IMPROVEMENTS IN MOULDS FOR FORMING ARTICLES OF PLASTIC MATERIALS
Year: 1881

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for an Invention of
66 'IMPROVEMENTS
IN MOULDS FOR FORMING ARTICLES OF PLASTIC MATERIALS." A communi-
cation from abroad by Henry Dean Atwood and William Driscoll, both of
Taunton, in the County of Bristol and State of Massachusetts, United States
of America
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 14th June 1881.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent. "IMPROVEMENTS IN MOULDS FOR FORMING ARTICLES OF PLASTIC
MATERIALS." [A communication from abroad by Henry Dean Atwood and
William Driscoll, both of Taunton, in the County of Bristol and State of Massa-
chusetts, United States of America.]
This Invention relates to moulds for forming crucibles, pottery ware, and other
articles of plastic materials, and especially that class of moulds in which the
moulding surface consists of a cloth lining.
The Invention consists in combining the lining with a skeleton frame mould
and backing which sustains the lining against the pressure during the operation of
moulding. The backing may be either rigid and non-porous or flexible and porous,
the latter being preferred, for the reason that it allows escape of water pressed from
the material.
The mould is made as usual in two portions, the line of division being longi-
tudinal. The frame consists of longitudinal ribs (of which there are six or more
to each portion) and end pieces or ring segments. The ribs are preferably made of
well seasoned wood, and are cut out to the proper shapo and length, and secured to
the segments by morticing and screws, or in any suitable manner whereby they
shall be securely held. The backing is secured on the inside of the frame, and
within that is the lining which forms the moulding surface. The backing is made
of heavy cloth or other material of flexible and porous character, and is secured to

page_text: the frame by tacks or staples, after which it is to be shaped by blocking. The
lining is of similar material but finer, and it is also secured by tacks. At the ends
both the flexible lining and backing or the lining alone may be turned back upon
the end pieces and secured by segment plates of metal, such plates serving also to
protect the wood. The edges of the two portions of the mould may also be rebated
to receive the edges of the lining. With this backing and lining the water pressed
from the composition can escape freely, and the lining will therefore be kept in a
comparatively dry condition. The backing may be made of thicker material, which,
as above mentioned, may be rigid and non-porous. It would be secured to ribs
and segments and lined with the flexible material secured as before described, so
that the backing shall give a rigid support to the lining.
The ribs at the division of the two parts of the mould are recessed and fitted
with spiral, elliptic, or other springs, which project so that when the parts aro
placed together they shall be compressed and thus tend to separate the mould. In
using the mould the two parts will be clamped together by a hoop in the usual
manner. As soon as the hoop is removed the springs will separate the mould a
short distance so that their entire separation and removal is thereby facilitated.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Great Seal Patent Office on the
10th December 1881.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent. "IMPROVEMENTS IN MOULDS FOR FORMING ARTICLES OF PLASTIC
MATERIALS." A communication from abroad by Henry Dean Atwood and
William Driscoll, both of Taunton, in the County of Bristol and State of Massa-
chusetts, United States of America.
This Invention relates to moulds for forming crucibles, potteryware, and other
articles of plastic materials, and especially that class of moulds in which the
moulding surface consists of a cloth lining.
The Invention consists in combining the lining with a skeleton frame, mould,
and backing, which sustains the lining against the pressure during the operation of
moulding. The backing may be either rigid and non-porous or flexible and porous,
the latter being preferred, for the reason that it allows escape of water pressed from
the material.
In the accompanying Drawings, Figure 1 is a vertical section of a crucible mould
constructed in accordance with this Invention; Figuro 2 is a horizontal section on
line x, x, of Figure 1, and Figure 3 is a perspective elevation of the same; Figure 4
is a vertical section of the mould as made with a non-porous backing, and Figure 5
is a horizontal section of the same on line y, y. Similar letters of reference indicate
corresponding parts.
The mould is made as usual in two portions A, A, the line of division being
longitudinal. The frame consists of longitudinal ribs a (of which there are six or
more to each portion A) and end pieces or ring segments b. The ribs a are pre-
ferably made of well seasoned wood, and are cut out to the proper shape and length,
and secured to segments by mortising and screws, or in any suitable manner
whereby they shall be securely held. On the inside of the frame is secured the
backing c, and within that is the lining & which forms the moulding surface. The
backing c, as illustrated in Figures 1, 2, and 3, is made of heavy cloth or other
material of flexible and porous character, and is secured to the frame by tacks or
staples, after which it is to be shaped by blocking. The lining d is of similar
material but finer, and it is also secured by tacks. At the ends both the flexible
lining and backing, or the lining alone, may be turned back upon the end pieces b,
and secured by segment plates of metal, as shown in Figure 4 at aº, such plates
serving also to protect the wood. The edges of the portions A, A, may also bo
rebated, as shown in Figure 5, to receive the edges of the lining. With this
backing and lining the water pressed from the composition can escape freely, and
the lining will therefore be kept in a comparatively dry condition.
In Figures 4 and 5 the backing c is shown as made of thicker material, which
may be rigid and non-porous. It is secured to ribs a and segments b, and is lined
with the flexible material d, secured as before described, so that the backing gives
a rigid support to the lining.
The ribs a at the division of the two parts of the mould are recessed and fitted
with spiral, elliptic, or other suitable springs c, e. These springs project so that
when the parts are placed together they shall be compressed and thus tend to
separate the mould.
In using the mould the two parts will be clamped together by a hoop in the
usual manner. As soon as the hoop is removed the springs e will separate the
mould a short distance, so that their entire separation and removal is thereby
facilitated.

page_text: The mould shown is shaped for formning certain crucibles, but it will be under-
stood that it may be of any shape required and used for potteryware and other
articles.
Having described the nature of the said Invention and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein before in part recited Letters Patent is,
1st. The mould above described having its lining secured to the frame and
supported by a backing, substantially as specified.
2nd. A mould for plastic materials, having walls or backing formed of porous
material, substantially as shown and described.
3rd. In moulds a backing of cloth or similar flexible porous material combined
with a skeleton frame, substantially as shown and described.
4th. In moulds the backing c and lining d of flexible porous fabric, the
longitudinal ribs a and segments b, combined substantially as shown and described.
5th. The combination with a two part mould of springs e, substantially as and
for the purposes set forth.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
iny hand and seal, this Tenth day of December, A.D. 1881.