Window Prism Lights having Vertical Grooves on the Receiving Sides.
Year: 1897

page_text: Date of Application, 13th July, 1897-Accepted, 4th Sept.,
1897
COMPLETE SPECIFICATION.
Window Prism Lights having Vertical Grooves on the Receiving
Sides.
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 window lights and the like, and has for its object to
provide a new and improved window light of which the following is a description,
reference being had to the accompanying drawings, wherein
Figure 1 is a face view of the section of window glass embodying my invention,
looking toward the prism side ;;
Figure 2 is a section.on line 2-2 of Figure 1;
Figure 3 is a section on line 3-3 of Figure 1;
Figure 4 is a section through a modified form of window light.
Like letters refer to like parts throughout the several figures.
In the use of ordinary prismatic glass having horizontal ribs or prisms upon
one side, the light from the sky which comes in vertical planes perpendicular
to the plane of the window, is changed in direction and is projected toward the
rear of the room in connection with which the glass is used. The oblique rays of
light which strike such prismatic glass, which are in planes not perpendicular to
the plane of the window, are practically lost, as they are not changed in direction
so as to be projected toward the rear of the room. It is the object of my present
invention to provide a window glass by which these oblique rays of light may be
utilized. In carrying out my invention I may take an ordinary section or plate A
of prismatic glass provided on one side with the ordinary prisms or projecting
ribs B. The other side of the glass is provided with a series of grooves Cat an
angle to the prisms or projecting ribs B. These grooves are provided with the
faces D D placed nearly perpendicular to the plane or receiving surfaces. The
oblique rays of light A¹, striking the outer face of the glass would be refracted
and would take the direction shown in dotted lines, thereby being projected against
the side of the wall in proximity to the window without being utilized in lighting
the rear of the room. When the glass is provided with the grooves C, these rays
of light A striking the surface D, are reflected as shown in full lines, their
direction being so changed that when acted upon by the prisms B they are
projected towards the rear of the room and are utilized in lighting the same.
will therefore be seen that in forming the window glass with these grooves, much
more light can be utilized than when the ordinary prismatic glass is used, and
hence a better illumination can be obtained in any given case.
It
In Figure 4 I have shown the glass provided with grooves C which are larger
than those shown in Figure 3. In this construction the plane surface E of the
glass is partly at the bottom of the grooves and partly at their outer ends, while
in Figure 3 the plane surface of the glass is all at the outer ends of the grooves.

page_text: Broadly speaking, this invention consists of a prism light comprising a body
of glass with the usual substantially horizontal prisms on one side and on the other
side a series of substantially vertical grooves having surfaces slightly inclined
to the plane of that side and also arranged so as to leave wide or large plane surfaces
on that side of the prism light, the plate made up of these lights is called a prism
plate.
By the words "extended plane surfaces" I mean any and all of the plane surfaces
on the receiving side which are substantially parallel to the body of the window
light.
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:-
As a new article of manufacture a prism light having a glass body and prism³
systematically arranged to produce an increased illuminating effect on one side,
a broken receiving surface on the other side, substantially as shown and described.
For the Applicant,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.