IMPROVEMENTS IN STEAM ENGINES
Year: 1881

page_text: PROVISIONAL SPECIFICATION left (by the said Henry James Coles at the
Office of the Commissioners of Patents on the 19th November 1881.
HENRY JAMES COLES, of Southwark, in the County of Surrey, Engineer.
"IMPROVEMENTS IN STEAM ENGINES."
My Invention relates to improvements in steam engines of the reciprocating
class, and principally to horizontal engines, although it may also be applied with
advantage to vertical or inclined engines, and it consists in a novel and improved
arrangement of the valves, slide valve chests, and ports with regard to the cylinder,
whereby the waste spaces are considerably reduced, the cylinder is drained of
water of condensation, the construction of the cylinder is simplified, and it is not so
liable to fracture from unequal expansion.
According to my Invention I place the slide valves at the ends of the cylinder,
and construct the cylinder covers hollow to form valve chambers, and connect them
with the interior of the cylinder by steam and exhaust passages situated by
preference respectively at the upper and lower side of the cylinder, in the case of
a horizontal engine, or in any other convenient position. I place one or more slide
valves within each cover, and arrange them to work across the said ports with a
reciprocating motion.
The cylinder covers are constructed in two parts, forming the valve chamber or
chambers, an inner part forming the end proper of the cylinder and having the
ports in it, and an outer part or cover enclosing the valves on this inner part. The
exhaust valves may work in chambers separate from the steam chambers, and in
that case the exhaust valves, instead of working against the inner covers as seats,
may in some cases work against the outer covers, which would have the necessary
ports in them.
The eccentric or connecting rods actuating these valves may either receive their
motion direct from the crank shaft of the engine or from a shaft or shafts driven

page_text: therefrom, the motion being transmitted to the valve rods through rocking beams
or levers, or directly, as the case may be.
.Tho valves at each end of the cylinders may be arranged either to give full
steam throughout the whole stroke or with a fixed grade of expansion. Or they
may be so arranged that the grade of expansion may be altered by hand, either
with or without stopping the engine. Or the valves may be combined with a
"trip" or "relay" gear in order that the expansion may be automatically
regulated by a governor. And, finally, they may be combined with any form of
reversing gear.
The advantages of the Invention are, that with valves of the simplest form and
least liability to derangement, and placed in a most accessible position, I obtain
great economy in steam, owing to the extreme shortness of the steam passages and
the complete drainage of the cylinder from water of condensation combined with
immunity from destruction, either from the piston striking water confined between
it and the end of the cylinder without possibility of escape, or from the unequal
expansion and contraction of the metal of the cylinder owing to the great irregu-
larity in thickness, as in the case of cylindors having the valve chest and steam
passages cast on the side.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Henry James Coles in the Great Seal Patent Office on the
19th May 1882.
HENRY JAMES COLES, of Southwark, in the County of Surrey, Engineer.
"IMPROVEMENTS IN STEAM ENGINES."
My Invention relates to improvements in steam engines of the reciprocating
class, and principally to horizontal engines, although it may also be applied with
advantage to vertical or inclined engines, and it consists in a novel and improved
arrangement of the valves, slide valve chests, and ports with regard to the cylinder,
whereby the waste spaces are considerably reduced, the cylinder is drained of water
of condensation, the construction of the cylinder is simplified, and it is not so
liable to fracture from unequal expansion.
According to my Invention I place the slide valves at the ends of the cylinder,
and construct the cylinder covers hollow to form valve chambers, and connect them
with the interior of the cylinder by steam and exhaust passages situated by
preference respectively at the upper and lower side of the cylinder, in the case of
a horizontal engine, or in any other convenient position. I place one or moro
slide valves within each cover, and arrange them to work across the said ports
with a reciprocating notion. The cylinder covers are constructed in two parts,
forming the valve chamber or chambers, an inner part forming the end proper of
the cylinder and having the ports in it, and an outer part or cover enclosing the
valves on this inner part. The exhaust valves may work in chambers separato
from the steain chambers, and in that case the exhaust valves instead of working
against the inner covers as seats, may in some cases work against the outer covers,
which would have the necessary ports in them. The eccentric or connecting rods
actuating these valves may either receive their motion direct from the crank shaft
of the engine or from a shaft or shafts driven therefrom, the motion being
transmitted to the valve rods through rocking beams or levers, or directly, as the
case may be. The valves at each end of the cylinders may be arranged either to
give full steam throughout the whole stroke or with a fixed grade of expansion.
Or they may be so arranged that the grade of expansion may be altered by hand
either with or without stopping the engine. Or the valves may be combined with
a "trip" or "relay" gear in order that the expansion may be automatically
regulated by a governor. And, finally, they may be combined with any form of
reversing gear.
The advantages of the Invention are, that with valves of the simplest form and
least liability to derangement, and placed in a most accessible position, I obtain
great economy in steam, owing to the extreme shortness of the steam passages and
the complete drainage of the cylinder from water of condensation, combined with
immunity from destruction either from the piston striking water confined between
it and the end of the cylinder without possibility of escape, or from the unequal
expansion and contraction of the metal of the cylinder owing to the great
irregularity in thickness, as in the case of cylinders having the valve chest and
steam passages cast on the side.
DESCRIPTION OF DRAWINGS.
Figures 1, 2, 3, and 4 represent examples of my Invention as applied to marine
engine cylinders, the Invention being especially useful in the case of war ships, as
their engines, which are usually horizontal, have cylinders of large diameter, and
consequently have very wide valve chests and are very liable to fracture by reason.

page_text: Figure 1 is a part longitudinal section and part elevation of a horizontal trunk
engine cylinder, and Figure 2 is an end elevation of the same with the valve chest
covers and one half of each of the valves removed, the steam and exhaust valves
being connected and working in the same chamber; Figures 3 and 4 are similar
⚫ views of a horizontal double-piston-rod cylinder, the steam and exhaust valves
being in this case contained in separate chambers. In each case it will be
understood that the arrangement of the valves is the same at both ends of the
cylinder, and that the particular arrangements of valves here shown as applied to
peculiar types of engine may be indifferently applied to either of these or to any
other form of engine with little or no modification, as the case may be, the
.Drawings merely representing examples of the numerous possible applications of
my Invention.
A is the cylinder, and B is the trunk of the piston, or the piston rod or rods, as
the case may be; C is the cylinder cover; D is the steam valve, and E is tho
exhaust valve, and d, e, are respectively the steam and exhaust ports in the cylinder
cover. It will be remarked that separate ports are used instead of the samo port,
serving both for the induction and eduction, and that the exhaust port is situated
at the lowest part of the cylinder for the purposes of drainage. is the valvo
chamber cast on the cylinder cover and having two openings to admit the valves
closed by suitable covering plates. In Figures 1 and 2 this chamber extends
completely across the cylinder cover, and the exhaust valve is of D form, the two
valves being connected by a pair of rods G, one at either side of the trunk gland.
In Figures 3 and 4 the exhaust valvo is a double faced valve having a through
port e and working between a seat on the cylinder cover and a second seat on the
valve chest cover provided with ports e corresponding to those e in the cylinder
cover; His the exhaust passage leading into an exhaust chamber I common to
both ends of the cylinder, from which the steam is conveyed to the condenser by a
pipe attached to pipe K. The steam and exhaust valves are in this case contained
in separate chambers and connected by a single central rod G, but in the case of a
single piston rod there would be a pair of rods G, as in the other example. In both
arrangements the valves at the two ends of the cylinder are operated by a rocking
benm L connected at its ends by links with the valve rods G₁ and fast on a rock
shaft M, receiving motion by an arm or lever N from a link motion or any gear
suitable for actuating the ordinary D slide valves: S is the steam pipe leading to
a chamber S¹ connected with the steam chest at both ends of the cylinder.
Figure 5 represents a part elevation, part longitudinal section of the cylinder of
a horizontal stationary engine, and Figure 6 represents an end elevation of the
same with the valve chest covers and one half of each of the valves removed. In
this example or application of the Invention the valves are worked by what is
known as a "trip" gear, which may be regulated by a governor or by hand for the
purpose of varying the point of cut-off. The letters A, B, C, D, E, d, e, F, J, K, S, S',
indicate parts similar to those correspondingly lettered in Figures 1 and 2. In
this case, however, the cylinder is steam jacketted, and an advantage incidental to
the use of my Invention is, that owing to the steam port opening through the cover
instead of entering at the side as usual, the lining A¹ extends the whole length of
the cylinder shell and is secured in place by the cylinder cover C, which also
ensures a perfectly tight joint between the ends of the shell and lining. O, P, are
two cross heads upon the steam and exhaust valve rods respectively and connected
by a pair of side rods Q jointed to their ends, each rod being in two parts jointed
together at gi R is a rock shaft mounted one across each cylinder cover, each rock
shaft being provided with a pair of crank arms T respectively jointed at t to the
lower parts of the corresponding pair of side rods Q; U is another crank arm on
one end of each shaft R, and V is a coupling rod connecting the cranks U of the
two rock shafts. This coupling rod is prolonged at one end v, to which is jointed
the rod from the eccentric by which the valve gear is worked. The crossheads P
are fast on the exhaust valve spindles, but the crossheads O are free to slide on the
steam valve spindles, which are of such sectional area that the steam pressure

page_text: acting thereon will be sufficient to raise the valves and close the ports. Each
crosshead O has an oscillating stirrup X pivoted upon it, straddling a step z on
the valve rod near its end, and this stirrup X has an arm fixed to it, which is
provided with an adjusting screw at its extremity that abuts upon a cam Y on a
shaft y provided with an arm y', which is coupled with the corresponding arm at
the other end of the cylinder by a connecting rod Z, so as to produce a corre-
sponding motion of the two cams. To one of these levers y'a rod from any
suitable governor is connected. The stirrup X and arm x rise and fall with the
crosshead, and as the arm comes in contact with the cain the stirrup is oscillated,
the valve rod released therefrom, and the valve closed by the steam pressure acting
on its rod. It will thus be seen that by shifting the cams the point of cut-off will
be varied according as the arms come sooner or later into contact with them.
Instead of a governor, any convenient arrangement of hand gear may be used for
varying the positions of the cams. In this arrangement single instead of double
ports are used, and the steam and exhaust valves at either end are shown in the
same chamber, but there may be a separate chamber for each valve without in any
way altering the gear, except that the exhaust valves would be through-ported
and work against faces on the valve chamber covers, which would have ports and
passages, as in Figure 3.
Having described the nature of my Invention, and the manner of performing
the same, I would observe that I do not restrict myself to any of the particular
arrangements herein shown and described for operating the valves, as this may be
done in various ways, nor do I confine myself to the direction of motion of the
valves, which may reciprocate in other directions across the cylinder cover, but I
declare that what I claim as my Invention to be protected by the herein before in
part recited Letters Patent is,
1st. Arranging the slide valves of a steam engine to work wholly within
appropriate chambers constructed in the ends or covers of the steam cylinder,
substantially as and for the purposes herein specified.
2nd. The construction of the ends or covers of steam engine cylinders with a
chamber or chambers for the steam and exhaust slide valves to work in, and with
ports leading into the cylinder through the ends thereof, substantially as and for
the purposes herein specified.
3rd. The combination with a steam engine cylinder of steam and exhaust
valves at the two ends of the cylinder arranged to work across the covers within
chambers constructed therein, substantially as shown and described.
4th. The combination with a steam engine cylinder provided with steam and
exhaust valves at both ends contained within chambers constructed in the covers
of the respective combinations and arrangements of parts constituting the
respective arrangements of gear for working the said valves, substantially as
herein shown and described.
In witness whereof, I, the said Henry James Coles, have hereunto set my hand
Witness,
A. M. CLARK,
A. M. & W. Clark,
Patent Agents,
53, Chancery Lane,
London.
HENRY J. COLES. (L.S.)