An Improved Automatic Balanced Slide Valve for Motive Power Engines.
Year: 1891

page_text: Date of Application, 19th June, 1891
Complete Specification Left, 11th Mar., 1892-Accepted, 9th Apr., 1892
PROVISIONAL SPECIFICATION.
An Improved Automatic Balanced Slide Valve for Motive Power
Engines.
1, PETER WRIGHT of 20 Eleanor Street, South Shields in the County of
Durham First Class Marine Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention relates to that class of slide valve for motive power engines in
which the frictional contact of the slide valve with the cylinder face is relieved
by means of a balance cylinder and piston fitted within the steam chest.
My improvement consists in giving to the piston of the balance cylinder a
positive motion within the balance cylinder at every traverse of the slide valve
so that the piston cannot become set or stick fast within its cylinder in the
manner which frequently happens in balance cylinders in which the piston occupies
constantly the same place in its cylinder.
For this purpose I make the surface at the interior of the steam chest cover
or partition upon which the balance cylinder slides inclined to the cylinder face
upon which the slide valve traverses so that during the traverse of the slide valve
the piston of the balance cylinder formed upon the slide valve enters more or less
into the balance cylinder according to the position taken up by the balance
cylinder upon the inclined plane upon which it moves to follow the movement of
the slide valve.
it
To keep the balance cylinder in contact with the inclined plane upon which it
slides I provide a small piston extending centrally within the balance cylinder and
entering a cylindrical bore in the piston of the balance cylinder formed upon the
slide valve. The said small piston and cylinder may be replaced by a spiral spring
held between the base of the balance cylinder and the back of the slide valve by
projecting piece at the back of the slide valve centrally placed to enter the spiral
spring and hold it in position. In order to avoid damage to the balance cylinder
by the positive movement of the piston therein in case of breakage of the said
spiral spring secure within the balance cylinder a guard in which pieces of the
spring would be held in case of breakage.
The base of the balance cylinder is perforated to provide for the passage by way
of a drain cock of any steam or other motive power gas or fluid which may pass
between the piston and the balance cylinder.
Dated this 19th day of June 1891
AYRTON & THOMAS,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improved Automatic Balanced Slide Valve for Motive Power
Engines.
1 PETER WRIGHT of 20 Eleanor Street, South Shields in the County of
Durham First Class Marine 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 that class of slide valve for motive power engines
in which the frictional contact of the slide valve with the cylinder face is
relieved by means of a balance cylinder and piston fitted within the steam chest.
My improvement consists in giving to the piston of the balance cylinder a
1 Loire 27

page_text: positive motion within the balance cylinder at every traverse of the slide valve
so that the piston cannot become set or stick fast within its cylinder in the
manner which frequently happens in balance cylinders in which the piston occupies
constantly the same place in its cylinder.
The following is a description of my invention reference being made to the
accompanying drawings in all the figures of which the same part is indicated by
like reference letters.
Figure 1 is a side view in section of a steam chest and part of a steam cylinder
to which it is applied.
Figure 2 is a plan view of Figure 1.
Figure 3 is a side view of a steam chest partly in section showing the application
of a spring to tend to separate the balance cylinder and its piston.
Figure 4 is an end view partly in section of a steam chest and part of a steam
cylinder to which it is applied.
Figure 5 is a plan of Figure 4 showing the steam chest cover removed.
I make the surface at the interior of the steam chest cover or partition A upon
which the balance cylinder 1 slides, inclined to the cylinder face upon which the
slide valve C traverses, so that during the traverse of the slide valve C the piston D
of the balance cylinder B formed upon the slide valve Centers more or less into
the balance cylinder B according to the position taken up by the balance cylinder B
upon the inclined plane represented by the cover or partition A upon which it
moves to follow the reciprocating movement of the slide valve C.
To keep the balance cylinder B in contact with the inclined plane A upon which
it slides provide a small piston E extending centrally within the balance
cylinder B and entering a cylindrical bore in the piston D formed upon the slide
valve C.
Any steam or other motive power gas or fluid pressure which would otherwise
accumulate in the balance cylinder by leakage past the piston rings is relieved by
the drain cock F communicating by a passage G with the apertures H in the base
of the balance cylinder B.
Instead of keeping the balance cylinder B in contact with the inclined plane A
by means of the fluid pressed piston E a spiral spring J may be interposed between
the base of the balance cylinder B and the piston D and held in position by suitable
projections K K cast upon the base of the balance cylinder B and upon the
piston Das shown in Figure 3. In order to avoid damage to the balance cylinder B
by the positive movement of the piston D therein, in case of breakage of the spiral
spring secure within the balance cylinder B a guard L in which any pieces of
the spring would be held in case of breakage.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed declare that what I
claim is
1. A slide valve provided with an automatic balance cylinder for relieving the
pressure of contact of the valve with the valve seating the plane of traverse of the
balance cylinder being inclined to the plane of traverse of the slide valve sub-
stantially as and for the purpose described.
2. In a slide valve provided with an automatic balance cylinder for relieving the
pressure of contact of the valve with the valve seating the subsidiary gas or fluid
pressed piston E tending to expel the piston D from the balance cylinder B under
varying conditions of stopping starting or running the engine substantially as
.described.
3. The guard L in combination with the piston D of a slide-valve-balance-
cylinder substantially as and for the purpose described.
This Mul f\LL 1000
AYRTON & THOMAS.