IMPROVEMENTS IN MARINE ENGINES
Year: 1856

page_text: LETTERS PATENT, to Charles Randolph and John Elder, both of the City
of Glasgow, in the County of Lanark, Engineers, for the Invention of
"IMPROVEMENTS IN MARINE ENGINES."
PROVISIONAL SPECIFICATION left by the said Charles Randolph and
John Elder at the Office of the Commissioners of Patents, with their
Petition, on the 15th March 1856.
We, CHARLES RANDOLPH and JOHN ELDER, both of the City of Glasgow, in
the County of Lanark, Engineers, do hereby declare the nature of the
Invention for "IMPROVEMENTS IN MARINE ENGINES," to be as follows:-
Our Invention consists in certain improvements in double-cylinder expan-
sion engines, or engines in which the steam is expanded out of one cylinder
into another, and the object of these improvements is to render this class of
engines more suitable than heretofore for propelling vessels.
As regards the arrangement of the cylinders in relation to the cranks; when
the vessel contains a pair of such engines one of the pistons of each engine is
connected with the same crank, that is to say, the pistons of the two smaller
cylinders to a crank, and those of the two larger cylinders to another crank,
or otherwise the piston of the small cylinder of one engine and that of the
large cylinder of the other engine to the same crank, and these arrangements
we effect commonly by direct connections with the cranks; but when the
vessel contains only a single engine, we connect the two pistons to opposite
ends of a beam lever, which communicates at one end with the single crank
by any of the ordinary methods, of connection, and this arrangement is also
applicable when the vessel contains more than one engine. The distinguishing
peculiarity of the steam valves is, that the first in order, namely, that to the

page_text: small cylinder, is merely an induction valve, and so adjustable as to have a
greater or less amount of cut-off, and thereby to permit the supply of steam
to be regulated at pleasure; and that the second or intermediate valve serves
the several purposes of eduction valve to the first cylinder, induction valve
to the second or larger cylinder, and eduction valve from this cylinder to the
condenser.
Another improvement consists in arranging the gearing for working the
valves of steam engines in such manner, that the engines can be made to
go. forwards or backwards or be brought to rest by the action of a single
handle. This handle commands a friction brake attached to a toothed wheel
carried loose on the crank shaft; this wheel gears into a companion wheel
which is fast on a shaft that revolves synchronously with the crank shaft.
Upon the same shaft are placed two pinion wheels, which gear into toothed
segments attached to the valve eccentrics. The nature of this train is such,
that by the action of the brake.on the first-mentioned loose, wheel the 'velocity.
of the eccentrics is increased beyond that of the crank shaft, and in con-
sequence of this difference of velocity the valves can be brought into any
required relation with the ports of the cylinders: The first effect is to cause
the steam to be cut off 'sooner; by continuing the action of the brake it is
entirely shut off; and a still further continuance of the action reverses the
relation of the valves, and admits the steam on the opposite sides of the
pistons, thereby enabling the engines to be reversed. For the better clearance
of the condenser of air and "vapour under high degree of expansion, such as
we are enabled to effect in engines constructed according to our method, we
make the air pump double-acting at a lower level than the in-take valves, and
the space between the level of the in-take and discharge valves rather larger
than the area of the stroke of the pump, so that the in-take valves may be
continually covered with water.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Randolph and John Elder in the Great Seal Patent 30
Office on the 12th September 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, CHARLES
RANDOLPH and JOHN ELDER, both of the City of Glasgow, in the County of
Lanark, Engineers, send greeting.
!
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters 3
Patent, bearing date the Fifteenth day of March, in the year of our Lord
One thousand eight hundred and fifty-six, in the nineteenth year of Her

page_text: reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said Charles Randolph and John Elder, Her special licence that we;
the said Charles-Randolph and John Elder, our, executors, administrators,
and assigns, or such others as we, the said Charles Randolph and John
Elder, our executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
MARINE ENGINES," upon, the condition (amongst others) that we, the said
Charles Randolph and John Elder, our executors or administrators, by an
instrument in writing under our or their hands and seals, or under the hand
and seal of one of us or them, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be per
formed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months, next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that we, the said Charles Randolph and John Elder,
do hereby declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :-
As regards the arrangement of the cylinders in relation to the cranks, when
the vessel contains a pair of such engines one of the pistons of each engine is
connected with the same crank, that is to say, the pistons of the two smaller
cylinders to a crank, and those of the two larger cylinders to another crank,
or otherwise the piston of the small cylinder of one engine and that of the
large cylinder of the other engine to the same crank, and these arrangements
we effect commonly by direct connections with the cranks; but when the
vessel contains only a single engine we connect the two pistons to opposite
ends of a beam lever, which communicates at one end with the single crank
by any of the ordinary methods of connection, and this arrangement is also
applicable when the vessel contains more than one engine. The distinguish
ing peculiarity of, the steam valves is, that the first in order, namely, that
to the small cylinder, is merely an induction valve, and so adjustable as
to have a greater or less amount of cut-off, and thereby to permit the
supply of steam to be regulated at pleasure; and that the second or inter-
mediate valve serves the several purposes of eduction valve to the first cylinder,
induction valve to the second or larger cylinder, and eduction valve from this
cylinder to the condenser.

page_text: Another improvement consists in arranging the gearing for working the
valves of steam engines in such manner, that the engines can be made to
go forwards or backwards or be brought to rest by the action of a single.
Landle. This handle commands a friction brake attached to a toothed wheel
carried loose on the crank shaft. This wheel gears into a companion wheel
which is fast on a shaft that revolves synchronously with the crank shaft.
Upon the same shaft are placed two pinion wheels, which gear into toothed
segments attached to the valve eccentrics. The nature of this train. is such
that by the action of the brake on the first-mentioned loose wheel, the
velocity of the eccentrics is increased beyond that of the crank shaft, and in
consequence of this difference of velocity the valves can be brought into any
required relation with the ports of the cylinders. The first effect is to cause
the steam to be cut off sooner; by continuing the action of the brake it is
entirely shut off, and a still further continuance of the action reverses the
relation of the valves and admits the steam on the opposite sides of the pistons,
thereby enabling the engines to be reversed. For the better clearance of the
condenser of air and vapour under high degree of expansion, such as we are
enabled to effect in engines constructed according to our method, we make
the air pump double-acting at a lower level than the in-take valves, and the
space between the level of the in-take and discharge valves rather larger
than the area of the stroke of the pump, so that the in-take valves may be
continually covered with water.
And in order that the nature of our Invention may be most fully understood
and readily carried into effect, we have made the series of Drawings hereunto
annexed, exhibiting three slightly differing forms of the kind of engine we
propose to employ in carrying the same into practice, including also plans of
valves, valve gearing, and air pump, as specified in these Drawings. The same
letters are used to indicate the same parts throughout.
Sheet 1, 2, and 3 contains sketches of the arrangements first referred to
in our Specification, that is to say, arrangement of cylinders A and B in
relation to the cranks m and n. When the vessel contains a pair of such
engines one of the pistons of each engine is connected with the same crank,
that is to say, the pistons of the two smaller cylinders A, A, to a crank m, and
those of the two larger cylinders B, B, to another crank n, or otherwise the
piston of the small cylinder of one engine and that of the large cylinder of
the other engine to the same crank, and these we commonly effect by direct
connections with the cranks, as shewn in these plans.
Sheet 4 contains a sketch, shewing an arrangement referred to also in our
Specification, with the pistons connected to two opposite ends of a beam lever

page_text: which communicates at one end with the crank n by any of the ordinary
methods, or such as shewn in this plan. The distinguishing feature of the
steam valves, as shewn in Sheet 1, 2, 3, and 4, is, that the first in order a, a,
namely, that to the small cylinder, is nierely an induction valve, and so
adjustable as to have a greater or less amount of cut-off, and thereby to
permit the supply of steam to be regulated at pleasure; and that the second
or intermediate valves c, c, serves the several purposes of eduction valve to the
first cylinder A, induction valve to the second or larger cylinder B, and
eduction valve from this cylinder to the condenser P through the eduction
pipe D.
Another improvement consists in arranging the gearing for working the
valves, as shewn in Sheet 1, 2, and 3. S, in Figure 2, is a toothed wheel,
carried loose on the crank shaft; on the side of the toothed wheel is fastened
a frictiou. pulley, with friction brake u and t (Figure 1); by tightening up
this brake handle when the engines are at work, the pinion s is made to
stand still, and the small synochronously carried pinion shaft v, which has a
pinion geared into each excentric, is made to accelerate the motion of the
eccentric till they come to the backing catch, when the engines will of course
go astern, and continuing the action of the brake handle, the engine will
ultimately stop altogether; in the same manner, when the engines are going
astern the brake handle can be tightened up, and the whole machinery will be
made to go ahead or stop, and when the engines are stopped the friction wheel
may be wound to either extremity for going ahead or astern by a hand wheel
and pinion, as shewn in Sheet No. 1. And we do not limit the excentrics to
two, but may be one or more, as may be found to suit different constructions.
In this case there are two; one high-pressure eccentric (Figure 2, Sheet No. 1),
and one low-pressure eccentric (Figure 3, Sheet No. 1) the low-pressure one
is shewn to have nearly a semicircular throw, as the eduction valves have little
lap, and the high-pressure one is shown with about a quadrant throw, as the
high-pressure valves are supposed to have great lap, and their reversing pinions
are made to suit the respective throw of each. The various eccentric rods
carry the motion to their respective valves from those excentrics. .
In Sheet No. 1, Figure 4, is shewn a section of the air pump referred to in
the latter part of the Specification. It will be observed that the pump is double-
acting, and that the in-take valves are on the same level and with equal access
to the condenser; the discharge valves are immediately above the in-take valves,
and placed so as the space between the level of the in-take and discharge valves
may be rather larger than the area of the stroke of the pump, so that the
in-take valves may be continually covered with water. In constructing this

page_text: pump care, should be taken to have the underside of the air pump.cover
inclined as shewn, and perfectly air-tight; also the communication from the
bottom of the air pump. to the discharge valve, should have the top inclined
upwards to that valve for the free discharge of the air, and in some cases an
injection of cold water immediately below the discharge valves may render
more efficient the action of the pump.
Having thus described these, modes of carrying our Invention into effect, we
would recommend the application of steam casings, and efficient felting in all
parts liable to loss of heat either in the boilers; or engines, and that the top and
bottom of the low-pressure cylinders should in all cases be double heated with
steam in order to evaporate any water that may, distil, and that efficient escape
valves, pipes, and cocks be placed at the top and bottom of all the cylinders.
Having thus specified and described the nature of our Invention, and the
best means we are acquainted with for performing the same, we, would have
it understood that what we claim is,-.
First, the arrangements of, the, cylinders, and pistons in relation to, the
cranks as specified.
Second, the arrangement of the steam and eduction valves of the cylinders..
Third, the reversing and valve, gear. The principle feature in reversing is the
causing the excentrics to overrun the crank shaft while at at work by tightening
up a friction brake, thereby reversing the engines without. so much. chance of
damaging the machinery as any other modes hitherto in use..
And, fourth, the air pump. as described and specified..
1
In witness whereof, we, the said Charles Randolph and John Elder,
have hereunto set our hands and seals, this Tenth day of September,
in the year of our Lord One thousand eight hundred and fifty-six.
Witness,
RICH S. CUNLIFF.
CHARLES RANDOLPH. (L.S.)
JOHN ELDER.
(L.S.)