IMPROVEMENTS IN ". MACHINES FOR MOULDING PIPES OR TUBES FROM PLASTIC MATERIAL AND FOR COVERING TELEGRAPH CABLES OR THE LIKE
Year: 1882

page_text: LETTERS PATENT to John Henry Johnson of 47 Lincolns Inn: Fields in, the.
County of Middlesex Gentleman for an Invention of "IMPROVEMENTS IN
".
MACHINES FOR MOULDING PIPES OR TUBES FROM PLASTIC MATERIAL AND FOR
COVERING TELEGRAPH CABLES OR THE LIKE A communication to bim from
abroad by George Freeman Lufbery of Paris in the Republic of France
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents on the 7th October 1882.
JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex:
"IMPROVEMENTS IN MACHINES FOR MOULDING PIPES OR TUBES FROM PLASTIC
MATERIAL AND FOR COVERING TELEGRAPH CABLES OR THE LIKE. A communication;
to me from Abroad by George Freeman Lufbery of Paris in the Republic of
France"
This Invention relates to Improvements in machines or apparatus for moulding
pipes or tubes of plastic material and 'is more especially applicable to machines for
making india rubber tubing with or without a solid or hollow core or lined with
helical coils of wire as in the case of tubing employed for exhaust or suction pipes
or pipes exposed to external pressure. These improved machines are also capable
of being eniployed for covering cables or telegraph wires with india-rubber the said
cables or wires being enclosed in a tube of india rubber. Machines constructed
according to this Invention are provided with two or more pairs of quick threaded
screws geared together so that the threads of one pair of screws engage with those
of the other pair of screws imparting motion thereto, the combined action of the
screws tending to push the materials under treatment towards a central space
between the ends of the screws where the said materials are moulded by being
forced through an orifice of annular or other suitable shape
Two pairs of screws are sufficient in ordinary cases but in making tubes of large
diameter and with sides of considerable thickness it is advisable to increase the
number of pairs of screws.

page_text: In carrying out this Invention the improved machine is constructed with a main
frame or support forming with a removable cheek or side plate a hollow case in the
interior of which are arranged two pairs of screws. One of the screws of each pair
ib keyed upon a separate shaft. or shaft that has no positive motion imparted to it
and the screws of the other pair are keyed upon shafts having a positive motion
imparted to them by suitable gearing.
These pairs of screws are geared together each pair being composed of a right-
handed screw and a left handed screw and the two pairs are arranged parallel to
each other so that the right handed screw of one pair, gears with the left handed
screw of the other pair and vice versa A space is formed between the adjacent
ends of the screws of each pair and communicates with an orifice of annular or
other suitable shape through which the materials are discharged in a moulded
form
When rotary motion is imparted to the screws in the manner bereinbefore
described and a plastic material such as caoutchouc or india-rubber in a plastic
condition is introduced, the action of the screws will propel the materials towards
the space herein before described between the ends of the screws whence it will
escape through the moulding orifice at the side which orifice is partially filled up
by a cylindrical mandril corresponding to the internal diameter of the pipe or tube
that is to be manufactured. The annular space around the mandril is limited
externally by a matrix or mould corresponding to the external dimensions of
the tubo
It is evident that tubes or pipes of any desired form and dimensions may be
manufactured by employing a mould or matrix and a mandril corresponding to the
form of tube or pipe that it is desired to produce. Moreover as india rubber
expands inwards as well as outwards on issuing from the annular orifice between
the mould and the mandril a wire helix or any substance or material in the form
of a cord or cable or bundle of telegraph wires for example introduced through the
hollow of the mandril will be laid hold of by the sides of the tube and drawn
forwards with the latter so as to fill or line it completely throughout its whole
length. One side of the case is secured by bolts and nuts and can be readily
removed for the purpose of exposing the interior of the machine.
The machine may be heated by steam pipes in the sides of the case or by other
suitable means
Screws are provided for the purpose of adjusting the mandril centrally in the
opening the said mandril being subsequently fixed in position by means of clamps
and screws.
I
The mandril is supported in a tube or socket cast on the side of the case and is
secured in position by set screws.

page_text: 1
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the
7th April 1883.
"
JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman IMPROVEMENTS IN MACHINES FOR MOULDING PIPES OR TUBES FROM
PLASTIC MATERIAL AND FOR COVERING TELEGRAPH CABLES OR THE LIKE
munication to me from abroad by George Freeman Lufbery of Paris in the
Republic of France
" a com-
This Invention relates to improvements in machines or apparatus for moulding
pipes or tubes of plastic material and is more especially applicable to machines for
making india rubber tubing with or without a solid or hollow core or lined with
helical coils of wire as in the case of tubing employed for exhaust or suction pipes
or pipes exposed to external pressure.
These improved machines are also capable of being employed for covering cables
or telegraph wires with india rubber the said cables or wires being enclosed in a
tube of india rubber..
Various machines have heretofore been employed for making tubing with or
without an interual helix some of these machines are provided with a single screw
revolving in a cylindrical cavity and others consist of presses acting on a piston in
a cylinder.
The former class of machines is objectionable on account of their not having a
good hold of the material with which they are supplied and also on account of
their requiring great power to drive them owing to the friction between the sides
of the cylinder and the material under treatment and moreover they do not readily
admit of the introduction during the manufacture of metallic helices or cores in the
interior of the tube because these helices or cores are obliged to follow a curved
path in order to reach the outlet orifice.
The second class of machines present the disadvantage of working with an inter-
mittent action whereas the improved machine constructed according to this
Invention is provided with two or more pairs of quick threaded screws each pair
being geared together so that the threads of one pair of screws engage with those
of the other pair of screws imparting motion thereto the combined action of the
screws tending to push the materials under treatment towards a central space
between the ends of the screws where the said materials are moulded by being,
forced through an orifice of annular or other suitable shape.
Two pairs of screws are sufficient in ordinary cases but in making tubes of large,
diameter and with sides of considerable thickness it is advisable to increase the
number of pairs of screws.
And in order that the said Invention may be fully understood I shall now;
proceed more particularly to describe the same and for that purpose shall refer to
the several figures on the annexed sheet of drawings the same letters of reference
indicating corresponding parts in all the figures.
Figure 1 of the accompanying drawings is an elevation of the improved machine.
one half being shewn complete and the other half being shewn with one side.
removed so as to show more clearly one of the pairs of screws.
Figure 2 is a sectional plan one half of the section being taken along the line 1-2
and the other half along the line 3-4 figure 1.
Figure 3 is a transverse section taken through the centre of the machine and
Figure 4 is a front view looking on the side on which the manufactured article is
discharged.

page_text: This machine is constructed with a main frame or support B forming with a
removeable cheek or side plate Ca hollow case in the interior of which are arranged
two pairs of screws u¹ and vv. The screws of the screws u ul are keyed upon
two steel second motion shafts D D₁ or shafts that are not geared or have no
positive motion imparted to them and the screws of the other pair are keyed upon
two shafts A A turning in bearings m m³ n n and having a positive motion
imparted to them by the intervention of toothed wheels R'R' fast on the ends of the
said shafts and gearing with pinions P P on the main or driving shaft E which
also carries a drum or pulley L by which motion is imparted to the machine.
The pairs of screws are geared together each pair being composed of a right
handed screw and a left handed screw and the two pairs are arranged parallel to
cach other so that the right handed scrow of one pair gears with the left handed
screw of the other pair and vice vera, A space is formed between the adjacent
ends of the screws of each pair and communicates with an orifice of annular or
other suitable shape through which the materials are discharged in a moulded
form:
.
"
11
(
1
If therefore the threads work in plastic material the said material will be pushed
17
יז
towards the axis *O.
This effect is produced by causing the shafts A A' and the screws v v³ to turn
from right to left in the direction indicated by the arrows a plastic material from
which the pipes are to be formed such as caoutchouc or India rubber in a plastic
condition is introduced between the screws through openings F F in the side of
the case:
.
i
The action of the screws will propel the materials towards the space at O figure 2
between the ends of the screws whence it will escape through an opening O' con-
stituting the moulding orifice which orifice is partly filled up by a cylindrical
mandril A corresponding with the internal diameter of the pipe or tube that is to
be manufactured.
3
The annular space a around the mandril M is limited externally by a matrix
or mould I corresponding to the external dimensions of the tube.
It is evident that tubes or pipes of any desired form and dimensions may be
manufactured by employing a mould or matrix and the mandril corresponding to
the form and dimensions of the tube or pipe that it is desired to produce.
Morcover as india rubber expands inwards as well as outwards on issuing from the
annular orifice between the mould and the mandril as shewn in figure 3 a wire
helix or any substance in the form of a cord or cable or a bundle of telegraph
wires for example introduced through the hollow of the mandril will be laid hold
of by the sides of the tube and drawn forwards with the latter so as to fill or line-it
completely throughout its whole length.
The cover or cheek C is bolted to the frame B and can be readily removed for
the purpose of exposing the interior of the machine.
The machine may be heated by steam pipes d d in the sides of the case or by
other suitable means.
'
Screws g'are provided for the purpose of adjusting the matrix H centrally in the
opening over the mandril M the said matrix being subsequently fixed in position
by means of the clamps and screws h.
+
i
When the machine is in action the materials are continuously introduced into
the machine through the two openings FF corresponding to each pair of screws.
The materials are then drawn towards the centre O of the machine and issuó
through the annular orifice in the form of a pipe or tube as hereinbefore
described.
"
The mandril M is supported in a tube or socket T cast on the side C and is
secured in position by set screws p.
One or both pairs of screws for propelling the material may be driven positively
by worm wheels and endless screws or by any suitable means but it is preferred to
drive only one pair positively as described.
In place of but two pairs of screws more than two pairs may be employed the

page_text: form of the case or support being modified according to the number of pairs of
screws employed.
Having now described and particularly ascertained the nature of the said
Invention and the manner in which the same is or may be used or carried into
effect I would observe in conclusion that what I consider to be novel and original
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is :-
In machines for moulding pipes or tubes from plastic material or for covering
telegraph cables or other like purpose the employment for feeding forward the
material of two or more pairs of screws engaging together and turning in cavities
into which the plastic material is introduced the said screws acting conjointly to
feed the said material into and force it through the moulding orifice substantially
as hereinbefore described with reference to the accompanying Drawings.
In witness whereof I the said John Henry Johnson have to this my
Specification set my hand and seal this sixth day of April One thousand
eight hundred and eighty three.
J. HENRY JOHNSON (L.S.)