Improvements in the Arrangement of the Valves and in the Ad- mission of Steam or other Fluid Under Pressure to Engines in which Double Faced Tapered Slide Valves are Employed.
Year: 1898

page_text: Date of Application, 27th Oct., 1898
Complete Specification Left, 27th July, 1899-Accepted, 7th Oct., 1899
Improvements in the Arrangement of the Valves and in the Ad-
mission of Steam or other Fluid Under Pressure to Engines in
which Double Faced Tapered Slide Valves are Employed.
I, JOHN WILLIAM MELLING, of 82, Swinley Road, Wigan, in the County of
Lancaster, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to improvements in the arrangement of the valves and in
the admission of steam or other fluid under pressure to engines in which double
faced tapered slide valves are employed in conjunction with expansion or cut off
valves and one object of my improvements is to limit as much as possible the area
of the main valves and steam chest exposed to the high pressure or live steam.
My improvements consist chiefly in admitting the high pressure or live steam
(by which I include other fluids under pressure) to that part of the main valve
or valves which is ordinarily used for the exhaust steam and in applying a cut
off valve or valves of any suitable type to control the admission of steam to this
part, and consequently to the cylinder.
In carrying my improvements into effect I admit the live steam through the
cut off valve directly through the double faced tapered slide valve to the ports
leading to the steam cylinder, and I exhaust through these ports back into the
chest which is usually filled with live steam.
In this way I reverse the usual practice and obtain dead or low pressure steam
in the steam chest instead of high pressure steam as heretofore.
Dated this 26th day of October 1898.
H. B. BARLOW & GILLETT,
Agents for Applicant.
Improvements in the Arrangement of the Valves and in the Ad-
mission of Steam or other Fluid Under Pressure to Engines in
which Double Faced Tapered Slide Valves are Employed.
-
I, JOHN WILLIAM MELLING, of 82, Swinley Road, Wigan, 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:-
My invention relates to improvements in the arrangement of the valves and in
FD 77

page_text: the admission of steam or other fluid under pressure to engines in which double
faced tapered slide valves are employed in conjunction with expansion or cut off
valves and one object of my improvements is to limit as much as possible the area
of the main valves and steam chest exposed to the high pressure or live steam.
My improvements consist chiefly in admitting the high pressure or live steam
(by which I include other fluids under pressure) to that part of the main valve
or valves which is ordinarily used for the exhaust steam and in applying a cut
off valve or valves of any suitable type to control the admission of steam to this
part, and consequently to the cylinder.
In carrying my improvements into effect I admit the live steam through the
cut off valve directly through the double faced tapered slide valve to the ports
leading to the steam cylinder, and I exhaust through these ports back into the
chest which is usually filled with live steam.
In this way I reverse the usual practice and obtain dead or low pressure steam
in the steam chest instead of high pressure steam as heretofore.
In the accompanying two sheets of drawings-
Fig. 1 is a side elevation of a steam cylinder to which my improved arrange-
ment of valves is applied, Fig. 2 a sectional plan on the line A B, Fig. 1, and
Fig. 3 a sectional end view on the line C D, Fig. 1.
Fig. 4 is a side elevation of a modified arrangement in which I employ a
separate valve and casing for each end of the cylinder, Fig. 5 is partly a plan and
partly a sectional plan on the line E F, Fig. 4, and Fig. 6 is a sectional view on
the line G H, Fig. 4.
In the arrangement illustrated in Figs. 1, 2 and 3 a single main valve is
employed to admit steam to both ends of the cylinder.
In these views,--2 designates the cylinder, 3 the admission pipe for steam, 4
the exhaust pipes, 5, 5 the cut off valves which may be of any convenient type
and are contained in a valve box or casing 6 from which is a port G" for each
valve 5 to conduct the steam to one or other of two passages 7, 8, through a main
valve 9 which is divided by a rib 10; this main valve 9 opens and closes alter-
nately ports 11 leading to both ends of the cylinder 2.
The valve 9 is a double faced tapered slide valve as shown in Fig. 3, being
widest at its upper end; at its narrow end it rests upon a facing 12 which may be
adjustable, and the valve is adjusted by a loose piece 13 held down by screws 14
and it is operated in the ordinary or in other convenient manner through a
spindle 15.
In the face 16 of the valve box 6 are formed two recesses 17 opposite the
ports 11, and steam is admitted from the ports through holes 18 in the valve 9,
in order to aid in balancing this valve.
In operation steam is admitted through the pipe 3 into the valve box or
casing 6, from which it passes alternately into the passages 7 and 8 of the main
valve 9, as illustrated in Fig. 2, where the steam pressure is through the passage 8
on the facing of the cylinder and valve casing and will be admitted to the
cylinder 2 through the right hand port 11 when the main valve 9 is moved to
open communication between 8 and 11, at the same time the port 11 at the other
end of the cylinder will be closed against 7 and opened to allow the exhaust
steam to pass into and away through the exhaust passage 4.
In Figs. 4, 5 and 6 my improvements are shown applied to two of the valves 9
one at each end of the cylinder. In this case steam is admitted from the steam
pipe 3 into the valve chest 6 of the cut off valve 5 from which it passes into the
passage through the opening 8 in the main valve into the port 11 and so to
the end of the cylinder 2; and when the main valve 9 in its return movement
partially uncloses the port 11 the exhaust passes away through the exhaust
passage 4.
The valves are duplicated at the other end of the cylinder as indicated in
Figs. 4 and 5.
Any convenient type of cut off valves may be employed, a special feature of

page_text: my invention being to reduce the area of the valve 9 and the valve chest 6 upon
which the high pressure steam acts and thereby materially reduce the tendency
of the valve chest to spring away from the cylinder, and also reduce the wear on
the valve and the faces against which it works, and in this manner much less
power is required to move the valve 9 as compared with the ordinary slide valve.
It will be readily understood that my improvements are equally applicable to
double faced tapered slide valves which admit steam to the cylinder at both sides
simultaneously whether such valves are placed parallel with the axis of the
cylinder or radially or in any other position.
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:-
•
In a steam engine fitted with a double faced tapered slide valve or valves in
conjunction with expansion or cut off valves:-
--
The herein described combinations and arrangements of parts whereby live
steam is admitted through the cut off valve directly through the double faced
tapered slide valve to the ports leading to the steam cylinder and the exhaust
steam passes back through these ports into the valve chest which is therefore
filled with dead or low pressure steam instead of high pressure or live steam as
hitherto customary.
Dated this 26th dow of Tul 1000
H. B. BARLOW & GILLETT,
Agents for Applicant, 17, St. Ann's Square, Manchester.