NEW OR IMPROVED PACKING FOR PISTON RODS AND PISTONS OF STEAM AND OTHER ENGINES, AND FOR SIMILAR USES
Year: 1878

page_text: LETTERS PATENT to Isaac Blue Harris, of Castle Mills, Fountainbridge,
Edinburgh, Scotland, for the Invention of "NEW OR IMPROVED PACKING FOR
PISTON RODS AND PISTONS OF STEAM AND OTHER ENGINES, AND FOR SIMILAR
USES"
Sealed the 15th April 1879, and dated the 22nd October 1878.
PROVISIONAL SPECIFICATION left by the said Isaac Blue Harris at the
Office of the Commissioners of Patents on the 22nd October 1878.
ISAAC BLUE HARRIS, of Castle Mills, Fountain Bridge, Edinburgh, Scotland.
* NEW OR IMPROVED PACKING FOR PISTON RODS AND PISTONS OF STEAM AND OTHER
ENGINES, AND FOR SIMILAR USES,"
A very useful, convenient, and extensively used packing has been manufactured
from textile materials, such as canvas, cloth coated with india-rubber, or india-
rubber compounds, and rolled up into a cord or rope, the function of the coating of
rubber being to cement or keep together the several layers of canvas or cloth
forming such rope or rope. Sometimes such cords and ropes are furnished with a
core of rubber or rubber compound. These packings though useful are liable to
rapid destruction by the wearing away of the side exposed to rubbing or
friction.
Now the present Invention is designed to obviate this disadvantage and to
secure the advantage of a metallic surface exposed to the friction of the rod or
moving part, or the part relatively in motion to the packing. This I accomplish
by cutting up webs of wire cloth coated with india-rubber into strips of suitable
width, and placing several layers or plies of them together on the side of the cord
or rope which I intend to be placed to or against the rubbing surface. The strips
of coated wire cloth I prefer to cut diagonally from the web. They are easily
stuck together by the rubber or rubber compound with which the web of wire
cloth is coated, and to the cord or rope by means of the rubber or rubber compound
spread on the textile material of which it is composed.

page_text: The compound cord or rope thus formed I prefer to surround with a wrapping
of textile material, also coated with rubber or rubber compound, when the cord or
rope is completed; it may be afterwards vulcanized in the ordinary way. The
_ cord or rope is now ready to be cut into pieces, which when bent into rings are
ready to be applied as packing 1-however prefer and it will be found a great
improvement to spin the completed compound cord or rope before vulcanization.
helically on to a mandril, with its metallic surface to the mandril, and vulcanize it
in that form, when it will be found to retain the spiral form, and thus permit of
pieces being cut off, and either expanded or contracted without injuriously
distorting or displacing their structure into rings suitable for various sizes of rods
which they may be required to embrace. Such rings being by construction broken
or discontinuous may be readily sprung open to pass over the piston rod or piston,
and they will immediately-close around it; hence they can be very easily and neatly
placed in position, and a steam-tight or other joint readily and effectually formed
by such packing. It will be equally as compressible as ordinary india-rubber
packing, and will have a metallic surface on the side exposed to tear and wear, and
will therefore be found to be very durable and economical.
Instead of placing the metallic strips on one side of a cord or rope made up from
textile materials they may be placed on one made of rubber or rubber compound
alone, or of any suitable compressible material, and such rope or cord may be formed
so as to be round, elliptical, or square in section.

page_text: I
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 22nd April
1879.
ISAAC BLUE HARRIS, of Castle Mills, Fountain Bridge, Edinburgh, Scotland.
"NEW OR IMPROVED PACKING FOR PISTON RODS AND PISTONS OF STEAM AND OTHER
ENGINES, AND FOR SIMILAR USES."
A very useful, convenient, and extensively used elastic packing has been manu-
factured from textile materials, such as canvas, cloth coated with india-rubber or
india-rubber compounds, and rolled up into a cord or rope, the function of the
coating of rubber being to cement or keep together the several layers of canvas or
cloth forming such rope or cord. Sometimes such cords and ropes are furnished
with a core of rubber or rubber compound.
These packings though useful are liable to rapid destruction by the wearing
away of the surface exposed to frictional action.
Now the present Invention is designed to obviate this disadvantage and to secure
the advantage of a metallic surface exposed to the friction of the rod or moving
part or the part relatively in motion to the packing. This I accomplish by the
introduction into the packing of wire cloth, placing several layers or plies of such
cloth together on that side of the packing or rope which is intended to be applied to
or against the rubbing surface.
The mode of carrying out this Invention admits of various modifications to suit
varying circumstances, that is to say, the degree of the elasticity of the rubber may
be greater or less by increasing or diminishing the proportion of compound india-
rubber employed, and the packing may be made of a certain determinate diameter
to suit a given diameter of rod, or it may be made in a helical form to admit of
receiving various diameters of rods or pistons, the packing space being filled with
several layers of rings.
In the accompanying Drawing I have shewn several modifications of my improved
packing suitable both for rods and pistons, in which cases the positions of metallic
friction surface will be reversed, the wire cloth for the packing of the piston rod
being inside, and that for the piston packing outside. I have also shewn the
packing as made in cords or continuous lengths, and also in the form of a cylinder,
in which latter case it may be divided up into rings or cut up helically into a con-
tinuous strip to be afterwards cut into pieces to form rings of any required internal
diameter. Fig. 1 shews in end view and Fig. 2 in side view a coil of packing for
piston rods, consisting of a cord of a square or rectangular section, and provided
with an external wrapping. The mode in which the packing is manufactured is
as follows: The wire cloth, preferably made of brass or copper, I cut up diagonally
across the web, and lay the diagonal pieces so cut end to end to get any required
length of wire cloth strip. It will be convenient to cut the strips from the wire
cloth web equal in width to several widths of cord or rope (if the cord is to be rect-
angular in section), and to divide up the compound fabric subsequently into
narrower strips for the cords or ropes. These metal strips are easily stuck together
by the rubber or rubber compound with which they are coated.
A length of metallic cloth thus prepared is laid upon a sheet of the elastic
material of which the packing is composed, and caused to adhere thereto by means
of the india-rubber with which the wire cloth has been previously coated. In
Fig. 2 a represents a thickness of india-rubber compound overlaid by plies of canvas
or other textile material b, and upon this are laid three plies of wire cloth c. When
the whole is firmly cemented together the broad strip or sheet is cut up to the
section shewn at Fig. 2, and a wrapping of india-rubber covered cloth & is laid
around the several strips.
Figures 3, 4, and 5 represent variations in the mode of forming the packing.
Thus Fig. 3 shews a block of india-rubber compound with plies of wire cloth c

page_text: on its inner or wearing surface, which plies are overlaid by wire cloth that extend
down both sides of the packing to the full depth thereof. The whole is then
surrounded by a wrapper of india-rubber covered cloth. Fig. 4 shews a somewhat
similar packing for piston rods, but without the side laps of metallic cloth; Fig. 5
shews-a-packing for pistons, in which the plies of wire cloth for the wearing surface
are reversed in position, and are, like the packing in Fig. 2, applied-to-a-layer-of-
fibrous material b, which material is interposed between the wire cloth and the
block of india-rubber compound a. In all these examples it will be understood
that a wrapping of cloth is by preference used to bind the several parts together.
The-strips. of packing when thus prepared may be wound upon a mandril, and
while so secured may be subjected to the curving or vulcanizing process.
-this-is effected a coil will be obtained which may be cut into rings of any desired
circumferential length, suitable for enclosing a rod or a piston, according to the
nature of the material.
When
It should be here remarked that in order to form a good steam-tight packing two
at least of these open or divided rings must be used together, the same being so
applied that they will break joint.
Instead of obtaining packing rings in the way just described they can also be
obtained in the following manner, namely:-By wrapping the rubber coated wire
cloth on to a mandril, then wrapping round this some rubber-coated cloth, then
applying a wrapping of rubber compound, and by preference lastly a second
wrapping of india-rubber covered cloth. This will form a compound hollow
cylinder or compound pipe or tube, similar to that shewn in edge view at Fig. 6,
and it can be cut at a lathe into rings, as shewn in cross section at Fig. 7, or it may
be cut helically from one end to the other, when there will result a helical cord or
rope of rectangular section, as shewn at Figures 8 and 9. From this helical coil
packing rings of any desired size can be cut off. The rings or washers shewn at
Fig. 7 can be cut through at one side to permit of their opening to pass over a
piston rod before being applied to the stuffing box. This improved packing will be
equally as compressible as ordinary india-rubber packing, and by having a metallic
surface on the side exposed to tear and wear will prove both durable and econo-
mical.
Having now set forth the nature of my Invention of "New or Improved Packing
for Piston Rods and Pistons of Steam and other Engines, and for similar Uses," and
explained the manner of carrying the same into effect, I wish it to be understood
that under the above in part recited Letters Patent I claim, applying to the wearing
or friction surface of elastic packing plies of wire cloth, in the manner and for the
purpose above described.
In witness whereof, I, the said Isaac Blue Harris, have hereunto set my
hand and seal, the Seventeenth day of April, in the year of our Lord One
thousand eight hundred and seventy-nine.
1. B. HARRIS. (L.S.).