Metallic Piston-rod Packing.
Year: 1891

page_text: Date of Application, 30th Sept., 1891
Complete Specification Left, 15th June, 1892-Accepted, 30th July, 1892
Metallic Piston-rod Packing.
I, HERBERT JOHN ALLISON, of 52 Chancery Lane, London, in the County of
Middlesex, Patent Agent, do hereby declare the nature of this invention (which
has been communicated to me from abroad by John B. Houston, of San Francisco,
in the State of California, United States of America, Engineer), to be as
follows:-
This invention relates to packing for the piston rods of engines, especially steam
engines, and consists in applying in one stuffing box two sets of elastic packing
rings, acting on the rod at two points by means of wedge rings, or those having
diagonal faces. The two sets of packing rings and compressing mechanism being
independent, except as to their adjustment, which is common to both and equal
on each.
Around the piston rod at two places is placed pairs of packing rings of the usual
construction. Around these a thin ring or band, as wide as both packing rings,
and outside of this, to press inward, are two wedge rings, one continuous and one
in segments, and still outside of this a shell or case containing the packing and for
attaching it to the nozzles or main part of the engine or other structure.
These double sets of packing rings are, in most cases, compressed or adjusted
reciprocally by means of screws. acting equally on each set of wedge rings behind
the packing. When screwed bolts are employed to set the packing the wedge
rings are net opposite, that is, their angular faces reverse ways, so a force between
tending to expand or press them apart will act equally on each, and the two
sets of packing rings receive equal adjustment, or equal pressure, one balancing the
other.
To attain this, the adjusting screws have a screw-threaded bearing in a pressing
ring, resting on one pair of the wedge rings, and an end bearing on another pressing
ring, acting on the second pair of wedge rings, so that by turning the screws in
unison, one pressing ring is pulled outward and the other is pressed inward,
acting, as before named, equally and reciprocally on the two sets of packing rings
around the rod.
Between the two sets of packing rings is placed a distance piece, or collar,
filling the whole diameter of the outer case, and the pressing rings just described
are embedded in the ends of this distance piece or collar, and the adjusting screws
pass through it.
.
In other cases, and especially in fitting my improved packing to nozzles not
especially prepared to receive it, I modify the construction by making the wedge
rings both to act in the same direction, and impart pressure to them by means of
studs or
pins, moved by a screw collar on the outside on which the studs bear and
slide, acting on an outer pressing ring, and then a second set of studs from that
to a second pressing ring; uniform and reciprocal action being secured by means
of springs placed between the first and second set of studs and the second pressing
ring.
The first or outer set of studs are, as before stated, moved uniformly by means of
a screw collar on which they bear. These studs press on a plain ring; next in
order is placed a spring, preferably a wave or corrugated one; next, another plain
ring bearing on the outer set of wedge rings, then, on this last named plain ring,
another set of studs that extend through the distance piece, between the packings,
and bear on another plain ring to press on the wedge or bevel rings around the
second or inner set of packing. The purposes attained being the same in effect
as in the first method described, that is, two sets of packing rings in the same

page_text: stuffing box, independent of each other except as to equal and reciprocal
adjustment from the outside, and the pressure strain on each being equal and
balanced.
Dated this 30th day of September 1891
ALLISON BROS.,
Agents for the Applicant.
COMPLETE
SPECIFICATION.
Metallic Piston-rod Packing.
I, HERBERT JOHN ALLISON, of 52 Chancery Lane, London, in the County of
Middlesex, Patent Agent, do hereby declare the nature of this invention (which
has been communicated to me from abroad by John B. Houston, of San Francisco,
in the State of California, United States of America, Engineer), 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 elastic or adjustable metallic packing for piston rods,
capable of compensating for wear and also, when required, permitting lateral
adjustment, commonly called floating, so that deviations of the rod from true
alignment will not permit the escape of steam or other fluid.
My invention consists in employing two sets of double packing rings, embracing
the piston rod at both the outer and inner ends of the stuffing box, or at two points
therein; behind or surrounding these rings, thin bands or collars, capable of flexure,
and outside of these bands, sections of a beveled or wedge ring, operated by screws
or a screw collar and studs; and still beyond and embracing these wedge sections,
a complete ring with corresponding beveled faces, on which falls the strain of
compression, independent of the main shell or stuffing box containing the packing.
My invention also includes the employment of two flat rings for compressing and
adjusting the sections of a wedge ring, before named; these flat rings being
operated by screws direct, or in some cases by means of a screw collar and struts,
which press uniformly and dependently upon them, producing like compression of
the packing at each end or at two places in the stuffing box. In applying my
invention to common stuffing boxes I arrange the bevel rings so that both will act in
one direction, employing a screw collar, struts, and a wave or corrugated spring to give
elastic pressure.
In other cases I employ independent screws, such screws being
multiple and connected together by means of tooth gearing; the adjustment will be
uniform and equal, not only in respect to the compression of the packing at both
ends, but also in respect to all sides of the piston rod.
My invention also consists in the employment of a collar or distance piece
between the two sets of packing rings, at the outer and inner ends of the stuffing
box, in which collar or distance piece, one or both of the flat rings before named
are embedded, and the ends of which have a ground fit against the packing, so as
to permit, when required, lateral adjustment of the packing as a whole, without any.
leak of steam or the fluid.
The object of my invention is to provide a sensitive adjustment of the bearing
surfaces, applied preferably at two points on the rod, and all adjustments to and
from the rod or in the line of wear, balanced and equal as between the two packings,
thus insuring a tight joint with a minimum of friction.
Referring to the drawings:
Fig. 1, is a section through my improved piston-rod packing, taken centrally on
the axis of the rod.
Fig. 2, is a partial top view on the line y-y of Fig. 1.
Fig. 3, is a partial section through Fig. 1, on the line -.
Fig. 4, is a detail showing the manner of connecting the adjusting screws, for
regulating the pressure of the packing on the rod.
Fig. 5, is a section through the centre of a modification of my improved piston

page_text: packing, having similar functions but adapted for use in common stumng Doxes suc
as have been made for fibrous packing.
Fig. 6 is a cross section through Fig. 5 on the line x-x.
Similar letters of reference indicate corresponding parts in the different figures
of the drawings, which will now be explained.
Referring first to Figures 1 to 4 of the drawings,
A represents a section of the piston rod and B a section of the head and packing
nozzle of a steam engine cylinder.
C is a shell or case containing the packing and is bolted to the nozzle B, by the
flanges D. This shell C has an internal flange E forming the bottom of the
stuffing box or chamber, so that by loosening the flange D the whole can be drawu
back on the rod A, clear of the nozzle B and of the steam cylinder.
Around the piston rod A is placed at each end of the stuffing box, pairs of split
packing rings F and F, at the inner end, G¹ and G2, at the outer end, the joints of
which are indicated at a and a, Fig. 2.
Around these rings F and G are placed thin flexible rings or bands H, also split
at one or more places to permit annular adjustment, and outside of these rings or
bands H, are a series of wedge shaped segments I' and I shown in section at the
top and by full view at the bottom in Fig. 1, also indicated in plan by dotted lines
in Fig. 2.
These wedge shaped segments are formed by preparing a continuous ring,
corresponding to the section at I', Figs. 1 and 5, which ring is then cut into pieces,
their number corresponding to the rigidity of the inner rings, the size of the rod, or
other conditions of use.
These segmental wedges I bear upon outer beveled rings J, which are continuous,
and in most cases are made smaller in their extreme diameter than the bore of the
shell C, so as to leave some space at e e, as shown in Figs. 1 and 5, the purpose
of which will be hereafter explained.
The object of employing these short segments I¹ and 1' is to secure a bearing at
a number of points against the outer ring J, because there could not otherwise be
any proper adjustment on the oblique surfaces between the segments and the
outer ring J.
Between the two sets of packing rings heretofore described, and which are the
same at each end of the stuffing box, is interposed a distance piece or collar K,
having a section as shown in Fig. 3, provided with holes through which pass the
screws L. The section of this collar K may be of any symmetrical form, or solid.
I construct it as shown to avoid weight and save material.
In the ends of the collar K are loosely embedded two rings, M¹ and M³, which
bear upon and press these rings outward, or apart, in the following manner:
The screws L have a nut or screw thread in the outer ring M³, as shown in
Fig. 1, and then extend to and bear upon the other or inner ring M³, so that by
turning these screws the two rings M¹ and M' are forced apart with equal force,
causing compression of the inner rings that bear on the piston rod A, by reason of
the beveled surfaces on the outer ring J.
The screws L have formed upon their outer ends tooth pinions O, meshing into
an annular gear wheel P, as shown in Figures 1 and 4, so that by turning either
screw they all move equally, producing an uniform adjustment of the packing on all
sides of the rod A.
The screws L may be two or more in number, as the diameter and character of
the parts may demand; four are shown in the drawing, so the pressure on the
rings M' and M' will not distort them when the proportions are as illustrated.
Covering and retaining the packing in the shell G is a plate R, and in this plate
are short packing glands S where the bolts L pass through, so that when the latter
are loosened all the internal parts contained in the shell C can, when required, be
withdrawn and replaced.
It will be observed in the drawing that some space is left where the piston rod A
passes through flange E, the plate Ř, and the distance piece or collar K; the only

page_text: parts bearing upon the rod A being the packing rings F1, F, G, and G². This
permits the packing to move laterally, sliding at the joints T, and permitting lateral
deviation of the piston rod A in case it runs out of truth, forming what is
technically known as floating packing. It will be understood that in cases where
no deviation of the piston rod A, can take place, as in the case of tail rods, the outer
rings J, may fit closely in the removable shell C, or be an integral part therewith,
without in any way interfering with the nature of my invention.
Reverting now to the modification of my invention shown in Figures 5 and 6.
A is a section of a piston rod, and B is a nozzle of a steam engine to receive the
piston packing.
C is an outer shell containing the packing corresponding to that in the former
figures.
The packing rings F1, F2, thin collar or band H, and bevel rings J and I are
identical with those heretofore described, but are placed in a different position
relatively, being nearer together and farther from the outer end of stuffing box.
The two pressing rings M', M², also correspond to those marked in previous figures,
but the action of each is inward, as will be presently explained.
Below, or outside of the pressing ring, is a wave or corrugated spring N, and
outside of this again another pressing ring M³.
Acting on this outer pressing ring M³ are studs, or struts L' which have a bearing
on the screw collar R².
This screw collar is fitted on a nipple or extension c, of the keeper or outer
member C, which confines and holds the packing in the shell C.
The edge of this screw collar R2 is serrated on its edge, so as to receive a spanner
in the usual manner, and as it is screwed up or down, the studs I are forced
inward or recede accordingly.
When the screw collar R³ is turned up, to increase the compression of the
packing rings G, G, on the piston rod A, the struts L' act on the outer pressing
ring M³, and this on the spring N, which bears on the second pressing ring M³.
From this second pressing ring M another set of studs L extends to the third
pressing ring M', so that the action of the screw collar R is communicated to both
sets of packing rings, as in the former case where screw studs were employed.
The inner bevel rings against which bear the pressing rings M, M², are
composed of segments the same as those shown in Figures 1 and 2, such segments
being sufficient in number to insure an even bearing all around, or at a large number
of points when the beveled faces are so adjusted as not to fit one upon the other.
The struts I have packing glands in the member C2 as shown, and the struts L³
slide through the distance collar K³, which corresponds to the one in Figures 1
and 3.
Instead of the wave or corrugated springs N, coil or other springs can be
employed between the collars M*, M. I show wave springs because they are the
most simple kind adapted to the purpose.
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a piston-rod packing, the double sets of packing rings consisting of the
various members herein described, similarly arranged at the outer and inner ends of
a stuffing box, or at two points thereof, with adjusting screws L, or struts L' and L,
acting equally on the wedge rings, and on cach set of packing rings, producing like
compression of the packing at two points on the rod A, substantially in the manner
and for the purposes set forth.
2. In a piston-rod packing, the segmental wedge_pieces I and outer rings J, in
combination with the adjusting screws L, or struts L and L³, producing equal or
nearly equal compression on the inner packing rings, independent of the shell or
chamber C, and thereby permitting, when required, lateral movement of the rod A
and its packing, so as to prevent leaking of steam or other fluid around the rod

page_text: when the latter deviates from a true rectilinear movement, substantially as herein
specified and for the purposes set forth.
3. In a piston-rod packing, the inner packing rings F, F, G and G2, the split
rings or bands H, segmental wedges I, with the bearing rings M' and M³ pressing
thereon, and an outer ring J, binding and sustaining the packing independent
of its outer casing C, substantially in the manner herein specified and for the
purposes set forth.
4. In a piston-rod packing, the two pressing rings M¹ and M³, with screws L
to force the rings in opposite directions, and balance the compressing strain on
two sets of packing rings, separated by a distance collar K through which the
adjusting screws pass, substantially as shown in the drawings and as herein
described.
5. In a piston-rod packing, the multiple screws L, two or more in number, con-
nected with and operating the pressing rings M' and M³, in conjunction with
beveled surfaces and inside packing rings, and moving uniformly by means of
pinions O and a gear wheel R, as shown in Figures 1 and 4, substantially in the
manner and for the purposes herein specified.
6. In a piston-rod packing, two sets of packing rings as herein described, acting
independently except as to their adjustment, and separated by a distance collar K
having pressing rings M¹ and M³ embedded in its faces, and adjusting screws L
passing through it, the whole constructed and operating, substantially as set forth.
7. In a piston-rod packing, the screw collar R and struts L and L, acting on
two sets of packing rings placed at different points on the piston rod, and within
the same stuffing box, so arranged that one adjustment acts on both sets of packing
rings, in the manner substantially as described and shown.
8. In a piston-rod packing, the screw collar R³, with double pressing rings M²
and M, a spring N interposed between, so as to equalize the pressure on the two
independent sets of packing rings placed in the same stuffing box, and operating
substantially in the manner and for the purposes specified.
9. In a piston-rod packing, the distance collar K, having the inner pressing
ring M¹ embedded therein and struts L³ passing through it, the faces thereof forming
steam joints against two sets of packing rings, substantially in the manner and for
the purposes set forth.
Dated this 18th day of June 1809
ALLISON BROS.,
Agents for the Applicant.