Improvements relating to Piston Valves and Pistons generally.
Year: 1898

page_text: Improvements relating to Piston Valves and Pistons generally.
I, WILLIAM JAMES HAY, of 9, Dalhousie Place, Arbroath, N.B., Engineer, do
hereby declare the nature of this invention to be as follows:-
My invention relates to piston valves and pistons generally and has for its object
to provide a piston and piston ring that shall provide a perfect steam tight joint,
and which shall be capable of automatic adjustment on the wear of the surfaces in
contact.
My invention consists in providing a piston ring longitudinally or axially cut and
with its abutting edges so formed or inclined as to permit of a wedge being thrust
between with the tendency of expanding or increasing the circumference to make
good the wear of the ring and cylinder or liner in which it works; and so as to
preclude the possibility of the wedge being forced back whatever the pressure of
steam ; and my invention further consists in the construction of the piston whereby
the rings are held so as to ensure a perfect steam tight joint while permitting freedom
of the outward radial movement of the piston rings.
In carrying my invention into effect in its application to a piston valve I provide
two piston rings which serve to operate in connection with the respective ports of the
engine cylinder, such rings being split or cut longitudinally or radially and having
the respective abutting extremities or faces inclined so as to permit of the intro-
duction of a wedge therein, which by its outward radial movement serves to increase
the circumference of the ring, the angle of the wedge being slightly less than the
angle of repose for the surfaces in contact so that whatever the pressure outside the
ring it can never force the ring inwards and press back the wedge thus causing
leakage of steam past the ring, and the springs may be adjusted to give the ring
just the small sufficient pressure against the walls of the liner to keep the ring
steam tight. It will thus be seen that a great advantage is thus secured over pistons
whose rings are forced outwards by means of springs at back thereof, that require to
be made strong enough so that when the ring covers the port during compression,
the pressure of steam will not force the ring inwards, and the ring must therefore be
pressed against the cylinder or liner with a great pressure causing excessive friction.
The wedges employed are preferably provided respectively with a bridge piece or
flange for the reception upon each end thereof of spiral springs held in position by
projections or pins provided thereupon, such springs abutting against corresponding
projections provided upon a segmental piece mounted in a position within the ring
immediately opposite to the wedge piece, such segmental piece being held to preclude
circumferential movement by means of a longitudinal rib provided upon the interior
of the cast iron ring which enters into a corresponding recess within the segmental
piece, or vice versa. By the arrangement of the spiral springs upon each side of the
wedge piece the valve spindle is capable of passing between. Each of the cast iron
rings is first turned to 18th of an inch larger than the finished size and the wedge
which is preferably provided in phosphor bronze is carefully fitted in with the ring
perfectly free. The wedge piece is then slightly soldered to the ring at each side so
that the ring becomes solid. The ring is next turned to the correct depth and to the

page_text: exact diameter of the cylinder or of the liner in which the piston is to work, and is
then ground and scraped to an accurate fit, the solder of course being afterwards
melted out.
The piston is constructed by arranging upon one end of the valve spindle a boss
carrying a lateral flange or cheek faced for the reception of the piston ring, which
piston ring is supported upon the other side by a corresponding faced flange or cheek
carried by means of a boss upon the spindle, such boss abutting against another
carrying a further lateral flange or cheek faced for the reception of the second ring
such ring being held upon the other side by means of another flange or cheek
mounted upon the spindle by means of a boss; the whole series of flanges and
intermediate rings being forced into close contact by means of a nut screwed upon
the extremity of the valve spindle. This nut is maintained in position under the
action of the spring tending to maintain the faces of the flanges in contact with the
respective faces of the rings by means of a keep carrying the spring which abuts
against a tail piece or projection provided upon the tightening nut so that thereby
good tight joints are maintained while to rings are free to move or expand.
I do not limit my invention to the actual construction of a piston having rings
provided as hereinbefore described, for it is obvious that such rings may be fixed in their
determined position by other convenient means without departing from the essential
feature of my invention. It is also obvious that other means may be provided than
those herein before described for the purpose of maintaining the wedge piece outwardly
thrusting to expand the ring.
Dated this 10th day of Marah 1000
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.
I, WILLIAM JAMES HAY, of 9, Dalhousie Place, Arbroath, N.B., Engineer, do
hereby declare the nature of this invention and in what manner the same is
to be performed, to be particularly des ribed and ascertained in and by the following
statement :-
This invention relates to piston valves and pistons generally and has for its object
to provide a piston and piston ring that shall effect a perfect steam tight joint and
that shall be capable of automatic adjustment on the wear of the surfaces in
contact.
as to
The invention consists in providing a piston ring longitudinally or axially cut and
with its abutting edges so formed or inclined as to permit of a wedge being thrust
between with the tendency of expanding or increasing the circumference to make
good the wear of the ring and cylinder or liner in which it works and so
preclude the possibility of the wedge being forced back whatever the pressure of
steam; and the invention further consists in the construction of the piston whereby
the rings are held so as to ensure a perfect steam tight joint while permitting
freedom of the outward radial movement of the piston rings.
In the accompanying sheet of explanatory drawings:-
Figure 1 is a part sectional elevation of a piston valve made in accordance with
the invention.
Figure 2 is a partial end elevation, and
Figure 3 is a sectional elevation on the line a b (Figure 1).
In carrying the invention into effect in its application to a piston valve as illus-
trated in the accompanying drawings I provide two piston rings A A¹ which serve to

page_text: operate in connection with the respective ports A2 A3 of the engine cylinder, such
rings heing split or cut longitudinally or radially and having the respective abutting
extremities of faces a a inclined so as to permit of the introduction of a wedge C
therein, which, by its outward radial movement, serves to increase the circumference
of the ring A, the angle of the wedge being slightly less than the angle of repose for
the surfaces in contact, so that whatever the pressure outside the ring it can never
force the ring inwards and press back the wedge, thus causing leakage of steam past
the ring. The wedges C employed are preferably provided respectively with a bridge-
piece or flange G for the reception upon each end thereof of spiral springs D held in
position by projections or pins H H provided thereupon, such springs abutting against
corresponding projections H1 H₁ provided upon a segmental piece I, such segmental
piece I being held to preclude circumferential movement by means of a longitudinal
rib J provided upon the interior of the cast iron ring A or A¹, which rib enters into a
corresponding recess J¹ within the segmental piece, or vice versa. The springs D
may be adjusted to give the ring just the small sufficient pressure against the walls of
the liner E to keep the ring steam tight. It will thus be seen that a great advantage
is secured over pistons whose rings are forced outwards by means of springs at back
thereof that require to be made strong enough so that when the ring covers the port
during compression the pressure of steam will not force the ring inwards and the
ring must therefore be pressed against the cylinder or liner with a great pressure
tending to set up excessive friction. By the arrangement of the spiral spring upon
each side of the wedge piece C the valve spindle K is capable of passing between.
Each of the cast iron rings such as A A¹ is first turned to about 18th of an inch
larger than the finished size, then cut and the wedge, which is preferably provided in
phosphor bronze, is carefully fitted in with the ring perfectly free. The wedge piece
is then slightly soldered to the ring at each side so that the ring becomes solid.
The ring is next turned to the correct depth and to the exact diameter of the cylinder
or of the liner in which the piston or piston valve is to work and is then ground and
scraped to an accurate fit, the solder of course being afterwards melted out.
The piston is constructed by arranging upon one end of the valve spindle Ka
boss L carrying a lateral flange or cheek for the reception of the piston ring A¹
which piston ring is supported upon the other side by a corresponding faced
flange or cheek M¹ carried by means of a boss N upon the spindle, such boss N
abutting against another carrying a further lateral flange or cheek M² faced for the
reception of the second ring A, such ring A being held upon the other side by means
of another flange or cheek M³ mounted upon the spindle by means of a boss o, the
whole series of flanges and intermediate rings being forced into close contact by
means of a nut Q screwed upon the extremity of the valve spindle K. The nut Q is
maintained in position by the action of a spiral spring Q₁ tending to maintain the
faces of the flanges in contact with the respective faces of the rings by means of a
keep carrying the spring Q¹ which abuts against a tail-piece or projection S provided
upon the washer R which is fitted on square part of valve spindle, so that thereby
good tight joints are maintained while the rings are free to expand.
I do not limit my invention to the actual construction of a piston having rings
provided as herein before described for it is obvious that such rings may be fixed
in their determined position by other convenient means without departing from
the essential feature of my invention. It is also obvious that other means may be
provided than those herein before described for the purpose of maintaining the wedge
piece outwardly thrusting to expand the ring.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The construction of pistons and piston valves substantially as herein before
described.
2. In pistons and piston valves means for making good the wear of the piston ring

page_text: and cylinder or liner consisting of a wedge-piece outwardly thrust in the manner
substantially as hereinbefore described.
3. In pistons and piston valves means for making good the wear of the piston ring
and cylinder or liner substantially as herein before described and as illustrated in the
accompanying drawings.
4. In pistons and piston valves means for holding the rings within lateral cheeks
or flanges so as to ensure a perfect steam tight joint while permitting freedom of the
outward radial movement of the rings in the manner substantially as described.
Dated this 10th day of December 1898.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., Agents.