Improved Piston-valve for Steam Engines.
Year: 1890

page_text: Date of Application, 22nd Aug., 1890
Complete Specification Left, 23rd May, 1891-Accepted, 4th July,
1891
PROVISIONAL SPECIFICATION.
Improved Piston-valve for Steam Engines.
I, JOHN PITT BAYLY, of 18 Fulham Place, Paddington in the County of
London, Patent Agent, do hereby declare the nature of this invention (a com-
munication to me from abroad by Carl Mellin, of Richmond, Virginia, U.S.A.
Inventor), to be as follows:-
By this invention the valve casing has double ports to each end of the cylinder.
The piston valve is formed with a middle space, and is provided with inner and
outer ports through the side, between the middle space, and each end. Longitu-
dinal passages are formed from the ends to the inner side ports, and longitudinal
passages are formed from the middle space to the outer ports, and intermediate to
and crossing or overlapping the passages from the outer ends to the inner side ports,
and thus forming a double ported steam and exhaust valve.
D
.. 01
Awoust 1800
J. P. BAYLY,
Applicant.
COMPLETE SPECIFICATION.
Improved Piston-valve for Steam Engines.
I, JOHN PITT BAYLY, of 18 Fulham Place, Paddington, in the County of
London, Patent Agent, do hereby declare the nature of this invention (a com-
munication to me from abroad by Carl Mellin, of Richmond, Virginia, U.S.A.
Inventor), and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
My invention consists of a contrivance of double ports both for the live steam
and exhaust in a piston-valve to facilitate quick action.
It also consists of pass-ports contrived to bring instant communication between
both ends of the cylinder just as compression commences on one side and directly
before the beginning of exhaust on the other side of the piston to use the steam
that has performed its work on one side to fill the clearance and cushion on the
other. Said pass-ports also act as inlet or steam ports, and, together with the
aforesaid double live-steam ports, make it a triple-port steam-valve, as hereinafter
fully described, reference being made to the accompanying drawings, in which-
Figure 1 is a longitudinal sectional elevation through a piston, valve-cylinder,
and engine-ports, illustrating my invention of double steain and exhaust-ports.
The section is taken on line 3-3, Figs. 3 and 4.
Fig 2 is a diagram of the surface of one section of the valve of Fig. 1 explained
in a plane.
Fig. 3 is a plan of the steam end of the valve.
Fig. 4 is a plan of the exhaust end.
Fig. 5 is a transverse section of the valve on line 1-1, Fig. 1; and Fig. 6 is a
section of the same on line 2-2, Fig. 1.
Fig. 7 is a longitudinal section of the double-ported steam and exhaust valve,
also provided with the over passports for filling the clearance and giving the
cushion on one side by the steam that has done its work on the other side, said
section being half on I K and half on K L, Figs. 8 and 9.
Fig. 8 is a half section on A B and a half section on C D, Fig. 7 ;
Fig. 9 is a half section G H and half section on E F, Fig. 7.
and
Fig. 10 is a longitudinal section of the valve, showing the pass ports arranged.
for triple steam-ports only.

page_text: There are two ports a and to the steam-way of each end of the engine-cylinder,
both extending around the valve-cylinder d, surrounding the valve e, and also being
in communication through passage c in the valve cylinder.
The valve is a piston of two sections located apart from each other along the rod,
to which both sections are coupled a suitable distance to provide requisite space for
the exhaust-way between them. It receives the live steam on the outer ends, and
the steam exhausts between the adjacent ends of the two sections. Besides
admitting steam directly from the ends into ports a, the valve has cored live-steam
passages in each section from the steam end communicating with the auxiliary
steam-port g through the side of the valve and opening to cylinder-ports b, where
the steam end of the valve opens to cylinder-ports a, and besides exhausting from
ports, at the inner or exhaust ends, the valve also has cored exhaust-passages h
from said ends communicating with the auxiliary exhaust-ports i through the side,
which open to cylinder-ports a, where the exhaust ends of the valve open cylinder-
ports to the exhaust-passagej. These live and exhaust steam passages and h
cross or overlap each other in the valve suitably to admit the live steam from the
steam end of the valve to the steam-ports through valve-port g, past the exhaust
port of the valve, and to allow the exhaust steam to escape from port a through
valve-port i past the steam-ports y, and out at the exhaust end of the exhaust-
passage. Both end sections are constructed alike and together distribute the
steam for both ends of the engine-cylinder. In Figs. 1 to 6, inclusive, I have
represented three of these overlapping passages for live and exhaust steam, each
in both sections of the valve, but may of course have more or less, as desired. In
Figs. 7 to 9, inclusive, I have represented four of each, besides the pass-ports
described farther on.
22
"
It will be understood that the live steam may be received at the middle space
and the exhaust delivered from the outer ends of the valve as well, if desired, the
operation being the same, the only difference being the proper change in the
angular position of the eccentric, although in such case it will be better to reverse
the conditions of the ports a b and gi as to their areas. I also propose to provide
what I will call ". over-pass or simply "pass-ports," which may be single, but are
also double as I have arranged them herein, and I class them as "outer and
"inner" passports, as above stated, for filling the clearance and cushioning the
piston on one side by the steam that has done its work on the other side. I repre-
sents the inner and m the outer pass-ports. They all communicate with the central
passage in the valve and bring instant communication between both ends of the
engine-cylinder just as compression commences on one side and directly before the
beginning of exhaust on the other side. For the purpose of these ports the valve
is necessarily made with inside or exhaust lap, which it may have or not, as desired,
so far as the rest of the invention is concerned, the said lap being equal to or
slightly greater than the length of the pass-ports in order that they shall always be
out of communication with the exhaust-ports.
The inner pass-ports are located behind or inside of and in the same range with
the inlet-ports g and have about the same shape, and the outer pass-ports have the
same relation to the exhaust-ports i. It will be seen that the arrangement is such
that at the moment when the inlet takes place neither the outer nor inner pass-ports
on the opening side are quite covered, so that for a short time they act as live steam
inlets also, and thus it is a triple-port inlet-valve as well, which with double
exhaust and double pass-ports makes it feasible to reduce the diameter and stroke
considerably as compared with ordinary piston-valves. It is in most cases desirable
to have the period of communication with both ends of the cylinder through these
pass-ports short as possible, but at the same time as effective as possible, which, it
will be seen, is greatly facilitated by the arrangement of double pass-ports,
especially as the actual opening only amounts practically to half the length of said
ports, for as they are opening on one side they are closing on the other-the
exhaust side-where the exhaust opens the moment the pass-port is closed.
It is to be noted that I have arranged the side ports and the pass-ports to extend

page_text: entirely around the valve, so that the length of the opening lines is correspondingly
increased and the size and length of stroke of the valve are reduced to the
minimum, and with this I have also constructed the lateral openings of the passage
into the respective ports in the flaring shape merging in said circumferential ports,
so as to render the whole of the circumferential lines of the ports available for
effective work. I may utilize these pass-ports for the triple steam-port only by
arranging them, as I have represented in Fig. 10, so far out in the lap that no
communication takes place between the ends of the cylinder.
In Figs. 7 and 10 the inner ends of the casing of passage k are fitted with a
ring y to confine them securely. 2 in Figs. 1 and 3 represents eyelets for hooking
into for lifting out the valve.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is:
1. The combination, with the valve-casing having double ports to each end of
the cylinder, of the piston-valve having the middle space and inner and outer ports
through the side between the middle space and each ends, with longitudinal
passages from the ends to the inner side ports, and other longitudinal passages
from the middle space to the outer ports and intermediate to and crossing or over-
lapping the passages from the outer ends to the inner side ports, and thus forming
a double-ported steam and exhaust valve.
2. The combination, with the valve-casing having double ports to each end of
the cylinder, of the piston-valve having the middle space and inner and outer ports
through the side and extending around the valve between said middle space and
each end, with longitudinal passages from the ends to the inner side ports, and
other longitudinal passages from the middle space to the outer side ports and inter-
mediate to and crossing or overlapping the passages from the outer ends to the
inside ports, said longitudinal passages having the flaring lateral openings from
between the overlapping passages into the said circumferential ports, substantially
as described.
3. The combination, with the valve-casing having double ports to each end of
the cylinder, of the piston-valve having the middle space and inner and outer side-
ports and the pass-ports through the side between said middle space and each end,
with longitudinal passages from the ends to the inner side ports, and other longi-
tudinal passages from the middle space to the outer side ports, and the central
longitudinal space connecting the pass-ports, the said passages of the inner and
outer side ports being intermediate to and crossing or overlapping each other, and
the central passage having lateral openings into the pass-ports intermediate to the
longitudinal passages from the end of the valve to the inner side ports.
4. The combination, with the valve-casing having double ports to each end of
the cylinder, of the piston-valve having the middle space and inner and outer side
ports and the pass-ports through the side and extending around the valve between
said middle space and each end, with longitudinal passages from the ends to the
inner side ports, and other longitudinal passages from the middle space to the outer
side ports, and the central longitudinal space connecting the pass-ports, the said
passages of the inner and outer side ports being intermediate to and crossing or
overlapping each other, and the central passage having lateral openings into the
pass-ports intermediate to the longitudinal passages from the ends of the valves to
the inner side ports, and all of said passages having the flaring lateral openings
into the said circumferential ports, substantially as described.
5. The combination, with the valve-casing having double ports to each end of
the cylinder, of the piston-valve having the middle space and inner and outer side
ports and inner and outer pass-ports through the side between said middle space
and each end with longitudinal passages from the ends to the inner side ports, and
other longitudinal passages from the middle space to the outer side ports, and the
central longitudinal space connecting the pass-ports, the said passages of the inner

page_text: and outer side ports being intermediate to and crossing or overlapping each other,
and the central passage having lateral openings to the outer pass-ports intermediate
to the longitudinal passages from the ends of the valve to the inner side ports,
and lateral openings to the inner pass-ports behind said passages from the ends to
the inner side ports and between the passages from the middle space to the outer
side ports.
6. The combination, with the valve-casing having double ports to each end of
the cylinder, of the piston-valve having the middle space and inner and outer side
ports, and the pass-ports through the side between said middle space and each end,
with longitudinal passages from the ends to the inner side ports and other longi-
tudinal passages from the middle space to the outer side ports, and the central
longitudinal space connecting the pass-ports, and thus being a triple steam and
double exhaust valve, substantially as described.
D
1 1
1001
J. P. BAYLY.
Per P. W.,
Applicant.