Pavement Lights with Prism Reflectors Supported on a Bed.
Year: 1897

page_text: Date of Application, 13th July, 1897-Accepted, 21st Aug.,
1897
COMPLETE SPECIFICATION.
Pavement Lights with Prism Reflectors Supported on a Bed.
I, JOHN MEIGGS EWEN, of No. 1129 The Rookery, Chicago, County of Cook,
State of Illinois, United States of America, Mechanical Engineer, do hereby
declare the nature of my 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 devices for illuminating basements, and has for its
object to provide means for receiving the light from the exterior, preferably
through a transparent or translucent pavement light, and then reflecting the
same from a prism reflector back into the basement to be illuminated along
horizontal lines.
The object is to get the greatest amount of light into the basements and to
reflect the greatest amount of light along horizontal lines.
The invention is illustrated in the accompanying drawings, wherein
Figure 1 is a section through the basement showing the preferred arrangement.
Figure 2 a similar view with the parts occupying a different position.
Figure 3 is a section through the preferred form of the reflector.
Figure 4 is a plan view of a prism reflector plate.
Like parts are indicated by the same letter in all the figures.
:
A is the basement, B the vault in front of the basement and beneath the side-
walk C. The side-walk is provided with a prism pavement D, which as shown in
Figure 1 may extend clear across the side-walk or, as shown in Figure 2, may be
toward the outer edge of the side-walk. When the arrangement is that shown
in Figure 1, the prisms of the pavement tiles are shaped so as to throw the light
downwardly in practically vertical lines. If the light comes vertically upon the
pavement or side-walk then no prisms would be necessary. If the arrangement
is that of Figure 2, prisms might be used, being varied according to the position
of the prism pavement and the position of the prism reflector, but they are not
usually necessary. The prisms of Figure 1 would differ of course from those of
Figure 2. In every instance, the pavement should be transparent or translucent,
or provided with glass tiles, and in many instances with prism tiles. A covered
vault is imperatively necessary, for the upper surfaces of the prisms on' the prism
refraction, to the inclined plane surface of the reflector and is reflected thence
speedily coated with dust or the like, so as to no longer permit the light to pass
through.
The prism reflector consists of a series of glass bodies E, having each a plane
surface F, and on the opposite side a series of prisms G, each of these prisms in
the form shown in Figure 1 has two surfaces meeting at a right angle. The
glass bodies E are made as thin as practicable and are then preferably united
by thin transverse translucent bors or cement sections H and longitudinal
supporting bars J, such as illustrated in Figure 4.
It is evident now that the light passing downwardly through the pavement
in Figure 2 falls upon the upper surface of the prisms, passes thence, with little

page_text: refraction, to the inclined plane surface of the reflector and is reflected thence
out into the basement on horizontal lines. None of these rays of light are inter-
rupted because in the body of the prism light there is no opaque separation
between two prisms; and at the joinings of the prism lights in the preferred
form the translucent transverse bars or cement sections permit the light to pass
through. In the form shown in Figure 3, the reflector consists of a bed K having
thereon the reflector sections E, which may be united by the bars J H or not, as
may be preferred. The sections may be finished on the edges and be then laid
close together on the bed.
In the device of Figure 2, either form of reflector may be used, though here the
reflector prisms would no longer be right-angled, the shape of such prisms depend-
ing upon the direction in which the light is delivered from the pavement prisms.
In Figure 1, the pavement prism illustrated is intended to operate as a refracting
prism for the purpose of directing the greater quantity of the light down upon the
prism reflector, but of course as previously suggested plain glass might be used.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
A device for illuminating basements, comprising side-walk lights and an in-
clined prism reflector composed of sections and a supporting. bed, therefor, the
whole situated and related substantially as described.
Dated this 13th day of July 1897.
Dated this 13th day of July 1897.
For the Applicant,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.