Year: 1886

page_text: Date of Application, 2nd Apr., 1886.
Complete Left, 10th Dec., 1886.
Complete Accepted, 11th Mar., 1887.
[Communicated from abroad by RUFUS N. PRATT, of Hartford, in the County
of Hartford and State of Connecticut, one of the United States of America,
Manufacturer.]
I, GEORGE GATTON MELHUISH HARDINGHAM, of 191 Fleet Street, in the County of
Middlesex, Civil Engineer and Patent Agent, do hereby declare the nature of this
Invention to be as follows:-
This invention relates to an improved manufacture of packings for glands and other
joints which are subjected to the pressure of steam, water and other fluids; and has
special reference to packings in the constitution of which asbestos is employed. This
invention also relates to certain novel appliances adapted for the efficient conduct of the
manufacture.
The primary object of this invention is to produce a packing composed mainly of
asbestos, and in which the fibre is preserved in filaments of considerable length, the
same being so thoroughly and evenly distributed throughout the mass as to produco a
packing of uniform density.
In forming an annular packing according to the improved method comprised in this
invention, a hollow cylindrical mould is employed, composed of steel or other suitable
metal and fitted with a piston or core. From one face of the latter a narrow stem is
extended parallel to the inner walls of the mould, an annular space being thus formed
between these walls and the stem. The lower surface of the mould and the upper
surface of the core are, by preference, parallel, so as to adapt them for ready insertion
between the base and platen of any ordinary form of press.
In carrying out this invention, asbestos is disintegrated in any manner that will
leave the material in a fibrous condition particular care being taken not to comminute
or triturate or otherwise reduce the material to a powdered condition. The asbestos
fibre is then thoroughly saturated with naphtha or like volatile fluid, in which certain
proportions of caoutchouc and sulphur have been dissolved and mixed; and these
מ'

page_text: ingredients, that is to say, the asbestos fibre and the naptha solution of caoutchouc and
sulphur, are thoroughly mixed together.
A suitable quantity of the saturated asbestos is distributed in the mould chamber
and the core put in place, the latter being supported upon a plug of greater or less
thickness depending upon the thickness of asbestos ring desired; the outer and inner
diameters of the ring depending upon the size of the forming chamber. The chamber
having been charged with the saturated asbestos, a tubular plunger is applied with
a slight downward pressure to pack and distribute the fibre evenly in the mould,
the operation being aided by imparting a slight rotary motion to the plunger. The
core and plunger are then withdrawn from the mould, the ring of saturated asbestos
being removed therewith, and the core and plunger having been taken apart, the
ring is carefully slipped off the core and laid aside to dry; care being nevertheless
taken to prevent it becoming thoroughly dry. When the ring is sufficiently dry
to permit of its being handled without injury to its form, it is replaced upon the
stem of the core in the mould, the plunger re-introduced and the ring subjected to
compression. It is then again removed from the mould and core, and allowed to dry
to a further extent; the compressing and drying processes being subsequently repeated
until the ring is considerably reduced in thickness; the final drying process being
thorough, in order to impart compactness to the mass.
The process described of alternately drying and pressing the ring whilst in course
of manufacture is essential for the production of a perfect article, for the reason
that if the ring be allowed to dry when of considerable thickness, and an attempt
be then made to press it, the sides thereof become seamed and creased to an extent
which in a measure destroys the utility of the product.
It is evident that the herein before described method of forming asbestos fibre into
compact bodies may be employed in the manufacture of blanks or sheets of various
forms and descriptions; the mould being in such instances modified and adapted to
the purpose in view. The packing may be made in continuous sheets by passing
the mass of saturated fibre between rollers while spread on a platen, and the drying
and pressing repeated in alternation until the desired thickness of packing is
produced.
When the saturated asbestos, or like fibre, is made into sheets, it may be cut into
any desired shape after it has been dried, and then placed in suitable moulds, or in
its final position in grooves or sockets in the part to be packed, and firmly compressed
therein, and afterwards vulcanized without removing it from the socket. In vulcanizing
the coated fibre after it has been formed to shape, it is preferred to hold the article
under pressure to secure an evener surface than can be produced if the rings or other
articles be vulcanized without pressure.
The hereinbefore described process is applicable for the manufacture of packing from
fibres other than asbestos. Or, to asbestos or other suitable fibre may be added
plumbago, shellac, Paris-white, chalk, lamp-black, litharge or certain other substances
of a similar nature.
I am aware that asbestos and similar fibres have been reduced to a comminuted con-
dition and then mixed with caoutchouc and other substances and made into rings and
other forms for packings; but such preparations have proved wanting in durability in
consequence of the cementing material, such as caoutchouc, wearing away rapidly and
carrying portions of the asbestos with it. In a packing of the present improved
description, the whole wearing properties of the fibre are utilised, and the caoutchouc
or like cementing material simply serves to hold the mass of fibres together, these being
so intertwined as to present, on the superficial cementing material wearing away, an
almost solid surface of asbestos to withstand the frictional wear.
G. G. M. HARDINGHAM.

page_text: I, GEORGE GATTON MELHUISH HARDINGHAM, of 191 Fleet Street, in the County of
Middlesex, Civil Engineer and Patent Agent, do hereby declare the nature of this
invention (a communication from abroad by Rufus N. Pratt, of Hartford, in the
County of Hartford and State of Connecticut, one of the United States of America,
Manufacturer,) and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention relates to an improved manufacture of packings for glands and other
joints which are subjected to the pressure of steam, water and other fluids; and has
special reference to packings in the constitution of which asbestos or other fibrous
material is employed.
The primary object of this invention is to produce a packing composed mainly of
asbestos, or other fibrous material, and in which the fibre is preserved in filaments of
considerable length, the same being so thoroughly and evenly distributed throughout
the mass as to produce a packing of uniform density.
In forming a gland packing according to the improved method comprised in this
invention, a hollow mould is employed, composed of steel or other suitable metal, and
adapted to the form of packing required. The mould is fitted with a piston or core
which may carry a stem arranged parallel with the sides of the mould, around which
stem the packing may be pressed in any desired shape. The lower surface of the
mould and the upper surface of the piston or core are, by preference, parallel; so as
to adapt them for ready insertion between the base and platten of any ordinary form
of press.
In carrying out this invention, asbestos or some other fibrous material is disinte-
grated in any manner that will leave the material in a fibrous condition, particular care
being taken not to comminute or triturate or otherwise reduce the material to a
powdered condition; the fibre is then thoroughly saturated with naphtha, or like
volatile fluid, in which certain proportions of caoutchouc and sulphur have been
dissolved and mixed; and these ingredients, that is to say, the fibre and the naphtha
solution of caoutchouc and sulphur are thoroughly mixed together.
A suitable quantity of the saturated fibre is distributed in the mould chamber and
the core put in place; the latter being supported upon a plug of greater or less
thickness, depending upon the thickness of fibre ring or other desired form. The
chamber having been charged with the separated fibre, a tubular plunger is applied
with a slight downward pressure to pack and distribute the fibre evenly in the mould.

page_text: The core and plunger are then removed from the mould, the form of saturated fibre
being removed therewith; and the core and plunger having been taken apart the
form is carefully taken ont and laid aside to dry. When the form is sufficiently dry
to permit of its being handled without injury to its form, it is replaced upon the core
within the mould, the plunger reintroduced and the form subjected to compression.
It is then again removed from the mould and core, and allowed to dry to a further
extent; the compressing and drying processes being subsequently repeated until the
form is considerably reduced in thickness; the final drying process being thorough in
order to impart compactness to the mass.
It is evident that the saturated fibre may be moulded as before stated, and dried out
before any pressing; after which one pressing may make it sufficiently compact for
many purposes. The process described of alternately drying and pressing the form
whilst in course of manufacture is however essential for the production of a perfect
article; for the reason that if the form be allowed to dry when of considerable thick-
ness, and an attempt be then made to press it, the sides thereof become scamed and
creased to an extent which in a measure destroys the utility of the product. For some
purposes, the complete drying and one or more pressings may be sufficient.
It is evident that the herein before described method of forming fibre (asbestos or
other fibrous material) into compact bodies may be employed in the manufacture of
blanks or sheets of various forms and descriptions; the mould being, in such instances,
modified and adapted to the purpose in view. The packing may be made in continuous
sheets by passing the mass of saturated fibre between rollers while spread on a platen,
and the drying and pressing repeated in alternation until the desired thickness of
packing is produced.
When the the saturated fibre is made into sheets, it may be cut into any desired
shape after it has been dried, and then placed in suitable moulds, or in its final position
in grooves or sockets in the parts to be packed and firmly compressed therein and
afterwards vulcanized without removing it from the socket or groove. In vulcanizing
the coated fibre after it has been formed to shape, it is preferred to hold the article
under pressure to secure a more even surface than can be produced if the form be
vulcanized without pressure. Although for many purposes, such as soft packings, the
fibre may be vulcanized without pressure; giving a softer product.
The hereinbefore described process is applicable for the manufacture of packing
from fibres other than asbestos. Or to such fibre (asbestos, or other) may be added
plumbago, shellac, Paris-white, chalk, lamp-black, litharge, or certain other substances
of a similar nature.
I am aware that asbestos and other fibrous materials have been reduced to a
comminuted condition and then mixed with caoutchouc and other substances and
made into rings and other forms for packings; but such preparations have proved
wanting in durability in consequence of the cementing material, such as caoutchouc,
wearing away rapidly and carrying portions of the fibro away with it.
In a packing of the present improved description, the whole wearing properties of
the fibre are utilized; and the caoutchouc, or like cementing material, simply serves
to hold the mass of fibres together, these being so intertwined as to present, on the
superficial cementing material wearing away, an almost solid surface of fibre to with-
stand the frictional wear.
Having thus particularly described and ascertained the nature of this invention (as
communicated to me by my foreign correspondent) and in what manner the same is to
be performed, I claim :-
:
First The within described process of forming asbestos or other fibres into a mass
for use as a packing, which consists in mixing them in a solution of india-rubber, and
then distributing the fibres while wet in moulds, then removing the moulded mass
and alternately drying and pressing the mass, the final pressure being applied after
the final thorough drying of the mass; all substantially as described.
Secondly The within described process of forming a composition of asbestos and
india-rubber into a mass of uniform density while in a fibrous state, which consists in

page_text: mixing the fibres with india-rubber in solution with naphtha or the like fluid, and
then subjecting the mass to the drying and pressing process; all substantially as
described.
Thirdly-The within described process of forming asbestos packing, which consists
in distributing the fibres in a wet state in a mould of the desired shape, next removing
it from the mould for drying and then subjecting it to pressure; repeating these
drying and pressing operations until the mass is compressed to the desired density;
all substantially as described.
Fourthly: The within described process of forming packing of asbestos fibre,
which consists in distributing the fibres in a wet state about the removable core in the
forming chamber, then compressing the mass with a plunger, then removing the form
and partly drying it, then subjecting it to further pressure within the forming
chamber and continuing these drying and pressing operations until the mass is com-
pressed to the desired thickness; all substantially as described.
G. G. M. HARDINGHAM.