Window Prism Plates having their Prisms set at an Angle to the Vertical.
Year: 1897

page_text: Date of Application, 13th July, 1897-Accepted, 28th Aug., 1897
COMPLETE SPECIFICATION.
Window Prism Plates having their Prisms set at an Angle to the
Vertical.
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 and the like and has
for its object to provide a new and improved device for diffusing the light, of
which the following is a description, reference being had to the accompanying
drawings wherein,
Figure 1 is a face view of a window light embodying my invention;
Figure 2 is an edge view of the same;
Figure 3 is a view of a window provided with window glass embodying my
invention;
Figure 4 is a view of a portion of a street illustrating the use of my invention.
Like letters refer to like parts throughout the several figures.
In the use of the ordinary prismatic glass for diffusing the light, plates of glass,
each provided with a series of projecting prisms or ribs substantially horizontal
are placed together in a window, the light being thrown by such prisms toward the
rear of the room. When this ordinary prismatic glass is used the window receives
the light from directly in front and directs it towards the rear portion of the room
to be lighted. It often happens that the light directly in front of the window is
obstructed, as for example, by a high building on the opposite side of a street, and
in such case the ordinary prismatic glass can not well be used.
It is the object of my invention to provide a device by which this and like
difficulties may be obviated. In the drawings I have simply illustrated one form
of my device in order to make its operation clear, but it is, of course, evident that
other forms may be used to obtain the desired result, the condition being that the
prisms when in the window will run diagonally or in an angular direction across
such window.
In Figure 1, I have shown a tile or Section A of glass provided with a series of
projecting ribs or prisms B. These prisms instead of running straight across the
face of the section so as to be parallel with one edge, run diagonally across such
section, the angle of the prisms, of course, depending upon the conditions to be
met. In Figure 3 I have shown a window composed of a series of these sections
of glass connected together. It is, of course, evident, that any number of sections
may be used, and that the prisms or projecting ribs thereon may be of any desired
size and form. In Figure 4 I have illustrated a condition wherein my invention
may be utilized. I have shown in this figure a room C to be lighted by a window D.
On the opposite side of the street from Room C is the tall building E, having on
either side the small buildings F and G. The conditions here are such that the tall
building E obstructs the light directly in front of the window D, so that, practically,
Pin B11

page_text: only the light coming over the smaller buildings will strike the window. In this
event the ordinary prismatic glass is impracticable, and such glass can not utilize
such side light, because of the horizontal position of the prism.
I have found that if the prisms used in the window are tilted at an angle, the
light which comes over either the building F or G will strike the outer surface of
the glass and the direction of the rays will then be changed so that the light will be
thrown towards the back of the room, and thereby utilized to light the room C. It
is, of course, evident that the angular position of the prisms will depend upon the
width of the obstruction in front of the window. It will, therefore, be seen that
although a room such as the Room C can not be lighted with the ordinary prisms,
it can be lighted by use of my invention.
In making up a complete window, or making what I have called the prism
plate or plate consisting of a series of prism lights to fill the window or opening
through which the light is to be received, I may therein employ prism lights on
which the prisms are set diagonally, mounting the prism lights so as to have the
prisms running diagonally across the prism plate when in position, or I may take
prism lights in which the prisms run straight across the prism light and then set
them up in a frame, their edges being tilted or inclined to the vertical so as to
produce the same effect of diagonal prisms in the complete prism plate.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:
A prism plate consisting of a series of prism lights and a frame, the lights
shaped and arranged in the frame as shown and for the purpose specified.
Dated this 13th day of July 1897.
For the Applicant,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.