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665,170 · Brown · "Prism Plate" · Page 1 Home > Prism Glass > Patent Index > Page 1 |
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To all whom it may concern: Be it known that I, JAMES G.
BROWN, a resident of Cleveland, in the county of Cuyahoga
and State of Ohio, have invented certain new and useful Improvements in
Prism-Plates; and I do hereby declare the following to be a full, clear,
and exact description of the invention, such as will enable others skilled
in the art to which it pertains to make and use the same.
My invention relates to improvements in
light-diffusing prism-plates.
The object of this invention is to provide a
prism-plate that has a large illuminating capacity and that is capable of
diffusing a large volume of light next, adjacent and in close proximity to
the plate, as well as over a great distance from the inner or light-diffusing
side of the plate.
With this object in view the invention
consists in a novel arrangement and configuration of the prism-forming or
light-diffusing ribs of the plate.
In the accompanying drawings, Figure I is
a view in perspective of a prism-plate embodying my invention. Figs. II
and III illustrate opposite side edges of the plate.
Referring to the drawings, a designates
the plate's body portion, that, as illustrated, is arranged in a vertical
plane and provided upon its inner or light-diffusing side with two series
of prism-forming or light-diffusing ribs. All of the ribs are parallel and
on the plate illustrated extend horizontally across the plate. Each rib
b of one of the series of ribs has its two sides or faces 5 and 5
curving outwardly in end elevation and converging from the plate's body
portion. Each rib c of the other series of ribs has its two sides
or faces 6 and 7 flat and straight and converging in end elevation from the
plate's body portion. All the ribs project, preferably, the same distance
from the body portion of the plate; but the ribs c of one of the
series of ribs alternate with the ribs b of the other series of
ribs. The prism-forming ribs c only have the capacity of refracting
light, and the rays of light emerge from the prisms at right angles or
approximately right angles to the plate's body portion. A prism-forming
rib c having one of its faces at an angle of sixty degrees and its
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other face at an angle of eighty degrees to the body portion of the
plate has given very satisfactory results.
The peculiar external contour of the ribs b
in end elevation renders them capable of reflecting as well as refracting
light. The said ribs b diffuse light not only at right angles to
the plate's body portion, but at every angle between an angle of forty-five
degree and an angle of eighty degrees to the body portion. The ribs b
consequently diffuse light in advance of and in close proximity to or through
the adjacent prism c of the plate.
A prism-plate having parallel ribs b with
their sides or faces curved outwardly, as hereinbefore described, possesses
a large light-diffusing capacity, and a prism-plate having the light-refracting
prism c alternating with the aforesaid light-diffusing ribs b is
capable of diffusing a remarkably large volume of light over a long distance,
as well as downwardly and upwardly in close proximity to the plate.
What I claim is—
1. A prism-plate having two series of ribs
formed upon one and the same side of the plate and extending transversely
of the plate, with the ribs of one series having outwardly-curved sides or
faces in end elevation and with the ribs of the other series having flat
and straight sides or faces, and with the last-mentioned ribs alternating
with the ribs having curved faces, substantially as and for the purpose set
forth.
2. A prism-plate having the following formed
upon one and the same side of tile plate: a series of parallel ribs b
extending transversely of the plate and having, respectively, two sides or
faces 5 and 5 curving outwardly in end elevation and converging from the
plate's body portion, and another series of ribs c parallel and
alternating with the ribs of the first-mentioned series and having,
respectively, two flat or straight sides or faces 6 and 7 coaverging from
the plate's body portion.
Signed by me at Cleveland, Ohio, this 17th day
of October, 1900.
C. H. DORER, A. H. PARRATT. |