IMPROVEMENTS IN APPARATUS EMPLOYED IN THE MANUFACTURE OF SOCKETTED PIPES OF PLASTIC MATERIAL
Year: 1877

page_text: LETTERS PATENT to Richard Cardwell Robinson, of the Albert Works, Preston,
in the County of Lancaster, Engineer, for the Invention of " IMPROVEMENTS
IN APPARATUS EMPLOYED IN THE MANUFACTURE OF SOCKETTED PIPES OF
PLASTIC MATERIAL"
Sealed the 15th February 1878, and dated the 17th December 1877.
PROVISIONAL SPECIFICATION left by the said Richard Cardwell Robinson
at the Office of the Commissioners of Patents on the 17th December 1877.
RICHARD CARDWELL ROBINSON, of the Albert Works, Preston, in the County of
Lancaster, Engineer. "IMPROVEMENTS IN APPARATUS EMPLOYED IN THE MANU-
FACTURE OF SOCKETTED PIPES OF PLASTIC MATERIAL."
This Invention relates to improvements in apparatus employed in the manufacture
of socketted pipes from plastic material, such as clay, and has reference to the
construction of the mould or die in which the socket part of the pipe is formed.
Moulds or dies for this purpose have been constructed with small circular perforations
for the escape and admission of air; but these perforations hinder the removal of
the pipe from the mould, and in time become stopped up with clay.
To overcome this difficulty, linings of cloth or other fabric have been used, through
which and the perforations above referred to the air gathering in the moulds during
the formation of the socket might escape.
In practice, however, it has been found that owing to the moisture exuding from
the clay whilst under pressure, carrying with it more or less solid matter, the inter-
stices in the lining are liable to gradually fill up, thus preventing the necessary
escape of air from, and admission of air to, the interior of the mould or die.
To obviate this serious inconvenience, whilst at the same time guarding against
adherence of the moulded socket to the mould or die, I dispense with the lining of
cloth or fabric, and construct the die or mould of solid metal, with slots or openings
of peculiar form arranged at intervals around that portion of the mould or die
which forms the shoulder of the socket, such slots or openings running longitudinally
of the mould (in other words, in the direction of the length of the pipe), and being
Prine &31

page_text: in cross view of a doubly inclined or V shape, the narrow parts opening into the
interior, whereas the said slots or openings widen out towards the exterior of the
mould or die. The slots or openings entering the mould in the form of narrow slits
or fissures provide not only for the escape and admission of air, but they are also
available, by widening or increasing the width of the openings in one (or more of 5
then, if necessary) for the escape of surplus clay when the socket part of the pipe is
being pressed into the mould.
A mould or die, constructed as above described, also admits of the grooves being
readily cleaned and kept open for the passage of air.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed 1
by the said Richard Cardwell Robinson in the Great Seal Patent Office on
the 17th June 1878.
RICHARD CARDWELI. ROBINSON, of the Albert Works, Preston, in the County of
Lancaster, Engineer "IMPROVEMENTS IN APPARATUS EMPLOYED IN THE MANU-
FACTURE OF SOCKETTED PIPES OF PLASTIC MATERIAL."
This Invention relates to improvements in apparatus employed in the manufacture
of socketted pipes from plastic matorial, such as clay, and has reference to the con-
struction of the mould or die in which the socket part of the pipe is formed.
Moulds or dies for this purpose have been constructed with small circular perforations
for the escape and admission of air; but these perforations hinder the removal of
the pipo from the mould, and in time become stopped up with clay.
To overcome this difficulty, linings of cloth or other fabric have been used, through
which, and the perforations above referred to, the air gathering in the moulds during
the formation of the socket might escape.
In practice, however, it has been found that owing to the moisture exuding from
the clay whilst under pressure, carrying with it more or less solid matter, the inter-
stices in the lining are liable to gradually fill up, thus preventing the necessary
escape of air from, and admission of air to the interior of the mould or die.
To obviate this serious inconvenience, whilst at the same time guarding against
adherence of the moulded socket to the mould or die, I dispense with the lining of
the cloth or fabric, and construct the die or mould of solid metal with slots or
openings of peculiar form arranged at intervals around that portion of the mould or
die which forms the shoulder of the socket, such slots or openings running
longitudinally of the mould (in other words in the direction of the length of
the pipes), and being (in cross view) of a doubly inclined or wedge shape, the
narrow parts opening into the interior, whereas the said slots or openings widen
out towards the exterior of the mould or die. The slots or openings entering
the mould in the form of narrow slits or fissures, provide not only for the escape
and admission of air, but they are also available by widening or increasing the
width of the openings in one of them (or more if necessary) for the escape of surplus
clay when the socket part of the pipe is being pressed into the mould.

page_text: A mould or die constructed as above described also admits of the grooves being
readily cleaned out and kept open for the passage of air.
In the accompanying Drawings, Fig. 1 is a vertical sectional view of part of a
pipe-moulding machine, embodying my improvements; Fig. 2 is a plan; and Fig. 3,
a sectional elevation of my improved mould or die.
In Fig. 1A is the ram; B, the clay in process of moulding; C, the bell; D, the
socket core; and E, the table.
F is my improved mould or die attached in the usual manner to the die plate G
by screws a, a.
Figs. 2 and 3 show my improved mould or die detached from the machine and
drawn to a larger scale, so that the details may be better seen and understood.
H is the shoulder part of the mould or die, around which are the doubly in-
clined or wedge-shaped slots or openings b, b, for the escape and admission of air to
the interior of the mould or die.
Openings c, c, in the outer portion of the mould or die are provided through which
moisture or surplus clay exuding through the narrow slots or openings 6 may pass
away.
In the arrangement of die shewn in the Drawing, the shoulder part H of the
mould or die does not fit close up to the plate G, but a narrow interval or space is
left between the two, thereby affording an additional opening for the escape and
admission of air.
The shoulder part H may be chamfered, as shewn in dotted lines in Fig. 3.
The slots or openings 6 may be easily cleaned or kept open by the application of
a flat wire or thin sheet metal instrument from the inside of the die.
Having now described the nature of my said Invention, and explained the manner
of carrying it into practical effect, I hereby declare that what I consider to be novel
and original, and therefore claim as the Invention secured to me by the herein-before
in part recited Letters Patent is, the constructing the mould or die with the oblong
doubly inclined or wedge-like slots or openings d, arranged and operating substan-
tially as described, and shewn in the Drawings, for the purposes specified.
In witness wheroof, I, the said Richard Cardwell Robinson, have hereunto set
my hand and seal, this Fourteenth day of June, in the year of our Lord One
thousand eight hundred and seventy-eight.
R. O. ROBINSON. (L.S.)