Improvements in Piston-rod and like Packing.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in Piston-rod and like Packing.
I, HENRY REES CURRY, of Scarsdale, Cathcart, in the County of Renfrew,
North Britain, Engineer, do hereby declare the nature of this invention to be
as follows:-
This invention relates to improvements in piston-rod and like packing and
consists of a packing composed of a combination of anti-friction metal and
asbestos or similar material; said invention forming additions to as well as
improvements on my British Patent No. 17,604 of 19th September 1893.
In carrying out my said invention I roll or otherwise form the metal into strips of
any desired length; said strips being of a wedge shape in section and of any desired
size or thickness. The said strips are then checkered, scored, grooved or other-
wise roughened on their two sides so as to enable the asbestos or other composition
or material to adhere the better thereto. The said strips are then by means of
saws or otherwise cut or slotted from the apex down to or past the centre line and
from the base up to or past the centre line alternately, so as to enable the strip to
be easily bent into a circle.
One, two, three or more of the said strips of metal are then embedded in
asbestos, in the following manner :-I form a hollow trough shaped strip of
asbestos into which I place (when two metal strips are used) a strip of asbestos,
preferably of a truncated conical shape in section, said strip being placed along
the centre of the trough with a metal strip on each side between it and the inner
walls of the trough, in such a manner, that the thickest edge or base of the metal
is in such a position as to bear against the piston or other rod when in use. The
said packing owing to the manner in which the metal strips are cut may be readily
bent into a circle around the rod and compressed by the gland without bulging
the metal owing to the cuts allowing the various pieces to approximately come in
contact with each other and so present a full wearing surface to the rod. In a
similar way the cuts from the apex side along the strip of metal, allow the metal
to expand so as to suit the bend.
When more than two metal strips are used I use more than one truncated-piece
of asbestos, that is to say I place a truncated piece between each two strips of
metal.
The whole thus forms an efficient packing, which owing to the wedge shape of
the metal enables a large wearing surface to be exposed to the rod by tightening
up the gland of the stuffing box.
As a modification, the metal strip or strips may be wrought into the asbestos
trough in various other ways besides in straight lines, such for example in a
zig-zag or wave form. Also the metal strips may be of any size or thickness, and
the cuts, recesses or notches may also be of various sizes and they may be spaced
close to each other or wide apart according to the diameter of the rod for which
the packing is to be used.
Also in accordance with my invention I preferably employ a backing between
the inside of the trough and the apex of the metal strip or strips, and I secure
them altogether by means of rubber or other solution and pressure.
Dated this 20th day of January 1896.
JOHNSONS,
115 St. Vincent Street, Glasgow, Petitioner's Agents.

page_text: Improvements in Piston-rod and like Packing.
:
I, HENRY REES CURRY, of Scarsdale, Cathcart, in the County of Renfrew,
North Britain, Engineer, do hereby declare the nature of this invention 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 improvements in piston-rod and like packing and
consists of a packing composed of a combination of anti-friction metal and asbestos
or similar material; said invention forming additions to as well as improvements
on my British Patent No. 17,604 of 19th September, 1893.
Figure 1 is a perspective view of the strip of metal prior to its insertion within
the packing material. And Figures 2 & 3. perspective views shewing the metal
strip in position within the packing material.
Referring to the said drawings I roll or otherwise form the metal into strips A
of any desired length; said strips being preferably of a wedge shape in section;
and of any desired size or thickness. The said strips are then checkered, scored;
grooved or otherwise roughened on their two sides so as to enable the asbestos to
adhere the better thereto. The said strips are then, by means of saws or other
means, cut or slotted from the apex down to or past the centre line and from the
base up to or past the centre line alternately, the said slots enabling the strips to
be easily bent into a circle.
One, two, three or more of the said strips of metal are then embedded in
asbestos, in the following manner :-
I form a hollow trough shaped strip of asbestos B into which I place (when two
metal strips are used) a strip of asbestos C preferably of a truncated conical shape
in section, said strip C being placed along the centre of the trough with one of the
metal strips A on each side between it and the inner walls of the trough B in
such a manner, that the thickest edge or base of the metal is in such a
position as to bear against the piston or other rod when in use. The said packing
owing to the manner in which the metal strips are cut may be readily bent into a
circle around the rod and compressed by the gland without bulging the metal
owing to the cuts or slots a allowing the various pieces to approximately come in
contact with each other as shewn in Figure 3 and so present a full wearing
surface to the rod. In a similar way the cuts from the apex side along the strip
of metal, allow the metal to expand so as to suit the bend. The said strips are
inserted within the material in such a manner that the slots of the one are not
opposite the slots of the other, thereby forming a bond.
When more than two metal strips are used I use more than one truncated piece
of asbestos, that is to say I place a truncated piece between each two strips of
metal.
The whole thus forms an efficient packing, which owing to the wedge shape of
the metal enables a large wearing surface to be exposed to the rod by tightening
up the gland of the stuffing box.
As a modification, the metal strip or strips may be wrought into the asbestos
trough in various other ways besides in straight lines, as for example in a zig-zag
or wave form. Also the metal strips may be of any size or thickness and flat or
other shape in section and the cuts, recesses or notches may also be of various
sizes and they may be spaced close to each other or wide apart according to the
diameter of the rod for which the packing is to be used.
The strips may be checkered, scored, grooved or otherwise roughened on both
sides so as to enable the asbestos to adhere the better thereto.
Also in accordance with my invention I may employ a backing of india rubber or
other material between the inside of the trough and the apex of the metal strip

page_text: or strips, and secure them altogether by means of rubber or other solution and
pressure.
An essential feature of my invention is that I am enabled to use strips of metal of
any thickness and still be able to bend the packing, with the strips inserted, round
the piston rod.
Having now particularly described aud ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
The packing for piston and other rods, consisting of a strip of white or other
metal preferably wedge shaped in section, having both its edges cut or slotted, in
combination with asbestos or other material, substantially as and for the purposes
hereinbefore described and shewn in the accompanying drawings.
Dated this 21st day of October 1896.
JOHNSONS,
115 St. Vincent Street, Glasgow, Petitioner's Agents.