Window Prism Plates having Prisms Inclined to One Another.
Year: 1897

page_text: Date of Application, 13th July, 1897-Accepted, 28th Aug., 1897
COMPLETE SPECIFICATION.
Window Prism Plates having Prisms Inclined to One Another.
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 light diffusing devices for windows or the like, and has
for its object to provide a new and improved light diffusing device for this
purpose. I have illustrated my invention in the accompanying drawings
wherein
Figure 1 is a view of a section of a window embodying my invention;
Figure 2 is a similar view showing a somewhat modified form;
Figure 3 is a section of glass showing a further modified form of my device;
Figure 4 is a section on line 44 of Figure 3.
Like letters refer to like parts throughout the several figures.
When ordinary prismatic glass is used in windows the light striking the
window is changed in direction and is projected toward the rear of the room and
greatly increases the illumination of such room. I have found, however, that
under some conditions, as, for example, where the light can only be received
through narrow openings on account of buildings or the like opposite a window
the illuminating effect produced by the use of the ordinary prismatic glass is very
much reduced. When the construction herein shown is used the light is more
thoroughly diffused throughout the room, such light being thrown in several
different directions instead of being projected straight forward as is the case when
the ordinary prismatic glass is used. I have illustrated several forms of glass
embodying my invention in order to more clearly illustrate its use, but it is of
course evident that other forms than those shown may be used to produce the
desired result, and I of course do not wish to be limited to the construction
shown.
In Figure 1 I have shown the portion A of a window provided with a series of
sections B of glass, such sections being provided with projecting ribs or prisms.
These sections as shown in Figure 1 are hexagonal in shape, and are so positioned
that the projecting ribs or prisms face in several different directions. The
position of the prism or ribs will of course depend upon the conditions to be met.
These prisms may however be so positioned as to direct the light towards any
given point, hence the window, instead of diffusing the light in a haphazard
manner, is constructed after a definite plan so as to direct the light towards
definite points.
In Figure 2 I have shown the portion of a window provided with a series of
sections C of ordinary prismatic glass, the sections being set up on end, as it were,
and so positioned that the prisms face in several different directions, thereby
throwing the light towards different parts of the room.
In Figure 3 I have shown a section of glass provided with a series of prismatic

page_text: sections D, such sections being formed so as to project the light in several
different directions. The section D' for example, projects the light in one direction,
while the section D2 throws the light in another direction. These sections are
formed after a definite plan so as to throw the light in certain given definite
directions.
It will be seen that when the glass is constructed as herein shown the light
may be directed toward any given point on either side of the window.
Of course I do not wish to be understood as indicating that I have shown all of
the arrangements of such prisms as might be made to accomplish the desired
result. Briefly stated, my invention is essentially as follows: When the prism
window light having prisms thereon) systemmatically arranged to increase the
illumination of the apartment is applied to a window, such prisms as ordinarily
arranged heretofore throw the light directly back into the room and thus
concentrate the light in certain parts of the room. Now, to secure a comparatively
even distribution of such light, it is necessary to set the prisms which go to make
up such prism plate angularly with reference to each other or to tilt them. By
this means the light can be distributed as desired, some being sent directly back
into the room, some of the light being thrown on one side of the course of such
direct light, and some light being thrown on the other side.
Having now particularly described and pascertained the nature of my said
invention; and in what manner the same is to be performed, I declare that what I
claim is :-
1. A prism plate for a window consisting of a series of prism sections or prism
lights combined together, substantially as shown and described.
2. A prism plate for a window provided with prisms systemmatically arranged
to produce an increased illuminating effect in the apartment, said prism plate
having on one side a receiving surface, said prisms arranged so that some are in
substantially horizontal lines and others inclined or tilted with reference thereto.
3. A prism plate for a window provided with a series of separate prism lights
combined together to form the plate, and presenting on one side a receiving
surface, and on the other a series of prism surfaces, the prisms on each prism
light systemmatically arranged to produce an increased illuminating effect in the
apartment, and the prisms on the several lights inclined or tilted with reference
to each other.
Dated this 13th day of July 1897.
For the Applicant,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.Ć., Chartered Patent Agent.