IMPROVEMENTS IN THE CONSTRUCTION OF ILLUMINATING GRATINGS FOR ROOFS, AREAS, FOOTWAYS, AND OTHER PLACES, AND IN THE GLASSES FOR COMBINATION THEREWITH FOR ILLUMINATING PURPOSES
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Thaddeus Hyatt at the Office of the
Cominissioners of Patents on the 12th April 1880.
THADDEUS HYATT, of 21, Addison Gardens, N., Kensington, London, in the
County of Middlesex. "IMPROVEMENTS IN THE CONSTRUCTION OF ILLUMINATING
GRATINGS FOR ROOFS, AREAS, FOOTWAYS, AND OTHER PLACES, AND IN THE GLASSES
FOR COMBINATION THEREWITH FOR ILLUMINATING PURPOSES."
As commonly made illuminating roof gratings and pavement lights for being
walked upon are constructed by combining "pressed" glasses with the gratings,
these glasses being handsomer in appearance than if cut from plates of glass,
illuminating gratings made of equivalent pieces of rough plate being comparatively
unsaleable, because of the untidy look of the rough edges of the glasses where they
are broken from the plate; but plate glass is stronger and tougher than "pressed,"
on account of the superior method of its annealing. It is also desirable to be able
to use plato glass in small pieces in combination with iron gratings where the
glasses are fastened in with hydraulic cement, for the reason that hydraulic mortar
or paste in setting gives out a large volume of heat, and when the glasses set by
this cement are pressed glasses this heat tells upon the imperfectly annealed ones,
many such existing always among pressed glasses because of the imperfection of
their annealing, and liable to crack under the influence of the heat of the cement,
thereby causing serious loss and annoyance. The object of my Invention is to
produce for the market a saleable article of illuminating grating made from pieces
or fragments of cut plate glass set in the gratings by a method that produces as
tidy an article as those made from pressed glasses; and this I accomplish by what
I call the covered-joint process of manufacture, my method consisting in covering
the joints on the weather surface of the grating by means of a fillet or overlap,
which while concealing the rough edges of the glasses also serves to protect them
in some degree from wear where the gratings are walked upon. This fillet I prefer
to cast upon the grating, and then set the glasses from the opposite side, the fillet
itself forming the seat for the glass. A part of my Invention in some cases consists
in setting one or more glasses in a small chase or frame, and then combining these
frames with the main grating. Another part of my Invention relates to prismatic
pavement lights. In a vessel's deck tho prismatic glass is unobjectionable, but
placed over an area to light a dark basement room under the building the prism
form is faulty, because one face of the prism is not only opposed to the reflecting
one that sends its rays into the basement but in a degree interferes with it. To
meet this difficulty my improvement, according to one method of procedure, consists

page_text: in serrating the objectionable slope of the prism with steps or teeth formed with
perpendicular or nearly perpendicular sides, the rays from the opposite reflecting
slope then passing freely through the serrated side into the dark basement rooin
without obstruction, while according to another method of procedure I form the
serrated slope of the prison with steps or teeth, each one of which is composed of a
straight or perpendicular face and a reflecting sloping one behind it. Prismatic
glasses thus made I prefer to form with but one serrated slope, all the reflecting
inclines of which face the apartment to be lighted. By another method of
procedure I utilize both reflecting surfaces of the prisin and produce a still better
result than by the foregoing methods. According to this part of my Invention I
combine a daylight reflector with prism glasses, and thus send into the dark base-
ment the light from both the direct and the opposing faces of the reflecting prism
surfaces. In carrying my Invention into effect I prefer to make use of a number
of reflectors, preferably in the form of slats or strips of about a foot long and from
three to six inches wide, placed as near to the prisms as possible in practice, and of
preference on two or more levels, the one breaking joints with the other. The
combination of sectional daylight reflectors and illuminating gratings substantially
as herein described, whether the gratings be made with prismatic or other shaped
glasses constituting a part of my Invention and improvement in lighting buildings.
Another part of my Invention relates to lens-light illuminating gratings, the
objection to which as commonly made for being walked upon is the button-like
shape of the glasses, and my improvement consists in shaping the face of the lenses
to present more flat surface, and thus less obnoxious to the feet of pedestrians,
which I effect hy making the lens surface in the form of an arch, the under face
being also arched but crosswise to the upper. These glasses I make either with
single lenses or lenses in clusters upon a plate of glass in manner similar to the
common ones, combining them with the gratings in the ordinary way. Another
part of my Invention relating to illuminating gratings as walking and roof
surfaces consists in combining the glasses with either a cast grating or a perforated
plate or sheet of wrought metal forined with wedge shaped crimps or corrugations,
which I fill with cement, concrete, or other suitable and cheap material, in which I
set the glasses. In carrying this part of my improvement into practice I set the
glasses within the channels or corrugations, placing each one within or over a light
hole, and there surround it with the cement or material that fills the corrugations.
Another part of my Invention relates to illuminating gratings as pavement lights,
the foot surface of which is a combination of glass, cement, and metal, the cement
being the safe or foot holding material in the combination. As usually made the
cement forms proportionately too small a part of the surface to produce the best
effects, and my improvement consists in forming the edges of the glasses with
indents where they take their bearing in the gratings, which increases the area of
the cement and the safety of the surface; where the grating is not flat but studded
with knobs of iron for safety, my improvement consists in making thein safer by
means of bits of rope on end, preferably boiled previously in rosin, inserted within
the knobs, which are made hollow to receive them.