A NEW OR IMPROVED MATERIAL FOR USE AS PACKING FOR THE PISTON RODS OF STEAM ENGINES, AND LIKE USES
Year: 1872

page_text: LETTERS PATENT to Isaac Blue Harris, of Castle Mills, Fountain-
bridge, Edinburgh, for the Invention of "A NEW OR IMPROVED MATERIAL
FOR USE AS PACKING FOR THE PISTON RODS OF STEAM ENGINES, AND LIKE
USES."
Scaled the 10th December 1872, and dated the 28th September 1872.
PROVISIONAL SPECIFICATION left by the said Isaac Blue Harris at the
Office of the Commissioners of Patents, with his Petition, on the
28th September 1872.
I, ISAAC BLUE HARRIS, of Castle Mills, Fountainbridge, Edinburgh,
do hereby declare the nature of the said Invention for "A NEW OR
IMPROVED MATERIAL FOR USE AS PACKING FOR THE PISTON RODS OF STEAM
ENGINES, AND LIKE USES," to be as follows:-
This Invention relates to the manufacture of a material suitable for
use as a steam-tight packing, and it has for its object the production of
an article which will become while in use of a consistency that will
resist the action of lubricants and heat, and yet possess compressibility
to form a neat and steam-tight joint, while it also possesses in itself
lubricative or antifrictional properties.

page_text: The packing for steam engines heretofore made with india-rubber has
been formed in two distinctive ways; first, in the form of rings of the
more or less hard and rigid form of vulcanized rubber, known as
vulcanite, and applied without any covering of cloth to the piston rod
or stuffing box. This form, although capable of resisting the action of
the lubricants, is apt to heat too much from the friction of the piston
rod and is little used.
The other distinctive form is that of a core of soft vulcanized india-
rubber, surrounded by several layers of canvas to protect it from the
action of the lubricants, and from contact with the piston rod, which
would otherwise soon decompose it. The function of the canvas in such
a combination is to receive the friction of the rod, while that of the
rubber core is to keep the canvas elastic or from too solid com-
pression.
By my present Invention I obtain an elastic packing free from the
defects of both these forms, not liable to beat the rod or to be decomposed
by the lubricants, yet possessing lubricative and antifrictional properties
in itself much desired in such an article, which under the influence of
the heat of the steam will form a thick semi-hard mass, possessing
elasticity, and therefore capable of being compressed to fit closely to the 1
piston rod, while of such a nature that it will not adhere thereto, but
will on the other hand offer a smooth, glossy, yet yielding and homo-
geneous surface thereto. It is further easy of application, and will form
a thoroughly steam-tight joint with very little pressure against the
piston rod.
This material I form of india-rubber and sulphur mixed together by
well-known methods with soapstone, or steatite, or French chalk in
powder, a very good compound being obtained from the following
proportions of these ingredients, namely, rubber, ten parts; sulphur,
five parts; and soapstone, thirty parts. This compound having been
thoroughly mixed is formed into a cord or strand of any desired size,
around which I wind a single or two layers of cloth, the object of which
is to keep the said strand in form, while I subject it to soft or partial
vulcanization by any of the well-known modes of vulcanizing india-
rubber, and also for keeping the strand from the piston rod when first
applied, until it shall have changed by the heat of the steam from the
soft vulcanized condition to the more consolidated semi-hard condition.
This cloth covering of the strand will very soon wear away, when the

page_text: strand itself will come in contact with the rod. Being vulcanized
partially the strand thus covered will be soft and flexible, and can easily
be bent round any piston rod in the form of an open ring. After two
or more of such rings are put into the stuffing box and screwed down by
the gland ring it is ready for use. The heat of the steam will very soon
soften the strand, and make its elements agglutinate together into a
semi-hard yielding flexible substance, capable of taking a smooth glassy
surface, and yet so plastic and clastic withal as to be eminently well
adapted for piston packing.
Instead of soapstone, or steatite, or French chalk, plumbago, or black
lead, or asbestos ground into a powder, or sulphate of barytes, or
equivalent mineral powders may be employed in combination with
rubber and sulphur.
Further, various other proportions of these materials may be employed
and even combinations of india-rubber and sulphur alone in the well-
known proportions that will produce vulcanite when subjected to heat
may be employed if prepared in the way herein-before described, namely,
by being formed into strands or cords wrapped around with one or two
layers of canvas, and subjected to partial vulcanization.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Isaac Blue Harris, in the Great Seal Patent Office
on the 28th March 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ISAAC
BLUE HARRIS, of Castle Mills, Fountainbridge, Edinburgh, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of September, in the
year of our Lord One thousand eight hundred and seventy-two, in
the thirty-sixth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Isaac Blue Harris, Her special
licence, that I, the said Isaac Blue Harris, my executors, administrators,
and assigns, or such others as I, the said Isaac Blue Harris, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term

page_text: therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "A NEW OR IMPROVED
MATERIAL FOR USE AS PACKING FOR THE PISTON RODS OF STEAM ENGINES, AND
LIKE USES," upon the condition (amongst others) that I, the said Isaac
Blue Harris, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Isaac Blue Harris, do hereby declaro
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
following statement (that is to say) :-
This Invention relates to the manufacture of a material suitable for
use as a steam-tight packing, and it has for its object the production of
an article which will become while in use of a consistency that will
resist the action of lubricants and heat, and yet possess compressibility
to form a neat and steam-tight joint, while it also possesses in itself
lubricative or antifrictional properties.
The packing for steam engines heretofore made with india-rubber has
been formed in two distinctive ways; first, in the form of rings of the
more or less hard and rigid form of vulcanized rubber known as
vulcanite, and applied without any covering of cloth to the piston rod
or stuffing box. This form although capable of resisting the action of
the lubricants is apt to heat too much from the friction of the piston
rod, and is little used.
The other distinctive form is that of a core of soft vulcanized india-
rubber surrounded by several layers of canvas to protect it from the
action of the lubricants and from contact with the piston rod, which
would otherwise soon decompose it. The function of the canvas in such
a combination is to receive the friction of the rod while that of the
rubber core is to keep the canvas elastic or from too solid compression.
By my present Invention I obtain an elastic packing free from the
defects of both these forms, not liable to heat the rod or to be decom-
posed by the lubricants, yet possessing lubricative and antifrictional

page_text: properties in itself, much desired in such an article, and capable under
the influence of the heat of the steam of being changed into a thick
plastic clastic mass that fits closely to the piston rod, but of such a
nature that so far from adhering to the rod it will offer a smooth, glassy,
yet yielding and homogeneous surface thereto. To attain this result I
form my packing material of india-rubber and sulphur mixed together
by well-known methods with soapstone, or steatite, or French chalk in
powder. A very good compound may be obtained from the following
proportions of the above-named ingredients, namely, rubber, ten parts;
sulphur, five parts; and soapstone, thirty parts. This compound having
been thoroughly mixed is formed into a cord or strand of any desired
size, around which I wind a single or it may be two layers of cloth, the
object of which is two-fold, viz., to keep the said strand in form, while
I subject it to soft or partial in contradistinction to complete vulcaniza-
tion by any of the well-known modes of vulcanizing india-rubber, and
also to keep the strand from the piston rod when first applied, until it
shall have changed by the heat of the steam in the engine cylinder from
the soft vulcanized condition to the more homogenous and consolidated
plastic condition, possessing the desired properties of such packing. The
covered strand being partially vulcanized will be soft and flexible, and
can easily be bent round any piston rod in the form of an open ring.
After two or more of such rings are put into the stuffing box and screwed
down by the gland ring, it is ready for use. The cloth covering of the
strand of these rings will very soon wear away, when the strand itself
will come in contact with the rod. Meantime the heat of the steam will
have softened the strand, and made its elements agglutinate together
into a semi-hard yielding flexible substance capable of taking a smooth
glassy surface, and yet so plastic and clastic withal as to be eminently
well adapted for piston packing.
Instead of soapstone, or steatite, or French chalk, plumbago or black
lead, or asbestos ground into a powder, or sulphate of barytes, or
equivalent mineral powders may be employed in combination with
rubber and sulphur.
Further, various other proportions of these materials may be employed,
and even combinations of india-rubber, and sulphur alone (in the well-
known proportions that will produce vulcanite when subjected to heat)
may be employed if prepared in the way herein-before described,
namely, by being formed into strands or cords wrapped around with onc

page_text: or two layers of canvas, and subjected to soft or partial vulcanization
before application to the piston rod.
In witness whereof, I, the said Isaac Blue Harris, have hereunto
set my hand and seal, the Twenty-sixth day of March, in the
year of our Lord One thousand eight hundred and seventy-three.