Improvements in Piston Packings for Steam and other Engines.
Year: 1895

page_text: Date of Application, 13th Nov., 1895
Complete Specification Left, 27th July, 1896-Accepted, 26th Sept.,
1896
PROVISIONAL SPECIFICATION.
Improvements in Piston Packings for Steam and other Engines.
We, JOHN ERNEST BAKER, of No. 209 Newport Road, Cardiff, in the County
of Glamorgan, Iron Merchant, and FRANK JONES of The Vicarage, Bassaleg,
near Newport, in the County of Monmouthshire, Engineer, do hereby declare the
nature of this invention to be as follows:-
The object of this invention is to provide an improved packing for the pistons
of steam and other engines. The latter is applicable also to hydraulic and
other pumps.
The invention consists in applying to a piston of ordinary construction, a conical
and spirally shaped coil or ring, the outside face being turned true and parallel for
wearing against the internal walls of the cylinder. The inside of the coil is
bored out in the form of a double cone, the larger diameters being on the
outside.
This coil is kept against the walls of the cylinder and expanded into contact
therewith, by means of a pair of conical rings sliding on the body of the piston.
These rings bave an outer projecting flange which fit, respectively, into the recess
in the junk ring and the flange of the piston. The object of this outer flange:is to
prevent the escape of steam between it and the flange or the junk ring. Holes.nre
bored through the flange and junk ring to admit steam to the back of each of
the conical rings, the pressure from which having the effect of forcing the conical
rings towards each other thereby pressing the coiled conical ring outwards
automatically against the walls of the cylinder. Studs or set pins with suitable
lock nuts may be passed through the flange and the junk ring to tighten up 'the
conical rings. A coil of soft packing may be inserted within the spaces between
the metal of the conical coil, in order to prevent the possibility of leakage.
Instead of the application of this form of packing to an ordinary piston with
junk ring and flange, the piston may be made for small diameters, of similar
halves, and split through the centre, thus obviating the necessity of a junk ring.
When so made, the construction would be very suitable for pumps or piston
valves.
Dated this 13th day of November 1895
PHILLIPS & LEIGH,
Agents for the Applicants..
COMPLETE SPECIFICATION.
Improvements in Piston Packings for Steam and other Engines.
We, JOHN ERNEST BAKER, of No. 209 Newport Road, Cardiff, in the County
of Glamorgan, Iron Merchant, and FRANK JONES, of The Vicarage, Bassaleg,
near Newport, in the County of Monmouthshire, 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:—
The object of this invention is to provide an improved packing for the piston's

page_text: In the accompanying drawing,
Figure 1 is an elevation, partly in section, of a piston made according to the
present invention.
Figure 2 is an elevation, likewise partly in section, of a modified piston, made
according to the present invention and includes the end of the piston rod and the
holding nut.
Both figures agree in shewing the piston as split in two halves A, A, in a
plane at right angles with its axis. Whether it is so split, or whether it is made
in one piece, is a matter outside the present invention. When, however, it is
decided to make the piston in two halves, a separate junk ring may be dispensed
with if there is a flange on each half piston A. In this way the flange A of the
outer half piston A may be regarded as the junk ring and that A of the opposite
half A, as the piston flange. In any case each half of the piston has three
diameters, the smallest being next the transverse centre plane and the largest
being that of the juuk ring or the Hange as the case may be.
D is a packing coil adapted to fit with its outer face against the internal face
of the cylinder, after the well known manner of the ordinary piston rings. The
inner surface of the coil D has the contour of a double cone, the smaller internal
diameter of the cone being half way between its two ends, that is, in the transverse
centre plane aforesaid. As to the length of this coil, measured in the direction
of the axis of the piston, it occupies the distance between the junk ring A¹ and
the flange A³, its coils standing clear of each othor by a short distance. Each of
the two internal conical surfaces of the coil D are separated from the piston body A
by a distance sufficient to receive a wedging ring E, E¹. The outer face of each
of these rings is tapered to the same angle as the respective internal surface of the
coil D, while the internal face, of each, is turned to fit up to the intermediate
and the smallest diameters of the piston body as well as to the annular surface G
which connects them. The width of each ring E E' is less than that of half the
above mentioned length of the coil as shown in the figures, in order that each may
be capable of motion towards its fellow.
F, F are steam ports establishing communication between each-face of the piston
on the one hand and the respective annular surfaces G, G and wedging rings E E¹,
on the other.
K is a coil of soft packing between the coils of the packing D and standing
flush with the working face of the latter. The object of it is to prevent leakage
between the said. coils.
The operation of the invention is self-evident. The steam in the cylinder is
always pushing half the packing coil D up to the cylinder side, by acting on it
through the respective port F and ring E É¹.
The steam may be allowed to press directly upon the wedging ring surface
opposite the surface G, in which case the fit of the wedging ring up to the piston
body is relied on to prevent leakage; or there may he a special packing H. This
is of leather or equivalent material and is U shaped in cross section, the
bottom of it standing in a groove turned in the corner of the ring E E opposite
to the surface G, and the sides standing in grooves turned on each side of the
port F, for as long a distance as the motion of the wedging ring may render
necessary.
Special provision for taking up wear between the coil D and each wedging
ring E E' may be made by the following means. I is a set screw screwed into the
ring from the outer face of the pistou in a line parallel with the axis of the latter.
J is a collar fast on the set screw I and bearing against the bottom of a recess
in the flange or the junk ring of the piston, as the case may be. The sides of both
collar and recess are parallel with the axis of the set screw and the shank of the
latter outside the said collar is free from any projections, so as not to present any
opposition by the screw to the wedging motion of the ring.

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 :-
1. The combination of packing coil, having a double coned internal surface, a
pair of wedging rings, recesses in the piston or the like to receive the said wedging
rings, and ports from the faces of the piston or the like to the recesses respectively,
as set forth. and illustrated.
2. The combination of packing coil having a double coned internal surface,.
intermediate soft packing, a pair of wedging rings, recesses in the piston or the
like to receive the said wedging rings, ports from the faces of the pistons or the
like to the recesses respectively, and special packings between the said ports and.
the wedging rings respectively, as set forth and illustrated.
3. The combination of packing coil having a double coned internal surface, a
pair of wedging rings, recesses in the piston or the like to receive the said wedging
rings, ports from the faces of the pistons or the like to the recesses respectively,
and set screws for taking up wear and tear between the packing coil and the
wedging rings, as set forth and illustrated.
Dated this 27th day of July 1896
PHILLIPS & LEIGH,
No. 22 Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicants.