Joint-packings.
Year: 1886

page_text: 5
Joint-packings.
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 performed, to be
particularly described and ascertained in and by the following statement:-
IJ
This invention relates to the class of packings made from the twisted or braided
fibres of asbestos, or other fibrous substances, used to make tight the joints of
valves, stuffing boxes,, pistons and other machines and structures, against the
passage of hot or cold fluids, steam or other vapour; and its object is to provide
an asbestos or other fibrous packing in the form of a rope, cord or wick, spun,
twisted or braided in the usual way, from asbestos fibres, or from other fibrous
substances that may be used to pack joints of various forms and outlines; that
shall be elastic, impermeable to a degree, and capable of being used to pack a joint
that may be repeatedly broken without requiring the renewal of the, packing.
According to this invention, a rope-or cord made; of asbestos, fibre, or the fibre of
some other substance, spun, twisted or braided into form in the usual manner, is
saturated with adhesive and elastic material, that in a measure holds the fibres
together and adds to the elasticity and durability of the whole mass, as more
particularly hereinafter described and pointed out in the claims.
In the method of saturating the separate strands, before they are twisted or
braided together, an important advantage is gained; inasmuch as the strands thus
saturated form a packing more dense and adhesive, and less liable to disintegration.
Referring to the drawings, Figure 1 is a detail view of a piece of ordinary fibrous
rope of asbestos or other fibrous substance, twisted to shape in the usual manner.
Figure 2 is a detail cross sectional view, to an enlarged scale, of the said rope,
treated and coated as in the practice of this invention. Figure 3 is a view of a

page_text: piece of the improved rope bent to form a ring packing, the ends united by a
scarfed joint. Figure 4 is a detail plan view of the improved rope packing for an
oblong joint. Figure 5 is a detail view in cross section of the improved rope
packing, illustrating its shape before and after use in packing a joint, and also its
adaptability to compression or change of form without destroying the integrity of
the mass or its elasticity.
In the accompanying drawings, a denotes a piece of rope made of fibrous asbestos
or other substance of a kind that is in general use for packing stuffing boxes,
pistons or the like; the dried fibre being spun in the usual way, and the requisite
number of strands twisted or braided into the several sizes of rope wanted for use.
A packing is ordinarily made by cutting off a piece of this rope (of asbestos or
other substance), bending it into shape to conform to the general outline of the
joint to be packed (as oval, round or rectangular) and then holding it in place by a
gland or like part in the usual manner. Such a packing is liable to be disenteg-
rated by friction of the wearing parts or by pressure of steam or other fluid coming
in contact with, or flowing past it. In order to prevent such wasting or wearing
of the packing, it has in some cases been saturated with tallow or wax, and treated
with plumbago and similar lubricants; but these means have not increased the
adhesiveness of the fibres in the mass in a proper manner to secure sufficient
elasticity and durability.
A joint packed with such a material as above described, when once broken,
cannot usually be made tight again with using a new packing.
In order to make a rope packing adaptable to the many and various uses to
which it may be put, in addition to having convenient form for enabling one to
obtain the required length to wrap about a piston or fit into an annular recess
(or one of irregular shape) it should possess in the highest degree-elasticity,
durability and sufficient cohesiveness between the fibres composing the mass to
enable a joint to be repeatedly packed and broken without requiring a renewal of
the packing; and it should also have a surface, that while yielding, and capable of
adapting itself to irregularities in the joint packed by it, shall be sufficiently firm
to prevent disentegration of the fibres composing it under the action of flowing
fluids, as steam, hot water and the like. Such a packing is prepared according to
this invention by taking a length of the ordinary fibrous rope (asbestos or other
substance) a [the separate strands of which may have been passed through a
solution of rubber, in naphtha (in which there is sulphur for vulcanising and
plumbago or soapstone to lessen the friction in wear) or through a solution of
other gums with the necessary ingredients for producing the same effect] in a dried
state and passing it through the same solution, and retaining the rope in the
solution long enough to allow the fluid to thoroughly penetrate the body; the
solution forming also a coating on the outside of the rope as the latter is removed
from the bath.
Such a rope packing is preferably run over one reel, down through the solution,
and up over another reel; the surplus solution being rubbed off as the rope emerges
from it, and the surface of the packing smoothed.
When the rope has been dried, it is advantageous to give it a surface coating of
dry plumbago or soapstone, or a mixture of the two, which adheres to the rubber
in the surface of the packing. The whole mass of rope is then vulcanised in the
ordinary manner. This improved packing (asbestos or other fibrous packing) may
be cut into suitable lengths, and the ends scarfed and united to form a ring packing
as shewn at c in Figure 3, or an oblong packing as d in Figure 4. Such a packing
or gasket is, when first formed, circular in cross section, as shewn at e in Figure 5;
but it may be compressed to a shape in cross section as shewn at f in Figure 5
.without destroying the integrity of the mass or its elasticity. When it is desired
to use the rope packing to make a special form of packing, as a ring packing,
that shall be permanent in its shape, it is slightly moistened, as with naphtha, after
being bent into the required form, and is then subjected to pressure between dies
of proper shape.

page_text: The rope, after saturation, may be first formed to the desired outline and pressed
to shape while moist and then vulcanised; a ring packing of considerable density,
yet elastic and sufficiently yielding to adapt itself to slight irregularities in the
joint to be packed, being thus produced.
Having thus particularly described and ascertained the nature of this invention,
and in what manner the same is to be performed, I claim :-
1. As an improved article of manufacture, a rope or cord of fibrous asbestos-or
other fibrous material-soaked and coated with a compound of rubber and sulphur
(or with a compound of gum with any material having the same or similar effect)
in a suitable vehicle, as naphtha, and further covered with plumbago or the like
lubricant; all substantially as described.
2. The improved method of manufacturing asbestos or other fibrous packing
substantially as herein described and consisting of immersing a fibrous rope or cord
of asbestos (or other like material) in a solution of india rubber and naphtha, or the
like vehicle containing sulphur, then removing the rope and wiping off the surplus
solution.
3. As an improved article of manufacture, a strand, cord or rope made of asbestos
fibre (or other fibrous material) spun, twisted or braided to shape, and treated by
immersion of the strands or cord in a cementing mixture of rubber, sulphur and
naphtha, or the like vehicle, that permeates the mass and forms a compact and
durable protection against wear; the product being rendered of greater density on
the exterior than within the mass, and the cementing mixture further serving as
an agent in the process of vulcanisation; all substantially as herein described.
Dated this 20th day of October 1886
G. G. M. HARDINGHAM.