Improvements in Balanced Slide-valves.
Year: 1888

page_text: Improvements in Balanced Slide-valves.
I GEORGE WASHINGTON CISCO, of Montvale, in the county of Bergen, and State of
New Jersey, United States of America, Engineer do hereby declare the nature of my
invention for IMPROVEMENTS IN BALANCED SLIDE-VALVES, and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement and accompanying drawings:-
This invention relates to slide-valves, and more particularly to that class of slide-
valves employed on railway-locomotives.
The object is to produce a slide-valve which shall be so constructed that the friction
and consequent wear of the parts while working will be greatly reduced, if not
entirely overcome; furthermore, to produce a slide-valve in which steam leakage will
be obviated, thus rendering frequent packing of the stuffing-boxes unnecessary ;
furthermore, to produce a slide-valve in which but a very small proportion of the
steam-power will be lost from condensation of the steam; and finally, to produce a
slide-valve which shall be simple of construction, efficient and durable in use, and
comparatively inexpensive of production.
Heretofore slide-valves as constructed have been defective in that the steam,
entering from the top of the chest, presses on the valve and tends to grind it upon its
seat, and thus create a large amount of friction also in rushing from one port to
another to lift the valve froin its seat, causing it to press the valve-stem against the
stuffing-box, resulting in uneven wear. Furthermore, the large amount of space in the
steam-chest tends to facilitate the rapid condensation of steam, a very troublesome
feature and one that is a source of constant annoyance to engineers.
It is the object of the present invention to overcome the objections by doing away
with all of the space in the steam-chest not actually employed by the valve and in con-
structing a steam-chest in which only the amount of steam requisite to drive the
engine will be admitted; furthermore, to supply means for the escape of the
;

page_text: condensed steam at all times without the necessity of the engineer having to attend
to it.
With these objects in view the invention consists in the combination, with the
cylinder, of a valve-chest seated thereon, and having suitable openings formed in the
bottom to allow the steam to enter the cylinder, and an opening for the escape of
the exhaust-steam; furthermore, in the combination, with the said valve-chest, of a
sliding valve designed to fit within and move upon the bottom of the valve-chest, and
having openings corresponding to those in the valve-seat, whereby upon each stroke of
the piston the valve will be made to open and close the parts alternately, and thus
supply the steam to the cylinder at proper intervals; furthermore, in the combination,
with the said valve-chest, of a bonnet or plate secured thereto and designed to hold the
slide-valve in position within the said chest ; furthermore, in the combination, with
tho slide-valve of a valve-stem connected therewith and extending to and connecting
with the crank-levers operated by the piston, whereby the said valve may be made to
perform the function for which it is designed; and, finally, in the various novel details
of construction whereby its objects are attained.
In the accompanying drawings, forming part of this specification, like letters of
reference indicate corresponding parts wherever they occur.
Figure is a perspective view of the valve-chest with the top and one side removed,
showing the arrangement of the ports.
Figure 2 is a perspective view of the slide-valvo, also showing the arrangement of
the ports.
Figure 3 is a vertical sectional view of the valve, showing the openings for the bolts
used in securing the valve-stem in position.
Figure 4 is a top plan view of the same, showing the grooves for supplying oil to the
valve-seat.
Figure 5 is a top plan view of the bonnet or plate for holding the valve in place.
Figure 6 is a side elevation of one of the sides of the valve-chest.
Figure 7 is a side elevation of the valve-stem.
Figures 8, 9, 10, 11, and 12 are detail views of various parts of the apparatus, which
will be described as they occur in the specification..
Figure 13 is a side elevation showing the apparatus put together.
Figure 14 is a sectional detail view of the end of the head of the valve-stem, and
Figure 15 is a vertical sectional view of the device with the parts assembled.
Referring to the drawings, A designates the valve-seat, which is to be placed on the
cylinder, and held securely thereon by means of bolts or screws. In the bottom of
this valve-seat, and preferably at its center, are formed, either in casting or otherwise,
a number of longitudinal openings, aa a², the openings a a² being designed as ports,
through which the steam escapes to the cylinder below, and the opening a¹ an
exhaust-port. At a point opposite the ports, and in the side a of the valve-chest, are
two openings, a³ a, through which the steam from the boiler enters.
The openings
are placed in this position in order that when the ports are opened the steam may pass
directly to the cylinder. thus preventing condensation and consequent loss of power.
B designates the slide-valve, the under face of which has slots cut therein
corresponding to those in the valve-seat. The inner portion is cut away, as shown
in in Figure 3, to form steam-rooms, and are closed at the sides by means of
plates and which are also provided with openings 6, to correspond to the
openings a³ and a' in the water-chest.
C designates the bonnet or plate for holding the valve in place. The center portion
has an opening, c, formed therein, which, when in position, is directly over the bolt-
holes 01612 in the valve.
E designates a block, designed to be secured to the valve by means of bolts, which
engage the bolt-holes and which move in the opening C, formed in the bonnet.
F designates a side of the valve-chest, made removable in order to allow easy access
to its interior should it be necessary to clean or repair it.
All of the various ports are made to fit with precision, while at the same time having
sufficient play to prevent any danger of binding of friction.

page_text: The manner of putting together and connecting the various parts is as follows:
The slide-valve B is placed in the valve-chest with the openings opposite each other.
The bonnet or plate C is then put on top of the valve, being held in place by the
flanges B2 on the upper portion of the chest. Bolts c are then screwed into the
openings in the flanges and force the bonnet against the valve to also keep it seated'
snugly on the valve-seat. The side F is then placed in position and serves to hold the
bonnet in place. The block E is then placed on the top of the valve, and the bolt G
is screwed to its seat, thus securely clamping the block to the valve. A plate, H, is
then placed over the flange c¹ of the bonnet. This plate has an opening h, through
which the head of the bolt G extends, and also openings h¹², through which smaller
bolts extend, and are screwed into the block E. These last-named bolts are headless,"
and are only screwed-threaded at that portion which enters the block, the upper portions
being smooth in order to allow the plate H to be removed without the necessity of
removing them. The valve-stem is then placed in position, the head of the bolt G
extending through the valve-stem, the bolts h² engaging depressions d in the bottom,
to prevent the valve-stem from turning to one side from the violent racking and
jarring incidental to the running of the engine. A wedge-shaped pin, I, is then
driven through an opening y, in the head of the bolt G, thus securely holding it in
place.
It is designed that this valve should prevent the tendency so common in all slide-
valves to allow the accumulation of condensed steam; but it will be impossible to
prevent entirely this evil, as the steam will inevitably become slightly cooled in passing
from the boiler to the valve-chest. It has been found that the larger the amount of
water in the steam-chest is the quicker the condensation of the steam, and as the
ordinary steam-chests are not provided with other means for getting rid of the
surplus water than by forcing it into the atmosphere by means of a petcock, and
as this has a tendency to lower the supply of steam to the cylinder, engineers often
allow a large amount of water to accumulate before they blow it out. In this
invention this obstacle is obviated in a large degree by having small channels a* cut in
the sides of the bottom of valve-chest, through which the condensed steam may escape
as fast as made.
When it is desired to oi! the valve while the engine is in motion, it is only necessary
to open the cock J on the bonnet and pour in the oil, which will immediately pass
down and out through the grooves, and thus lubricate the entire valve and valve-
seat.
Should the valve become worn to such an extent as to allow the escape of steam,
the bolts which engage threaded openings 613 in the flange B of the chest and
bear upon the valve, are turned down enough to take up the wear and render the valve
steam-tight.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. The combination of a valve-chest having openings for the entrance and escape of
steam, a valve fitting and sliding therein and having openings curresponding to those
in the chest, and a bonnet fitting under the flanges on the steam-chest and resting
upon the valve, whereby the said valve will be held in place in the chest, substantially
as described.
2. The combination of a valve-chest having openings for the entrance and escape
of steam, a valve fitting and sliding therein and having openings corresponding to
those in the chest, a bonnet fitting thereon and provided with an opening, and a block
secured to the top of the valve and moving in the opening in the bonnet, substantially
as and for the purpose set forth.
3. The combination of a valve-chest. having suitable openings for the admission
and escape of steam, a valve fitting and sliding therein, a bonnet placed thereon,
provided with an opening, a block secured to the valve and moving in the opening,

page_text: and a cap or plate for covering the said opening to prevent the escape of steam, sub
stantially as described.
4. The combination of a valve-chest having suitable openings for the admission and
escape of steam, a valve fitting and sliding therein, a bonnet placed thereon, provided
with an opening, a block secured to the valve and moving therein, a cap or plate for
covering the opening, and a valve-stem connecting with the block to move the valve,
substantially as described.
5. The combination, with the flanges 62 of the valve-chest, of the bolts c³, passing
through the flanges and resting on the bonnet, whereby the bonnet may be forced
down to take up any lost motion caused by wearing of the valve, substantially as
described.
D
'
T
1000
DUTTON & FULTON,
1, St. James Square, Manchester,
Agents.