Improvements in Asbestos and other Fibrous Packing.
Year: 1893

page_text: Date of Application, 25th Oct., 1893
Complete Specification Left. 24th Aug., 1894-Accepted, 29th Sept., 1894
PROVISIONAL SPECIFICATION.
Improvements in Asbestos and other Fibrous Packing.
I, CHARLES MCLAREN of Acre House, Derker, Oldham, Packing Manufacturer,
do hereby declare the nature of my said invention to be as follows:-
These improvements consist in the application to asbestos and other fibrous
packing used in the stuffing boxes of steam engines and the like of a spring backing
to cause said packing when in position to always press against the piston rod or
other working part intended to be packed.
This spring packing consists, by preference of a series of spiral metallic springs
arranged within a longitudinal opening formed in the packing, said opening being
lined or fitted with strips of metal to give stiffness thereto and to which the springs
are attached. These springs on pressure being applied to the outside of the
packing become compressed, whilst immediately the pressure is removed the
springs extend themselves and so expand the packing.
In this way it will be seen that as applied for packing a piston rod, the elasticity
of the packing will serve to always keep it against the piston rod and compensate
for any uneven running.
Instead of spiral springs, curved sheet metal springs may be used with their ends
free to slide to and fro in the opening aforesaid.
The springs are, by preference arranged at equal distances apart and are soldered
or otherwise fixed in position.
Dated this 24th day of October 1893.
JOHN G. WILSON & Co.,
Agents.
COMPLETE SPECIFICATION.
Improvements in Asbestos and other Fibrous Packing.
I, CHARLES MCLAREN of Acre House, Derker, Oldham, Packing Manufacturer,
do hereby declare 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 the
following statement :—
These improvements consist in the application to asbestos and other fibrous
packing used in the stuffing boxes of steam engines and the like of a spring
backing to cause said packing when in position to always press against the piston
rod or other working part being packed. This spring backing consists of a series
of by preference steel springs arranged within a longitudinal opening formed in
the packing, said opening being lined or fitted with strips of metal to give stiffness
thereto and to which the springs are attached. These springs on pressure being
applied to the packing become compressed, whilst immediately the pressure is
removed they extend themselves and so expand the packing.
And in order that my said invention shall be the more readily understood and
carried into practical effect I have hereunto annexed a sheet of drawings and will
now proceed to describe the same with the assistance of the various figures and
letters of reference marked thereon.
Fig. 1 is a transverse section of my improved packing and Fig. 2 is a plan view
of such packing made up in a form suitable for packing piston rods.

page_text: Fig. 3 is a transverse sectional view of an engine stuffing box and gland shewing
the application of my improved packing thereto. A small portion of the packing
is shewn in section.
Fig. 4 is a transverse section of a modification of my improved packing and
Fig. 5 is a plan view.
a
In accordance with my invention as applied to packings for piston rods and the
like I take by preference core or ring of asbestos or other similar packing
material (A) and on the back of or surrounding such core I fix two hoops or rings
of thin sheet metal (B) (B) whereof the outer ring (B') is about an inch larger
in diameter than the inner ring (B) thus leaving a space or cavity (C). Between
these rings and in the said cavity (C) spiral springs (D), (D) are introduced which
are arranged by preference at equal distances from each other and which being
fixed rigidly in position keep the two rings apart and in proper relation to each
other. To the upper & under sides of the core (A) and the edges of the metal
rings (B) (B) a ring (E) of asbestos is applied the outside circumference of which
coincides with that of the metal ring (B') whilst the inner circumference coincides
with that of the asbestos core (A) thus closing in & forming the cavity (C). Said
rings (E) are cemented to the core (A) and then the whole is surrounded by a
covering of braid (F) and afterwards treated with an anti-friction compound. In
applying the said packing to a piston rod the packing is cut diagonally as at (G)
(see Figs. 2, & 3) or if desired the packing may be cut in halves or a greater
number of pieces to facilitate the placing of the packing round the piston rod and
to allow of the proper working of the packing.
In applying my improved packing to a stuffing box I prefer to place a disc of
vulcanite (H) between each of the rings and to render the packing still further
steam tight the joints or diagonal divisions (G) should be arranged to "break"
with each other as is well understood and as shewn in Fig. 3.
The action of my improved packing is as follows:-Any unevenness in the
working of the piston rod causes the spiral springs which feed the wearing face of
the packing at that point to immediately "give" or close, but as soon as such
unevenness is passed, the springs extend themselves and so press the working face
forward and keep it constantly in touch with the piston rod.
Although I have described the application of the rings to the interior of the
packing, I wish it to be understood that I should consider it to be part of my
invention to put the springs outside the packing, say, for instance by omitting the
covering braid (F), but it would obviously be a less convenient way of carrying
out my invention.
In lieu of spiral springs I may employ sheet metal springs (I) shewn in Figs. 4
and 5 fixed at their centres to the outer ring (B') or inverted and fixed to the inner
ring (B) the extremities of the springs being curved or rounded to allow of the
sliding movement of the springs, or I may employ crinkled strips of metal or
volute springs as shewn in Figs. 6 and 7, or a continuous coiled spring.
Fig. 5 illustrates one half of the packing under compression the flat springs
being flattened out to the extent of the supposed irregularity of the piston rod
shewn by the dotted line at (X). In the case say of unevenness in the diameter
of the piston rod at different points along its working length the packing will give
and take radially.
The internal diameter of the packing should be slightly less than the piston rod
so that when placed in position it always grips the piston rod.
Having thus particularly described and 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:-
1st. The use and application to asbestos and other similar fibrous packing of
metallic springs acting within a cavity formed in the packing substantially as and
for the purposes set forth.

page_text: 2nd. In the manufacture of asbestos and other similar fibrous packing the
asbestos core (A), strips (B), (B¹), springs (D) or (1) or crinkled or volute springs.
(by preference braided together) when mounted and operating substantially as
herein before described and illustrated on the accompanying drawing.
Dated this 26th day of July 1894.
JOHN G. WILSON & Co.,
Agents.