. 8 Quality Court, London, Middlesex, Woollen
Manufacturer, 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 electric incandescent lamps with interior
reflectors, that is, with reflectors arranged within the evacuated bulb in order to increase
the illuminating power of the said incandescent lamp.
Two or more reflectors or reflecting pencils or rods of appropriate form and length
are arranged within the bulb so that the incandescent light emitted by the filament or
filaments is reflected in all directions thus increasing the illuminating power of the lamp
to a very great extent.
For such reflectors I employ any suitable material and accommodate the form of
the same to the form of the filament or the desired reflector of the light emitted by
the same; for instance, drawn or other metal tubing closed at one end and plated or
coated with a highly polished coating of platinum, silver or other appropriate metal
or material can be used or glass tubes or hollow bodies provided in the interior with
or material can be
a layer of mercury silver or other light reflecting metal
employed.
It is important that the reflectors be so arranged in the bulb of the lamp that the
light emitted by the filament is not obstructed by the reflectors or reflecting rods or
pencils which would otherwise have the tendency to render the advantages sought to
be obtained by the application of the said reflectors illusory whereas when the reflectors
are judiciously located the illuminating power of the filament will be enormously
increased.
Fig. 1 is the elevation of one of my improved lamps.
Fig. 2 is a horizontal section of Fig. 1 on the line a―y.
a is the bulb of the lamp attached in any well known manner to the socket b. The
insulating core c carries the platinum wires d to which the filament e is attached in
appropriate manner. f, f¹ are the hollow reflectors which can be made of any
desired form and size and which can be fixed to the core c within the bulb a.

page_text: According to the accompanying figures two reflectors ff are employed which will
reflect the light emitted by each arm of the filament independent of the fixing or the
position of the lamp thus increasing the power of the same.
The reflectors or reflecting rods or pencils are preferably arranged laterally to the
filament so that a line drawn through the centre of the reflectors will form a right
angle to the filament although for special purposes another position of the same can
be chosen.
If, for instance, the lamp is so fixed that in looking at the same one of the arms of
the filament is covered by the reflector f, the light emitted by the said filament arm
will be reflected by the second reflector so that the conical space shadowed by the
one reflector will be illuminated by the reflected light from the second reflector thus
rendering the illuminating power of the lamp as perfect as could be desired and
preventing all shadowing which could otherwise take place.
It will be evident from the foregoing that although I have represented the applica-
tion of two round reflecting rods or pencils in the accompanying drawings, I by no
means restrict my invention to the special form or the number of such said
reflectors.
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. The manufacture and construction of electric incandescent lamps with two or
more reflectors or reflecting rods or pencils within the bulb of the same, substantially
as and for the purpose set forth and shown on the drawings.
2. My improved electric incandescent lamp containing two or more reflectors or
any mere modification of the same, substantially as and for the purpose set forth and
shown on the drawings.
Dated this 8th day of September 1888.
GEO. DOWNING,
Agent for Applicant.