Improvements in the Manufacture of Cornices and other Articles of Plaster and the like which have Surface Ornamentation in Relief
Year: 1897

page_text: Date of Application, 5th Oct., 1897-Accepted, 4th Dec., 1897
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Cornices and other Articles of
Plaster and the like which have Surface Ornamentation in
Relief
I, AUGUST CARLEWITZ, of 83 & 85 Plane Street, Newark, in the County of Essex
and State of New Jersey, United States of America, Sculptor, do hereby declare the
nature of this invention 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 in part to a method of making a mold for use in casting
from plaster, or similar materials, cornices and other articles having undercut relief
ornamentation on their faces and in part to a mold for the purpose having a face of
elastic, yielding material, of sufficient thickness to form a mold, for the relief
ornamentation, and a stiff, rigid backing on the said elastic face.
The invention will be described with reference to the accompanying drawings
which illustrate an embodiment thereof in the case of a cornice.
Figure 1, is a vertical, transverse section of the mold, as it appears just after the
backing D has been cast on the clay.
Figure 2, is a similar section of the mold, showing it after the clay B has been
removed and the backing has been bored or perforated and replaced.
'
Figure 3, is a similar section of the mold, showing it after the elastic yielding
face I has been cast to fill the space formerly occupied by the clay.
Figure 4, is a vertical, transverse section of the mold, showing it inverted and the
pattern removed to make ready for casting the cornice, and Figure 5 is a side
elevation of the same.
Figure 6, is a perspective view of the mold as seen in Figures 4 and 5.
Figure 7, is a plan view of the face of the mold as it lies on the backing D, as
seen in Figure 6 with the frame G removed.
"
The first step in carrying out my invention is to prepare the mold, and in doing
this I proceed by preference, as follows:
The pattern for the cornice, designated by A in the several figures of the
drawings, will correspond in size and configuration to the section of cornice to be
produced, and it will be made to fit in a metal casting-frame, G, as seen in Figs. 1,
2 and 3. This frame having been placed as indicated in Fig. 1, and the
pattern A placed in it, the face of the pattern is covered with soft clay, B, which
is carefully pressed into all the cavities of the ornamention on the pattern and
applied in quantity sufficient to imbed all of the relief ornamentation on the pattern
and cover the same to a depth of about one and one-half to two inches. The back, or
upper side of this clay facing will be left uneven by preference, and it will follow the
general configuration of the design on the pattern; that is, the ornamentation in
the cove or on the face of the pattern of the cornice.
After the clay B has been placed, .I mount on the metal frame G, a frame C,.
having V-shaped ends (c in Fig. 5) which fit down into the metal frame G and
close the ends of the same. This frame C provides an edging or border for the
backing D, which is formed by pouring onto the clay B, a mixture of plaster and water, or
DOJ1

page_text: similar material and allowing it to set or harden. If the plaster is used in a slightly
stiff pasty form instead of being thin enough for pouring, it may be formed on
the clay by hand, or a temporary board used in place of a regular frame.
It will be observed that the clay B now occupies a position between the
pattern.A and the backing D; and the pattern A will be a little shorter than the
frames C and G so that the clay may also be pressed down about the ends of
the pittera, between its en Is and the en is c of the frame C.
After the backing D shall have become hard and firm, the frame C is removed,
leaving the backing resting on the clay; the backing is now detached from the
clay and lifted off and the clay carefully removed from the pattern.
The next step is to prepare the elastic, flexible face-portion of the mold, and in
doing this I bore holes b; at suitable points through the plaster backing D, and then
replace it on the frame G, as seen in Fig. 2. Two good sized holes at proper
distances apart along the center of the mold will answer every purpose, but there
may be
a number of holes, as shown. The primary purpose of these holes
being to permit the escape of air during the process of making the
gelatine facing, and the final object thereof being obtained
formation of fingers on
by the
the back of the gelatinous facing of the mold,
which will fit into the opening when the operation of casting the cornices is
being performed. The mixture to form the elastic flexible face, I, is a liquid,
gelatinous compound which will congeal into a tough elastic inass when cooled;
this mixture is now poured into the mold through a hole b, when it will fill the
space before occupied by the clay. When the gelatinous compound reaches
the top of the vent holes such holes may be stopped by plugs of clay as
shown at d in Fig. 3. If the projections of gelatine which have solidified in the
holes are inconveniently long such portions may be shortened by cutting them off,
the design being to hold the elastic facing in place on the plaster backing by means
of suitable integral protuberances on the back of the same, the exact form or size
of the projections not being material.
I have found that a suitable compound for the elastic face I, may be made from
a good quality of gelatine (and preferably that known to the trade as rabbit
gelatine), to which is added about twenty per cent. of glycerine and small quantities
of rosin, chalk and turpentine. In the operation of casting, oil or varnish may be
used as a wash over the surfaces of the mold, as a precaution against the plaster
adhering to the elastic facing as is usually practised by those skilled in such a
work.
After the elastic compound has cooled and set, the mold is inverted and the
pattern A removed. The mold will now present the appearance seen in Figs. 4, 5
and 6. The backing D now serves as a base, supporting the elastic face I, which
will thus be held firmly during the molding operation. The frame G now has its 4
narrow base uppermost, and in this base is a longitudinal opening H, through which
the mixture of plaster to form the section of cornice is now poured, this mixture
filling up the entire space before occupied by the pattern A. In the operation of
casting, the metal frame G rests upon and is supported by the backing D, and the
mixture when poured in through the opening H will be confined within the lines of 4
the frame. The diagonal sides and back of a cast cornice being formed by the
inside of the metal frame, and the face or ornamental front by the elastic facing of
the other part of the mold. In some cases where heavy work is being done the
frame C. may also surround the plaster backing D, so as to provide against injury
from cracking, but it will be apparent that the mold may be used without the 5
frame C.
After the plaster has set in the mold, the mold is again turned over to the
position seen in Figs. 1 and 2 and the plaster backing D lifted off from the elastic
face I, after which the said face is carefully pulled off from the plaster cast. The
face I is of such a nature that although the plaster cast may be very much 5
undercut, and the figure delicately sculptured, the elastic face will bend and yield,
owing to its pliability, so as to be removed without the least injury to the fine lines

page_text: of the cast. The elastic facing although comparatively thin is always deep enough
to receive the ornamentations of the design.
After being removed from the cast, the face I may be returned to its position on
the backing D for use again, and in this way many casts may be made from the
same elastic facing.
The gelatinous material flows into the holes in the backing D, and thus forms on
the back of the flexible face, projections which serve to steady the lining in place
after it is made.
The frame should be made perfectly true and exact, and will be made of steel, by
preference, to impart rigidity and prevent warping or twisting during the casting
operation. This frame should be secured to the other parts of the mold by tying, or
otherwise, during the operation of casting the plaster cornice.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what
I claim is
1. The herein described method of forming a mold for casting articles from
plaster, and like materials, which have surface ornamentation in relief, which
consists in first placing a pattern in a frame then forming a coating of clay over the
face of the pattern, then casting a thick backing of plaster on the clay, then
removing the clay, and then filling the space previously occupied by the clay with
a gelatinous compound, and finally removing the pattern after the gelatinous
compound shall have congealed, substantially as set forth..
2. A mold for casting cornices and other articles which have a surface orna-
mentation in relief, consisting essentially of a base D of plaster with a removable
facing I of tough elastic gelatinous composition, having formed in it the mold for
the relief ornamentation of the front of the casting, and a frame G to form the back
of said casting, substantially as shown and described.
3. The combination to form a mold for casting articles of plaster, and like
materials, which have surface ornamention in relief, of the metal frame G, the
frame C, adapted to fit on the frame G, the backing D, of plaster in the
frame C, and the removable face I, on the backing D, said face being of tough,
elastic, gelatinous composition and having formed in it the mold for the relief
ornamentation of the article to be cast, substantially as set forth.
Dated this *th day of October
GOT
STEPHEN WATKINS
Wolverhampton Agent [for the Applicant.