Year: 1886

page_text: Date of Application, 31st Dec., 1886
Complete Left, 31st Oct., 1887
Complete Accepted, 16th Dec., 1887
I, JOHN TWEEDY of the firm of Wigham Richardson & Co. Shipbuilders and
Engineers, Newcastle-on-Tyne in the County of Northumberland, do hereby declare
the nature of this invention to be as follows:-
This invention has for its object to improve the mode of arranging and combining
together the cylinders and other parts of marine engines such as described or referred
to in the provisional specification of my application for Letters Patent dated the 24th
day of November 1886, No. 15324.
In carrying out my present invention in the case of engines having four cylinders
I place the two smaller cylinders between the two larger cylinders.
The smaller cylinders may be in the same plane as, or in a plane or planes making
a small angle or angles with tho plane or planes of the larger cylinders. In one
modification of the valve gear of my improved engines I use only two sets of gear to
operate the main valves of the four cylinders which valves may either be independent
valves, i.e., one for each cylinder, or one combined valve may be used for each pair
of cylinders working on opposite or nearly opposite cranks. In another modification
I use three sets of valve gear arranged so that one set of gear operates a combined
valve or a pair of independent valves controlling a pair of cylinders working on
opposite or nearly opposite cranks while the remaining two sets of gear oporate the
independent valves of the other two cylinders.
[
as a
The valve used to control the cylinders acting in pairs and hereinbefore referred to.
combined valve" may be a slide valve or a piston valve. Where the latter kind
is adopted I prefer to provide three working rings, the two outer of these rings being
prolonged or an equivalent substitute being provided on their inner edge so as to
regulate more perfectly the admission of the steam to the cylinder. Orifices are
provided in the prolongation or its equivalent to allow the steam to pass from one port
to the other; the middle rings regulate the exhaust and the space between it and the
outer rings serves as a receiver for the steam exhausted from one cylinder before the
prolongation of the valve opens to admit the steam to the second of the pair of
cylinders controlled by the "combined valve."
In carrying out my invention in the case of engines having five cylinders working
on a four-throw crank shaft as described or referred to in my above mentioned

page_text: provisional specification, I place a cylinder over one of the four cylinders arranged as
hereinbefore described. In another modification I use six cylinders, two for the last
stage of expansion and two for the first or either of the intermediate stages, two of the
six cylinders are placed over two of the four lower cylinders which latter are arranged
as hereinbefore described for four cylinder engines.
Various modifications approximating more or less closely to the combination just
described may be used, for example the larger cylinders may be placed between the
smaller ones or a small cylinder may alternate with a large one but the method of
constructing such modifications is made so clear by the foregoing description of the
more perfect and complete arrangement as to render unnecessary a detailed description
of them.
In all the modifications I provide in certain applications of each modification suitable
reversible pipes or valves or a combination of reversible pipes and valves to facilitate
the disconnection, in case of accident, of one or more cylinders. These pipes and
valves are also available for disconnecting a cylinder or cylinders, when it is desired to
work with a reduced pressure of steam or to largely reduce the power when the
higher pressure of steam is used; where either of the latter conditions are to be
specially provided for as for example, in the case of war vessels where it is often
required to run at greatly reduced speed, I prefer to connect the high pressure
cylinder and one of the intermediate pressure cylinders, in engines having four
cylinders, to the two after cranks so that the adjuncts of the cylinders to be detached
may also be readily separated from the working engines. The four-throw crank shaft
may be made in one piece or built up from a number of pieces but by preference I
use the following modifications
--
1. Two solid or built two-throw shafts exact duplicates of each other bolted together
to form a four-throw shaft.
2. A four-throw shaft made up of short pieces of shaft provided with flanges and
bolted to the webs of the cranks.
3. A four-throw shaft similar to the 2nd modification but having either the crank
pins or the main bearing parts of the shaft shrunk and keyed into the webs instead of
being bolted as in that modification.
Dated this 31st day of December 1886
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.

page_text: Improvements in Compound Marine Steam Engines.
I, JOHN TWEEDY, of the Firm of Wigham Richardson & Co., Ship-builders and
Engineers, Newcastle-on-Tyne, in the County of Northumberland, 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 an invention forming the subject of a previous application for Letters
Patent made by me under date the 24th day of November 1886, No. 15,324, quad-
ruple expansion marine steam engines having (according to one arrangement) four
cylinders are arranged in such a manner that the steam does duty in all the cylinders,
and is expanded in each of them successively, and the power from each is transmitted
through a different crank.
Now my present invention relates to improvements in engines made in accordance
with that invention, and has for its object to effect (as I will hereinafter explain) con-
siderable saving in first cost, and to increase the efficiency of the engines.
In a four-throw crank engine with the power distributed approximately equally
between the four cranks, the pressure on the bearings of any one crank will be only
half that on the bearings of either crank of a two-crank engine when developing the
same power, with the same number of revolutions per minute. And it will be in like
manner three-fourths of the pressure on the bearings of each crank of a corre-
sponding three crank engine. But as the total power given out and the revolutions
per minute are taken to be the same in each case, the mean torsion of the shafts will
be also the same.
It follows from this that the diameter of the shaft at the after
crank, will, in the four-crank engine, be reduced only so much as is due to the more
uniform turning movement of the four-crank engines, as was explained in the specifi-
cation of my before mentioned application. This reduction, although of importance
in reducing the weight and cost of the shaft, is unimportant as affecting the bearing
surface. Consequently the bearings of the after crank may either be reduced in
length or in number.
Now an object of my invention is to so arrange the cylinders, valve, and gear as to
enable a corresponding reduction to be made in the distance apart of the centres of the
adjoining engines. Since it is always advisable to make the bearings of the shaft
uniform in diameter throughout, and to arrange it so that one part can be readily
interchanged with another, it will be evident that any reduction such as can be
obtained by my present invention in the longest distance necessary between the
centres, will enable an aggregate reduction of three times that amount to be made.
In four-crank engines the stress on the fourth and third cranks will be the same
whether the second and first cranks (taking the cranks in order from forward to aft)
be placed at right angles or opposite to each other, but the maximum stress on the
second crank will be reduced if it be placed at right angles to the first crank and that
part of the shaft can, if so arranged, be reduced in size, or, if made the same size,
greater security from accident will be obtained. When, however, the cylinders are

page_text: arranged over the cranks in the order in which the steam passes through them, as is
shown in the drawings annexed to the specification of my previous application above
referred to, this advantage can only be obtained at the expense of a considerable
increase in the size of the receivers.
According to my present invention, the mode of arranging and combining together
the cylinders and other parts of marine engines, such as described or referred to
above, is such as to obviate inconveniences that might arise in engines constructed
in the manner alluded to; I also provide for the use, in certain cases, of only two
or three sets of valve gear in engines constructed in other respects according to my
present and former specifications.
3
Fig. 3 is a plan of so much as is necessary to the understanding of my invention of a
four cylinder quadruple expansion marine engine constructed and arranged in
accordance therewith.
Figs. 4, 5, and 6 are respectively an end elevation, front elevation, and plan of a
modified arrangement of the above, in which two valves are used for the third, and
two valves for the fourth stage cylinders.
Figs. 7, 8, and 9 are respectively an end elevation, a front elevation, and a plan of
another modification, in which the first and second stage cylinders are placed between
and at a slight angle with the third and fourthi stage cylinders.
Figs. 10 to 21 inclusive are plans, and detail drawings illustrating various modified
arrangements of valves and valve gear and other parts to be hereinafter more
particularly referred to.
In these drawings, the same letters of reference indicate the same or like parts
wherever they are repeated. The general features only of the arrangements are
shown, and it is to be understood that any parts or details which are not delineated
are intended to be arranged and constructed in the ordinary manner.
According to the arrangement illustrated in Figs. 1 to 3, the smallest cylinder A
is placed over the crank c next to the largest cylinder D which is placed over the
crank d. The second stage cylinder B is placed over the crank b. and between A.
and the third stage cylinder C. which latter is placed over the crank a. The steam
from the boiler is supplied through a pipe I to the valve J of the first stage or high
pressure cylinder A.
After expansion in that cylinder, it passes to the valve K. of
the second stage cylinder B. The valves J and K are shewn in this case combined,
but this is not an essential feature of the design as separate casings and valves may
be applied. The steam after working in the cylinder B, passes through the pipe 3.
and valve L to the third stage cylinder C. and after expansion in this cylinder, it
passes through the pipe 4. and valve chest M. to the fourth or last stage cylinder D
whence it is led through the passage or pipe 6. to the condenser 5 the small size of
the cylinders A. and B. making a very direct and compact connection with the
condenser possible, while giving great accessibility to the valves and freedom to the
designer in arranging them and their connections and fittings. In this arrangement
and in a modification thereof to be afterwards referred to, I have arranged the valve
chests J. K. L. and M. for piston valves, but although I prefer valves of this type
for the first and second stage cylinders A. and B. I do not limit myself to their use
for these, nor for the cylinders C. and D. The mode of applying other ordinary
forms of valves being obvious, I have not thought it advisable to complicate this
specification or the drawings by shewing more than one kind of valve; excepting that
I shew in Figs. 17, 18, and 21 how a piston valve may be combined with another
piston valve, or with a slide valve. In general, the sum of half the diameters of the
cylinders A and D. will be greater than the sum of half the diameters of A. and B
or of B and C. so that in all such engines where the crank shaft occupies the same o
less space between the centres of its cranks c. and d. than is required between the
centres of the cylinders A and D. the centres will be determined by the diameters of
the cylinders A. and D. instead of the cylinders D. and C. as would be the case were

page_text: the cylinders placed in the order of the expansion of the steam as shewn in my
previous drawings herein before referred to. In this same modification the cranks a.
and b. are at right angles to each other, and consequently the stress on the crank b.
is reduced to a minimum. The crank c. is placed opposite to b, and d. at right
angles to c. and opposite to a. There are therefore two cylinders B and D in which
the period for admission of steam coincides very nearly with the period of exhaust of
the cylinders A. and C. from which they receive their steam, instead of one as in the
case of cylinders arranged in the order of the action of the steam in them, the
condition as to the relative position of the cranks being complied with in both cases.
I use any of the known forms of valve gear, and I shew in Figs. 1. 2. and 3. how
the ordinary link motion, the commonest form of gear, and probably the most
difficult to apply to engines of this kind may be applied. In this modification I shew
3 sets of gear, one set 7 being connected through the lever 8 to the controlling valve
placed in the chest L. of the cylinder C. another set 9 is connected to the combined
valves J. K. (or to separate valves J and K. when for any reason it is desired not to
combine the valves) and the third set 10. is connected through the lever 11. to the
controlling valve placed in the chest. M. of the cylinder D. In some modifications of
this and equivalent arrangements of valves, I only use two sets of valve gear, and in
the plan view Figs. 10 and 11, I show two sets of gear applied to the engines shewn
by Figs. 1. 2 and 3. The valve gear 10, in Figs. 10. and 11. is arranged to work the
valves of cylinders C. and D. The levers 8. are connected to the lever 11 by the
shaft 15 the valves J. K. being worked by the gear 9 as before.
When because of the size of the engines or of the design of the crank shaft or for
any other reason it is considered inadvisable to place valve gear between the engines,
I place one gear, say 9, Fig. 12. on the outer end of the crank a, and connect it
through the levers 16 and shaft 17 to the valves J. K. and another set of gear, say 10),
at the outer end of the crank d. and connect it to the valves L and M through
lever 11 and shaft 15, but as these are all details which any skilled designer can
arrange to suit the special requirements of oach case, at once proceed to explain
another set of drawings. Figs. 4, 5, and 6, shew how my improvements may be
applied to a set of engines which, whether because of their large size, or high speed,
or both, require two valves each for the third stage cylinder C. and the fourth stage
cylinder D. and for the purpose of illustrating another modification in the arrangement
of cylinders suitable for engines whose cranks could not be got into the space occupied
by half the diameters of the cylinders A. and D. I have in these figures shewn the
cylinder B. between A. and D. I have also varied the valve gear of which there may
be any number, from 2 to 6 sets, depending on the arrangement adopted, the power
of the engines, and the fancy of the user. The steam, as in the former case, passes
first into the cylinder A, through the valve J, then to B through the valve K, then
to C, through L, and L 1, then to the cylinder D. through the valves M and M. 1.
and finally to the condenser as before. The gear shewn is of the well known
Hackworth or Marshall type and needs no explanation. Another modification by
which the space is still further reduced is shewn by Figs. 7, 8, and 9, Fig. 7 being an
end elevation, Fig. 8, a front elevation and Fig. 9 a plan. In this modification the
first and second stage cylinders A and B. are placed between and at a slight angle
with the cylinders C. and D. and in some cases with each other. The order in which
the steam passes through the cylinders is the same as in the previously described
modification, and the valves may be arranged similarly, but for the purpose of
shewing another modification in these arrangements I shew a combined valve L. M.
for the cylinders C. and D. instead of the separate valves L and M in Figs. 1. 2. and 3,
the valve J. K. of the cylinders A and B. being combined in one chest as before.
also use these figures to illustrate a convenient form of crank shaft for four-crank
engines. This shaft is made up of two interchangeable and reversible halves each
half having two cranks, a and b in the one, c and d in the other, either forged solid
or built up of several pieces by any of the well known methods. The halves are
connected together at 12, Fig. S. by bolted flanges. In the space occupied by these
flanges and their bolts and nuts, a set or two sets of eccentrics may be fitted. In the

page_text: Fig. 7. and shew two sets applied each to a set of ordinary link motion, one
set 13 of which I connect to the valve L M placed immediately over it, and between
the cylinders CD the other set 14 is connected to the valve JK placed between the
cylinders A B and immediately over the gear. The gear may, if required, be placed
at the extreme outer ends of the shafts, and be connected to the valves through
rocking shafts and levers, or one gear may be so placed, the other remaining between
the engines as shewn.
Various other modifications embodying the essential features of this invention
may be made to meet the very varied requirements of users of such engines, and the
valves may be placed at the front of the engines or at the back over the condenser as
shewn in most of the modifications, or partly at the front and back and partly over
the shaft.
Figs. 10, 11, 12, 13 and 14 shew plan views of five such modifications. The
order of the passage of the steam through the cylinders in these modifications is the
same as in the previous modifications herein before explained; the valves may be
piston or slide valves, and the gear may be of any of the known types, and there
may be a set of valve gear for each of the valves.
I show in one set of modifications how two sets of gear may be arranged in
combination with two combined valves, and in other modifications I show how two or
three sets of gear may be arranged in combination with one combined valve and two
separate valves, or in combination with four separate valves in the case of engines
having one valve or part of a combined valve for each cylinder, and I have also
shown how in larger or very high speed engines having at least one valve for each
of the cylinders, the valves may be compactly and conveniently arranged about
the cylinders, and how even six sets of gear may be applied if required. I also
shew by Figs. 15 and 16 two modifications of arrangements of valves suitable for
two and three sets of valve gear in engines whose cylinders are not arranged to
give minimum centres. As already mentioned, I use any of the known descriptions
of slide or piston valves, and I shew by Fig. 17 how such piston valves, and by
Fig. 18 how a piston and a slide valve may be combined in one chest to control the
action of the steam working in two cylinders connected to opposite cranks. In
Fig. 17 the lower pair of valves 18 and 19 are in connection with the cylinder a, the
space 20 between them receiving steam from the boiler when a is a high pressure
cylinder, and from the preceding cylinder when a is an intermediate stage
cylinder. The stuffing box 21 is thus protected from the action of the higher
pressure steam; the exhaust from the cylinder a passes into the spaces 22 and 23
and 24 and thence into the cylinder y past the steam edges 25 and 26 of the
valves 27 and 28. The inner edges 29 and 30 of the valves 27 and 28 control
the exhaust from the cylinder y, the exhaust steam passing from the space 31
between the valves 27 and 28 to the steam chest of the following cylinder or to
the condenser, as the case may be.
In Fig. 18 is shown a pair of valves 32 and 33 similar to and controlling the
steam to the cylinder in the same way as the corresponding valve in Fig. 17 but
in this Fig. 18 I shew an ordinary slide valve 34 instead of the pair of valves 27
and 28 in the former figure, worked by the same spindle as the valves 32 and 33.
The steam from the cylinder is exhausted into the space 35 surrounding the slide
valve 34 which controls the admission to and exhaust from the cylinder y. in the
usual way.
In some modifications I make the face of the slide valve straight as shewn in the
plan, Fig. 19; in others curved, as shewn by the Fig. 20.
Another modification of a
combined slide and piston valve is shewn by Fig. 21 in which the slide valve is made
in two parts 36, and 37, one being placed above, and the other below the piston
valves 38 and 39. In this case also, the slide valves are made either straight on the
face, or curved.
In carrying out my invention in the case of engines having five and six cylinders
working on a four-throw crank shaft, I place a small cylinder next to the largest
cylinder either parallel to or at an angle with that cylinder, and between two larger

page_text: cylinders as in the drawings of the four cylinder engines herein before referred to, and
over these lower cylinders I place one or two cylinders, depending whether five or six
cylinders are used, in the same way as is indicated by the drawings and specification
of my previous application No. 15,324 of 1886 hereinbefore referred to.
My improved modes of arranging and combining four or six steam cylinders to
operate with four stages of expansion on a four-throw crank shaft may be used when
the engines are placed horizontally or diagonally. In these cases the framing, valves,
and gear are modified in relation to the cylinders in the manner usual with horizontal
and diagonal marine engines. In cases where it is desirable to provide for greatly
reduced power, I arrange in any of the modifications of my engines suitable reversible
pipes or valves or a combination of reversible pipes and valves to facilitate the
disconnection, in case of accident, of one or more cylinders. These pipes and valves
are also available for disconnecting a cylinder or cylinders, when it is desired to work
with a reduced pressure of steam, or to largely reduce the power when the higher
pressure of steam is used; where either of the latter conditions is to be specially
provided for, as, for example, in the case of war vessels where it is often required to
run at greatly reduced speed, I prefer to connect the high pressure cylinder and one
of the intermediate pressure cylinders, in engines having four cylinders, to the two
after cranks so that the adjuncts of the cylinders to be detached may also be readily
separated from the working engines. Thus, for example, I arrange the pipe 3
(Fig. 3) so that it can be disconnected from the chest of the valve L and connected
to the chest M at the junction of the pipe 4 with that chest, the pipe 4 having been
previously removed. In some modifications, instead of providing roversible pipes, I
fit shut off valves such as 40 on the pipe 3 and 41 joining the pipes 3 and 4 and 42
on the pipe 4 so that on removing the pipe 4 and reversing the pipe 3 from the
chest L to the chest M or when valves are fitted, on closing the valves 40 and 42 and
opening the connection between the pipes 3 and 4 by the valve 41 and the bolts of
the coupling z, Fig. 2, of the crank shaft being withdrawn, the engines would be then
triple expansion engines, of which A would be the high pressure cylinder, B. the
intermediate, and D the low pressure cylinder.
As will be evident engines of various constructions differing in detail from those
illustrated by way of examples in the annexed drawings may be constructed in
accordance with my invention hereinabove described & set forth in the following
claiming clauses.
And having now particularly described and ascertained the nature of the said
invention, and in what manner it is to be performed, I declare that what I claim is :-
1. In a quadruple expansion marine steam engine, the arrangement of four
cylinders and four cranks substantially in the manner hereinabove described with
reference to the cylinders A, B, C, D, and cranks a, b, c, d, in the example Figs. 1, 2,
and 3; and in the example Figs. 4, 5, and 6 of the drawings annexed, for the purpose
specified; whether with or without additional cylinders and whether or not crank a
be at right angles to crank b.
2. In a quadruple expansion marine steam engine, the arrangement of four
cylinders and four cranks (at any suitable angles,) substantially in the manner
hereinabove described with reference to the cylinders A, B, C, D, and cranks a, b, c, d,
in the example Figs. 7, 8, and 9, of the drawings annexed, for the purpose specified,
whether with or without additional cylinders.
3. In a quadruple expansion marine steam engine, the arrangement substantially as
described with reference to Figs. 1, 2, and 3 of the drawings annexed of the cylinders
and valves in conjunction with four cranks and three sets of valve gear.
4. In a quadruple expansion marine steam engine, the arrangement substantially
as described with reference to Figs. 7, 8, and 9, or according to the modifications
illustrated respectively in Figs. 10, 11, 12, and 15 of the cylinders and valves in
conjunction with four cranks and two sets of valve gear.
5. In a compound marine steam engine, the arrangement and combination of the
cylinders and crank shafts substantially in the manner hereinabove described with

page_text: reference to Figs. 1, 2, and 3; to Figs. 4, 5, and 6; and to Figs. 7, 8, and 9, so that
with the two forward cranks at right angles or nearly at right angles the period of
exhaustion and admission shall be more nearly coincident in two pairs of cylinders
instead of in one pair of cylinders only.
6. In a compound marine steam engine the arrangement together substantially as
hereinabove described with reference to Figs. 17, 18, and 21 of the drawings of slide
and piston valves for the purpose specified.