Year: 1885

page_text: I, JOHN HAYTHORN, of Commercial Bank House, Dumbarton, in the County of
Dumbarton, North Britain, Engineer, do hereby declare the nature of this
Invention to be as follows, that is to say :-
My said Invention has for its object to improve the construction of metallic
packings for pistons and piston valves, to render such packing tight and efficient
without excessive or unequal pressure, and to render it capable of easy and
satisfactory adjustment.
In one modification of my improved metallic packing suitable for the piston of
a steam-engine cylinder, there are two packing rings held as usual between the
piston flange and a junk ring, and each cut through at one part to allow of their
expansion or distention. The packing rings require not only to be distended but
also to be kept, one in close contact with the piston flange and the other in close
contact with the junk ring, and for this purpose I apply a continuous spring or a
series of springs in such a way as to tend to press the rings apart from each other.
When using a continuous spring according to one modification I form grooves
opposite each other in the meeting faces of the two rings and in the space formed
by the grooves I place spring wire bended into a curved zig-zag form so that
successive parts of it bear alternately on the two rings. The wire may be bended
in various ways provided that it will press as equally as possible on the rings.
When using a series of springs for the same purpose I form indentations in the
meeting faces of the rings to receive the suitably bended middle part of each
spring in the socket formed by a pair of such indentations whilst the two ends of
the spring are bended so as to bear against flanges formed on the inner sides of the
rings. Any other suitable kind of spring may be used if preferred.
For the purpose of distending the packing rings I arrange a series of strut links
around within the rings these links being jointed to each other and to small blocks
or pads which bear outwards against the rings. At one part there is interposed
between two of the small blocks a helical or other suitable spring which being in
a compressed state presses the series of links so as to tend to distend them and
thereby to cause the several small blocks or bearing pads at the joints to press with
practically equal pressures radially outwards on the packing rings. For one of the

page_text: links, by preference the one diametrically opposite to the spring, there is substituted
a pair of short links connected by a right-and-left screw coupling by adjusting
which the approximate circle formed by the series of links may be enlarged or
reduced or the distending spring may be more or less compressed. The screw
coupling may for the purpose of adjustment be formed with worm wheel teeth
having in gear with them a worm which can be turned by means of a key either
through or on removing the junk ring; or the coupling may simply be made like
a capstan head so that it can be turned by means of a rod when the junk ring has
been removed; or any other convenient means of turning the coupling may be
adopted. Instead of the distending spring being arranged to act tangentially it
may be arranged to act radially on a wedge acting on bevilled blocks jointed to
the series of links; and the adjustment may in any case be provided for by means
of a screw applied so as to act directly on the spring.
For piston valves the two packing rings may be used; but a simpler, and for
some cases more convenient modification may be made with a single packing ring,
the series of links being applied within the ring for the purpose of distending it.
The packing ring is by preference made wider at its outer bearing surface than at
the parts of it which are held between the junk ring and the flange on the
valve body.
In the case of piston valves and even cylinder pistons of small or moderate size
the spring for distending the packing ring or rings may be dispensed with, the
adjusting appliance, being however retained, allowing of the piston being very
accurately adjusted to the cylindrical surface in contact with which it has to work.
Instead of the strut links being jointed to the pressing blocks or pads or to each
other they may be made with ball-and-socket surfaces, or with bearing surfaces of
cylindrical or other suitable form, since as they are always in compression when in
action they do not require to be tied together except for convenience in handling.
Dated this seventh day of December 1885

page_text: Valves.
I, JOHN HAYTHORN, of Commercial Bank House, Dumbarton, in the County of
Dumbarton, North Britain, 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, that is to say :-
My said Invention has for its object to improve the construction of metallic
packings for pistons and piston valves, to render such packing tight and efficient
without excessive or unequal pressure, and to render it capable of easy and
satisfactory adjustment.
In one modification of my improved metallic packing suitable for the piston of a
steam-engine cylinder, there are two packing rings held as usual between the piston
flange and a junk ring, and each cut through at one part to allow of their expansion
or distention. The packing rings require not only to be distended but also to be
kept, one in close contact with the piston flange, and the other in close contact
with the junk ring, and for this purpose I apply a continuous spring or a series of
springs in such a way as to tend to press the rings apart from each other.
For the purpose of distending the packing rings I arrange a series of strut links
around within the rings, these links being jointed to each other and to small blocks
or pads which bear outwards against the rings. At one part there is interposed
between two of the small blocks a helical or other suitable spring which, being in
a compressed state, presses the series of links so as to distend them and thereby
cause the several small blocks or bearing pads at the joints to press with practically
equal pressures radially outwards on the packing rings. For one of the strut links,
by preference the one diametrically opposite to the spring, there is substituted a
pair of short links connected by a right-and-left screw coupling by adjusting which
the approximate circle formed by the series of links may be enlarged or reduced,
or the distending spring may be more or less compressed. Or an equivalent
adjustment may be provided for in various other ways; and instead of the
distending spring being arranged to act tangentially it may be arranged to act
radially on a wedge acting on bevilled blocks jointed to the series of links, and
the adjustment may in any case be provided for by means of a screw applied so
as to act directly on the spring.
For piston valves the two packing rings may be used; but a simpler, and for
some cases more convenient modification may be made with a single packing ring,
the series of links being applied within the ring for the purpose of distending it.
In the case of piston valves and even in that of cylinder pistons of small or
moderate size the spring for distending the packing ring or rings may be dispensed
with, the adjusting appliance being however retained, allowing of the piston being
very accurately adjusted to the cylindrical surface in contact with which it has
to work..
.Instead of the strut links being jointed to the pressing blocks or pads or to each
other they may be made with ball-and-socket surfaces, or with bearing surfaces of

page_text: cylindrical or other suitable form, since as they are always in compression when in
action they do not require to be tied together except for convenience in handling.
And in order that my said Invention and the manner of performing the same
may be properly understood, I hereunto append three sheets of explanatory
drawings to be hereinafter referred to and showing various modifications of my
improved metallic packings for pistons and piston valves. In these drawings the
same reference letters and numerals are used to mark the same or like parts
wherever they are repeated.
Figure, 1, on sheet, 1, of the drawings is a partially sectioned plan or face view
of a cylinder piston, and figure, 2, is a section as at right angles to figure, 1. The
piston is provided with two packing rings, R, held as usual between the piston
flange, F, and the junk ring, J, (only a small portion of the latter being shown in
figure, 1,). The rings, R, are pressed outwards by a series of small blocks or
bearing pads, B, to which are jointed strut links, L, connecting the blocks, B, to
each other. At one part of the circular series of blocks and links short links or studs,
31, are formed on two of the blocks, B, and are inserted into the opposite ends of a
helical spring, H, which is in compression and acts on the blocks, B, like a strut
having a tendency to lengthen and thereby enlarge the circular series of links and
blocks and producing a radial or outward pressure of the blocks again the inner
surfaces of the packing rings, R. At another part, preferably diametrically opposite
to the spring, H, an adjusting device is provided which in the example now being
described consists of two short screwed links, 32, jointed to blocks, B, and con-
nected by a right-and-left screw coupling, C. This coupling, C, is formed with
worm teeth with which there gears a worm, W, on a spindle, 33, fitted in the body
of the piston and formed with a squared outer end for the application of a turn
key. This spindle, 33, may be covered by the junk ring, J, as shown in figure, 2;
or it may be made accessible through a hole in the junk ring, J, as shown in
figure, 4. Figure, 5, is a side view of one of the blocks or pressing pads, B, with
one of the screwed links, 32, in section.
Figures, 3, and 4, are similar views to figures, 1, and 2, but showing a slightly
modified arrangement of the links, L, and blocks or pressing pads, B, the links, L,
being made with concave spherical ends to bear on convex spherical surfaces
formed for them on the blocks, B, one of which is shown in side view in figure, 9.
Figures, 6, 7, 8, 10, 11, show examples of the various forms of springs, Ș, that
may be used for pressing the packing rings, R, apart so as to keep them in contact
with the piston flange, F, and the junk ring, J. The form of spring, S, shown in
figure, 6, is also shown as applied in figure, 2, there being grooves formed opposite
each other in the meeting faces of the two rings, R, to receive the spring, S, which
is a wire bended into a curved zig-zag form so that successive parts of it bear
alternately on the two rings. A single length of this kind of spring passing
entirely round the piston may be used, or there may be a set of shorter lengths.
The wire may be bended in various ways provided that it will press as equally as
possible on the two rings, R. A series of quite separate springs may be used for
the same purpose, one form being shown in figures, 7, and 8; and when using such a
spring S, indentations are formed in the meeting faces of the rings, R, to receive
the suitably bended middle part of each spring in the socket formed by a pair of
such indentations, whilst the two ends of the spring are bended so as to bear against
flanges formed on the inner sides of the rings, R. In the modification shown in
figures, 10, and 11, the spring, S, is of a double-S form being held at its middle by
a clipping piece which is itself held in indentations formed in the two rings, R, as
for the modification shown in figures, 7, and 8. Another modification of separating
springs, S, is shown as applied in figures, 3, and 4, the springs consisting of short
helical coils inserted in sockets formed for them in the rings, R. Any other suit-
able kind of separating spring may be used if preferred.
Figure, 12, on sheet 2, is a partially sectioned plan or face view of a piston with
a modification of my improved packings, and suitable for a small or moderately
sized cylinder; and figure, 13, is a corresponding section as at right angles to

page_text: figure, 12. In this modification there is a single packing ring, R, pressed out-
wards by blocks or bearing pads, B, jointed to strut liuks, L, and acted on by a
wedge, 34, on the outer end of a radially placed screw spindle, 35. On the screw
spindle, 35, there is an internally screwed nut, 36, formed with a capstan head
for adjustment by means of a key; and this nut, 36, is pressed outwards by a
helical spring, 37, with which arrangement the packing is both adjustable and
elastic. When adjustability without elasticity is desired the spring may be
dispensed with, the nut, 36, being in that case made to bear against the
piston boss.
Figure, 14, is a partially sectioned plan or face view of a modification suitable
for a valve piston; and figures, 15, and 16, are sections as at right angles to
figure, 14. There is in this modification a single packing ring, R, which may be
made as shown in figure, 16, with its inner or back part by which it is held
between the flange, F, and junk ring,. J, narrower than its outer surface. No
spring is applied in this modification but the packing ring, R, is distended by
blocks or bearing pads, B, jointed to strut links, L, which are adjusted by means
of a screw coupling, C. In this case as also in others in which such a screw
coupling, C, is used it may be made right-and-left handed to act on corresponding
short links, or it may be made one-handed only one of the spindles being screwed
in that case the coupling being free to turn on the other spindle.
Figure, 17, on sheet, 3, is a partially sectioned plan or face view, with the junk
ring removed, of a piston with a single packing ring R. Figure, 18, is an inside
view corresponding to the upper part of figure, 17; and figure, 19, is a section as
at right angles to figure, 17. In this modification the combination of strut links, L,
and pads, B, which distend the ring, R, is provided with a spring, H, as in figure, 1,
whilst for adjustment there is provided a coupling, C, made with a central capstan
head with a screw spindle on one end and a plain spindle on the other which work
in an internally screwed and a plain tubular link, 38, jointed to two of the pads, B.
In these figures I also show the construction which I adopt for covering the cut
which is made through the ring, R, to allow of its distention. This covering
piece, 39, is formed in the same piece with one of the strut links, L, and is shaped
with lateral parts entering rebates formed completely across the insides of the ends
of the ring, R, and with top and bottom flanges extending through rebates formed
across the top and bottom edges of the ring, so that the cut in the ring is covered
both on the inside and at the top and bottom.
Figure, 20, is a section as taken through a valve piston and through the ported
casing, P, in which it works. Figure, 21, is an inside view showing the covering
piece, 39, like the one herein before described with reference to figures, 17, 18,
and 19, and which is arranged to work against a part of the casing, P, that is not
cut by a port. Figure, 22, is a section as at right angles to figure, 20, but showing
only the packing ring, R, the strut links, L, and the covering piece, 39. Figure, 23,
is another section as at right angles to figure, 20. In this simplified modification
there are four strut links, L, jointed together in pairs; and the ends of two of the
links bear on the covering piece, 39, made with suitable recesses on its inner side
for the purpose. The middle joint of each pair and the further ends of the other
two links are shaped externally to bear on the inside of the ring, R, whilst the
ends are bevilled internally to be acted on by a wedge, 34, on the end of a radial
screw spindle which is adjusted outwards as required by a screw nut, 36.
Figure, 24, is a half sectional face view or plan of a piston with packings similar
to those shown in figure, 1, hereinbefore described but with the strut links, L,
connected to each other by an elastic metal band, 40, the parts of which between
the links bear against the insides of the rings, R, and at the same time act as hinge
joints between the links.
I prefer, where springs are employed with two packing rings, to have the
rings, R, pressed apart and against the piston flange, F, and junk rings, J, by springs
separate from those used to distend the series of strut links, L, and the blocks or
bearing pads, B, or equivalent parts; but when it is wished to make the distending

page_text: spring or springs also serve for pressing the rings apart, the blocks, B, may be
made with bevilled or inclined bearing surfaces to act on bevilled flanges formed
on the insides of the packing rings, R.
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
1-The improved metallic packings for pistons and piston valves and consisting
in each case of one or more ordinary packing rings combined with a series of
connected strut links bearing against their insides and provided with adjustable
distending devices and with or without distending springs the parts being arranged
and operating substantially in any of the modes herein before described.
2-The application to metallic packings for pistons or piston valves when two
rings are used in each case, of springs tending to press the rings apart, such springs
being of any of the kinds and applied in the manner substantially as herein before
described with reference to figures, 1, 2, 3, 4, 6, 7, 8, 10, and 11, of the accompanying
drawings.