Improvement in Incidence Windows or Vault Lights.
Year: 1886

page_text: Improvement in Incidence Windows or Vault Lights.
I, LOUIS NELKE, lithographer, of Baltimore City, in the State of Maryland,
United States of America, do hereby declare the nature of my invention for
INCIDENCE WINDOWS OR VAULT LIGHTS 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 Incidence Windows or Vault Lights. The art of
illuminating vaults, cellars and basements by means of incidence windows has
long been practiced, but difficulty has been experienced in setting the glasses in
the frames in such manner as to afford the most light and at the same time prevent
the leakage of water. The lenses or glasses have heretofore been countersunk
in the frames, or set like steps of stairs, but when thus done the water shed is
imperfect.
:
The invention as hereinafter described overcomes. the difficulties and objections
mentioned, and said invention consists in a lens or glass of prismatic or approxi-
mately prismatic form having two shoulders or offsets-one at one side near the top
at the plane of incidence, and the other at the opposite side and below the first at
the plane of reflection, whereby the glass may be set on a frame which shall have a
slanting position, so that the upper surface or plane of incidence will be horizontal-
this position being the most appropriate to receive and transmit the light.
My invention also consists in the combination of the said lens and the slanting
frame on which it is supported.
It also consists in the entire structure as shown in Figure 2 having between the
lenses ventilating openings which are provided with covers.
The invention is illustrated in the accompanying drawing in which
Figure 1 is a perspective view of a lens or glass formed according to my
invention.
Figure 2 is a view of a frame supporting my improved lenses and also showing
the ventilating openings, one of which is uncovered.
Figure 3 is a sectional view of the slanting frame and one lens of the form of
that shown in Figure 1.
Figure 4 is a view of a lens formed according to my invention but differing
somewhat from that shown by Figure 1.

page_text: Figure 5 is a sectional view of the slanting frame and a lens like that shown in
Figure 4.
:
The lenses A are of prismatic form and are held in place on a slanting frame B
by the shoulders or offsets, c, and.c', on their sides. The offset o, is situated at one
side near the top and plane of incidence d, and the other offset c', is at the opposite
side and lower down at the plane of reflection e. The frame B has holes which are
filled by the lenses like a plug, the offsets hold the lens in position on the frame B,
and maintain the plane of incidence d, level; the light from above striking the
plane of incidence penetrates to the plane of reflection e and thereby is thrown in
a horizontal direction indicated by the dart in Figures 3 and 5. While the desired
light is thus obtained, the slanting position of the frame acts as a water shed.
The frame may be provided with ventilating slots of between the rows of lenses,
and hinged covers g employed to close said slots. This ventilating feature
may however be dispensed with and the advantage of the glasses for reflecting
light may be employed in the windows opening on spaces or alley ways between
buildings.
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:-
1st A lens of prismatic or approximate prismatic form having shoulders or
offsets c, o, one at one side near the top at the plane of incidence, and the other
at the opposite side and below the first one at the plane of reflection, as set forth.
2nd The combination of a lens having shoulders or offsets c, c¹, one at one side
near the top at the plane of incidence, and the other at the opposite side and
below the first one at the plane of reflection and a frame having holes each of
which is filled by a lens inserted in it like a plug, as set forth.
3rd An incidence window comprising the frame B provided with the described
lenses placed in rows and having slots of between said rows provided with suitable
covers, as set forth.
4
1.
1
CA 1006