IMPROVEMENTS IN HOLLOW GLASS REFLECTORS FOR LAMPS AND OTHER PURPOSES, AND IN THE PROCESS FOR MANUFACTURING THE SAME
Year: 1880

page_text: LETTERS PATENT to Alexander Specht, of the Firm of Specht, Ziese, & Co.,
of Hamburg, in the Empire of Germany, for an Invention of "IMPROVEMENTS
IN HOLLOW GLASS REFLECTORS FOR LAMPS AND OTHER PURPOSES, AND IN
THE PROCESS FOR MANUFACTURING THE SAME" A communication by Otto
PROVISIONAL SPECIFICATION left by the said Alexander Specht at the
Office of the Commissioners of Patents on the 28th May 1880.
ALEXANDER SPECHT, of the Firm of Specht, Ziese, & Co., of Hamburg, in the
Empire of Germany. "IMPROVEMENTS IN HOLLOW GLASS REFLECTORS FOR
LAMPS AND OTHER PURPOSES, AND IN THE PROCESS FOR MANUFACTURING THE
SAME." [A communication by Otto Schumann, of Hamburg, in the Empire of
Germany.]
The object of this Invention is a hollow glass reflector coated inside with silver
or similar substances, which in form of a cupola may be put over the cylinder of a
lamp for the purpose of reflecting the light from an ordinary burner either
downwards or sideways, and in the process of manufacturing the same.
Reflectors made of so-called silverglass have up to the present time only been
manufactured and used as side reflectors.
In this Invention a recess a is pressed into the reflector, the glass is bent to
form a neck, and by cutting the top of this recess at ca hole is formed large
enough to permit the cupola to pass over the lamp cylinder, see Figures 1 and 2.
The essential point in manufacturing these reflectors consists in cutting the hole in
both glass skins. This may be done in two different manners, either by pressing
the inner and outer skin of the reflector into a kind of neck, or by cutting directly
circular openings in the glass.
The form into which the outer skin of the reflector is pressed is so arranged that
a large bulb is added, leaving sufficient space for the neck to be pressed into the
inner skin.

page_text: This being performed, the bulb of the outer and part of the inner neck b is cut
off and a thin plate d is put over the opening, leaving room for the cylinder, see
Figure 3.
Instead of this plate a hollow neck may also be fixed, protecting the edges of
the holes previously cut, and preventing dirt or dust from passing between the
outer and inner skin.
The silver coating inside is performed in usual manner by a solution of silver,
but to give this solution a permanent hold on the glass and pretect it against the
influence of the atmosphere and of heat the inventor uses a thin coating of asphalt
varnish, preventing thus all chipping of the silver, and gaining a lasting and
durable silver glass cupola.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Specht in the Great Seal Patent Office on the 27th
November 1880.
ALEXANDER SPECHT, of the Firm of Specht, Ziese, and Co, of Hamburg, in the
Empire of Germany. "IMPROVEMENTS IN HOLLOW GLASS REFLECTORS FOR
LAMPS AND OTHER PURPOSES, AND IN THE PROCESS OF MANUFACTURING THE
SAME." A communication by Otto Schumann, of Hamburg, in the Empire of
Germany.
The object of this Invention is a hollow glass reflector coated inside with silver
or similar substances, which in form of a cupola may be put over the cylinder
of a lamp for the purpose of reflecting the light from an ordinary burner either
downwards or sideways, and in the process of manufacturing the same.
Reflectors made of the so-called silver glass have up to the present time only
been manufactured as side reflectors without an opening for the cylinder pierced
through both glass skins.
The accompanying Drawing represents three different kinds of reflectors, as will
be described hereafter.
The essential point in manufacturing these reflectors consists in cutting the hole
in both glass skins. This may be done in two different manners, either by pressing
the inner and outer skin of the reflector into a kind of neck, or by cutting directly
circular openings in the glass.
The form into which the outer skin of the reflector (Figures 1 and 2) is pressed
and so arranged that a large bulb a is added, leaving sufficient space for the neck b
to be pressed into the inner skin. This being performed, the bulb of the outer and
bottom of the inner neck b is cut off at c, and a thick plate d, Figure 3, is put over
the opening, leaving room for the cylinder.
Another mode of manufacturing is represented by Figure 4-6, where instead
of the tube b circular openings are cut directly into the inner and outer skins,
into which (Figure 6) a hollow neck b' is fixed, protecting the edges of the holes
previously cut, and preventing dirt and dust to pass between the outer and inner
skin.
Figure 7 represents a side reflector manufactured as shewn in Figure 4, having
the opening o for the cylinder, instead of in the centre, as in Figure 3 or 6, near
the circumference of the cupola, into which a short tube or neck is fixed for the
same purpose as in Figure 6, in order to reflect the light in a skew direction
downwards.
The silver coating inside is performed in the usual manner by a solution of
silver, but to give this solution a permanent hold on the glass and protect it
against the influence of atmosphere or heat the inventor uses a thin coating of
asphalt varnish, preventing thus all chipping of the silver, and gaining a lasting
and durable silver glass cupola.
Having now described and particularly set forth the nature of the said Invention,
and the manner of carrying the same into effect, I would have it understood that
what I claim is,―
First. In manufacturing hollow glass reflectors the employment of a bulb a,
Figures 1 and 2, so arranged to leave sufficient space for the neck b of the inner
skin, substantially as described.
Second. A hollow glass reflector with a central opening o, Figure 5, into which
is fixed a neck or tube b¹ intended for the passing through of the cylinder,
substantially as and for the purposes described.

page_text: Third. A hollow glass reflector intended for reflecting the light partly down-
warts, partly sideways, with an opening o near the circumference of the base of
the cupola, into which is fixed a neck or tube b², substantially as and for the
purposes described.
In witness whereof, I, the said Alexander Specht, have hereunto set my
hand and seal, this Twenty fifth day of November, in the year of our Lord
One thousand eight hundred and eighty.
ALEXANDER SPECHT. (L.S.)