Improvements in Lamp Reflectors, Applicable for Use in Shop Windows and other Places.
Year: 1884

page_text: Improvements in Lamp Reflectors, Applicable for Use in Shop
Windows and other Places.
I, DAVID KINNEAR SIMPSON of 6, St George's Crescent, Liverpool, in the County
of Lancaster, Hatter do hereby declare the nature of my said invention for
"IMPROVEMENTS IN LAMP REFLECTORS APPLICABLE FOR USE IN SHOP WINDOWS
AND OTHER PLACES to be as follows:-
"
Shop window lamp reflectors "Jeweller's" lamps and the like are formed usually
of a truncated cone or pyramid of glass "silvered." Now as the angle of reflexion
is equal to the angle of incidence the effect of the light meeting the reflector at an
angle is doubled and most of the rays instead of being reflected straight downward
are reflected outward in all directions. Now while it is not desirable to have a
perfectly parallel reflexion it is desirable to have as many of the rays as possible
reflected on to the goods below, and this can be done even if the angle of incidence
varies within certain limits.
To enable me to effect this object I form each side of my square or polygonal
Deflector of several parallel reflecting glasses set at different angles. Each is set
as near as possible at such an angle that the light striking the centre of the
reflecting strip shall be reflected straight downward, or as near as possible to the
centre of the place to be lighted. The strip is then made of such a width that
the light reflected from close to each side of the strip shall fall close to the extreme
edge of the space to be illuminated, all the other direct rays then fall into the space
to be illuminated. In shop windows three to four tiers of reflecting plates are
sufficient and the whole can be made for the price of an ordinary lamp or for very
little more.

page_text: Windows and other Places.
I DAVID KINNEAR SIMPSON 6 St George's Crescent, Liverpool, Lancashire, do
hereby declare the nature of my said invention for "IMPROVEMENTS IN LAMP
REFLECTORS, APPLICABLE FOR USE IN SHOP WINDOWS AND OTHER PLACES" and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:—
5
Shop window lamp reflectors, "jewellers" lamps and the like with a vertically
downward reflection are formed usually of a truncated pyramid of glass "silvered"
Now the angle of reflection is equal to the angle of incidence the effect of a
difference in the angle at which the light meets the reflector is doubled, and most
of the rays instead of being reflected straight downward are reflected outward in 1
all directions. Now while it is not desirable to have a perfectly parallel reflection
it is desirable to have as many of the rays as possible reflected on to the goods
below and this can be done even if the angle of incidence varies within certain
limits.
The drawings show a section of a hexagonal jeweller's lamp reflector in 1
accordance with my invention, in which Figure 1 is a perspective view and
Figure 2 a section; the light lines show the angles of reflection.
In this reflector each side of my square or polygonal reflector is formed of
several (four in this case) parallel reflecting glasses set at different angles. Each
is set as near as possible at such an angle that the light striking the centre of the
reflecting strip shall be reflected straight downward or as near as possible to the
centre of the place to be lighted. The strip is then made of such a width that
the light reflected from close to each side of the strip shall fall close to the extreme
edge of the space to be illuminated, all the other direct rays then fall into the
space to be illuminated. In shop windows three to four tiers of reflecting plates
are sufficient, and the whole can be made for the price of an ordinary lamp or for
very little more.
It will be seen that the plates are all placed at right angles to the line bisecting
the angle formed by the ray of light striking the centre of the plate and the line it
is desired to take in, being radiated therefrom. Now I am well aware that concave
parabolic mirrors are well known as scientific curiosities, but they are very costly
in construction and are practically utterly in-admissible for the purpose for which
'I have designed my invention; also that circular side reflectors formed of a series
of pieces of flat glass have been arranged in an arc of a circle in order to save the
expense of circular reflectors, but I believe there has been no instance in which a
square or pyramidal reflector has been formed with several tiers of reflecting plates
Bet at different angles so as to reflect all the light upon the same field,

page_text: Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
I claim is
Reflectors for lamps applicable for use in shop windows and other places where
the light is desired to be reflected into a comparatively small field below, in which
the reflectors have several tiers of flat reflecting plates placed at such different
angles with the source of light that the reflections from all the plates shall cover
approximately the same limited field, substantially as described.
WP. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, and
323, High Holborn, London,
Patent Agents for the Applicant.