Improvements in Rod Packings.
Year: 1899

page_text: Date of Application, 8th Sept., 1899-Accepted, 28th Oct., 1899
Improvements in Rod Packings.
A communication from JAMES SMITH & COMPANY, Incorporated, a Corporation
organized under the laws of the State of West Virginia having an office at
Charlestown, in said State, and also at Philadelphia, State of Pennsylvania,
United States of America.
I, GEORGE DAVIES, of 4, St. Ann's Square, Manchester, in the County of Lan-
caster, Chartered Patent Agent, 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 packing for piston rods, valve rods and the like,
the object of the invention being to so construct the packing as to increase the
term of usefulness of the same and to better enable the packing to perform
its duty of preventing the escape of steam or water along the rod."
The packing can, moreover, be removed from the stuffing box more readily
than usual when it becomes necessary to repack said stuffing box, and, in the
case of composite packing rings, or rings made up of a number of elements, the
individuality of these elements is preserved so that the capacity of the elements
of each ring for adjustment independent of those of another ring or rings in
order to compensate for wear is not interfered with.
In the accompanying drawings:
Fig. 1 is a sectional view of part of a piston or valve rod with the ordinary
stuffing box and follower and with packing constructed in accordance with this
invention, the packing being shown in the uncompressed form as it appears
when first introduced into the stuffing box;
Fig. 2, is a view similar to Fig. 1 but showing the packing compressed, as
it appears after it has been used for some time;
Fig. 3, is a sectional view of a packing ring of a different character from
that shown in Fig. 1, but illustrating some of the features of the invention;
and
Fig. 4, is a perspective view of a short piece of the casing which forms part
of the packing ring.
!
In the drawings, 1 represents part of a piston or valve rod,
part of the
stuffing box, and 3 the usual follower whereby the packing is compressed in
said stuffing box.
The packing shown in Fig. 1 consists of two rings, each comprising an inner
portion and an outer casing, the inner portion being composed of V-shaped
rings 44 and 5-5 disposed point to point and contained within a braided
or other fibrous wrapping or covering 6, and the outer casing 7 being in the
form of an arch, which encloses the inner portion of the packing except on
the side towards the rod, on which side the casing is open, the ends of the casing
bearing upon the rod in front and rear of the bearing of the inner portion of
the packing ring on said rod.
The casing 7 is preferably composed of alternate layers of rubber and textile
fabric similar to ordinary fire or garden hose so that said casing is flexible,

page_text: elastic, and liquid-proof, and the wedge shaped rings 4 of the inner packing
are preferably composed of comparatively unyielding textile material while the
rings 5 are of more compressible material, the whole being thoroughly saturated
with lubricating material of any desired character.
The outer casing may be applied to the inner portion of the packing either
by bending the casing strip around said inner portion and holding it in position
by tying or otherwise until it is introduced into the stuffing box, or the casing
may be held in position on the inner portion of the packing by means of an
outer braided covering, such for instance as shown at 8, that portion of the said
covering which comes into contact with the rod being worn away soon after
the packing is put into use, so as to permit the ends of the arch-shaped casing
to bear directly upon the rod.
In order to facilitate the bending of the casing around the rod, the back of
the casing is incised as shown at 9, in Fig. 3, so as to increase the flexibility
of this portion of the casing and overcome its tendency to straighten out from
the ring form, and, in order to prevent spreading or buckling of the inner
portions of the arched casing when the same is bent into ring form around
the rod, it is advisable to form, in these portions of the casing, longitudinal
incisions 10, which are preferably waved or corrugated, as also shown in Fig. 3.
When the arch-shaped casings of the packing are subjected to the pressure
of the follower, they are flattened and compressed, as shown in Fig. 2, thereby
imparting pressure to the rings 5 of the internal packing and causing the
latter to force apart the rings 4, the inner ring being pressed firmly against
the rod so as to insure a tight joint, and the attainment of this latter result
being aided by the pressure of the inner edges of the casing 7 upon the rod
on each side of the ring 4. The casings 7 serve to preserve the individuality
of the inner masses of packing and insure the wedge-like or expansive action
of the same until the packing is worn out, whereas if the packing consisted
wholly of rings composed of wedge-like elements, the pressure of the follower 3
would soon reduce the rings to a common mass in which the identity of the
wedges, would be lost.
:
As the casing is proof against the passage of liquids, it protects the inner
portion of the packing from injurious contact with said liquids, and, owing to
its elasticity, it increases the resiliency of the packing and enables a tight joint
to be formed without excessive pressure and without the necessity of frequent
adjustments of the follower. The casing, furthermore, prevents the access of
grit and scale from the sides of the stuffing box to the inner fibrous portion
of the packing and it facilitates repacking of the stuffing box, for even when
the packing has become so worn as to necessitate replacement, the individuality
of each packing ring is still preserved and said ring can be removed as a unit,
whereas if each packing ring did not have the outer casing, as described, the
packing would be squeezed into a compact mass and would have to be labor-
ously picked or dug out of the box.
The use of the casing is not limited to packing rings having an internal
portion composed of wedge rings, for instance, in Fig. 3 is shown a section
of the packing ring in which the outer casing is combined with an inner
structure consisting of a central rectangular core 12. of rubber or other elastic
material, contained within a mass of fibrous braids 13 which may be saturated
with any available lubricant.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
!
First. A rod packing consisting of an inner mass of packing material and
an elastic, liquid-proof, fibrous casing enclosing the same on three sides but
open on the side towards the rod and bearing against said rod, substantially
as specified

page_text: Second. A rod packing consisting of an inner portion having wedge shaped
rings disposed so as to forced apart by pressure exerted in the length of the
rod, and an outer casing of elastic material containing said inner portion but
open on the side towards the rod and having a bearing on the rod on each side
of the inner portion, substantially as specified.
Third. The within described casing for a rod packing, said casing consisting
of a segment of a tube incised on the back so as to facilitate the bending of
the same around the rod, substantially as specified.
Fourth. The within described casing for a rod packing, said casing consisting
of a segment of a tube having external longitudinal incisions adjacent to its
edges, substantially as specified.
!
Fifth. The within described casing for a rod packing, said casing consisting
of a segment of a tube having external waved or corrugated longitudinal
incisions adjacent to its edges, substantially as specified.
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