IMPROVEMENTS IN MACHINERY OR APPARATUS FOR MOULDING AND CASTING FUSIBLE OR PLASTIC MATERIALS, AND IN COVERING OR COATING ARTICLES WITH SUCH MATERIALS
Year: 1855

page_text: PROVISIONAL SPECIFICATION left by John Henry Johnson at the Office
of the Commissioners of Patents, with his Petition, on the 18th April
1855. A communication.
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I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of Glasgow, North Britain, Gentleman, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN MACHINERY OR APPARATUS
FOR MOULDING AND CASTING FUSIBLE OR PLASTIC MATERIALS, AND IN COVERING OR
COATING ARTICLES WITH SUCH MATERIALS," a communication from abroad, to be
as follows:-
This Invention relates to certain constructions and arrangements of
machinery or apparatus for moulding articles of india-rubber, gutta percha,
or compounds thereof, while the material is in a melted or plastic state,
and for covering or coating other articles with such materials. The same
machinery is also applicable to the manufacture of articles composed of any
other fusible or plastic material.
According to one arrangement, the india-rubber, if such be the material
employed, is contained in a horizontal cylinder, and is kept in a melted or
plastic state therein by means of a steam or hot water jacket round such
cylinder, the water in such jacket being heated by a small fire-place below it.
The plastic or melted india-rubber is forced out of one end of the cylinder into
any suitable mould, by means of a piston or plunger on the end of a screwed

page_text: shaft or piston rod, which rod works through a fixed nut, and is rotated by
a suitable fly wheel.
The mould when in use is contained in a cage or frame, and is placed on a
table which is raised or lowered by means of a vertical screw spindle and hand
wheel. By this means, the opening in the mould for receiving the india-
rubber may be accurately adjusted to correspond with the supply opening in
the end of the cylinder. Previous to admitting the plastic material therein, the
mould is firmly screwed up to the feed aperture by means of a second hori-
zontal screw spindle worked by a hand wheel. The feed aperture of the
cylinder is formed in a separate piece from the cylinder, such piece being fitted
on to the end thereof, and is furnished with a stop-cock worked by a lever for
opening or closing the feed aperture. A slight modification of the machine
may be effected by placing the cylinder vertically. In this case the plastic or
melted material, whatever it may be, is forced downwards by the descent of the
piston or plunger, which is brought down by means of a lever. The working
centre of the lever is adjustable in a rack worked by a screw spindle and fly
wheel, so that it may be lowered as the material is expended. A screwed
spindle and fly wheel is fitted to the piston rod, by which means the piston
may be kept elevated when not working at any desired height, so as not to tend
to force out the material. The cylinder may be heated in a similar manner to
the first described cylinder, but this heating apparatus may be dispensed with
sometimes, according to the nature of the material employed. The moulds
may be of any form & of any suitable material, according to circumstances.
In coating tubes, wires, or cords with india-rubber or other plastic or fusible
material, such material is made to pass through a double draw-plate, hollow
inside, to receive the material under pressure, and perforated with as many
holes as are found desirable. The wire, if such be the article to be coated,
passes through a hole in the first plate, which hole is just large enough to
admit it; after passing through the material inside of or between the draw-
plates; the wire passes out by another hole in the opposite side, which hole is
sufficiently large to permit of a coat of the material, more or less thick, to
adhere to the wire.