Improvements in Valve-operating Devices for Direct-action Engines.
Year: 1897

page_text: Date of Application, 29th Apr., 1897
Complete Specification Left, 27th Jan., 1898-Accepted, 2nd Apr., 1898
Date Application, 25th Apr., 1037
Complete Specification Left, 27th Jan., 1898-Accepted, 2nd Apr., 1898
[Communicated from abroad by WILLIAM ALFRED DREWETT, of 202, Rutledge
Street, in the City of Brooklyn, State of New York, United States of America,
Engineer.]
Improvements in Valve-operating Devices for Direct-action Engines.
I, HENRY EDWARD NEWTON, of the Office for Patents, 6, Bream's Buildings,
Chancery Lane, in the County of London, Patent Agent, do hereby declare the
nature of this invention to be as follows:
This invention relates to direct-action engines, the valve-operating devices of
which are first actuated to commence the movement of the induction and eduction
valve by some moving part of the engine deriving motion from its piston, and
afterwards actuated to complete the movement of the said valve by the steam or
other fluid employed in the engine as its motive agent.
The invention consists in the combination of a cylindrical or other valve chest,
to which there is an outlet for the motive agent, and in which is a valve seat
having ports communicating respectively with the ends of the engine cylinder and
with an exhaust outlet, a piston having two heads fitted to the bore of said chest,
with an intermediate space which includes said inlet and ports, the two heads having
passages through them which form constant communication from said intermediate
space to the spaces between the piston and the ends of the chest, and having also
lateral ports communicating with the last mentioned spaces, a "D" valve fitted
to said seat, and capable of a lost motion between the two piston heads, and con-
taining lateral exhaust ports, and two passages outside of the valve chest, each of
said passages having two terminal ports communicating with the valve chest, one
of said terminal ports being within range of one of the lateral ports of the valve,
and the other of said terminal ports being within range of the lateral ports in one
of the piston heads.
In carrying out this invention, the valve chest has the seat for the sliding valve
which controls the induction and eduction of steam to and from the engine cylinder.
In this seat are the two ports leading to opposite ends of the cylinder, and an
intermediate main exhaust port leading to an exhaust pipe. This valve is like
an ordinary short "D" valve, its cove being of a length to include the exhaust
port and one of the ports in the seat, and of a width corresponding with the said
ports, but it has, besides the cove, two narrow side ports, which debouch laterally
from the cove.
A two-headed valve piston is fitted to the valve chest, and having its rod pro-
jecting through a stuffing box in one end thereof. On the projecting portion of
the said rod, there are adjustably affixed two tappet stops, between which, there
is fitted loosely to the rod, a tappet, which is connected by a rod and lever with the
rod of the engine piston in such manner as to be moved by the engine piston in
the opposite direction thereto, for the purpose (by the action of the said tappet on
one of the stops) of giving to the valve piston, as the engine piston approaches

page_text: the end of its stroke, a movement which produces the first part of the movement of
the valve, the which works with lost motion in the ever-open central steam space
between the two piston heads. In each piston head there is a cavity, and from these
cavities very small openings lead respectively to the spaces between the two pistons
and the closed ends of the valve chest. Through these openings, steam flows
constantly between the central space to the spaces in the ends of the valve
chest, so that the piston heads, having steam on both sides of them, are in equilibrio,
except at the times when the space in either end is opened to the ports in the valve
and to the exhaust cove and exhaust port, through one of the two side passages,
for the purpose of completing the movement of the valve by the greater pressure
of the steam on the inner end of that piston, the space at whose outer end has been
thus opened.
The side passages just mentioned, which may be termed the supplemental ex-
haust passages, running lengthwise within the walls of the chest, and have ports
communicating with the valve seat at points within the range of the lateral exhaust
ports of the valve, and other ports communicating with the bore of the valve chest,
within the range of lateral ports, one in each piston head, the said ports being
always in communication, through passages in the piston heads, with the spaces
between the said heads and the closed ends of the valve chest.
NEWTON & SON,
Agents for the Applicant.
arve-operating DEVICES TO DIaction Engines.
I, HENRY EDWARD NEWTON, of the Office for l'atents, 6, Bream's Buildings,
Chancery Lane, in the County of London, Patent Agent, 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:-
This invention relates to direct-action engines, the valve-operating devices of
which are first actuated to commence the movement of the induction and eduction
valve by some moving part of the engine deriving motion from its piston, and are
afterwards actuated to complete the movement of the said valve by the steam or
other fluid employed in the engine as its motive agent.
I will first describe the engine with reference to the accompanying drawings,
and afterwards point out its novelty in claims.
Figure 1 is a longitudinal vertical sectional view of those parts of a steam engine
which are necessary to illustrate my invention.
Figure 2 represents a vertical section of a part of the engine cylinder, of the
valve chest, and the valve, and its operating devices, shewing the parts in different
position.
Figure 3 represents a transverse vertical section in the line 3-3 of Figure 2;
Figure 4 a transverse vertical section in the line 4-4 of Figure 2.
Figure 5 represents a horizontal section taken through the centre of the valve-
chest, shewing the parts in the same position as Figure 2.
Figure 6 is a diagrammatic sectional view corresponding with Figure 5, but
shewing some of the parts displayed, to better illustrate their mutual relations.
Similar letters of reference designate corresponding parts in all the figures.
A is the engine cylinder, and B the valve chest, to which steam is admitted by
the pipe S, and in which is the seat for the sliding valve C which controls the in-
duction and eduction of steam to and from the cylinder A. In this seat are the

page_text: two ports a, a, leading to opposite ends of the cylinder, and an intermediate main
exhaust port b leading to the exhaust pipe E. The valve chest B is preferably of
cylindrical form from end to end, and the valve C is of corresponding form in
its transverse section. This valve is like an ordinary short "D" valve, its cove
being of a length to include the exhaust port 6 and one of the ports a a', and of
a width corresponding with the said ports, but it has, besides the cove, two narrow
side ports, cc (see Figures 3 and 6), which debouch laterally from the cove, an
the function of which will be hereinafter explained.
D, D', is a two-headed valve piston fitted to the cylindrical bore of the valve
chest, and having its rod projecting through a stuffing box in one end thereof.
On the so projecting portion of the said rod g, there are adjustably affixed two
tappet stops i, ', between which there is fitted loosely to the rod a tappet j, which
is connected by a rod F and lever with the rod G of the engine piston H, in
such manner as to be moved by the engine piston in the opposite direction thereto,
for the purpose, by the action of the said tappet jon one of the stops i, i¹, of giving
to the valve piston, as the engine piston approaches the end of its stroke, a move-
ment which produces the first part of the movement of the valve, the which works
with lost motion in the ever-open central steam space between the two piston
heads D, D. In each piston head there is a cavity or k, and from these cavities
very small openings lead respectively to the spaces between the two pistons and
the closed ends of the valve chest. Through these openings 1, 1, steam flows con-
stantly between the central space to the spaces in the ends of the valve chest, so
that the piston heads having steam on both sides of them are in equilibrio, except
at the times when the space in either end is opened to the ports ec in the valve,
and to the exhaust cove e* and exhaust port b, through one of two side passages d, d',
to be presently described, for the purpose of completing the movement of the valve
by the greater pressure of the steam on the inner end of that piston, the space at
whose outer end has been thus opened.
The passages d d just mentioned, which may be termed the supplemental ex-
haust passages, running lengthwise within the walls of the chest, are best shown
in the diagrammatic view Figure 6. These passages have ports e, e¹, communi-
cating with the valve seat at points within the range of the lateral exhaust
ports c, c, of the valve, and other ports f, f', communicating with the bore of the
valve chest, within the range of lateral ports n, n¹, one in each piston head, the
said ports, being always in communication, through passages m, m', in
the piston heads, with the spaces between the said heads and the closed ends of
the valve chest.
To explain the operation, I will first suppose the parts to be in the relative posi-
tions shown in Figure 1, the valve piston and valve being in their extreme right-
hand positions, steam entering the engine cylinder at the left-hand end, and ex-
hausting therefrom at the right-hand end, the engine piston having made the
greater portion of its stroke to the right, and the tappet having just arrived at
the stop on the rod of the valve piston. At this time, the supplemental exhaust
passages d, d, are both closed at both ends, their ports e e' being closed by the
valve C, and their ports f, f¹, being both closed by the valve piston heads. The
further movement of the engine piston acting through the tappet j, produces
the movement of the valve piston to the left, without moving the valve, until the
shoulder on the piston head D' comes in contact with the valve, when the con-
tinued movement of the valve piston by the tappet starts the valve, and carries
it to the position in which it closes both ports a, a. Up to this time, the exhaust
passages d, d, remain closed, because, although the port n' in the piston head 1)'
has been passing, and open to the port fl of the passage d', the port el at the other
end of said passage is closed by the valve, while the other passage d has its port e
closed by the valve, and its port f closed by the piston head. The steam pressure
is thus equal on the outer ends of both piston heads; but just as the tappet brings
the valve to the position last mentioned, the side port e in the valve begins to open
to the port e, and the piston head D begins to open its port n to the port f, as shewn

page_text: in Figures 2, 5, 6; and then, there being an opening from the left-hand end of
the valve chest through the passage m, ports n, †, passage d, and ports e, c, to the
exhaust cove c* and port b, while the ports n', f', remain closed, the pressure between
the valve piston and the left-hand end of the valve chest being reduced, the pre-
ponderating pressure on the right-hand end of the valve piston quickly completes
the movement of the valve piston and the valve to the left, and admits steam to
the right-hand end of the engine cylinder A, and the movement of the engine pis-
ton to the left takes place.
A similar operation to, but the reverse of that described, takes place between the
tappet, the tappet stop i, the valve piston, the valve, and the several ports and
passages in the valve, piston heads, and valve chest, during the latter part of the
movement of the engine piston to the left, for the purpose of opening the left-hand
end of the cylinder to the steam, and the right-hand end to the exhaust.
In the completion of the movement of the valve piston in either direction beyond
the point at which the ports e, f of the passage, or the ports e, f, of the passage d'
have been closed, there is, by reason of the smallness of the passages in the
piston heads, a cushioning of the steam between the valve piston and the adjacent
end of the chest.
It may be here explained, that the length of the valve and the distance between
the shoulders h on the heads of the valve piston, by which the valve is acted
upon, are so proportioned that the lost motion between the piston and the valve,
is just sufficient to permit the port or in the piston heads to pass by, and close
the port for f in the valve chest, before the valve piston moving in either direction
begins to act upon the valve.
The piston heads are represented as furnished with packing rings o, but ex-
cepting this packing, and the tappet mechanism by which the operation of the
valve is commenced, the valve-operating devices consist of only three parts, riz.,
the valve chest, the valve, and the two-headed valve piston.
Having now particularly described and ascertained the nature of the said in-
vention, and in what manner the same is to be performed (as communicated to
me from abroad), I declare that what I claim is:-
1. In an engine, the combination with a valve chest, a two-headed piston therein,
and a single valve interposed with a lost motion between the piston heads, of a
main exhaust port in the chest controlled by the valve, and two supplemental ex-
haust passages, each communicating with the valve chest by two ports so located
that one of them is opened and closed to the main exhaust port by the passage
by it of the valve, and the other of them is opened and closed to the space between
the adjacent end of the chest and the piston by the movement over it of the piston
itself, substantially as herein described.
2. The combination of a valve chest and a valve therein for controlling the in-
duction and the eduction of the motive fluid to and from an engine, and a two-
headed piston working within said chest, and between the heads of which said
valve works with a lost motion, the said chest being provided with external pas-
sages, each of which has ports communicating with the interior thereof at two
points in its length, the said piston having, in each head, a lateral port in com-
munication with the space between the said head and the adjacent end of the chest,
and the valve itself having two lateral exhaust ports, one for each of said passages,
each of said lateral exhaust ports being capable of communicating with one end
of its respective passage, while the other end of said passage is in communication
with the said lateral port in one of the piston heads, substantially as herein described,
3. In an engine, the combination of a cylindrically bored valve chest, to which
there is an inlet for the motive agent, and within the bore of which is a valve seat
having ports communicating respectively with the ends of the engine cylinder
and with an exhaust outlet, a piston having two heads fitted to the bore of said
chest, with an intermediate space which includes said inlet and ports, the two
heads having passages through them, which form constant communication from

page_text: 66
said intermediate space to the spaces between the piston and the ends of the chest,
and having also lateral ports communicating with the last mentioned spaces, a
D" valve fitted to said seat in the bore of the chest, and capable of a lost motion
between the two piston heads, and containing lateral exhaust ports, and two pas-
sages outside of the valve chest, each of said passages having two terminal ports
communicating with the valve chest, one of said terminal ports being within range
of one of the lateral ports of the valve, and the other of said terminal ports being
within range of the lateral ports in one of the piston heads, substantially as herein
described.
T
Ort 1
T
1000