Improvements in Piston-valves for Steam and other Engines.
Year: 1889

page_text: Date of Application, 31st Aug., 1889
Complete Specification Left, 27th May, 1850-Accepted, 28th June, 1890
PROVISIONAL SPECIFICATION.
Improvements in Piston-valves for Steam and other Engines.
I, WALLACE FAIRWEATHER, C.E. of 62 Saint Vincent Street, in the City of
Glasgow, Registered Patent Agent and Fellow of the Institute of Patent Agents, do
hereby declare the nature of this invention (a communication to me from abroad by
JAMES MKECHNIE, presently residing at Bilbao in the Kingdom of Spain) to be as
follows:-
The improved piston valve constituting this invention is composed of a hollow
annular casing in section resembling an ordinary D-slide valve but having a
port face in the form of a cylinder enclosing an annular steam space and being open
at the central part which serves as an exhaust passage to the atmosphere or condenser.
The piston valve reciprocates in a closed cylindrical chamber formed on the engine
cylinder or between the cylinders and its central open part to which an actuating rod
is attached is separated by a cylindrical web or partition from the steam space which
is formed between said partition and the cylindrical port face or shell of the piston
valve, the partition joining the shell at its ends where it is fitted with packing rings.
In the movement of the valve the ends of the piston cover and uncover the steam
ports leading to the ends of the cylinders to which the piston valve is applied, whilst
the ports for the steam inlet from the boiler or steam casing in the valve chamber or
cylinder placed intermediate between the first mentioned steam ports are covered and
uncovered by the shell of the piston valve in which ports opening to the annular steam
space are formed.
Steam or other fluid admitted by the cylinder ports from the steam inlet or casing
passes through the ports in the shell of the piston valve to the annular steam space is
thence distributed through ports at either end to the steam passages leading to the
ends of the cylinder one passage receiving steam in this way whilst the other is
uncovered by the valve and exhausts to the open central part of the piston. The
course of the steam or other fluid may however be reversed the central part of the
piston serving as the steam casing and the exhaust passage being formed intermediate
between the steam ports in the cylinder in the usual way.
The weight of the piston valve is or may be supported by means of a small piston
attached to the actuating rod and working in a small cylinder in the end of the valve
chamber.
Dotad this Think th
L 1000
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow, Agents.
COMPLETE SPECIFICATION.
Improvements in Piston-valves for Steam and other Engines.
I, WALLACE FAIRWEATHER C.E. of 62 Saint Vincent Street, in the City of
Glasgow, Registered Patent Agent and Fellow of the Institute of Patent Agents, do
hereby declare the nature of this invention and in what manner the same is to be
performed, as communicated to me to be particularly described and ascertained in
and by the following statement :-
The improved piston valve constituting this Invention and which is represented in
vertical section at figure 1 and in cross section at figure 2 of the accompanying
drawings is composed of a hollow annular casing, in section as seen at figure 1
resembling an ordinary D-slide valve but having a port face A in the form of a
cylinder enclosing an annular steam space B, and being open at the central part C,
I Price Gd1

page_text: which serves as an exhaust passage to the atmosphere or condenser. The piston valve
reciprocates in a closed cylindrical chamber D, formed on the engine cylinder or
between the cylinders and its central open part to which an actuating rod C¹³, is
attached is separated by a cylindrical web or partition E from the steam space which
is formed between said partition and the cylindrical port face or shell A of the piston
valve, the partition E joining the shell at its ends where it is fitted with packing
rings F. In the movement of the valve the ends of the piston cover and uncover the
steam ports g, g, leading to the ends of the cylinders to which the piston valve is
applied, whilst the ports h, h, for the steam inlet from the boiler or steam casing in
the valve chamber or cylinder placed intermediate between the first mentioned steam
ports g, 9, are covered and uncovered by the shell A of the piston valve in which
ports i, i, i opening to the annular steam space B are formed.
Steam or other Huid admitted by the cylinder ports g, g, from the steam inlet or
casing passes through the ports i, i, in the shell of the piston valve to the annular
steam space B, is thence distributed through the ports i, i at either end to the
steam passages 9, 9, leading to the ends of the cylinder one passage receiving steam
in this way whilst the other is uncovered by the valve and exhausts to the open
central part of the piston from which it passes by the pipe M. The steam retained
within the annular space in the valve after steam has been cut off enters the cylinder
as the piston is moving towards the end of its stroke and acts as compression. The
course of the steam or other fluid may be reversed the central part of the piston
serving as the steam casing and the exhaust passage being formed intermediate
between the steam ports in the cylinder in the usual way.
The weight of the piston valve is or may be supported by means of a small
piston K, attached to the actuating rod C, and "working in a small cylinder L in the
end of the valve chamber.
Having now particularly described and ascertained the nature of the said Inven-
tion and in what manner the same is to be performed (as communicated to me)
I declare that what I claim is :-
:-
A piston valve for steam or other engines constructed and arranged to operate
substantially as described.
Di
· 11 1
1000
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow, Agents.