Year: 1887

page_text: Date of Application, 26th Aug., 1887
Complete Left, 26th June, 1888
Complete Accepted, 27th July, 1888
1, JOSEPH FREDERICK THOMPSON, of 3 Gray Road, Sunderland, in the county of
Durham, Engineer, do hereby declare the nature of this Invention to be as follows:-
The object of my invention is to provide an improved method of working the valves
of steam engines, by means of which I am enabled to dispense with the eccentrics,
and the various rods, links and levers, ordinarily employed for such purpose.
I affix to or near the cylinder of a steam engine a small automatic valve steam
engine, of any suitable type. Such automatic engine consists essentially of a cylinder
and piston and a valve or valves. I connect the piston of this automatic engine to the
valve of the main engine, and the valve of the automatic engine is worked directly
by the steam from the boiler. Such working being regulated by the motion of the
main engine.
In the case of engines having more than one cylinder, an automatic engine will be
supplied to each of such cylinders.
Automatic engines may also be provided to work the air pumps and other pumps on
the main engine and to turn the said engine when required.
My invention is more particularly applicable to marine engines, but is not necessarily
confined thereto.
T: 06th day of Angust 1887
AMBROSE MYALL,
21, Cockspur Street, London, S. W.,
Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in Steam Engines.
I, JOSEPH FREDERICK THOMPSON of 3 Gray Road 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:—
The object of my invention is to provide an improved method of working the
valves of steam engines by means of which I am able to dispense with the large
eccentrics and the various rods links levers and heavy reversings gear ordinarily
employed for such purpose and at the same time to secure more accurate working.
I affix to or near the cylinder of a steam engine a small auxiliary cylinder, provided
with a piston, the rod of the said piston being connected, either directly, or through
the medium of suitable mechanism, with the valve of the main cylinder. The auxiliary
cylinder is provided with a valve of any suitable type, worked automatically through
the medium of suitable mechanism from the crank-shaft, or other suitable part of the
main engine.
In the case of engines having more than one main cylinder, an auxiliary cylinder is
fitted to each such main cylinder, but one main cylinder may have two or more
auxiliary cylinders fitted to it, or one auxiliary cylinder, may, in certain cases, work
two or more main valves.
'
In the accompanying four sheets of drawings, Fig. 1 is a side elevation of a
triple-expansion marine steam engine, having my invention applied thereto, according
to one method of carrying out the said invention in practice; Fig. 2 is an end
elevation of Fig. 1., shewing the high pressure cylinder only; Fig. 3 is a plan
of Fig. 1, and Fig. 4 is an elevation on an enlarged scale of the reversing gear, with
the cover removed, and partly in section; Fig. 5 is a side elevation and Fig. 6 is. an
end elevation, shewing an alternative form of gear for operating the valves of the
auxiliary cylinder.
Similar letters of reference denote similar parts throughout the drawings.
A A¹ A² are the three main cylinders of the engine, B B¹ B², the slide valve chests,
C, C, C², the slide-valve rods, and D the crank shaft, all of the usual type. Only
such parts of the main engine being shewn as are actually necessary in order to
explain the nature and operation of my invention. E E E² are the cylinders of the
small auxiliary engines, which are used to drive the slide valves of the main engines.
The piston-rods F. FF2 of these auxiliary engines form continuations of, or are con-
nected directly to the main slide-valve rods CCC, so that the said slide valves are
actuated directly by the pistons of the auxiliary engines. The motion of the
auxiliary engines, and in consequence the motion of the main slide-valves is
governed from the crank shaft D in the following manner :-
Each auxiliary engine is fitted with a slide valve of any usual or suitable type, and
these slide valves are worked by the eccentrics H H H³, on the shaft J. A ring

page_text: bevel wheel K is fixed on the crank shaft and drives a bevel pinion L on the short
countershaft M, a bevel pinion N on this shaft M drives a bevel wheel P on the vertical
shaft Q, and a bevel pinion R on the top of the shaft Q drives the bevel wheel S on
the shaft J. By this means the shaft J is driven from the crank shaft, and the gears are
necessarily so proportioned that the two shafts rotate at the same speed. The
eccentrics H H H², are adjusted to admit steam to the auxiliary cylinders, so that
the said auxiliary cylinders shall operate the slide valves of the main cylinders at the
proper times. The reversing gear is shewn attached, to the valve chest of the main
high-pressure cylinder A, but it may be placed any where along the shaft Q, where
there is a convenient point of attachment to the engine framing. The shaft Q is not
one continuous shaft, but is in two lengths, the upper length Q being driven from Q,
through the medium of the reversing gear. The said gear is constructed as shown
in Fig. 4. T is a casing holted to the valve-chest (the outer half being shewn
removed) within which the ends of the shafts QQ meet. The end of the shaft Q¹
seats in the enlarged end of the shaft Q. Two spur wheels U U¹ Fig. 1, are journalled
upon studs VV, fixed to the casing T and gear with each other. They are rotated
by means of the handwheel W. The ends of the shafts QQ are surrounded by
a sleeve X. The end of the shaft Q' has a long key way or slot Y cut through
it, and a pin Z passes through this slot and the sleeve X.
Helical grooves a a
are cut in the end of the shaft Q, and pins 6 in the sleeve X engage with the
said grooves. On both sides of the sleeve X, racks c c slide in guides in the casing T.
Studs d d on these racks engage with an annular groove in the sleeve ✗. Pinions e e
are fixed on the backs of the spur wheels U U, to engage with the racks cc, so
that when the hand wheel W is rotated, the racks are raised or lowered and the
sleeve X is also raised or lowered, but by reason of the helical grooves a a in the
end of the shaft Q, the said sleeve is caused to partially rotate, carrying with it, by
means of the pin Z, the shaft Q1, and consequently partially rotating the shaft J, and
so moving the valves of the auxiliary engines into the required new position. a is
a quadrant bolted at the side of the casing T, and having a curved slot within
which an arm with a pointer, projecting from the hand-wheel W, can work and be
secured by a lock nut. The party is suitably divided and marked, so that the pointer
indicates thereon the position of the valve gear. By means of this light and readily
operated reversing gear, which has only to move the light valves of the auxiliary
engine the main engines may be readily started, stopped, or reversed.
I do not necessarily confine myself to the use of a reversing gear, constructed
as above described, in combination with the auxiliary engines, as other mechanical
devices which will effect the desired purpose may be employed. As shewn, high
pressure steam is admitted from the boiler direct to the auxiliary high pressure
cylinder E by the pipe f, and the exhaust is supplied to the intermediate and
low-pressure auxiliary cylinders E¹ E² by the pipes on the triple expansion
system, the same as the main engines, the final exhaust from E² being discharged into
the final exhaust of the main engine; or, fresh steam from the boiler may be admitted by
the pipes g' g², controlled by the stop valves h¹, 2, to the intermediate and low-pressure
auxiliary cylinders E' E, the high pressure and intermediate auxiliary cylinders E E',
respectively exhausting into the valve chests B' B2, of the intermediate and low pressure
main cylinders A1 A2 by the alternative exhaust pipes in, which are fitted with the
stop valves jj. The stop valves kk provided in the exhaust pipes f¹ f" are necessarily
closed in this case. This alternative exhaust arrangement becomes necessary in cases
where the exhaust steam from the high pressure auxiliary may not prove powerful
enough to work the heavy valves of the intermediate and low-pressure main cylinders,
and it is obvious that the arrangement of stop-valves admits of the alternative exhaust
arrangement being used for the intermediate auxiliary cylinder only, or for both high
pressure and intermediate, as may prove desirable. Any other suitable arrangement
may however be employed. Thus for example each of the cylinders E E E may be
of equal size, or of sizes varying to suit the varying resistance of the main valves, and
be supplied direct from the boiler and the exhaust be discharged into any or all the
cylinders of the main engine working at a lower pressure. Although the valves of the

page_text: main engine aro described as slide valves, it is obvious that piston-valves, double-beat;
equilibrium, or other suitable kinds of valves may equally well be operated by
auxiliary engines. I is a throtle valve on the auxiliary steam pipe f operated by the
ball pendulum governor m to prevent the engines racing when the vessel is in a see
way. In place of the system of bevel gearing shewn in Figs. 1, 2, 3, and 4, for driving
the auxiliary engine valves, I may employ the arrangement shewn in Figs. 5 and 6.
In this case I affix to the end of the crank shaft D, a small crank pin n carrying an
arm o, on which another crank pin p is fixed at right angles to n. The shaft J is
provided with eccentrics H H H2, for operating the valves of the auxiliary
cylinders E EE2, as before. A disc q is keyed upon the shaft J and an arm is
journalled on the said shaft and carries crank-pins n² p', similar to the crank pins np.
These pins are connected respectively by the long rods s s¹. Projections t¹ aro
provided on the disc q, against either of which the loose arm can bear, and so rotato
the shaft J, one of the said projections is in the correct position for going ahead and
the other for going astern. A pin u may be inserted through holes in the arm r, and
disc q, to secure them in position, and a central hole u may be provided for use when
the engines are to be stopped. To reverse the engines with this arrangement, it is
obvious that it is only necessary to rotate the disc q until the other projection comes in
contact with the arm r. In certain cases the governing of the auxiliary engines by
the motion of the crank shaft may prove inadequate to prevent a waste of power from
possible excess of pressure in the auxiliary engines beyond the pressure needed to drive
them at the required speed, and I therefore propose to employ, when necessary, a
further governing arrangement which shall automatically prevent such waste of power.
The said arrangement consists essentially of a spring or other equivalent contrivance
adjusted to the frictional resistance of the parts to be moved by that body of steam
which acts through the auxiliary cylinders. This spring is so arranged as to yield to any
pressure in excess of the required pressure, and so by means of a valve, or other suitable
contrivance, either to prevent the access of an undue volume of pressure to the auxiliary
cylinder, or to permit the escape of such excess volume of pressure from the auxiliary
cylinder to another cylinder, steam-chest, or part of the engine where such volume can
be more usefully employed. In the less probable event of the steam in the auxiliary
cylinders proving insufficient to drive the valves at the required rate, the supply of
power can be increased by turning on more steam at the valves h h h², also in
certain cases by altering the adjustment of the lead of the valves of the auxiliary
engines.
Although I have only shewn my invention as applied to a triple-expansion marine
engine in the accompanying drawings, it is obvious that its application is not confined
to such type of marine engine, nor to marine engines in particular, although it is more
especially intended for use in connection with marine engines. Nor again is my inven-
tion necessarily confined to steam engines, for engines driven by gas, compressed
air, or other suitable clastic power medium, may have their valves operated by its
means.
Having now particularly described and ascertained the nature of my said Inven-
tion, and in what manner the same is to be performed, I declare that what 1
claim is :-
.1. In an engine driven by steam, or other suitable elastic power medium, the use of
an auxiliary engine, or engines, for operating the valve, or valves, of the main engine,
the valve, or valves, of the said auxiliary engine, or engines, being operated through
the medium of suitable mechanism from the crank shaft, or other suitable moving
part of the main engine, substantially in the manner and for the purposes as herein set
forth.
.
2. In an engine, fitted with an auxiliary engine, or engines, for operating the valves,
the use of a hand reversing-gear operating the valve, or valves, of the auxiliary engine,
or engines so that the said auxiliary engine or engines may automatically reverse the
main engine, substantially in the manner and for the purposes as herein set forth.

page_text: 3. The construction and arrangement of auxiliary engines, for operating the valves
of a main engine, or engines, substantially in the manner and for the purposes as herein
set forth, with reference to Figs. 1, 2, 3, and 4 of the accompanying drawings.
4. In an engine fitted with an auxiliary engine or engines for operating the valves,
the construction and arrangement of bevel gearing for operating the valve, or valves
of the said auxiliary engine, or engines from the crank shaft of the main engine,
substantially as herein set forth with reference to Figs. 1, 2, 3 and 4, of the accoun-
panying drawings.
5. In an engine, fitted with an auxiliary engine, or engines for operating the valves,
the method of operating the valve, or valves of the said auxiliary engine, or engines
from the crank shaft of the main engine, substantially as herein set forth with reference
to Figs. 5 and 6 of the accompanying drawings.
6. In an engine, fitted with an auxiliary engine or engines for operating the valves,
the hand reversing-gear constructed in the manner and for the purposes, substantially
as herein set forth, with reference to Figs. 1, 2 and 4 of the accompanyiny drawings.
7. In an engine, fitted with an auxiliary engine or engines for operating the valves,
the use of a compensating arrangement for automatically limiting and controlling the
volume or pressure of steam admitted to the auxiliary cylinders, substantially in the
manner and for the purposes as herein set forth.