Improvements in Metallic Packings for Pistons.
Year: 1894

page_text: Date of Application, 19th June, 1894
Complete Specification Left, 16th Mar., 1895-Accepted, 20th Apr.. 1895
PROVISIONAL SPECIFICATION.
Improvements in Metallic Packings for Pistons.
We, JOHN HENRY HARGREAVES and Joux GEORGE HUDSON, both of the
Solo Iron Works, Bolton, in the County of Lancaster, Engineers, do hereby
declare the nature of this invention to be as follows, that is to say:-
Our said invention has for its object the constructing of metallic packings for
pistons in an improved manner, and so that whilst expansible rings, formning part of
the packing, are free to adjust themselves to the bore of the cylinder at the ends
of the strokes, they are locked and act as if solid whilst pressure acts on the piston
in either direction.
In carrying out the invention two or more expausible rings are employed for
cach piston, these rings being of any suitable known construction, but preferably
narrow as regards their outer bearing surfaces. The expansible rings are retained
upon the body of the piston by and between two solid rings, each of which is formed
with an outer retaining flange, and with an inner inwardly projecting flange by
which latter each solid ring is itself retained upon the piston body between a
projecting part of that body and a junk ring bolted on after the other parts are
placed. The expansible rings are also separated from each other by one or more
unflanged solid rings accordingly as there are two or more expansible rings. The
flanged solid rings are fitted to the piston body and junk ring so that either can
move towards the other to a slight extent when pressure acts upon its outer
annular surface; and when either flanged solid ring is thus acted on by pressure
the expansible rings and rings between them become firmly gripped or locked
between the two flanged solid rings. When however the pressures on opposite
sides of the piston are equal as at the end of a stroke, the grip is relieved and the
expansible rings are free to adjust themselves.
The unflanged solid rings serve to support the piston in the case of a horizontal
cylinder, and may be free to turn or be capable of being turned so as to bring
different parts in succession to the lowest part.
Holes may be drilled through the flanged solid rings to admit steam to the spaces
behind the expansible rings to force them outwards if found desirable.
Dated this Eighteenth day of June 1894.
EDMUND HUNT,
Applicants Agent.
Improvements in Metallic Packings for Pistons.
We, JOHN HENRY HARGREAVES, and JOHN GEORGE HUDSON, both of the
Soho Iron Works, Bolton, in the County of Lancaster, Engineers, 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:-
Our said invention has for its object the constructing of metallic packings for
pistons in an improved manner, and so that whilst expansible rings, forming part

page_text: of the packing, are free to adjust themselves to the bore of the cylinder at the
ends of the strokes, they are locked and act as if solid whilst pressure acts on the
piston in either direction.
In carrying out the invention, two or more expansible rings are employed for
each piston, these rings being of any suitable known construction, but preferably
narrow as regards their outer bearing surfaces. The expansible rings are retained
upon the body of the piston by and between two solid rings, each which is
formed with an outer retaining flange, and with an inwardly projecting dange, by
which latter each solid ring is itself retained upon the piston body, between a
projecting part of that body and a junk ring bolted on after the other parts are
placed. The expansible rings are also separated from each other by one or more
untlanged solid rings, accordingly as there are two or more expansible rings. The
flanged solid rings are fitted to the piston body and junk ring so that either can
move towards the other to a slight extent, when pressure acts upon its outer
annular surface; and when either flanged solid ring is thus acted on by pressure,
the expansible rings, and rings between them, become firmly gripped between the
two flanged sold rings. When, however, the pressure on opposite sides of the
piston are equal, as at the end of a stroke the grip is released, and the expansible
rings are free to adjust themselves.
The unflanged solid rings serve to support the piston, in the case of a horizontal
cylinder, and may be free to turn, or he capable of being turned, so as to bring
different parts in succession to the lowest part.
Holes may be drilled through the flanged solid rings to admit steam to the
spaces behind the expansible rings to force them outwards if found desirable.
And in order that the said invention and the manner of performing the same
may be properly understood, we hereunto append a sheet of explanatory drawings,
10 he hereinafter referred to, and shewing packings for pistons as made recording
to the invention.
The drawing is a sectional elevation of a piston fitted with our improved
construction of packings. The same reference letters are used to mark the same
or like parts wherever they are repeated.
In the arrangement shown, two expansible rings, A, A, are employed, these
rings being of any suitable known construction, but preferably narrow as regards
their outer bearing surfaces. These expansible rings, A, A, are retained upon the
hody, B, of the piston, by and between two solid rings, C, C, each of which is
formed with an outer retaining flange, and with an inwardly projecting flange, D.
by which latter each solid ring, C, is itself retained upon the piston body, B,
between a projecting part, E, of that body, and a junk ring, F, bolted on after the
other parts
rts are placed. The expansible rings, A, A, are also separated from each
other by one or more unflanged solid rings, G, accordingly as there are two or
more expansible rings, A. The flanged solid rings, C, are fitted to the piston
body, B, and junk ring, F, so that either can move towards the other to a slight
extent, when pressure acts upon its outer annular surface; and when either
flanged solid ring, C, is thus neted on by pressure, the expausible rings A, A, and
ring or rings, G, between them, become firmly gripped between the two flanged
solid rings, C, C. When, however, the pressures on opposite sides of the piston
are equal, as at the end of a stroke, the grip is released, and the expansible
rings, A, A, are free to adjust themselves. The effective gripping pressure
depends on the steam pressure and on the area of the annular surface of the part of
each solid ring, C, neted on by the steam; and that area may be varied to suit
different cases.
The unflanged solid rings, G, serve to support the piston, in the case of a
horizontal cylinder, and may be free to turn, or be capable of being turned, so as
to bring different parts in succession to the lowest point.
Holes, H, may be drilled through the flanged solid rings, C, to admit steam to
the spaces behind the expansible rings, A, to force them outwards, if found
desirable.

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
The improved metallic packings for pistons, and consisting of two or more
expausible rings and one or more interposed solid rings combined with and held
between flagged solid rings fitted to the piston body in a manner to be acted on by
the steam essure so as to grip the expansible rings and the interposed solid ring
or rings substantially as and for the purposes hereinbefore described.
L-
Dated this Fifteenth day of March 1895.
EDMUND HUNT,
Applicants' Agent.