IMPROVEMENTS IN THE PRODUCTION OF ORNA- MENTAL PATTERNS OR OTHER DEVICES UPON THE SURFACES OF GLASS OR OTHER MATERIALS
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by James Couper, the younger, at the
Office of the Commissioners of Patents on the 16th March 1878.
JAMES COUPER, the younger, of Glasgow, in the County of Lanark, North
Britain, Flint Glass Manufacturer. "IMPROVEMENTS IN THE PRODUCTION OF ORNA-
MENTAL PATTERNS OR OTHER DEVICES UPON THE SURFACES OF GLASS OR OTHER
MATERIALS."
This Invention, which relates to the production of ornamental designs or devices
upon the surfaces of glass or other materials, has for its object to produce such
designs more economically and with a greater degree of accuracy than hitherto. The
improvements are especially adapted for the production on glass surfaces, such for
example as lamp shades, or globes, decanters, and other table glass, besides flat glass
surfaces, such as plate glass, such designs as are used to ornament the same.
According to the first modification of carrying out my improvements the surfaco
of glass or analogous material on which the design is to be produced is coated with
a varnish or its equivalent, which will resist the action of an acid, such as that
which is used for etching glass. The coating of varnish or its equivalent being
allowed to dry, a stencil plate having the required design cut therein is laid over or
fastened upon those parts of the surface on which the design is to be produced.
Those portions of the varnished or coated surface which are seen through the open
portions of the pattern in the stencil plate are then removed by the action upon
them of what is known as "Tilghmann's Sand Blast," this having the effect of
leaving those portions of the surface corresponding to the pattern in a state ready
to be acted upon by an etching liquid whilst the varnish or coating protects the
other portions. In this state the surface is submitted to the action of an etching
liquid until the device is sunk into the surface to the required depth.
According to the second modification of working my improvements stencil plates
are used, in which the portions to correspond with the patterns to be produced are
closed in place of open as in the first modification. In using stencil plates of the
kind last mentioned the "sand blast" has the effect of removing or obscuring the
whole of the surface excepting those portions on which the stencil plates now last-
De

page_text: mentioned are laid, the effect of this action being to leave the pattern or ornamental
device with a smooth surface standing out in slight relief from those portions of
the surface on which the "sand blast" has operated. A conting of acid-resisting
varnish, or its equivalent, is then applied to those parts of the surface on which the
"sand blast" has operated, and the surface has then applied to it an etching liquid,
which, acting upon the smooth surface portions in relief, removes them to the
required depth, and with a correspondingly smooth surface of pattern remaining.
It is to be understood that if desired the ordinary glasscuttor's wheel may be
used for finishing, that is to say, cutting over the pattern produced by the "sand
blast" operating so as to impart to them the appearance of cut glass, and an
engraving wheel may be used for filling in portions of patterns or devices which
are too fine or small to be well produced by either modification of my present
improvements.