IMPROVEMENTS IN METALLIC PACKINGS
Year: 1881

page_text: LETTERS PATENT to Thomas Tripp, of East Stoughton, in the County of
Norfolk and State of Massachusetts, United States of America, for an
COMPLETE SPECIFICATION filed by the said Thomas Tripp at the Office of
the Commissioners of Patents on the 6th January 1881.
THOMAS TRIPP, of East Stoughton, in the County of Norfolk and State of
Massachusetts, United States of America. "IMPROVEMENTS IN METALLIC
PACKINGS."
This Invention consists principally in the employment in connection with a
piston rod of a flexible or separable ring or sleeve enclosing and hugging the rod
with a steam tight joint, and susceptable as it wears of automatic universal
contraction about such rod, this ring or sleeve being composed of a series of parallel
metallic plates, each of which in cross rection is preferably a quadrant of a tube
of square exterior and circular bore, and all of uniform length, and operating with
a second series of plates of like length enclosing the first and breaking the joint
between its sections; the entire series of plates being confined permanently together
as regards each other, and crowded up to and about the rod by annular caps or
heads enclosing their conjoint ends; the ends of the ring thus composed of the
united plates, as well as the bores of the annular caps which enclose them, being
conical or tapering in order that the contraction of said caps shall crowd the plates
up to the rod; and the whole being enclosed within a cylindrical case or stuffing-
box secured to the head of the cylinder or valve chest, and operating as hereinafter
explained.
The Drawings accompanying this Specification represent in Figure 1 a longi-
tudinal section, and in Figures 2 and 3 cross sections of a packing containing my
Invention; Figure 4 is a view of one of the inner plates of the packing ring; and
Figure 5, a view of one of the outer plates of such ring; while Figure 6 is a cross
section of a modified construction of the said ring; Figure 7 is a section showing a
modified construction of the check ring, so called.
In the above named Drawings A represents the flange in which the head of the
steam cylinder or chest of a steam engine usually terminates, and through which
.

page_text: the piston rod shown at B loosely passes, while secured at its inner end rigidly to
this flange is a cylindrical case or cup C, by means of an intermediate annulus D, the
cup being secured to the annulus by bolts a, a, while the annulus in turn is securely
bolted to the flange A.
The case or cup C constitutes what is usually termed the stuffing-box, and it 5
contains the sectional packing constituting my Invention, which I will now
describe.
The flexible or contractile packing ring, to which allusion has been made, is
shown at E as composed, as shown in the Drawings, of two sets of plates b, b, b, b,
and c, c, c, c, the plates b being sections of a circle in cross section and of uniform
length, and with the plates c surrounded by an elastic metallic band d to confine
them in place about the rod B and prevent misplacement at such times as the
packing may be separated from its enclosing case.
The conjoint plates are in the present instance eight in number, and in two sets,
those of one set b, b, b, b, being right angled triangles in cross section with their
inner faces e of a segment of a circle equal, when the facing is new, to one fourth
the circumference of the rod B, therefore the united inner faces of these plates b, b, b, b,
make up a cylindrical bore which encloses the rod.
The outer series of plates c are also four in number, and have flat faces ƒ to
conform to the outer faces of the plates b, and cover the joint between each pair of
said plates b, the width of each plate c being by preference, about equal to that of a
plate b, and its exterior being preferably a segment of a circle struck from the
centre of the rod B, though this is not essential.
The plates c, overlying and breaking joints with the plates b, as stated, constitute
the outer circumference of the ring E, and are surrounded by the band d. It will
be observed that the meeting faces of the plates b, b, b, b, and c, c, c, c, are parallel
with each other and with the axis of the rod B, hence any slight endwise slip
between them does not disturb their positions relatively to each other and the rod,
so far as preserving a tight joint about the latter is concerned.
It will also be seen that as fast as the concave inner faces e of the rings b wear
by contact with the rod, and their outer faces approach the latter, the outer
plates c follow, and their inner faces begin to wear by contact with such rod, and
that as the said concave faces of the inner plates decrease in cross area those of
the outer plates c increase (by wear upon the rod) to a corresponding degree;
hence the entire series of plates preserve their original length practically intact,
and the entire circumference of the rod is covered by the plates until the latter are
worn out.
In Figure 3 of the Drawings I have shown the parts as they will appear when
the ring is considerably worn after long service, in which the inner faces of the
outer plates have become for a portion of their area concave by contact with the
rod, the wearing away of the inner faces of the inner plates having allowed
the outer plates access to the rod.
It will thus be seen that after the inner plates have become worn sufficiently to
allow the outer plates to have access to and be worn by contact with the rod, that
the edges of the inner plates separate, but it will also be seen that the joints
between such edges and the rod are broken by the outer plates.
To crowd the plates b and c permanently up to the rod B I slope or bevel their
conjoint ends, that is, the ends of the ring E, composed of the said plates, as shown
at h, i, and I cover or enclose these tapering ends of the ring each by an annular
disc or caps F or G, the inner circumference J or k of which is of the same slope
as that of the end of the ring which it encloses, the faces of both being flat.
The cap F is disposed at or near the outer end or head of the box C, while the
cap G is disposed near to the annulus D. before named, and the entire series of packing
plates and caps are crowded outward by spiral or other springs. l, l, etc., interposed
between the cap G and the said annulus D, or the flange A, should the annulus be
omitted, as in some instances, may be the case.
The outer end of the annular cap F is tapering or conical at a slope parallel or

page_text: approximately so to the outer end of the ring E, as shown at m, this surface m being
flat and encircled by a ring H, which is disposed between it and the head o of the
box C, the orifice p in the said head o through which the piston rod passes being
of larger diameter than the latter, in order to permit of slight lateral movements of
the rod and packing with the ring within the box without disturbing the position
of the latter upon the cylinder head.
The inner periphery of the ring H is convex or crowning in cross section, as
shown at q, in order that any irregular lateral movements or swaying of the rod B
may not result in a separation or leak between the cap F and the head of the
stuffing box. Should any such movements occur by the rod being thrown out of
truth, the ring H moves laterally upon the head o, and its convex surface adapts
itself to the sloping end of the cap F, and a tight joint between the two is
maintained; the bore of the ring H being somewhat larger than the diameter of
the rod to permit of the lateral movements of the latter without allowing steam
to escape from the stuffing through the passage q in its head.
In lieu of the bore of the ring H being convex or crowning as stated, it may be a
flat surface, and the teat upon the cap or hub F with which it operates be convex,
as shown in Figure 7 of the Drawings. This however would be a mere transposition
of parts.
It will thus be seen that I obtain a packing ring which is practically a single
ring, and one that is susceptible of uniform contraction as its bore wears; hence
the joint between it and the rod is always intact and tight, and one which cannot
be disturbed by irregular lateral movements of the rod, since it follows the latter
in any such movements.
The check ring H is not literally a component part or necessary adjunct to the
packing ring E, as the end of the latter may be concave or convex to enter a
corresponding opening in the head of the box C. I prefer to employ the ring Has
it permits of free lateral movements of the rod and packing within the box without
disturbing the latter, and is an effectual check upon escape of steam from such box
by the opening p in the cylinder head through which the rod passes.
Should the lengths of the plates b and c vary under wear, the shorter ones would
not be crowded laterally up to the rod by the action of the caps F, G, and hence
a leak might take place, but if eight plates are employed and the meeting faces of
each are equal, and the inner ones are quadrants of a circle, as would necessarily
be the case, the entire series will approach the rod under wear at a uniform rate,
hence their lengths are always uniform and the joints between the ends of the
ring E and the said caps remain intact.
It is for this reason that I prefer to divide the packing rings or cylinder É into
two sets of plates, the inner ones of which are segments of one fourth a tube in
cross-section as stated; but it is evident that my Invention is not restricted to
the precise number or form of the plates which in aggregate make up the ring, as
for instance, as shown in Figure 6 of the Drawings, two sets of eight plates each,
sixteen plates in all, may be employed, as shown at r,r, etc., and 8, 8, etc., each bearing
at its inner face upon the rod, and each plate of one series being arranged between
the two adjacent plates of the other series. In this case however, the plates are of
unequal size and shape in cross-section, hence the wear upon one set would be
more or less than that upon the other set, and they would approach the rod as
they become worn at unequal rate of speed, hence their lengths would vary,
and the ends of those most worn would fall away from the others, and a leak
between them and the caps F, G, and the rod be the result.
I consider my present Invention to consist first in a metallic packing ring
composed of two sets of plates, the wearing faces of which with respect to each
other and the periphery of the rod are parallel to the latter, and the inner plates
being each a prism with its inner face concave to adapt itself to the periphery of
the rod:
And I consider my present Invention to consist further in the beveling of the ends

page_text: .
of the ring thus built up, and enclosing such tapering ends in annular caps, the bores
of which act upon each beveled ends to crowd the plates together about the rod;
springs being employed as the agent to crowd the caps toward each other, and the
outer cap against the outer end of stuffing box as before explained. I also consider
my Invention to consist in the employment in combination with the outer one
of the annular caps, of a flat ring disposed between such cap and the head of the
stuffing box, and having its inner periphery convex in cross-section, and bearing
upon a beveled or conical teat formed upon the outer end of the said outer cap
for purposes stated.
'
In some instances the ring F may be omitted, and the annular caps extended in
length, and one enclosing the other, the bores of the extensions being larger than
the rod to provide an annular chamber surrounding the latter, and this chamber is
to be filled with a fibrous packing in lieu of the said ring F. A modification of my
packing is seen in Figures 8 and 9 of the Drawings, which are respectively a
section and end view of the packing, in which but four plates 65, 66, etc., altogether
are employed, each plate in cross section being made up of one of the outer plates c
and an inner plate b formed in one piece of metal, the flat inner portion a³ of each
plate overlapping the contiguous end 63 of the next adjacent plate. The ends of
the conjoint plates in this case are square, and the overlapping caps G being
omitted, the elastic band d alone being employed to crowd the plates up to the rod,
unless it be the pressure of such steam as enters the box from the cylinder; and in
lieu of the cap G I employ a flat ring G2, which is contained within a rebate u in
the outer end of the annulus D. The inner end of the cap F is flat, and bears
squarely upon the contiguous ends of the packing rings 65, 66, etc., while its outer
end is tapering and surrounded by the convex ring H before alluded to. In this
form of construction it is important that the four plates move up to the circum-
ference of the rod in the direction of a radial line struck through their inner
concave faces c³, as shown at a, b, which are segments of one fourth of a circle;
and to guide the plates in these paths of movement I create in one end of each
a straight groove d³ parallel to the said line a, 64, and I form upon the contiguous
faces of the annular plate or ring G2, which is disposed between the inner ends of
the plates and the annulus D, straight ribs e to enter the said grooves. As the
above named grooves and ribs compel the four plates to preserve their original
positions as they wear, they approach the rod in given paths, and the wear upon
each is uniform. I also propose with some forms of packing to employ a check
ring to prevent entrance of steam to the stuffing box or case from the cylinder
about the rod, and to this end I employ, as shown in Figure 10 of the Drawings,
which is a sectional elevation of the parts, a flat annular elastic diaphragm u of
suitable metal, and I dispose this diaphragm at its edge between the inner edge of
the cup or box C and the outer end of the ring G2, it being securely confined in
this position by the bolts a, a, with a tight joint in order to prevent passage or
leakage of steam about its edge from the cylinder by-the way of the passage about
the piston rod. The diaphragm is sufficiently elastic to follow any slight end
movement of the packing plates, while as the ring G2 ensures a tight joint between
the annulus D on the one side, and the cup C and packing plate on the opposite
side, access of steam to the stuffing box or case C at this point is entirely
excluded. For this reason the packing rings are removed from the pressure of
steam, and their undue friction upon the rod avoided, by which means the wear
'upon both is greatly prolonged. The elastic band d crowds the plates up to and
about the rod with sufficient pressure to ensure a tight joint. The diaphragm u is
stationary with the case C, the annulus D, and the cylinder flange A, while the
ring G2 and packing plates move upon or about the diaphragm by and with any
irregular lateral movements of the rod.
t
In this last form of construction the grooves d³ are formed in the opposite or
outer ends of the packing plates, and the ribs upon the inner ends of the cap or
ring F,

page_text: CLAIMS.
First. I claim a metallic packing ring for piston rods composed of a series of
prismatic plates, the meeting faces of which are parallel with each other and with
the periphery of the rod, such plates encircling the rod and the joints between
their meeting edges, or between such edges and the periphery of the rod, being
covered by a second series of plates overlapping the first, and the whole being
crowded up to the rod by spring impelled rings, substantially as explained.
Second. In metallic packing rings composed of two sets of parallel plates, as
stated, beveling the ends of such ring, and enclosing such ends in annular caps,
which operate by spring pressure and by their bores to contract the ring about the
rod, substantially as explained.
Third. The combination with the packing ring built up of parallel prismatic
plates, and provided with the annular compression caps, as stated, the employment
of a flat annulus or. check ring disposed between the outer cap and the head of the
stuffing box, the bore of the check ring enclosing a conical annular teat upon the
cap, and operating to prevent escape of steam from the interior of the stuffing box
during irregular movements of the rod by adapting itself to such movements of
the rod while maintaining a tight joint with the head of the box, substantially as
explained.
Fourth. A metallic packing ring for piston rods composed of two sets of plates,
four in each set (eight in all), the wearing faces of these plates with respect to each
other and the periphery of the rod which they enclose being parallel to the latter,
and the plates of the inner series being in cross section a quadrant of a tube of
square exterior and circular bore, the outer plates breaking joints with the inner
ones and the rod, and the whole being as stated.
Fifth. In combination with the rod B, ring E, composed as stated, annular
caps F, G, check ring H, and springs 1, 1, with the box C, the latter being secured
rigidly to the cylinder head, and the rod and packing ring being susceptible of
lateral play within the box, substantially as explained.
Sixth. The plate c as being prismatic in form and an equilateral triangle in cross
section, with the exception of one face being concave, and with all its longitudinal
faces parallel and its ends beveled, as explained.
Seventh. In combination with the piston rod, the annular caps F, G, and a
fibrous packing interposed between the two, substantially as explained.
Eighth. The elastic diaphragm u in combination with packing rings, rod B,
ring G², box or case C, and annulus D, substantially as explained.
Ninth. The plates 65, 66, as made up of the plates b, c, in one integral piece,
substantially as explained.
In witness whereof, I, the said Thomas Tripp, have hereunto set my hand and
seal, this 4th day of November 1880.