Year: 1899

page_text: Date of Application, 10th Nov., 1899
Complete Specification Left, 27th June, 1900-Accepted, 4th Aug.,
1900
A communication from OLIN HANSEN BASQUIN, of Ritterstrasse 26, Berlin,
Germany, Engineer.
WO, THE BRITISH LUXFER PRISM SYNDICATE, LIMITED, of 16, Hill Street, Fins-
bury, in the City of London, Lucical Engineers, do hereby declare the nature of
this invention to be as follows:-
This invention has reference to a construction of prismatic glass plates specially
adapted for windows, and having for object the introduction or distribution of a
greater quantity of light than that obtained through an ordinarywindow when such
window is supplied with plain glass. The prism plates used for this purpose are in-
tended to introduce light along practically horizontal lines into a room, and to re-
receive the same from a sky area or are measured somewhere between the angles of
40 and 70 degrees, or approximately those angles. Such prism plates may be pressed
or rolled in plates of any desired size, and if small plates are needed, they may
be assembled together in any desired manner to form a finished plate of the
proper size to fit any desired window. Heretofore the practice has been to make
such prism plates with but a single practical augle or refracting surface, or in
other words to make them so that they were practically useful only when placed
in a certain predetermined position with a certain end up, each plate therefore
being useful only for a certain comparatively small are of sky. This necessitated
the use of as many different moulds or rolling tables as there were angles to be
employed.
According to this invention it has been found that by combining the angles
in a certain way there can be obtained, with one half the number of plates or
angles, the same result as heretofore obtained. In the plates heretofore employed
the lower face only of the prism has been treated so as to be useful, but according
to this invention both faces are so formed that either of them may be used to
refract the light by inverting the plate.
Figs. 1, 2 and 3 of the accompanying illustrative drawings are cross sections
of parts of three different plates constructed according to this invention.
As will be seen, each plate has on one side a light receiving surface and on the
other side a prism or set of prisms.
By making the base angles of each prism on the first plate (Fig. 1) of approxi-
mately 60° and 65° the angles of each prism on the second plate (Fig. 2) of
approximately 55° and 6740; and the angles of each prism on the third plate
(Fig. 3) of approximately 50° and 70°, the above-mentioned result desired can
be obtained. Of course these angles can be slightly varied, but with a set of
such plates formed as described it is possible by inverting each plate and suitably
combining them when necessary in one and the same window, to take advantage

page_text: of practically all of the ordinary conditions which prevail in cities, so as to bring
the light into the room in substantially horizontal lines. Experience shows that
in most such cases, the light necessary to be treated by vertically placed prism
plates comes from some portion of the sky measured by an are lying somewhere
between 38° and 70° from the vertical.
By the construction described there is obtained a prism plate having on one
side a receiving surface formed as desired, and on the other side a prism or set
of prisms, the two base angles of the prism or each prism being between approxi-
mately 50° aud 70°, and the two faces of the prism or each prism being so related
to the receiving surface, that when the plate is placed vertically with the proper
end upwards, either of the faces will refract the light received on the receiving
surface from a particular portion of the sky, measured by an arc lying somewhere
between angles of approximately 38° and 70° from the vertical, and direct such
light into a room in substantially horizontal lines.
By the use of prism plates of the kind described, one half of the number of
moulds or tables used for rolling the glass can be dispensed with, and only one
half the stock of prism glass need be carried that has heretofore been necessary.
To render the prism plates commercially practical, there must be an apparent
uniformity in the size of the prisms and the thickness of the plates, and this is
accomplished by the peculiar groupings of the angles illustrated in the accom-
panying drawings. Moreover, experience has demonstrated that there are certain
angles which occur in practice most frequently and to avoid confusion in the
use of these plates, it is desirable to associate these frequently recurring angles
in any given plate, with those less frequently, used, and this also has been done
in the forms illustrated in the accompanying drawings. Thus angles of approxi-
mately 50°, 55° and 60° are most commonly used.
Dated this 10th law of Narambar 1800
A communication from OLIN HANSEN BASQUIN, of Ritterstrasse 26, Berlin,
Germany, Engineer.
We, THE BRITISH LUXFER PRISM SYNDICATE, LIMITED, of 16, Hill Street, Fins-
bury, in the City of London, Lucical Engineers, do hereby declare the nature of
this invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
-
This invention has reference to a construction of prismatic glass plates specially
adapted for windows and having for object the introduction or distribution of n
greater quantity of light than that obtained through an ordinary window when Buch
window is supplied with plain glass. The prism plates used for this purpose are in-
tended to introduce light along practically horizontal lines into a room, and to re-
ceive the same from a sky area or are measured somewhere between the angles of
380 and 70 degrees, or approximately those angles. Such prism plates may be
pressed or rolled in plates of any desired size, and if small plates are needed, they
may be assembled together in any desired manner to form a finished plate of the
proper size to fit any desired window. Heretofore the practice has been to make
such prism plates with but a single practical angle or refracting surface, or in

page_text: other words to make them so that they were practically useful only when placed
in a certain predetermined position with a certain end up, each plate therefore
being useful only for a certain comparatively small are of sky. This necessitated
the use of as many different moulds or rolling tables as there were angles to be
employed.
According to this invention it has been found that by combining the angles
in a certain way there can be obtained, with one half the number of plates or
angles, the same result as heretofore obtained. In the plates heretofore em-
ployed, the lower face only of the prism has been treated so as to be useful, but
according to this invention both faces are so formed that either of the refracting
angles formed between such faces and the light receiving surface of the plate
can be used to refract the light by inverting the plate.
Figs. 1, 2 and 3 of the accompanying illustrative drawings are cross sections
showing, to an enlarged scale, parts of three different plates constructed accord-
ing to this invention. Figs. 4 and 5 show, also to an enlarged scale, one of the
plates in two different positions and how light will be refracted in passing through
the same.
As will be seen, each plate has on one side a flat light receiving surface and on
the other side a prism or set of prisms.
By making the base angles of each prism on the first plate (Fig. 1) of approxi-
mately 60° and 650; the angles of each prism on the second plate (Fig. 2) of
approximately 55° and 6710; and the angles of each prism on the third plate
(Fig. 3) of approximately 50° and 70°, the above-mentioned desired result can
be obtained. Of course these angles can be slightly varied, but with a set of
such plates formed as described, it is possible by inverting each plate and suit-
ably combining them when necessary in one and the same window, to take ad-
vantage of practically all of the ordinary conditions which prevail in cities, so
as to bring the light into the room in substantially horizontal lines. Experience
shows that in most of such cases, the light necessary to be treated by vertically
placed prism plates comes from some portion of the sky measured by an are lying
somewhere between 38° and 70° from the vertical.
By the construction described there is obtained a prism plate having on one
side a light receiving surface formed as desired, and on the other side a prism
or set of prisms, the two base angles of the prism or each prism being between
approximately 50° and 70°, and the two faces of the prism or each prism being
so related to the receiving surface, that when the plate is placed vertically with
the proper end upwards, one or other of the refracting angles of the prism, or
each prism, according to which end of the plate is uppermost, will refract the
light received on the receiving surface from a particular portion of the sky,
measured by au are lying somewhere between angles of approximately 38° and
70° from the vertical, and direct such light into a room in substantially horizontal
lines.
Fig. 4 shows the plate illustrated in Fig. 2, placed vertically with the refract-
ing angle of 55° of each prism lowermost and how a beam of light meeting the
flat outer receiving surface of the plate will be refracted on passing through such
lower refracting angle and directed in an approximately horizontal direction.
Fig. 5 shows the plate inverted so that the refracting angle of 674° of each prism
is the lower and effective refracting angle of light impinging upon the outer
surface of the plate.
By the use of prism plates of the kind described, one half of the number of
moulds or tables used for rolling the glass can be dispensed with, and only one
half the stock of prism glass need be carried that has heretofore been necessary.
To render the prism plates commercially practical, there must be an apparent
uniformity in the size of the prisms and the thickness of the plates, and this is
accomplished by the peculiar groupings of the angles illustrated in the drawings
referred to. Moreover, experience has demonstrated that there are certain angles
which occur in practice most frequently, and to avoid confusion in the use of

page_text: these plates, it is desirable to associate these frequently recurring angles in any
given plate, with those less frequently used, and this also has been done in the
forms illustrated in the drawings. Thus angles of approximately 50°, 55° and
CO° are most commonly used.
Having now particularly described and ascertained the nature of the said in-
vention and in what manner the same is to be performed we declare that what
we claim is :-
1. A prism plate having on one side a light receiving surface formed as de-
sired, and on the other side a prism or set of prisms, the two base angles of the
prism or each prism being between approximately 50° to 70°, and the two facea
of the prism or each prism being so related to the light receiving surface that
when the plate is placed vertically with the proper end upwards, one or other of
the refracting angles of the prism or each prism will refract the light received
on the receiving surface from a particular portion of the sky, measured by an arc
lying between angles of approximately 380 and 70° from the vertical, and direct
such light into a room in substantially horizontal lines, as set forth.
2. The improved prism plates constructed substantially as described and shown
'
Or June 1900.
For the Applicants,
W. LLOYD WISE.
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.