Year: 1897

page_text: Date of Application, 13th July, 1896-Accepted, 4th Sept., 1897
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 per-
formed, to be particularly described and ascertained in and by the following
statement:—
My invention relates to devices for framing or mounting tile or similar sections
into a plate and is particularly applicable to the mounting of what is known as
prism lights to form prism plates. It is illustrated in the accompanying drawings,
wherein
Figure 1 is an elevation of a prism plate;
Figure 2 is an elevation of a prism light;
Figure 3 is an elevation of one of the ties, and
Figure 4 is a section through the plate on the line 4-4 of Figure 1 with parts
broken away.
Like parts are indicated by the same letter in all the figures.
A is the surrounding sash or frame which contains the prism light and B B
represent the prism lights having each thereon the prisms C C; D are the warps
which run continuously from one side of the frame to the other; E E are the ties
or other connecting pieces; F, the keys which overhang the corners of the prism
lights. It will be evident that these several details need not all be used or united
in any given device, but this is a particular case to which my invention is
applicable.
Figure 4 illustrates the manner in which such prism plate is used, the light
descending upon the plate as indicated by the single arrow and passing thence,
as indicated by the two arrows. Now the net or grid which is made up of the
warps
and ties or indeed of any desired or necessary parts, is essential as a support
to the prism lights. I prefer to incorporate the prism lights in such grid or net
and then to immerse the whole in an electrolytic hath to electro-glaze the lights
into the frame, but of course my improvement is applicable to other arrangements
as well as this particular one. Obviously any opaque cross bars or ties which
form a part of this frame, net or grid will intercept a very considerable quantity
of light, as for example, all the light falling from a given direction included
between the dotted lines (Fig. 4). Now by leaving the openings G in the cross
bar or warp, it is plain that the greater portion of such light will pass through
and be refracted, thus adding to the volume of light transmitted by the prism
plate. These openings or spaces may be, if necessary, filled with some sort of
transparent paste, though this is probably not essential, certainly not in many
cases. The cross bars may be of any desired length, but I have shown them
by what I have called ties. I have shown but one arrangement of the plate in
which the cutting out of the bar is of importance but there are many others and
indeed almost every instance where prism lights are mounted into prism plates,
it is a matter of importance to thus minimize the obstruction of the light offered
by the opaque supporting bars.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is :-
A prism plate comprising a series of prism sections placed close together edge
to edge, interposed frame consisting of flat bars between the several edges, the
cross bars cut out internally so as to admit of the passage of light therethrough,
while at the same time presenting an unbroken exterior surface.
Dated this 13th day of July 1897.
For the Applicant,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.