Year: 1898

page_text: I, NOEL CHANDLER, of Cannock Chase Engine Works, Hednesford, in the County
of Stafford, do hereby declare the nature of this invention to be as follows:-
This invention has reference to improvements in single acting steam engines
having one or more air buffers or air compressing chambers for cushioning the
pistons and attached parts as they near the top of their up-strokes, and it has for
object to avoid the increasing pressure which occurs in such chamber or chambers
(hereinafter called the cushioning cylinder or cylinders) as the air piston or cross-
head or each of them arrives at the end of its upstroke.
For this purpose in the case of a single crank engine having a single cushioning
cylinder I connect this cylinder to a receiver into which air is pumped, the receiver
acting as a large clearance space to the cushioning cylinder and serving to keep
the air pressure therein moderate.
In the case of a multiple crank engine having two or more cushioning cylinders,
instead of making each cushioning cylinder independent of the other or others
as heretofore I connect them together so that a practically constant pressure of
air is maintained in all of them, an air pump or other suitable means being pro-
vided for replacing any air lost by leakage. The cushioning cylinders may
be connected together in various ways as by pipes or passages connecting them in
series, or by connecting them to a common receiver containing the necessary air
pressure to maintain a practically constant downward pressure on the top of the
air piston or cross-head working in each cushioning cylinder.
In one arrangement of this kind each cushioning cylinder is formed at its upper
end with a plate by which it is suspended in the crank chamber, the said plate
being provided with a central stuffing box and gland through which the engine
piston rod connected to the air piston and cross-head works and with an air
opening located to one side of the said stuffing box and gland. Located between
the unner side of the said plate and the lower end of the low pressure engine
cylinder above, and connected to both, is a box or chamber that forms a distance
piece between the said parts and is provided at the top with a stuffing box for
the piston rod and, it may be with a stuffing box for the valve rod, and has suitably
arranged openings through which ready access can be obtained to the several
stuffing boxes, as in the construction of engine described and shown in the
Specification of my Patent No. 22631 of 1896. The box or chamber has extending
horizontally through it a pipe or passage which may be cast in one with the box
or chamber, is flanged at its outer ends, and is provided at a point within the box
or chamber with a downwardly extending branch passage provided with a flange
by which it is secured over the laterally arranged air opening in the plate carrying
the cushioning cylinder. The arrangement is such that when the several cushion-
ing chambers, engine cylinders and intermediate boxes or chambers are properly
put together, the horizontal pipes or passages in the several boxes or chambers
come into line and are then connected together by their flanged ends. The common
receiver or passage thus formed is closed and is connected to a pipe by which it

page_text: is placed in communication with a small pump for charging the connected cushion-
ing cylinders and common receiver with air, under pressure and for replacing
air dost by leakage so as to maintain a practically constant pressure, in the air
cushioning cylinders.
'.
Improvements in Single Acting Steam Engines.
I, NOEL CHANDLER, of Cannock Chase Engine Works, Hednesford, in the County
of Stafford, 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 has reference to improvements in single acting steam engines
having one or more air buffers or air compressing chambers for cushioning the
pistons and attached parts as they near the top of their up-strokes, and it has for
object to avoid the increasing pressure which occurs in such chamber or chambers
(hereinafter called the cushioning cylinder or cylinders) as the air piston or cross-
head, or each of them, arrives at the end of its upstroke.
For this purpose in the case of a single crank engine having a single cushioning
cylinder I connect this cylinder to a receiver into which air is pumped, the receiver
acting as a large clearance space to the cushioning cylinder and serving to keep
the air pressure therein moderate. In the case of a multiple crank engine having
two or more cushioning cylinders, instead of making each cushioning cylinder
independent of the other or others, as heretofore, I connect them together so that
a practically constant pressure of air is maintained in all of them, an air pump
or other suitable means being provided for replacing any air lost by leakage.. The
cushioning cylinders may be connected together in various ways as by pipes or
passages connecting them in series, or by connecting them to a common receiver
containing the necessary air pressure to maintain a practically constant down-
ward pressure on the top of the air piston or cross head working in each
cushioning cylinder.
In the accompanying illustrative drawings Fig. 1 is a longitudinal vertical
section partly on the line A B and partly on the line C D of Fig. 2, and Fig. 2
is a sectional plan on the line E F of Fig. 1, showing part of a single acting
multiple cylinder engine with one arrangement of connected cushioning cylinders
according to this invention.
According to this arrangement, each cushioning cylinder 1 is formed at its upper
end with a plate 2 by which it is suspended in the crank chamber 3, the said
plate 2 being provided with a central stuffing box 4 with gland 4"
through which the engine piston rod 5 connected to the corresponding
combined air piston and cross-head 6 works, and with an air open-
ing 7 located to one side of the said stuffing box and gland. Located
between the upper side of the plate 2 and the lower end of the
low pressure cylinder 8 above, and connected to both, is a box or chamber 9 that
forms a distance piece between the said parts and is provided at the top with a
stuffing box 10 for the piston rod 5 and, it may be, with a stuffing box for the valve
-

page_text: rod (not shown) and has suitably arranged openings through which ready access
can be obtained to the several stuffing boxes, as in the construction of engine
described and shown in the Specification of my Patent No. 22631 of 1896. The
box or chamber 9 has extending horizontally through it a pipe or passage 11,
which may, as shewn, be cast in one with the box or chamber 9, is formed with
flanges 11 at its outer ends, and is provided at a point within the box or chamber
with a downwardly extending branch passage 116 provided with a flange 11° by
which it is secured over the laterally arranged air opening 7 in the plate 2. As
will be seen, the arrangement is such that when the several cushioning cylinders 1,
engine cylinders 8, and intermediate boxes or chambers 9 are properly fitted
together, the horizontal pipes or passages 11 in the several boxes or chambers 9
come into line and are connected together as by bolts passed through their flanged
ends 11. The common receiver or passage thus formed is closed at its ends and
is connected to a pipe 12 by which it is placed in communication with a small
pump, that is indicated diagrammatically at 13 and is driven in any suitable
manner for charging the connected cushioning cylinders 1 and common receiver 11
with air under pressure and for replacing air lost by leakage, so as to maintain
a practically constant pressure in the air cushioning cylinders.
Fig. 3 is a vertical cross section, and Fig. 4 is a plan, showing a modified arrange-
ment of connected cushioning cylinders. In this case a pipe 11" forming the
common receiver is arranged horizontally outside the crank chamber 3 and is
connected to the upper end of each cushioning cylinder 1 by a lateral pipe 11b
extending through the wall of the crank chamber, the pipe 11" being connected
by a pipe 12 to an air pump as and for the purpose hereinbefore explained.
In an engine of the kind referred to having high and low pressure cylinders
of 8 inches and 12 inches respectively in diameter, working with steam having an
initial pressure of about 130 pounds to the inch, and running at a speed of 480
revolutions per minute, I have obtained satisfactory results when maintaining
the pressure of air in the common receiver at about 40 pounds to the square inch.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. In a single acting steam engine of the type herein referred to, connecting
the cushioning cylinder or each such cylinder to a receiver adapted to form a
large clearance space and into which air is pumped so that a practically con-
stant pressure of air is maintained therein and a practically constant downward
pressure exerted on the top of the air piston or cross-head in the cushioning
cylinder, or in each such cylinder, substantially as described for the purpose
specified.
2. In a single acting multiple crank engine of the kind herein referred to, con-
necting the several air cushioning cylinders together and to means for supplying
air thereto, substantially as herein described for the purpose specified.
3. In a single acting steam engine of the kind herein referred to, the com-
bination with the cushioning cylinders, of a common receiver connected to the
said cylinders and to an air pump, the several parts being constructed and arranged
substantially as hereinbefore described with reference respectively to and shown
in Figs. 1 and 2, and in Figs. 3 and 4 of the drawings annexed.
Dated this 14th day of November 1898.
Dated this 14th day of November 1898.
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.