Improvements in Valves for Steam Engines.
Year: 1891

page_text: Date of Application, 16th Sept., 1891
Complete Specification Left, 1st June, 1892-Accepted, 9th July, 1892
PROVISIONAL SPECIFICATION.
Improvements in Valves for Steam Engines.
I JAMES ADAMSON of 166 Bolton Road Elton, Bury, in the County of Lancaster
Engineer do hereby declare the nature of this invention to be as follows:-
This invention relates to the construction of the valves employed for regulating
the admission of steam to, and the exhaustion of steam from the cylinders of steam
engines, the object of the invention being to construct a valve for this purpose on
the continuous revolving type whereby the motion of the valve not having to be
arrested and reversed at each end of the stroke, there is less vibration and less wear
and tear of the working parts of the invention.
For the purposes of my invention I make the valve box of a cylindrical form and
the valve facing at one end thereof. In the centre is a circular recess from which
the exhaust passage leads, and on each side is a concentric curved port or passage
leading to the ends of the cylinder.
It is
The valve consists principally of a circular plate packed round the edge so as to
revolve steam-tight in the cylindrical box, and ground to fit the facing.
provided with curved exhaust ports near the centre, and two concentric steam ports
outside the same.
At the back of this plate is cast on a "dee" somewhat like that of an ordinary
slide valve, but this "dee" is cast on excentric, and is of such a diameter that it
embraces one steam port and both exhaust ports, leaving the other steain port a
clear opening through the plate ouside the "dee" for the admission of steam.
This valve is keyed on the end of a valve rod or shaft which passes out through
a stuffing box in the valve box cover and a continuous rotary motion is given
thereto by means of bevil gearing from the main shaft of the engine.
.It will be evident that. as the valve revolves, the open steam port will be brought
alternately, over the two ports in the facing and thus admit steam first to one end
and then to the other end of the cylinder, and at the same time the opposite port
will, by means of the excentric "dee” be put into communication with the exhaust
passage.
This valve may be made to work expansively by means of a "cut-off" plate
working over the back of the valve. This plate will be made with one curved
opening.only and will be mounted on a tubular shaft or sleeve working outside the
valve shaft and driven in the opposite direction by an additional bevil wheel; and
by setting this, plate so that its opening is more or less in advance of the admission
port of the main valve, it can be made to "cut-off" steam at any desired portion of
the stroke.
Job... 1001
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Valves for Steam Engines.
I JAMES ADAMSON of 166 Bolton Road, Elton, Bury in the County of
Lancaster, 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 :—
This invention relates to the construction of the valves employed for regulating.

page_text: the admission of steam to, and the exhaustion of steam from, the cylinders of steam
engines, the principal object of the invention being to construct a valve for this
purpose of the continuous revolving type whereby the motion of the valve and its
adjuncts not having to be arrested and reversed at each end of the stroke of
the piston there is less vibration, and less wear and tear of the working parts of the
engine.
The nature of my said invention and the manner in which the same is to be
performed or carried into practical effect will be readily understood on reference to
the sheet of drawings hereunto annexed and the following explanation thereof.
Fig. 1 on the drawings shows a partial vertical section and Fig. 2 a horizontal
section of the valve box and cylinder of a steam engine showing clearly the
application of my invention thereto, and Figs. 3 and 4 are similar views illustrating
a modification of the "cut-off" arrangement. Fig. 5 is a detached view of the
cylinder facing, and Fig. 6 a face view of my improved revolving valve.
a is the engine cylinder, the piston, and c the piston rod. d is the valve box
which for the purposes of my invention I make of a cylindrical form, having at one
end the valve facing with the exhaust passage f in the centre, and on each side a
concentric curved port or passage 9, 9x, leading to the ends of the cylinder a as
shown at detached view of the facing Fig. 5.
The improved valve consists principally of a circular plate h packed round the
edge so as to revolve steam-tight in the cylindrical box d and ground to fit the
cylinder facing.
It is provided on the face with a "dee" or recess somewhat like that of an
ordinary slide valve, but this "dee" is cast or formed excentric (see Fig. 6) and is
of such a diameter that it embraces the central exhaust port and one of the steam
ports g, leaving the other steam port a clear opening through the plate at h*
outside the "dee" for admission of steam.
This valve is keyed upon the end of the valve rod or shaft which passes out
through a stuffing box in the valve box cover, and a continuous rotary motion is
given thereto by means of the bevil wheels m and m', the latter of which is keyed
ou a line shaft driven by bevil gear from the main shaft of the engine.
It will be evident that as the valve h revolves, the open steam port h* will be
brought alternately over the two ports g and gx in the facing, and thus admit steam
first to one end, and then to the other end, of the cylinder a and at the same time
the opposite port will by means of the excentric "dee" i be put into communication
with the exhaust passage f.
This valve may be made to work expansively by means of a "cut-off” plate o
working over the back of the valve h (Figs. 1 and 2).
This plate o will be made with one curved opening o* only, and will be mounted
on a tubular shaft or sleeve p working outside the valve shaft k and driven in the
opposite direction by an additional bevil wheel m² (Fig. 2) and by setting this
plate
o so that its opening is more or less in advance of the steam admission
port of the main valve h, it can be made to "cut-off" the steam at any desired
portion of the stroke.
I find it however preferable, instead of giving the "cut-off" plate o a continuous
revolving motion as above described, to give an alternate rotary motion thereto by
the means shown at Figs. 3 and 4.
In this case the "cut-off" plate o is made with two curved openings o* instead of
one (see Fig. 3) and its oscillation is produced by mounting on its sleeve pa
lever q, one end of which is attached to a coiled or other spring r, and the other
acted upon by a revolving tappet or "wiper" 8, keyed on a short counter-
shaft which may be driven by bevil gear u from the line shaft n as shown at
Fig. 4.
By this alternate arrangement, as soon as the lever q escapes from the end of the
tappets, the spring works the "cut-off" instantaneously.
Having now particularly described and ascertained the nature of my said

page_text: invention and in what manner the same is to be performed I declare that what
I claim is :-
The construction and use in combination with a central exhaust passage and
between two concentric curved steam ports, of a circular continuously revolving
valve formed with an excentric recess or "dee" and a concentric curved opening or
steam port substantially as herein before described and illustrated by the drawings
annexed.
Secondly. I claim the combination with a continuously revolving circular valve
(of the type herein before described) of a circular "cut-off" plate provided with a
single curved opening or port and caused to revolve continuously in the opposite
direction to the valve as hereinbefore described and illustrated, and
Thirdly. I claim the combination with a continuously revolving circular valve
(of the type hereinbefore described) of a circular "cut-off" plate provided with two
curved openings or ports and caused to oscillate or partially revolve in alternate
directions by means of a lever acted upon by a tappet or "wiper" and re-acted
upon by a spring substantially as hereinbefore described.
Dated this 31st day of May 1892.
GEO. DAVIES & SON,
4, St. Ann's Square, Manchester, Agents for the Applicant.