An Improved Packing Ring for Pistons and the like.
Year: 1894

page_text: Date of Application, 27th June, 1894
Complete Specification Left, 27th Mar., 1895-Accepted, 4th May, 1895
An Improved Packing Ring for Pistons and the like.
I, WILLIAM LOCKWOOD, of City Standard Piston Works, Bramall Lane,
Sheffield Yorkshire, Engineer, do hereby declare the nature of this invention to
be as follows:-
This invention relates to an improved packing-ring for pistons and the like,
especially applicable for use in locomotives and high-pressure engines in which an
axial pressure of the packing (tending to keep it from clattering between the
opposing parts of the piston) somewhat exceeding the radial pressure thereof
(tending to keep the packing steam-tight against the cylinder-wall) is of advantage;
a main object of the invention being to dispense with separate spring-rings (of
which there are numerous forms more or less effective in present use) and to render
the packing-ring self-expansive and operative in the improved manner hereinafter
described.
To this end, I construct the ring as a compound ring of a somewhat greater
width (measured radially) than depth (measured axially), forming the saine of two
co-acting parts each of a right-angled triangular section, produced, as it were, by
diagonally dividing the packing-ring through its radial cross section.
By such construction, the one or inner part of the ring has a base of the width
of the ring, an altitude of the depth of the ring, and an hypothenuse equal to the
diagonal of the rectangle formed by the radial cross section of the compound
ring, so that its upper external surface is of a conical formation. The other or
outer part of the ring is of a reversely formed triangular section and conical shape,
forming, in fact, the complement of the rectangle formed by the radial cross
section of the compound ring, and is adapted to rest with its under conical surface
on that of the inner part of the ring; the conical faces of the two parts of the
ring being coincident at all parts.
As the compound ring is somewhat wider than its depth, and as the conicality of
the opposing faces is coincident with the diagonal of the oblong rectangle of the
radial cross section of the ring, it follows that the angle of such conical surfaces
will be somewhat less than 45°, from the base of the cone, which will ensure that
the axial pressure of the inner part of the ring on the outer part of the ring, shall,
as desired, exceed its radial pressure.
The extent of such excess of the axial action may be determined by the relative
width and height of the compound ring, and by the consequent position of the
diagonal thereof.
The useful limits of variation, I, at present, consider to be between an angle
somewhat less than 45° as aforesaid and an angle of about 30°, the most useful
limits lying between angles of about 35° and 40°.
The meeting ends of each part of the ring are cut so as to leave an extension on
each end of about one-half the width of the ring adapted to engage with a corre-
sponding recess in the opposite part of the other end of the ring, the outer one of
such recesses being deeper at its inner part than at its outer periphery (when
viewed in cross section) so as to produce an inclined recess adapted to hold the
correspondingly shaped extension of the opposite meeting end with its outer
periphery coincident with that of the compound ring.
In applying the ring to a piston, both parts of the ring are placed in compression,

page_text: the radial action is principally dependent upon the outer part of the ring, and the
axial action is principally dependent upon the action of the inner part of the ring
on the outer part thereof.
The action of the inner part of the ring when of large diameter may be to some
extent increased by locating coiled springs in the opposing ends thereof tending to
separate such ends.
Dated this 27th day of June 1894.
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C., Agents for the Applicant.
An Improved Packing Ring for Pistons and the like.
I, WILLIAM LOCKWOOD, of Bramall Lane, Sheffield, Yorkshire, Manager to
the Standard Piston Ring and Engineering Company Limited, do hereby
declare the nature of the said invention, 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 an improved packing ring for pistons and the like,
especially applicable for use in locomotives and high pressure cugines in which an
axial pressure of the packing (tending to keep it from clattering between the
opposing parts of the piston) somewhat exceeding the radial pressure thereof
(tending to keep the packing steam tight against the cylinder wall) is of advantage,
à main object of the invention being to dispense with separate spring-rings (of
which there are numerous forms more or less effective in present use) and to render
the packing ring self-expansive and operative in the improved manner hereinafter
described.
The accompanying drawings represent the improved ring both as applicable to a
shallow piston and as applicable to a deep piston.
The improved ring is constructed as a compound ring formed of inner and outer
parts b, a, formed with opposing conical co-acting faces b', a', of a somewhat greater
width (measured radially of the ring) than depth (measured axially thereof), the
angle of such conical faces being between an angle of somewhat less than 45° with
the base of the cone and an angle of about 30° with such base (vide Fig. 1.) which
will ensure that the axial pressure of the inner part of the ring upon the outer
part thereof shall, as desired, exceed its radial pressure thereon within the most
useful limits.
In the construction represented in Figs. 1 and 2 the part b, of the ring is of a
right angled triangular form in cross section, having a base of the width of the
ring, an altitude of the depth of the ring, and its conicality determined by such
base and altitude, in the plane of the diagonal of the rectangle formed by the
radial cross section of the compound ring, its upper external surface b¹, being of a
conical formation; and the part a, of the ring is of a reversely formed triangular
section and conical shape, forming, in fact, the complement of the rectangle formed
by the radial cross section of the compound ring, and is adapted to rest with its
under conical surface a', on that 6', of the part b, of the ring, the conical faces of
the two parts of the ring being coincident at all parts.
In applying the ring to deep pistons (Figs. 4 and 5) in cases where there is but
little radial width for the ring to occupy, the parts a, b, may be made of a sufficient
depth (Fig. 4); or the part a, may be duplicated (Fig. 5) and applied to each side
of a double-acting part b, which may also be duplicated, so as to make three or
four rings operating as aforesaid.
In such an application, a self-expansive supplementary packing ring ², may be

page_text: inserted in a groove around the ring b, to aid in keeping a steam tight-joint,
Fig. 5.
The meeting ends of each part of the ring are cut (Figs. 2 and 3) so as to leave
an extension as a², on each end of about one-half the width of the ring adapted to
engage with a corresponding recess in the opposite part of the other end of the
ring. The outer one of such recesses may be deeper at its inner part thau at its
outer periphery so as to produce an inclined recess adapted to hold the corre-
spondingly shaped extension of the opposite meeting end with its outer periphery
coincident with that of the compound ring.
In applying the ring to a piston, both parts of the ring are placed in compression,
the radial action is principally dependent upon the part a, of the ring, and the
axial action is principally dependent upon the action of the part b, on the part a.
The action of the part b, when of large diameter, may be, to some extent,
increased, by locating coiled springs d, (Fig. 2.) in the opposing ends thereof so as
to tend to separate such ends.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
The improved packing ring for pistons and the like constructed and adapted to
operate as herein before described with reference to the accompanying drawings.
Dated this 21st day of March 1895.
DAY, DAVIES & HUNT,
321, High Holborn, London, W.C., Agents for the Applicant.