Improvements in or relating to Metallic Packing for Piston Rods and the like.
Year: 1893

page_text: Date of Application, 28th Aug., 1893
Complete Specification Left, 28th May, 1894-Accepted, 14th July, 1894
TRUVIDIONAL DIMITICATION.
Improvements in or relating to Metallic Packing for Piston Rods
and the like.
I, CHARLES WILLIAM CARTER, of 1 Buckingham Street, Liverpool in the
County of Lancaster, Engineer, do hereby declare the nature of this invention
to be as follows:-
My present invention relates to metallic packing for piston rods and the like,
the construction being as follows:-
The packing consists of several packing rings held within a stuffing_box_ora
casing fitting fluid-tight therein, as hereinafter more particularly described. In its
simpler form, each packing ring of which the packing is composed is made in
three or more segments, and between the ends of the segments which would
otherwise abut, I interpose wedges or wedge-shaped pieces with their apices or
smaller ends at the inside of the ring, the ends of the segments being accurately
fitted to bear against the sides of the wedge pieces.
The segments and wedge pieces are elastically pressed inwards towards the rod
by an encircling spring hoop embedded in a groove, or by independent springs
bearing against the inside of the stuffing box or casing within which the packing
is placed, or by other equivalent means.
The inward pressure of the spring or springs and that transmitted from the
wedge pieces co-operate to close the packing on the rod as the wear takes place.
The wedge pieces are preferably made of a softer or less wear-resisting material
than the segments in order that their radial wear against the rod shall be rapid
enough to ensure that the sides of the wedge pieces shall always be in contact with
the ends of the segments, and transmit pressure thereto as the segments wear.
It will be seen from the construction described, that no matter how much the
segments and wedge pieces may be worn, there is never any gap between the
segment ends through which the fluid can pass, as the wedge pieces always fill
the gaps and are themselves in contact with the rod.
In some cases I prefer to make each packing ring of two or more detached sets
of segments; the outer segments may be of L or T cross section and the inner
segments, which break joint with the outer segments, may be of rectangular or
approximately rectangular or triangular cross section and fill the angles of the L
or the T as the case may be, the wedge pieces being shaped to suit so as to make
the contour of the outer part of the ring continuous. The inner segments may be
of harder quality than the outer segments.
As already stated, I generally use several superposed rings, such as I have
described, in packing a piston rod or the like, the rings being of course arranged
to break joint. If the packing is to be "floating," that is to say, so arranged as
to permit of slight lateral movement of the rod, the packing is preferably fitted
within a casing which may be built up in parts and fits fluid-tight within the
stuffing box. The casing has internal rims or flanges to locate the packing
longitudinally, and springs are fitted to keep the packing rings in intimate contact
with these rims or flanges. In order to permit the necessary lateral movement of
the packing to accommodate the rod, the bearing surfaces of the rims or flanges
are flat and the internal diameter of the casing is somewhat larger than the
external diameter of the packing.
If the packing is not intended to be "floating," it is located longitudinally
between a neck bush and a gland; chamfered rings are interposed between some or
all of the rings, the sides of the rings being chamfered to suit; the bearing

page_text: surfaces of the gland and neck bush are also similarly chamfered so that
longitudinal pressure transmitted from the gland co-operates with the springs in
tending to close the packing on the rod.
Dated this 26th day of August 1893.
SLOAN & LLOYD BARNES,
Castle Chambers, Castle Street, Liverpool, Agents for the Applicant.
Improvements in or relating to Metallic Packing for Piston Rods
and the like.
I, CHARLES WIlliam Carter, of 1 Buckingham Street, Liverpool in the
County of Lancaster, 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 :-
My present invention relates to metallic packing for piston rods and the like,
the construction being as follows.
The packing consists of several packing rings held within a stuffing box or a
casing fitting fluid-tight therein, as hereinafter more particularly described. In its
simpler form, each packing ring of which the packing is composed is made in three
or more segments, and between the ends of the segments which would otherwise
abut, I interpose wedges or wedge-shaped pieces with their apices or smaller ends
at the inside of the ring, the ends of the segments being accurately fitted to bear
against the sides of the wedge pieces.
The segments and wedge pieces are clastically pressed inwards towards the rod
by an encircling spring hoop embedded in a groove, or by independent springs
bearing against the inside of the stuffing box or casing within which the packing
is placed, or by other equivalent means.
The inward pressure of the spring or springs and that transmitted from the
wedge pieces co-operate to close the packing on the rod as the wear takes place.
The wedge pieces are preferably made of a softer or less wear resisting material
than the segments in order that their radial wear against the rod shall be rapid
enough to ensure that the sides of the wedge pieces shall always be in contact
with the ends of the segments, and transmit the pressure thereto as the segments
wear.
In the accompanying drawings, which illustrate my invention as applied to piston
rod packing, Figs. I and II show one form of the packing consisting of two pairs
of rings carried in a casing adapted to take the place of the gland in the stuffing
box, Fig. I being an elevation partly in section on the line A. A. of Fig. II
and Fig. II a plan partly in section on the line B. B. of Fig. I. Figs. III and IV,
and V and VI are analogous views of modified forms of the packing; in the
latter the casing is dispensed with; in these figs. the sections are taken on the
lines CC, DD, EE and FF, respectively. In Figs. 11 IV and VI a portion of
the upper ring is removed to show the relative positions of the parts of the
interposed rings.
Throughout the drawings, similar parts are indicated by the same reference
figures, and in the case of sections, the direction in which they are viewed is
indicated by the small arrows placed adjacent to the letters denoting the plane of
section.
Referring in the first instance to Figs. I and II, 1 is the casing made in two
halves each of which is secured to a central ring 2; the casing has a flange 3
through which the gland bolts pass and a joint is made between the casing and the
cylinder by the lead ring 4.
Each of the packing rings consists of six segments 5 and six wedges 6; the

page_text: number of segments and wedges vary of course with the diameter of the rod to be
packed, small rods requiring but, say, three of each, and larger rods a proportion-
ately greater number. The inner surface of the segments and the apices of the
wedges form a continuous surface adapted to fit the rod to be packed and, in the
outer surfaces of the segments and wedges, a continuous groove is formed to locate
the encircling spring 7. It will be seen that the inward pressure of this spring
exerted on the segments both directly and through the wedges, tends to close the
packing on the rod as the wear takes place and, as the wedges are made of a
softer or less wear resisting material than the segments, their radial wear is always
sufficient to ensure the necessary contact between the bevelled surfaces of the
wedges and segments. The angle of the wedges may vary considerably but I have
found the angle shown in the drawings to answer well in practice. The plane
portions of the rings are accurately surfaced so as to bed evenly on each other
and on the surfaces which locate them longitudinally. The necessary pressure
between the rings, and between each ring and the locating surface, is obtained by
means of a series of compressed springs 8 located in cavities in opposite sides of
the central ring 2 and exerting pressure through the cylindrical plugs 9; this
pressure is rendered more uniform by means of interposed thin rings 10.
The wedges and segments of the adjacents rings are arranged, as shown, to break
joint and the rings are kept in proper relative position by a pin 11 engaging in a
radial slot 12.
The internal bore of the flanges of the casing may be made to fit the rod, or,
there may be sufficient clearance to allow the rod and the packing rings to have a
limited lateral motion relatively to the casing; or the casing itself may be adapted
to have such motion relatively to the stuffing box, being located longitudinally by
steam-tight surfaces.
In Figs. III and IV the casing 1' is adapted to fit in an ordinary stuffing box
and the joint between it and the neck ring is made by the lead ring 4 as shown.
In this arrangement there are four segments 5¹ and four wedges 6' and the angle
of the wedges is such that their inclined edges act as parallel guides for the
segments as the latter are pressed by the spring as they wear. The springs to
produce the longitudinal pressure are now located in the wedges and exert
pressure on the centre of the segments. In other respects the arrangement is
similar to that described.
There may of course be a greater number of rings in contact, than two, as
shown, and a number of bow springs may in some cases be substituted for the
encircling spiral spring.
In Figs. V and VI a form of packing is shown in which the casing is dispensed
with the rings being simply placed in the stuffing box, the springs 8, to give the
longitudinal pressure are, in this form, located in the ring 13 which abuts against
the neck ring, and the top ring makes joint against the gland, or against a thin
ring 14 attached thereto. The rings, of which three are shown, are constructed as
already described.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, 1 declare that what I
claim is ;-
1. The improved metallic packing which consists of a series of superposed
rings, each of which is formed of segments such as 5, and wedges such as 6 of less
wear resisting material than the segments, the said rings being pressed inwardly
by a spring or springs and arranged to break joint, substantially as described and
illustrated.
2. In metallic packing, in combination; the rings of Claim 1, a casing fitting in
the stuffing box to hold the said rings, and longitudinally compressing springs
located either in an interposed ring such as 2 or in the wedge pieces, substantially
as described and illustrated.

page_text: 3. The combination and arrangement of parts forming the improved metallic
packing, substantially as described and illustrated in Figs. I and II.
4. The combination and arrangement of parts forming the improved metallic
packing, substantially as described and illustrated in Figs. III and IV.
5. The combination and arrangement of parts forming the improved metallic
packing, substantially as described and illustrated in Figs. V and VI.
Dated this 26th day of May 1894.
SLOAN & LLOYD BARNES,
Castle Chambers, 26, Castle Street, Liverpool, Agents for the Applicant.