Improvements in Lamp Reflectors.
Year: 1894

page_text: Date of Application, 7th Aug., 1894-Accepted, 29th Sept., 1894
COMPLETE SPECIFICATION.
Improvements in Lamp Reflectors.
We, ERNEST TILMANN of No. 237 Centre Street, Lamp Manufacturer and
CHARLES KING LEXOW of No. 130 West 32nd Street, Lawyer, both in New
York City, County and State of New York, U.S.A., 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:-
The object of this invention is to furnish for bicycles, cabs and other vehicles an
improved reflector which is to be used with a small incandescent electric lamp or
with any other suitable lamp, said reflector being so constructed that the light of
the lamp is thrown to a considerable distance, so that objects in front of the
vehicle are clearly illuminated; and the invention consists of a reflector for
bicycles, cabs and other vehicles, which is made of parabolic shape and provided
with a parabolic socket at the centre of the main portion, and a source of light so
situated within the parabolic main and socket-portions that the foci of the parabola
are located within the source of light and that the rays issuing from each focus are
thus reflected in parallel lines from each parabolic surface. The invention consists
further of a reflector formed of a parabolic main-portion and parabolic socket-
portion at the centre of the same, and incandescent or other lamp located in said
socket-portion, a glass cover, an exterior sheet metal casing provided with a
contracted rear-portion, and means for retaining the lamp in position in the socket-
portion.
The invention consists further of a reflector formed of a parabola, the vertex
and focus of which are located in a plane in front of the source of light and at
right angles to the axis of the reflector, as will be fully described hereinafter and
finally pointed out in the claims.
In the accompanying drawings,
Figure 1 represents a vertical longitudinal section of my improved reflector for
bicycles and other vehicles,
and
Figure 2 is a like reflector showing a modified form of parabolic main-portion,
Figures 3 and 4 are diagrams illustrating the paraboli on which the reflectors
shown in Figures 1 and 2 are constructed.
Similar letters of reference indicate corresponding parts.
Referring to the drawings, A represents the main-portion of my improved
reflector for the lamps of the bicycles, cabs and other vehicles, and A2 the central
or socket-portion of the same. The main-portion A is made in parabolic shape,
while the centre or socket-portion A2 is likewise made in parabolic shape but with
a greater degree of curvature. The foci of the two parabolic portions A and A²
of the reflector are sc arranged as to be located within the bulb of a small
incandescent electric lamp B, which is secured into the socket-portion A². The
relative position of the light giving filament b of the incandescent lamp B towards
the double parabolic reflector A, Ä², is so arranged that the focus of the main-
portion of the reflector is preferably located near the outer end of the loop b of
the lamp, while the focus of the parabolic socket-portion A2 is at a short distance
from the focus of the parabolic main-portion A, as shown in Figure 3. The
main and socket-portion of the reflector are formed contiguous to each other,
and are made in one piece of sheet metal, which is suitably spun so as to form the
parabolic main-portion A and the parabolic socket-portion A2, the surface of said
reflector being silver-plated and polished in the usual manuer. The metal at the
front-edge of the reflector A is bent outwardly and then rearwardly, so as to form

page_text: a cylindrical surface a over which the cylindrical rim d of the glass-front D is
placed, said rim being retained in position on the rim a by frictional contact
therewith. The glass-front D may be made either of a circular plate of glass that
is plane on both sides, as shown in Figure 1, or may be of convexo-concave shape,
as shown in Figure 2. The edge of the glass-front D is retained within a groove d²
formed at the front edge of the rim d. The glass-front D and its rim d can be
removed whenever it is desired to clean the reflector and the lamp, in case dust
should have settled on the same.
To protect the reflector A, A2, and the small incandescent lamp B against injury
or destruction by contact with stones on the ground or with the road-bed caused
by the fall of the bicycle or the upsetting of the carriage, the reflector is enclosed
by a casing E of sheet metal. This casing corresponds in its general outlines to
the form of the reflector, and is made of such dimensions that it leaves an annular
space between it and the reflector. The front-edge of the casing E has a bead e
which engages the slightly outwardly-flaring rear-edge of the circumferential rim a
of the reflector. To the casing E is soldered or otherwise attached a metal strip
or keeper E2 of suitable form, by which the casing may be connected by a leather-
strap to the bicycle or other vehicle. The central portion of the casing E is
concaved to form a shallow cup e², which encloses the looped or hooked ends of the
conducting-wires 62 which lead through the base of the bulb of the lamp to the
filament at the interior of the same. The cup has at its centre an opening e³
for the passage of the conducting-wires b³, said opening being sufficiently large to
prevent said wires from coming into contact with the casing E. To retain the
bulb of the lamp B in position in the socket A2 of the reflector, the rear part of
its globular portion is made to rest against the socket A2 while its base or stem
extends into the central opening of the socket A2. Near the glass-stem of the
bulb, the conducting-wires are twisted so as to form coiled springs that may be
imbedded either in a layer of plaster of Paris that is interposed between a disk g
of card-board and the stem of the lamp B, as shown in Figure 1, or the plaster of
Paris may be dispensed with and the bulb of the lamp B retained by placing the
disk g of card-board on the rim of the cup e² as in Figure 2, and causing the
hook-shaped ends of the coiled wires 2 to bear against the rear-face of the card-
board, as shown in Figure 2. The hooked-shaped ends of the conducting-wires 2
are connected with electric wires which lead to a battery, dynamo or other suitable
source of electricity, which supplies the current for lighting the filament of the
lamp. In case the filament of the lamp is worn out by use, the lamp can be easily
removed and a new one inserted in place of the same. In place of an incandescent
electric lamp, a small arc-lamp or any other light-giving medium may be used in
connection with the reflector provided that the foci of the paraboli of the main and
socket-portions are located within the source of light.
In place of the parabolic main-portion shown in Figure 1, the reflector may be
made in the parabolic form shown in Figure 2, in which case the vertex and focus
of the parabola is located in front of the source of light and in a plane at right
angles to the axis of the reflector, preferably in a plane at or near the front edge
of the reflector, as shown in Figure 3. This arrangement of the parabola
concentrates some of the reflected rays of the electric lamp within the lamp and
does not throw them in a forward direction in parallel rays, as would a parabolic
reflector of the construction shown in Figures 1 and 3. Instead of throwing a
strong beam of light in a forward direction, a luminous concentrated body of
considerable power is produced by which the cycle can be immediately seen and
collision with the same avoided.
The advantages of our improved reflector and lamp for cycles, cabs and other
vehicles, are: First, that by the arrangement of the parabolic main and socket-
portions the lamp can be set back into the reflector so that a flat or slightly convex
glass-cover can be used with the same, and thereby the reflector and lamp
protected against injury by accidents to the cycle or other vehicle. Second, that
by the use of the parabolic main and socket-portions, the light of the lamp is

page_text: thrown in parallel rays to a considerable distance in front of the vehicle, so that
all objects on the road are clearly illuminated and thereby considerable security
against accidents is obtained. Third, the entire reflector and its lamp are of very
small and compact shape, and furnish a very powerful light-giving device for cycles
and other vehicles while the same are in motion.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. The combination, with a reflector formed of a parabolic main-portion and a
parabolic socket-portion at the centre of the main-portion, of a source of light
located within the paraboli, so that the foci thereof are located within the source
of light, the rays from each focus extending in parallel lines from the corresponding
parabola substantially as set forth.
2. The combination, with a reflector formed of a parabolic main-portion and a
parabolic socket-portion at the centre of the main-portion, of an incandescent
electric lamp so situate in the socket-portion that the foci of both parabolæ are
located within the bulb of said lamp, and that the rays issuing from each focus are
reflected in parallel lines from the corresponding parabola, substantially as set
forth.
3. The combination, with a reflector formed of a parabolic main-portion and a
parabolic socket-portion at the centre of the same, of a lamp located in said
socket-portion, a glass-cover, an exterior sheet metal casing provided with a
contracted rear-portion, and means located at the rear-portion of the casing for
supporting said lamp in position in the socket-portion, substantially as set forth.
4. The combination of a reflector formed of a parabolic main-portion, a lamp
located at the centre of said parabolic main-portion, a glass-cover, and exterior
sheet metal casing provided with a contracted rear-portion, a non-metallic disk
resting against the rear portion of the casing, conducting wires passing through
said disk, and means for holding the lamp, disk and conducting wires in position,
substantially as set forth.
5. A reflector for cycle and other lamps, formed of parabolic shape, the vertex
and focus of which are located in a plane at right angles to the axis. of the reflector
in front of the light-giving body, substantially as set forth.
Dated this 7th day of August 1894.
PHILLIPS & LEIGH,
No. 22, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicants.