other Engines and in the Means of Operating same.
Year: 1887

page_text: Date of Application, 15th Sept., 1887
Specification Accepted, 21st Oct., 1887
other Engines and in the Means of Operating same.
I WILLIAM ALLAN of Scotland House Sunderland in the county of Durham,
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:-
According to the usual construction of high speed engines when ordinary slide
valves are used for admitting steam to the cylinders it is found that great clearances
or distances intervening between the ends of the piston stroke and the slide valves are
required to obtain the necessary port openings from which the loss is so excessive
that great inefficiency of working results; moreover great difficulty has been ex-
perienced in the construction of cylinders of such shape with large steam ports owing
to the castings of the cylinders having necessarily been subject to severe tensile and
other strains caused by irregularity in the cooling of the casting, and this has often
resulted in cracks and fractures.
The object of the present improvements is to so construct and operate the valves and
arrange the ports and passages for admitting and exhausting steam as to obtain per-
fectly balanced valves with a minimum of travel, by the use of which the least possible
clearances are obtained while any required area of steam port is available; also
according to this invention greater simplicity in construction is ensured than hereto-
fore, intricate and difficult castings are avoided and less weight of metal is employed,
whence results greater safety economy and working efficiency. In order to accomplish
these results I construct and operate the valves and arrange the steam ports and
passages connected therewith in the following manner.
I construct the cylinders of two concentric barrels fixed at a suitable distance apart,
steam is admitted to the inner harrel (being the piston cylinder proper) by narrow
ports formed circumferentially about either end thereof of sufficient length to give
proper openings; each port is controlled by a circular ring valve placed over it and
fitted into the annular space intervening between the outer surface of the inner
cylinder and the inner surface of the outer cylinder or shell, the faces of the said ring
alves and their seatings or working surfaces being truly turned and bored respectively.
The ring valves are maintained at the proper distance apart by collared bolts or
uitable equivalent means. The steam inlet port or ports and passages are formed
pon the exterior of the outer cylinder or shell and steam is admitted to the annular

page_text: space intervening between the outer sides of the ring valves and the cylinder covers at
either end, which spaces thus become virtually the steam chests: the annular space
between the inner surfaces of the valves and the inner and outer cylinders being the
exhaust passage which may be open to the atmosphere, or in a compound engine to
the port or inlet passage or passages to the next expansion cylinder; or by a reverse
arrangement the said inner annular space between the ring valves may be the inlet or
steam chest and the spaces at the ends outside the ring valves may be the exhaust
passages in which case the exhaust steam passes through a port or ports in the outer
cylinder or shell:
By the above described arrangement it is evident that with any number of cylinders
the inlet and exhaust of steam to each may be continued in like manner until it
escapes to the condenser. The necessary travel may be imparted to the valves by
moans of ordinary eccentrics and gear but preferably by the gear for which I have
obtained Letters Patent No. 6866 of A.D. 1887 actuating spindles passed through the
cylinder covers and connected to a cross head actuated by levers as hereinafter more
fully set forth.
I will now describe my invention in detail and the best construction known to me
for the various parts referring in so doing to the accompanying drawings which
illustrate its application to a quadruple expansion marine engine arranged according
to my latest improvements. Figure 1 is a plan. Figure 2 is a vertical section
through the cylinders on line ab figure 1, showing inner and outer barrels or cylinders
with the annular spaces, ring valves, ports and passages, distance bolts, and means of
operating the valves. Figure 3 is a fore end elevation of first and second cylinders
showing the connections and valve operating gear to which my patent aforesaid is
particularly applicable. Figures 4 and 5 are sections of two alternative forms of ring
valves hereinafter described. Like letters represent like parts in all of these figures,
the index letters 1, 2, 3, 4 being used to represent the first, second, third, and fourth
expansion cylinders respectively. A' A² A³ A are the four expansion cylinders bored
out internally in which the piston works in the usual manner and around which ex-
ternally the concentric barrels or shells a' a² a³ a are placed at suitable distance and
held in position by the internal spigots or flanges of the top and bottom cylinder
covers; 123 are the steam ports formed circumferentially at the top and bottom
of each cylinder proper these are made narrow and the required area of opening is
obtained by the length, and by this means the least possible clearance is obtained. The
said steam ports b¹ 63 63 bare controlled by the ring valves B1 B2 B3 B the whole of
the working surfaces of which as well as those of the inner and outer cylinders are
faced in the usual way. The ring valves may be of steel, gun metal, cast iron, or
suitable material and are made of sufficient depth to give the required admission cut
off, and exhaust stages. The rings are kept at the proper distance apart corresponding
to the distance apart of the steam ports by the collared bolts CC. Two alternative
methods of construction of the ring valves are shown in figures 4 and 5. In order to
render the valves steam tight I form them of channel section as in figure 4 and turn
the inside of the vertical flanges bb with a tapering thinness to a suitable bevel to
allow the steam (acting on the channel side) to press them outwards. I also fit an
adjusting ring C turned to suit the bevel of the channel through which four or more
bolts c c pass which are threaded at the ends and screwed into one or other of the
adjusting rings, and on being screwed from one end both rings are acted upon so as
to set out the flanges when necessary and adjust them to bear equally against their
working surfaces by the wedge like action of the said rings C¹ C. In some cases I
fit light metallic packing rings around the outside and inside peripheries, or I form
grooves therein for the lodgement of condensed vapour to keep the valves steam tight
or according to the construction shown in figure 5 I may make each valve ring in two
pieces as shown in the figure, or they may be cut diagonally and having the usual
tongue pieces inserted as in ordinary piston rings, and for keeping them steam tight I
may insert spiral or other springs between the flanges, or I may adopt other known
means for the purpose. Dis the main steam inlet to the passages d' d' of the first
cylinder A¹. In the design illustrated the steam is intended to pass through D' d¹ to

page_text: the outer ends above and below the ring valves B' and exhaust into the annular inter-
mediate space E' from whence it will pass through the port and passages D2 d² to
cylinder A² exhausting through E to pori D³ and so on successively through the
cylinders A3 A' and port E to the condenser.
In order to give the ring valves B1 B2 B3 B4 the requisite motion I fix to the upper
ring valve for each cylinder two or more spindles G G which are extended up through
stuffing boxes and glands in the cylinder covers and connected to a cross head H.
Vertical reciprocating motion is imparted to the cross head H by a vibrating lever I
having its fulcrum suitably disposed and preferably operated by the arrangement of
gear patented by me A.D. 1887 No. 6866, but it is obvious that the valve cross head H
may be operated from a spindle actuated by the ordinary link motion arrangements
or in such a manner as may suit the design and arrangement of individual cases.
It is evident that the above described design of valve is perfectly balanced while it
can be readily adjusted to bear equally on the exterior of the piston cylinder and the
interior of the outer cylinder and by the disposition of the ports round the periphery
of the inner cylinder a shorter travel of valve is obtained by reason of the greater
opening for steam at command, also, the clearances are reduced to a minimum, which
points especially in high speed engines are of the utmost importance for efficiency in
working it will also be apparent that the abolition of the usual large valve casings
cast with the cylinders, also the usual port passages in connection therewith simplifies
and cheapens the construction of the engine, for, by the above described arrangement
the cylinders are simply plain shells open top and bottom with covers for each end
while the inspection repairs or renewal of the inner or piston cylinders can he accom-
plished without disturbing the outer cylinders at all, also with this arrangement each
cylinder is jacketed.
Having now particularly described and ascertained the nature of this invention and
in what manner the same is to be performed I declare that what I claim is :
1. The improvement in valves for controlling the admission and exhaust of steam to
the cylinders of engines consisting in constructing each valve in the form of a ring
arranged and working in an annular space intervening between the piston cylinder
proper and an external cylinder or casing.
2. The improvement connected with the use of ring valves such as are hereinbefore
specified consisting of the construction and arrangement of the cylinder and casing
and disposition of the steam inlet and exhaust ports and passages substantially as
described and illustrated.
3. The herein before described forms and construction of ring valves substantially as
and for the purposes set forth.
4. The hereinbefore described means of adjusting ring valves so as to render them
steam tight substantially as set forth.
5. The combination with my improved valves of the hereinbefore described means
of imparting the required motion to same consisting of spindles G attached to the
valve or valves and to a cross head and adapted to be operated substantially as set
forth.
6. The general arrangement and construction of valves and parts connected there-
with and the means of operating the said valves substantially as herein before described
and illustrated by the accompanying drawings.
Dated this Fourteenth day of September 1887
J. C. CHAPMAN,
70, Chancery Lane, W.C.,
Agent for Applicant.