Improvements relating to Processes of Chipping Glass.
Year: 1893

page_text: Date of Application, 4th Apr., 1893-Accepted, 6th May, 1893
COMPLETE SPECIFICATION.
Improvements relating to Processes of Chipping Glass.
I REGINALD HADDAN of the firm of Herbert Haddan and Co. of 18 Buckingham
Street, Strand W.C. London, Patent Agent do hereby declare the nature of this
invention a communication to me from abroad by Samuel Evans, Charles Leonard
Rawson and Charles Turner Brown all of 423 Temple Court, Chicago, in the State
of Illinois, United States of America and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement :--
This invention relates to a process of chipping glass, wherein the sheet of glass
to be chipped is prepared for and ground by the sand blast process and a chipping
compound is afterward applied to such glass in a manner to produce, when the
sheet of glass on the part thereof chipped by this process was clear glass before
being treated thereby, ornamentation consisting of combined portions of clear and
chipped surfaces forming a determined design; and to produce, when such glass
was a combination of clear, ground and clear glass before being treated, ornamenta-
tion consisting of combined portions of ground and chipped surfaces forming a
determined design.
In this process the preparation of the glass for the sand blast process demands
that the pattern employed be the negative of the design to be produced upon the
surface of such glass, and after the pattern has been placed upon the sheet of glass
to be ornamented and attached thereto it is allowed to remain thereon till after the
grinding of the glass and the application of the chipping compound, in a heated and
liquid condition, thereto, when such pattern, with the chipping compound thereover,
is removed from the glass. By thus placing the pattern on the glass and allowing
it to remain there during the grinding and during the placing of the chipping
compound completely over the glass and the pattern thereon, and then removing
the pattern, (and by such removal of the pattern removing the chipping compound
from the portion of the glass, ground or unground, to be unchipped), the boundary
line of the ground glass to be chipped and the boundary line of the chipping
compound remaining on the glass are necessarily co-incident, while in all processes
heretofore known the boundary line of the ground glass to be chipped and the
boundary line of the chipping compound remaining on the glass during the
process of chipping are not and cannot be made to be co-incident, but only
approximately so.
The invention is illustrated by the drawings accompanying and forming a part
hereof, in which―
Fig. 1, is a plan view of a pattern, of the kind and adapted to be used for the
purposes above referred to;
Fig. 2, a plan view of a sheet of glass having the pattern illustrated in Fig. 1
secured thereon, in a manner hereinafter described, after such glass and pattern
have been subjected to the sand blast process;
Fig. 3, an elevation of the glass and pattern illustrated in Fig. 2;
Fig. 4, an elevation of the glass and pattern thereon illustrated in Figs. 2 and 3,
and with a chipping compound spread over the glass and pattern, such pattern
being partially raised from the glass with the chipping compound thereover in a
liquid or semi-liquid condition;
Fig. 5, an end elevation of Fig. 4; and
Fig. 6, a view of a chipped piece of glass ornamented by this process, and by the
use in such process of the pattern illustrated in Fig. 1.
The same letter of reference is applied to a given part of the several devices

page_text: and things illustrated in the drawings, where more than one view thereof is
shown.
A, is a pattern, the negative of the design to be produced in the completed
design, and is necessarily constructed of flexible material readily removable from
the sheet of glass while the chipping compound is in a liquid or semi-liquid
condition thereover, without disturbing such glass chipping compound upon the
portion of the glass which is to be thereby chipped; such pattern must also be
constructed of material adapted to resist the direct action of the sand blast process
when subjected thereto upon a sheet of glass. The material preferred for such
pattern as best adapted to meet all the requirements demanded thereof is paper or
thin cloth, preferably paper, and of the particular kind known in the paper trade
as heavy document manilla paper. When paper is used it should be well oiled and
allowed to dry before use, and if cloth be used it should be sized, as with glue and
glycerine, and allowed to dry.
B, is a sheet of glass; and b, is a portion thereof which has been ground by the
sand blast process with the pattern A thereon. C, is a chipping compound.
D, is a portion of the sheet of glass B which remains in the same condition after
the glass has been subjected to this process in which it was before the glass was
subjected thereto. E, is a portion of the sheet of glass B, which has been chipped
by this process.
as,
It will be observed that in the drawings a pattern of a very simple character has
been illustrated as one which may be employed in the carrying out of the process;
but it is not to be understood that patterns of a complex character cannot be used
in fact, the process has been and is now being carried on by the use of patterns
of a very complex character, including ornamental marks, letters, figures, scrolls,
flowers, etc., and a pattern of kind chosen to illustrate this Specification is used to
ensure a good understanding of the process and without diversion from the main
features thereof to the pattern employed. In the description of the process, such
description will hereinafter be confined to the use of a paper pattern, made from
the kind of paper named, which has been well oiled and allowed to dry. Such a
pattern may be obtained by attaching a sheet of the paper, well oiled and
thoroughly dried) to the sheet of glass to be ornamented and then cutting the
desired design therefrom or thereout of and removing the portions of the sheet not
forming a part of the pattern from the surface of the sheet of glass; or if preferred,
the designs can be cut out of or from the oiled paper before attaching such oiled
paper to the sheet of glass. Where a single design is to be made by this process
upon a number of sheets of glass the patterns required may be obtained at small
cost by superimposing a number of sheets of oiled paper upon each other and
cutting out the desired designs therefrom; from eight to twenty five of such
patterns having been cut by this method, where the designs were not particularly
involved.
To ornament a sheet of glass by this process the surface thereof on which the
ornamentation is to be applied is cleaned and spread completely over with a thin
film of soap, or other equivalent material. A coating of asphaltum, obtained by
applying asphaltum cut or digested in spirits of turpentine in the ordinary way to
form a paint compound readily applied by a brush, constitutes at times a desirable
substitute for the film of soap. One of the other of the above coatings having
been applied to the glass the pattern A is laid thereon and attached thereby to
the surface of the glass. The choice, if any choice there be, of the one of such
coatings to be employed is determined principally by the character of the design
to be chipped upon the sheet of glass. That is to say, if the ornamentation
consists of a large number of surfaces or bodies of single chipped glass on a sheet
of clear glass, or if such surfaces are of small area, the coating of asphaltum will
be found preferable in use instead of the film of soap, for the reason that such
coating of asphaltum will be removed from the portions of the glass not covered by
the pattern by the action of the sand blast in the sand blast process at the same
time such portions of glass are being ground, and after such grinding the

page_text: pattern is nearly, if not quite, as readily removed in the manner and at the time
hereinafter described, as where the film of soap is employed; while the film of
soap must be removed from the surface of the glass on the parts thereof to be
ground by the sand blast before the sheet of glass is subjected to the sand blast
process; such film of soap constituting what is termed in the art a resistant to the
sand blast process; and as the removal of the film of soap necessitates the
application thereto of a wet or dampened sponge or cloth or other article, there is,
in the cases named, a liability to loosen or start the pattern from the sheet of
glass sufficiently to injure the definiteness of the contour line of the portion of the
glass which is ground when subjected to the sand blast process with the pattern
laid thereon.
Where double chipping is to be obtained by this process the preferable way of
doing is to first apply a coating of liquid asphaltum to the glass, over the entire
surface thereof, allow it to dry, and then apply a thin film of soap so as to
entirely cover the coating of asphaltum, and then apply pattern A to the glass, as
above described.
The film of soap coating, over the coating of asphaltum, where exposed to
view through the apertures of the pattern or around the design, is removed by a
wetted sponge or cloth in the same way as when the film of soap coating is alone
used, as before described, before the glass is subjected, protected by the pattern,
to the sand blast process.
After the glass with the pattern thereon as described has been subjected to the
sand blast process and sufficiently ground thereby, an ordinary glass chipping
compound is applied, in a heated condition, to the entire surface of the glass,
covering both the glass and the pattern still thereon. This glass chipping
compound is preferably applied with a brush, in the ordinary way.
After the surface of the glass has been well covered with the chipping compound,
the pattern is raised from off the glass, using when desired a suitable instrument,
as for instance a knife blade, such instrument being inserted between the pattern
and the glass whenever necessary. The manner in which the pattern is thus
raised off the glass is illustrated in Figs. 4 and 5 of the drawings, and must be
effected while the chipping compound is in a semi-liquid condition, and so as to
carry therewith the glass chipping compound thereover and to leave upon the
glass the glass chipping compound covering such parts and such parts only of the
glass as were unprotected by the pattern from the action of the sand blast process.
It has been found in practice that where the pattern is constructed of paper of
the kind named, and well oiled, and the material employed for sticking it to tho
glass is a coating consisting of a film of soap, either with or without a coating of
asphaltum thereunder, such pattern will adhere in place during the grinding or
marking thereof by the sand blast process so as to obtain definite contour lines to
the ground portions thereof, while at the same time it can be readily and rapidly
removed from the glass after the chipping compound has been applied thereto and
while such chipping compound is in a liquid or semi-liquid condition, thereby
carrying therewith the glass chipping compound thereover.
The glass with the chipping compound is placed, after the pattern and the
chipping compound immediately thereover has been removed as described, in racks,
and allowed to remain until the glass is chipped in the ordinary way.
A second coating of glass chipping compound can be applied to the entire
surface of the glass as soon as the glass has received its first chipping when both
the coating of asphaltum and the coating of soap, or its equivalent, has been
applied to the glass, as described; a sufficiently heavy coating of asphaltum
remaining on the unchipped portion of the glass to protect it from the action of
such second coating of chipping compound; but where the coating of asphaltum
is used as
substitute for the film of soap coating (for attaching the pattern
to the sheet of glass), such glass cannot be again completely coated with a
chipping compound until a second coating of asphaltum, shellac, or other material
adapted to protect the glass when interposed between it and a glass chipping

page_text: compound from the action of the chipping compound has been applied thereto, as
parts of the glass to be unchipped will be uncovered of the coating of asphaltum
by its adhering to the pattern in the removal of the pattern and chipping
compound thereover.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. The process of chipping glass which consists in covering the surface of the
glass with a thin film of soap, in applying a flexible pattern thereover adapted
to resist the action of a sand blast process, of removing the film of soap exposed
in the openings of the pattern, in subjecting the glass with the pattern thereon to
the sand blast process, in applying a glass chipping compound in a liquid condition
on the surface of the glass and the pattern thereon, in lifting the pattern off
the glass together with the chipping compound thereover while such chipping com-
pound is in a liquid or semi-liquid condition, and in allowing the chipping
compound to dry in the ordinary way; substantially as described.
2. The process of chipping glass which consists in covering the surface of the
glass with a coating adhering to the glass sufficiently well to form a means of
attaching a flexible pattern thereover to the glass, in applying a flexible pattern
thereover adapted to resist the action of the sand blast process, in subjecting the
glass with the pattern thereover to the action of the sand blast process and thereby
simultaneously grinding the glass and removing the coating thereover in the open
places of and around the pattern, in coating the entire surface of the glass and the
the pattern thereon with a glass chipping compound in a liquid condition, in
removing the flexible pattern from the glass together with the glass chipping
compound thereover, and in allowing the glass chipping compound to dry in the
ordinary way; substantially as described.
3. The process of chipping glass which consists in covering the surface of the
glass with a coating adapted to protect the glass from the action of a glass chipping
compound when interposed between the glass and such glass chipping compound,
in applying a coating adapted to adhere to the first named coating and to a pattern
sufficiently well to form a means of attaching such pattern to the glass, in applying
a flexible pattern thereover adapted to resist the action of the sand in the sand
blast process, in removing the second named coating from the glass where the same
is exposed through the opening of the pattern, in subjecting the glass with the
pattern thereover to the action of the sand blast process, in coating the entire
surface of the glass and pattern thereon with a glass chipping compound in a
liquid condition, in removing the flexible pattern from the glass together with the
glass chipping compound thereover, in allowing the glass chipping compound to
dry in the ordinary way and in applying a second coating of glass chipping
compound over the entire surface of the glass and allowing the same to dry in the
ordinary way; substantially as described.
Dated this 4th day of apie 1.
R. HADDAN,
Herbert Haddan & Co.,
18, Buckingham Street, Strand, London.