IMPROVEMENTS IN THE MANUFACTURE OF POTTERY WARE "" AND IN THE APPARATUS TO BE EMPLOYED THEREIN
Year: 1872

page_text: PROVISIONAL SPECIFICATION left by Bristow Hunt at the Office
of the Commissioners of Patents, with his Petition, on the 17th
February 1872. A communication from abroad by Samuel Rogers
Thompson, of Portsmouth, County of Rockingham, State of New
Hampshire, United States of America.
I, BRISTOW HUNT, of No. 1, Serle Street, Lincoln's Inn, in the
County of Middlesex, Gentleman, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF POTTERY WARE
""
AND IN THE APPARATUS TO BE EMPLOYED THEREIN, (a communication to me
from abroad by Samuel Rogers Thompson, of Portsmouth, County of
Rockingham, State of New Hampshire, United States of America,)
to be as follows:-
This Invention relates to certain simple and useful improvements in
the manufacture of pottery ware, and in apparatus therefor.
The apparatus employed consists mainly of a vertically reciprocating
core entering a mould from above, and a similar reciprocating piston or
plunger entering the same from beneath in combination with a peculiar
arrangement of cams and other details of construction (herein-after

page_text: described) whereby the said parts are operated; the essential objects of
the Invention being the facilitation of the manufacture of pottery ware,
and the provision of a simple and effectual means whereby the same may
be removed from the machine.
The construction of the apparatus is as follows:-At one end of the
frame of the machine is placed the mould, in the cavity of which rests
the piston or plunger which is provided with a vertical reciprocating
rod. On each side of the mould are standards, connected at the top
by a cross piece on which are placed two pulleys, one at each end.
Over each of these pulleys passes a cord, the inner end of which is
attached to a vertically sliding carriage, which slides freely up and down
the standards, and at the outer end of which is placed a counterbalance
weight, by means of which weights the carriage is suspended in a certain
position.
The core is attached to the under part of the carriage and immediately
over the mould, and is shaped to conform to the interior of the latter; it
is further provided with a projecting flange, and with an air passage
The surface of the core and the interior of the mould are
each provided with a coating of plaster; the coating in the mould is
protected and held therein by a metallic flange.
and valve.
Below the mould and at right angles thereto is a driving shaft (held
in suitable bearings in the lower part of the frame), which is provided
with a driving wheel, and with three sliding cams connected together by
a rod. A lever hinged or pivotted near its centre to a beam of the frame
is bifurcated at its lower end, and there pivotted to the collar of the
middle cam. This lever is kept in a certain position by means of a
spiral spring attached thereto and to the beam. Near the mould is
placed an adjustable standard to which is pivotted a joint piece, and to
the latter is pivotted near its end a swinging lever, the opposite end of
which rests between projecting guides of another standard. Against the
under side of this swinging lever bears a vertical rod passing through the
frame, and having a vertical reciprocating motion therein, which
however is limited by two pins and a spiral spring.
The action or mode of operation is as follows:-The plastic material
in suitable quantity is placed in the cavity of the mould, and rests on the
piston or plunger at the bottom thereof. The sliding carriage is then
depressed and causes the core to enter the mould, leaving an annular

page_text: space of the form of the vessel to be moulded between itself and the
mould, the projecting flange limiting its descent. The carriage is held
in this position by the swinging lever which is moved forward until its
foremost end rests upon the upper side of the carriage. The three cams
are then moved along their shaft by the bifurcated lever, until the inner
one of them is directly under the vertical reciprocating rod of the
swinging lever, when the middle one of them will be in a similar
position with relation to the vertical reciprocating rod of the piston or
plunger.
The driving shaft being rotated the inner cam bearing against its rod
raises the rear end of the swinging lever and causes its opposite or
foremost end to press downwards upon the carriage and hold the core
firmly in position. At the same time the middle cam bearing against
its rod raises the piston or plunger, which thus forces the plastic material
resting thereon into the space between the core and the mould. This
cam ceases to act thus on the plunger when the latter is within
sufficient proximity to the core to form the bottom of the vessel, but the
piston or plunger is held in the same position by a spring which engages
with a notch in the plunger rod.
The inner and middle cams are so arranged that the latter releases its
rod a moment in advance of the former, consequently after the vessel is
moulded the inner cam releases its rod, which immediately falling releases
the swinging lever, which then resumes its former position and allows
the carriage to rise, thus removing the core from the mould, the core
parting readily from the plastic material by reason of its air passage and
valve; the air passage and valve extend through the core so that when
the core is being withdrawn from the vessel the valve opens and allows
the air to pass into the vessel, and allows of the core parting readily
therefrom.
The newly formed vessel now rests upon the plunger alone, which as
above mentioned is held by the spring and notch. The three cams are
then moved backwards along their shaft and towards the driving wheel
thereon by the bifurcated lever until the outer lever is in a position to
actuate the plunger rod. This cam being of greater radius than the
middle one forces the plunger still farther upwards and until its upper
surface is about flush with the upper surface of the mould (in which
position it is again held by the spring as before), thus bringing the
vessel into an accessible position where it can be readily separated from

page_text: the plunger by a wire or otherwise, and when removed the spring is
disengaged from the rod, when the plunger resumes its former
position.
The employment of the plaster covering to the core, and lining to the
mould, dispense with the necessity of the use of oil as hitherto indispen-
sable in moulding by pressure, as the plastic material adheres to wooden
or other moulds, but parts readily from the plaster.
The core and mould can be removed from the machine, thus enabling
the same mechanism to be used in the manufacture of vessels or articles
of different sizes or shapes.
When more power is required for moulding large ware, instead of the
outer cam, a chain attached to a clutch on the driving shaft is used;
and in heavy ware instead of using the joint piece and swinging lever,
steel latches are employed operating in slots formed in the upper parts
of the carriage standards, so that when the carriage is brought down the :
core is carried into the mould, and a screw attached to the core is set
against the core so as to "jack" it down solid into the mould, and also
setting the latches hard against the carriage standards.