IMPROVEMENTS IN THE ARRANGEMENT AND MANUFACTURE OF PACKING FOR STEAM ENGINES, PACKED COCKS, AND OTHER LIKE PURPOSES, AND WHERE A PACKING OR MEANS OF MAKING A TIGHT JOINT IS USED OR REQUIRED, APPLICABLE ALSO FOR OTHER PURPOSES, SUCH AS BUSHING OR LINING THE HOLES IN INDIA-RUBBER AIR PUMP AND OTHER VALVES, AND OTHER RUBBING SURFACES.
Year: 1878

page_text: LETTERS PATENT to Thomas Greenacro, of Rotherhithe, in the County of
Surrey, Engineer, and Charles Frederic Trelawny Young, of New Cross, in the
County of Kent, Consulting Civil and Mechanical Engineer, for the Invention
of "IMPROVEMENTS IN THE ARRANGEMENT AND MANUFACTURE OF PACKING
FOR STEAM ENGINES, PACKED COCKS, AND OTHER LIKE PURPOSES, AND WHERE
A PACKING OR MEANS OF MAKING A TIGHT JOINT IS USED OR REQUIRED,
APPLICABLE ALSO FOR OTHER PURPOSES, SUCH AS BUSHING OR LINING THE
HOLES IN INDIA-RUBBER AIR PUMP AND OTHER VALVES, AND OTHER RUBBING
SURFACES.
"
Sealed the 20th August 1878, and dated the 22nd May 1878.
PROVISIONAL SPECIFICATION left by the said Thomas Greenacre and
Charles Frederic Trelawny Young at the Office of the Commissioners of
Patents on the 22nd May 1878.
THOMAS GREENACRE, of Rotherhithe, in the County of Surrey, Engineer, and
CHARLES FREDERIC TRELAWNY YOUNG, of New Cross, in the County of Kent,
Consulting Civil and Mechanical Engineer. "IMPROVEMENTS IN THE ARRANGE-
MENT AND MANUFACTURE OF PACKING FOR STEAM ENGINES, PACKED COCKS, AND
OTHER LIKE PURPOSES, AND WHERE A PACKING OR MEANS OF MAKING A TIGHT
JOINT IS USED OR REQUIRED, APPLICABLE ALSO FOR OTHER PURPOSES, SUCH AS
BUSHING OR LINING THE HOLES IN INDIA-RUBBER AIR PUMP AND OTHER VALVES,
AND OTHER RUBBING SURFACES."
This Invention has for its object improvements in the manufacture of packing or
means for making tight joints by the use of asbestos fibre in combination with
india-rubber or other suitable material or materials, or combination of the same,
which are arranged so as to secure more satisfactory results in their application,
and also in the manufacture and use of the asbestos fibre without the combination
of other material or materials, except so far as to render the same more convenient
for transport and handling, whereby we are enabled to manufacture at a cheaper
rate, to obtain greater convenience in the use of the manufactured article, secure

page_text: greater durability, and render the same more generally applicable to the purposes
herein-before mentioned.
In carrying out our Invention, when applied to packing the glands of steam
engines or other motors, where leakage is required to be prevented at those parts
where rods, or spindles, or other moving parts pass or are situated, we give the
asbestos and rubber, or other material or materials, or combination of the saine used
in connection, such a form and arrangement as will enable the elasticity of the
packing to be maintained and form the asbestos fibre, which, by preference, is used
in its natural length, into rings or strips before being put into or arranged with the
india-rubber or other material or materials, or combination of the same, by which
means the cost of grinding or pulping the asbestos, or spinning and weaving or
braiding the same is saved, and also enables us to apply the asbestos only on the
rubbing surface or surfaces, or where the contact takes place, and yet maintain the
required amount of elasticity; and we may use a core of india-rubber, and cover or
embed the same in asbestos.
The same arrangement of asbestos fibre in rings or strips, in combination with
india-rubber or other material or materials, or combination of the same, or a modi-
fied arrangement, to suit the particular application, will be found of great utility for
packing cocks and valves, and forming the rubbing or bearing surface or surfaces
with which or which comes in contact with the part which controls or closes the
passage or way through the same, and far better and more durable than merely
packing the same by forcing in the loose asbestos fibre as has hitherto been
"the case.
For other joints, such as the flanges of steam and water pipes, or other pipes
where a packing is used or required, we form and combine the asbestos fibre into a
sheet or flat ring, or other convenient form, and, in the case of the sheet, we cut
from the same a ring or rings, strip or strips, of the dimensions required. These
sheets, or rings, or strips, we form of the natural length of the fibre, and subject
them to such pressure as is needed to produce the needed thickness, and then for
convenience of transport or handling, cover the material with sufficient india-rubber
of the necessary thickness, or other suitable material or materials, or combination of
the same, such as thin paper, metal, or woven fabric, for the purpose of keeping the
same in its proper form, and allow of its being transported or handled without
injury.
Q
We may sometimes employ an adhesive material or substance, or mixture of the
samo, in combination with the asbestos fibre, during the process of manufacture, to
obtain the same result, in addition to the plan of covering it, when made into the
sheets, or rings, or strips.
In those cases where the asbestos fibre may be found useful for lining bearings, the
lining may be formed of the fibre in its natural length, formed in a mould with the
requisite pressure to the required dimensions, and then covered with suitable
material or materials, or combination of the same, to prevent injury by transport or
handling; or the adhesive matter may be used with the fibre during the process of
manufacture.
Where necessary, metal or other suitable moulds may be used, in some cases
heated, and the necessary pressure employed to cause the fibre to take and maintain
its required form during and after the process of manufacture.
For bushing or lining the interior of the opening in india-rubber air pump valves
through which the rod of the pump bucket passes, or where the valves are placed on
spindles or bolts, we may either apply the asbestos fibre lining in the form of a hard
rubber ring, or part enclosing the fibre, and attach or combine the same with the
flexible rubber valve; or we may insert or attach the asbestos fibro lining or bush
into the soft rubber valve either as a ring, formed as herein-before described, or wo
may apply the fibre to the valve and form it in the same, as desired or preferred, or
the fibre may be formed in a soft rubber ring or part combined or not with other
suitable material or materials, and then insert and combine the same with the
rubber valve itself.

page_text: The fibre in its natural length may, by our arrangement, be so arranged and
formed as to be conveniently applicable to those employments for which it may be
found suitable or desirable, in a cheap and ready manner, and with greater promise
of durability than in those cases where from its previous disintegration and com-
bination with adhesive material, on which its adhesion and durability depend, as
thereby the interlacing or matting of the longer length of fibre, and the strength
and durability attained thereby, are entirely lost.
For convenience in manufacture, we by preference use the asbestos in a damp or
moist condition, and, in some cases, work it in a thoroughly wet condition, or in
combination with water or other liquid, or combination of the same, in order to
prevent the elasticity of the fibre, which exists when worked in a dry state, inter-
fering with the satisfactory carrying out of the manufacture.
Where the asbestos fibre is used in long lengths, the same may be combed out or
otherwise laid in an even position, to meet the requirements of the case, and the
shorter portions may be employed for making the sheets out of which the rings or
strips may be afterwards formed, as herein-before described.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Greenacre and Charles Frederic Trelawny Young in the
Great Seal Patent Office on the 22nd November 1878.
THOMAS GREENACRE, of Rotherhithe, in the County of Surrey, Engineer, and
CHARLES FREDERIC TRELAWNY YOUNG, of New Cross, in the County of Kent,
Consulting Civil and Mechanical Engineer. "IMPROVEMENTS IN THE ARRANGE-
MENT AND MANUFACTURE OF PACKING FOR STEAM ENGINES, PACKED COCKS, AND
OTHER LIKE PURPOSES, AND WHERE A PACKING OR MEANS OF MAKING A TIGHT
JOINT IS USED OR REQUIRED, APPLICABLE ALSO FOR OTHER PURPOSES, SUCH AS
BUSHING OR LINING THE HOLES IN INDIA-RUBBER AIR PUMP AND OTHER VALVES,
AND OTHER RUBBING SURFACES."
This Invention has for its object improvements in the manufacture of packing or
means for making tight joints by the use of asbestos fibre in combination with
india-rubber, or other suitable material or materials, or combination of the same,
which are arranged so as to secure more satisfactory results in their application, and
also in the manufacture and use of the asbestos fibre without the combination
of other material or materials, except so far as to render the same more convenient
for transport or handling, whereby we are enabled to manufacture at a cheaper rate,
to obtain greater convenience in the use of the manufactured article, secure greater
durability, and render the same more generally applicable to the purposes herein-
before and herein-after mentioned.
In preparing the material for use, and in order to obtain a separation of the
fibres, various modes may be adopted, such as pressing it between corrugated or
fluted reciprocating rubbing surfaces, between rollers or a roller, corrugated or,

page_text: fluted, acting in connection with a surface, or by combining two or more of theso
arrangements, pressure by a spring or weights being used, if needed, or in any other
suitable and convenient manner, using sufficient pressure to obtain the desired
result, but not enough to break up or damage the fibre in the operation, and it may
be so treated in a dry, damp, moist, or wet condition or state, according to the
nature or condition of the material and treatment required.
It may also be soaked in hot, warm, or cold water, or exposed to the action of
steam in an open or closed vessel, as necessary, in order to obtain an easy softening
and removal of the earthy or other matter attached to or connected therewith, but
in all cases it is preferred to avoid the use of acids or chemicals, either in its
preparation or manufacture, in order to prevent the ill effects caused by the contact
of the same on the material or parts with which it comes in contact, and in which
it is employed, such being found objectionable.
In carrying out our Invention when applied to packing for the glands of steam
engines or other motors where leakage is required to be prevented at those parts
where rods or spindles or other moving parts pass or are situated, we give the
asbestos and rubber or other material or materials, or combination of the same
used in connection, such a form and arrangement as will enable the elasticity of
the packing to be maintained, and form the asbestos fibre, which by preference is
used in its natural length, into rings or strips before being put into or arranged
with the india-rubber compound or other material or materials, or combination of
the same, by which means the cost of grinding or pulping the asbestos, and the
waste of the same occasioned thereby, or spinning and weaving, or braiding the
same, is saved, and also enables us to apply the asbestos only on the rubbing
surface or surfaces, or where the contact takes place, and yet maintain the required
amount of elasticity.
In manufacturing our packing rings of asbestos in combination with india-rubber,
canvas, hemp, jute, flax, cotton, or other suitable or convenient material or materials,
or combination of the same, and to form or arrange it in such a manner as to
enable the elasticity of the packing to be maintained, we take a ring or rings of
the asbestos fibre of a form, size, and dimensions suited to the object which is or
are formed, as herein-after described, and surround the exterior of the said ring
with a backing or larger ring of india-rubber, canvas, or other suitable material
of sufficient thickness to make up the deficiency in the stuffing box caused by the
asbestos ring not being used of a width sufficient to fill it entirely, and on the top
and bottom of this compound ring we place a flat ring or washer of india-rubber or
other material, the hole or central opening in which or them is of a larger diameter
than that in the asbestos ring, and either cement it, or them, or otherwise attach
it, or them, to the rubber backing and asbestos ring, so as to form a whole, whereby
we are able to use a less quantity of the asbestos fibre, and make a packing, which
by its form and arrangement will maintain its elasticity, and to dispense with the
necessity of grinding or pulping the asbestos, and avoid the disadvantages caused
by want of continuity in the fibres, and the liability to tearing or disintegration
from friction. These rings may be made so as to allow of one or more at a time
being used in a stuffing box, and by a diagonal cut through one side of the ring
the same may be slipped round the rod and placed in the stuffing box, care being
taken that the openings "break joint" when placing them in the stuffing box.
We also arrange and form the rings of asbestos packing so that the asbestos
shall be on the interior only, and in contact with the rubbing surface, such asbestos
being surrounded on its exterior circumference with a backing of "hemp," flax,
canvas, india-rubber, wire gauze, jute, cotton, or any other suitable material or
materials, or combination of the same, in order to obtain the benefits of the use of
asbestos with the minimum amount of that material, it being obvious that in a
stuffing box it is only the part in contact with the rubbing surface or moving part
that is exposed to wear. By placing a ring containing the asbestos on the inside,
so as to come in contact with the rubbing surface, and a ring of flax, canvass, or
other material or materials without asbestos over it, and then another ring with

page_text: asbestos, and so on, or vice versa, until sufficient is put in the stuffing box to make
the joint, we use a less quantity of asbestos, and yot obtain a tight joint.
In manufacturing rings for packing with asbestos only we form a core or body
out of the asbestos itself by winding the fibres round a nandril, which is larger
than the part in which the ring is to be used, and then, as in making a "grommet "
or "grummet," as it is called by sailors, wind round and round the core or ring so
formed, taking care to join the ends of the fibres or interlock them as more length
is required, as much of the fibre as will bring it up to the required size or dimen-
sions, or allow of its becoming so when finished, causing each round of the fibres
to pass partially over the former round so as to break joint, as it is termed, the
object being to cause the rubbing or friction of the moving part against the ring to
act in the direction of the length of the fibres in place of across them, whereby
more durability in the same will be obtained, and less likelihood of tearing or
disintegrating the fibres.
If desired, the core or body may be formed of india-rubber, vulcanised or not, of
hemp, jute, cotton, flax, wire gauze, or any other suitable or convenient material,
or combination of the same, and the ring when formed may be pressed so as to
remove the moisture or consolidate the whole and then dried; and when dry
enough a slight coat of india-rubber solution, elastic varnish, or other suitable and
convenient material or substance, or combination of the same, may be given to it
to enable it to withstanding the action of transport or handling.
In some cases we moisten the core or parts of the same when forming it with
the before-mentioned solution or material, or substance, and also tho fibres whilst
being wound round, and in other cases we may use it on the core only, or in
winding on only, in addition to the light coat given when finished.
The same arrangement of asbestos fibre in rings or strips, in combination with
india-rubber or other material or materials, or combination of the same, or a
modified arrangement to suit the particular application, will be found of great
utility for packing cocks and valves, and forming the rubbing or bearing surface or
surfaces, with which, or which comes in contact with the part which controls or
closes the passage or way through the same, and far better and more durable than
merely packing the same by forcing in the loose asbestos fibre, as has hitherto been
the case.
In preparing rings or strips for packing cocks the same may be formed on a coro
of rubber, asbestos, or other suitable material by winding the fibre round the same.
until large enough, and then compress it, or them, to the shape and dimensions of
the part or place it, or they, is, or are, to occupy, after which, when dried, it may
be coated as herein-before described, or the solution or elastic varnish may be used.
in the manufacture.
Where the glands or parts used for setting up or compressing the packing in
the cocks come in contact with the packing or asbestos, one or more thin metal
washers may be placed between the packing and the gland or part, so as to prevent
the action of screwing-up from tearing the fibre, and in some cases it will be found
beneficial to hollow out that part of the gland or part which comes in contact with.
the asbestos to prevent tearing it, grease or tallow being used on the same to aid
this object.
The rings may also be made by taking long fibres of the asbestos and winding
them lengthwise round a mandril, passing the ends through the wound part several
times to secure them when fastening off; and the whole may be subjected to
pressure if necessary and dried before coating, as herein-before described.
They may also be formed, as well as the strips, of strips or portions cut from the
sheet or asbestos leather rolled or wound round a rubber or other core when desired,
so as to form the required length and size, which also may be used as a packing, and
for various other purposes. Cord for back nuts, joints to pipes, and other uses, may
be so formed; or the sheet may be cut into strips, platted together and pressed,
where desired or preferred.
For other joints, such as the flanges of steam and water pipes, or other pipes.

page_text: where a packing is used or required, we form and combine the asbestos fibre into
a sheet or flat ring, or other convenient form; and in the case of the sheet we cut
from the same a ring or rings, strip or strips, of the dimensions required. These
sheets, or rings, or strips, we form of the natural length of the fibre, and subject
them to such pressure as is needed to produce the required thickness, and then for
convenience of transport cover the material with sufficient india-rubber or com-
pound of the necessary thickness, or other suitable material or materials, or com-
bination of the same, such as thin paper, metal, or woven fabric, for the purpose of
keeping the same in its proper form, and allow of its being transported or handled
without injury.
Wo may sometimes employ an adhesive material or substance, or mixture of the
same, in combination with the asbestos fibre during the process of manufacture to
obtain the same result, in addition to the plan of covering it when made into the
sheets, or rings, or strips.
In forming the sheets or "boards," which when manufactured in our improved
manner we term "asbestos leather" from their toughness and flexibility, we take
the long fibres in as long lengths as possible in a dry, damp, moist, or wet condition,
as required or as most suitable, and lay or spread them evenly in the same direction
on a sheet or web of wire gauze, canvas, or other suitable material, to the required
width of the sheet, taking care that they shall be interlapped, i.e., that there shall
be no spaces between them breadthwise until there is a sufficient amount to give
the required thickness; and then to get the required length of sheet we interlap
or lock the ends of another length of fibres with the end or ends of those already
in place, so as to obtain continuity of fibre lengthwise and avoid leaving open
spaces, adding the fibre until the required length and breadth are reached, turning
over the ends of each length if longer, so as to form a selvage. In this condition
we place another sheet or web of wire gauze over the material, and pass the whole
between rollers heated or not, as required, or subject it to sufficient pressure, also
under heat if desired, to consolidate it to the desired amount, and to remove the
moisture which may have been in it when being made up; and we may also place
another layer of fibre across at right angles, turning over the edges of the longer
part, though we may make it without turning the edges over. When it has been
sufficiently pressed we allow it, if moisture has been used in making up, to dry, and
then, having removed the wire gauze, coat it on both sides with a thin solution of
india-rubber, elastic varnish, or other suitable inaterial or substance not acted on
by water or damp. The sheet when so formed may be as thin as possible, say, a
little thicker than stout paper; and to form the thicker board we employ several
such sheets, placing them in layers; the second with the fibres lengthways across the
breadth of the sheet, turning the longer end over the shorter or narrower part
to form a selvage and bind the parts together; the third with the length of the
fibres placed diagonally, still turning over the ends as before; the fourth also
diagonally, but at an angle to the third, turning over the ends also; and the last
with the length of fibre as in the first, again turning over the end or ends, placing
a coat of the thin solution between each, and then pass the whole through rollers
or subject it to other suitable pressure, as herein-before described, so as to con-
solidate the same and reduce it to the required thickness. In subjecting it to
pressure it may be placed between two sheets of wire ganze or other suitable
material, as herein-before described; and when dry, a thin coat of the solution or
elastic varnish may be brushed over the same, as herein-before described; but when
wire gauze is used the pressure should be given between elastic or flexible surfaces,
so as to prevent the pressure flattening down the wires where they cross each other,
and so damaging or breaking them.
In place of forming the thick board by assembling together the required number
of sheets, as herein-before described, we may make it in one thickness by placing the
necessary amount of fibre lengthwise, across the breadth, diagonally thereto, then
diagonally again in the other direction, and lastly lengthways, as in the first layer,
and if preferred add other layers in a similar manner, turning over the ends of

page_text: each layer if longer, so as to form a selvage to the sheet; and the asbestos fibre
may be moistened with the thin solution or clastic varnish in forming the layers,
or each may be brushed over with the same, and the whole subjected to the
required pressure between sheets of wire gauze, canvas, or other suitable material,
and lastly covered with a thin coat of the solution or elastic varnish. If the fibro
be used in a wet, damp, or moist condition, it will be better to dry it before
applying the solution or elastic varnish.
It will be found that the sheets or boards made on our improved system will
possess a pliability and toughness at present unattained in other modes, or whero
it is pulped or ground up, or the "flock" or short staple is used in the manufacture
of the same, and from being free from acids and not held together by glutinous
matter soluble in water, it will when used for making joints exposed to wet and
pressure, or both combined, be free from leakage or "blowing out," or any injurious
action on the materials or metals with which it is in contact.
From the sheets so formed, flat rings or other shapes requiring greater breadth
or length than thickness, may be cut, punched, or stamped, and holes or slots may
be punched or cut in the same as required; out of sheets of this kind strips may be
cut and twisted or wound together round a mandril, so as to form rings or packing
in a similar manner to that done with the loose fibres ns herein-before described,
and when the rings are so formed, they may be subjected to pressure to consolidate
them and cause them to maintain the required form, and by using the form of the
part in which they are to be employed to act as the pressing surface, they may be
caused to take and maintain a round, square, Hat, or bevelled form, according to
the conditions required and the shape of form used, and such rings or washers when
formed out of the loose fibres as herein-before described, may be treated in a similar
manner. The sheet may be cut into parts and rolled round a rubber or other
suitable core, so as to form a packing of the length and diameter required.
We employ the asbestos leather as herein-before described, to protect persons
using fire-escapes from the action of the flames or heat when such apparatus is in
use, by applying in place of the ordinary netting or gauzo used with the same, a
sheet or sheets of the asbestos leather formed or placed between two sheets or webs
of metal gauze or fine netting, to which it may be firmly fastened by sewing or
working the edges with metal wire, and stabbing or quilting it between the edges
and ends also with metal wire which passes through both sheets or webs of the
gauze or metal, and through the asbestos leather between them, making thereby
a flame, heat, or fire proof shief of sufficient flexibility.
In some cases we form the body or core of the flat washers or flanges of wire
gauze worked or wound over with the asbestos fibre or thin coat of the solution or
elastic varnish as herein-before described, being in some cases put on or over the
wile gauze before putting on the asbestos, or with each layer or round of the
asbestos a coating may be used, in addition to that placed over all when the washer
or flange is pressed and dried if the asbestos has been used in a damp, moist, or wet
condition. By this arrangement and combination great strength is obtained, and
such is likely to be useful for joints exposed to heat from fire or steam, or other
high temperature.
In those cases where the asbestos fibre may be found useful for lining bearings,
the lining may be formed of a core or body of the fibre and wound over by other
asbestos fibres in its or their natural length, and so as to present the length of the
fibres to the line of motion, and then pressed or formed in a mould with the requi-
site pressure to the required dimensions, and when dried, if moisture has been used,
covered with solution or elastic varnish, or other suitable material or materials, or
combination of the same, to prevent injury by transport or handling, or the solu-
tion, or varnish, or adhesive matter may be used with the fibre during the process
of manufacture.
Where necessary, metal or other suitable moulds may be used in all cases, and the
necessary pressure employed to cause the fibre to take and maintain its required
form during and after the process of manufacture.

page_text: For bushing or lining the interior of the opening in india-rubber air puinp valves,
through which the rod of the pump bucket passes, or where the valves are placed
on spindles or bolts, we may either apply the asbestos fibre or lining in the form of
a hard india-rubber ring enclosing the fibre, and attach or combine the same with
the flexible rubber valve, or we may insert or attach the asbestos fibre lining or
bushing into the soft rubber valve, either as a ring formed as herein-before des-
cribed, or we may apply the fibre to the valve and form it in the same, as desired
or preferred, or the fibre may be formed in a soft rubber ring combined or not with
other suitable material or materials, and then insert and combine the same with
the rubber valve itself.
The fibro in its natural length may by our arrangement be so arranged and
formed as to be conveniently applicable to those employments for which it may be
found suitable or desirable, in a cheap and ready manuer, and with greater promise
of durability than in those cases whore from its previous disintegration and com-
bination with adhesive material soluble in water or damp on which its cohesion
and durability depend, as thereby the interlacing or matting of the longer length
of fibre, and the strength and durability attained thereby are entirely lost..
For convenience in manufacture we by preference use the asbestos in a damp or
moist condition, and in some cases work it in a thoroughly wet condition or combi-
nation with water or other liquid, or combination of the same, in order to prevent
the elasticity of the fibre which exists when worked in a dry state interfering with
the satisfactory carrying out of the manufacture. Gum water, gum in solution,
or other sticky material may be used to keep the fibres in place when being
manufactured.
Where the asbestos fibre is used in long lengths, the same may be combed out, or
otherwise smoothed or laid in an oven position to meet the requirements of the case,
and the shorter portions may be cimployed for making the sheets, out of which the
rings or strips may be afterwards formed, as herein-before described.
The accompanying Sheet of Drawings illustrates some of the modes in which our
Invention may be carried out, when applied to forming packing for glands, packing
for cocks, sheet or tape, or what we terin "asbestos leather," and will illustrate tho
manner in which the parts may be arranged.
Fig. 1 is an clevation of a completed compound, square, round, or flat ring of our
improved packing ready for use, showing the inclined cut through one side for
enabling it to pass round tho rod or spindle; a, a, is the rubber or other backing and
top or bottom of the ring; b is the asbestos, the vertical lines showing the fibres in
the same direction as the line of notion of the moving part.
Fig. 2 is a section across the ring from side to side, showing the asbestos and
rubber or other backing.
Fig. 3 is a section across the ring from side to side of a rubber or other core,
surrounded by the asbestos fibre, as herein-before described.
Fig. 4 is a similar section of a compound ring, in which the rubber at the top and
bottom is made thickest at the circumferential edges.
Fig. 5 is one with the thickest part on the interior circumference.
Fig. 6 is a modification, showing the use of alternate rings of asbestos fibre next
the rod or rubbing surface; and flax or other suitable material next the side of the
stuffing box, the asbestos and flax or other material being backed with india-rubber,
canvas, or other suitable material; a, the flax or other material; b, the asbestos ;
c, the backing; by this arrangement we are enabled to use less asbestos and place it
only in contact with the rubbing surface, as hercin-before described.
Fig. 7 is another modification for the same purpose.
Fig. 8 shows the flat wire gauzo ring or flange in progress of manufacture, showing
how the asbestos is put on.
Fig. 9 shows the mode of making a ring on a core or central part of asbestos,
india-rubber, or other suitable material, as herein-before described.
Fig. 10 shows a strip of any suitable material in progress of manufacture.
'

page_text: Figure 11 shows the way of disposing the fibre in forming sheets or "asbestos
leather;" similar parts are denoted by similar letters of reference.
Having now described the nature of the said Invention of "Improvements in the
Arrangement and Manufacture of Packing for Steam Engines, Packed Cocks, and other
like Purposes, and where a Packing or Means of Making a Tight Joint is Used or
Required, Applicable also for other Purposes, such as Bushing or Lining the Holes in
India-rubber Air Pump and other Valves and other Rubbing Surfaces," and the manner
in which the same is to or may be performed or carried into practical effect, wo
desire to state that we do not limit or confine ourselves to the precise details shown
in the accompanying Sheet of Drawings, as the same may be modified without
departing from the nature of our said Invention, nor do we claim as of our Inven-
tion the use of packing for making tight joints, as this is not new, nor the use of
india-rubber or asbestos for such purpose, as these have been used before, but what
we do claim as of our Invention, and desire to have protected by Letters Patent is,
the manner or mode of forming packing, sheet, rings, strips, &c., as herein-before
described, out of the fibres of asbestos used in their natural lengths, and prepared
and manufactured without the use of acids or chemicals, and also in using the samo
in combination with india-rubber or other suitable material or materials, in the
manner and for the purposes herein-before described and specified, and as shown in
the accompanying Sheet of Drawings.
In witness whereof, we, the said Thomas Greenacro and Charles Frederic
Trelawny Young, have hereunto set our hands and seals, this Twenty-second
day of November, in the year of our Lord One thousand eight hundred and
seventy-eicht.
THOMAS GREENACRE.
(L.S.)
CHA³. F. T. YOUNG, C.E. (L.S.)