IMPROVE- MENTS IN STEAM ENGINES
Year: 1870

page_text: LETTERS PATENT to Max Eyth, of the Steam Plough Works, Leeds,
in the County of York, Engineer, for the Invention of "IMPROVE-
MENTS IN STEAM ENGINES."
PROVISIONAL SPECIFICATION left by the said Max Eyth at the
Office of the Commissioners of Patents, with his Petition, on the
5th August 1870.
I, MAX EYTH, of the Steam Plough Works, Leeds, in the County of
York, Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN STEAM ENGINES," to be as follows:-
This Invention has for its object improvements in steam engines.
In steam engines in which a slide valve is employed I replace the
ordinary link motion by an arrangement which is less complicated, less
costly, and less liable to wear and tear. For this purpose I mount a
cylindrical block on the crank shaft of the engine. The axial line of
the block is inclined to that of the shaft, and the block is divided
longitudinally in the plane of the two axes. The block is able to slide

page_text: along the shaft, but it is prevented from rotating upon it by a key
passed through the shaft and projecting between the two parts of the
block. A plate or ring at either end of the block holds its two halves
or parts together. The eccentric or tumbler which by means of an
eccentric rod gives motion to the valve is mounted upon the block.
The two projecting ends of the aforesaid key are firmly fixed to the
tumbler and prevent by this means any lateral movement of the tumbler,
and compel it to revolve with the shaft. When the block is moved
along the shaft it slides through the tumbler, and in consequence of its
inclination to the shaft it in so doing varies the distance of the centre
of the tumbler. from that of the shaft, thus the position of the block
may be set so as to give any amount of throw required to the tumbler;
or by the movement of the block the centre of the tumbler may be
transferred from one side of the shaft to the other to reverse the motion
of the engine. The block may be shifted along the shaft by means of a
hand lever or otherwise.
Also, according to my Invention, I employ a single eccentric to give
motion to the slide valves of a double cylinder engine. The one
eccentric may be adjustable and reversible as above described and is
mounted on the crank shaft. The eccentric strap has two lugs or pro-
jections upon it at right angles to each other (provided the cranks of the
two cylinders are, as is usual, turned at right angles), one lug or pro-
jection is connected directly to the valve of one engine, the other is
connected with one arm of a right angle lever, to which it conveys a
rocking movement, and the other arm of this rocking lever communicates
motion to the valve of the second engine. Whenever the cranks of the
two cylinders to which the motion has to be applied are not placed at
right angles to each other I alter the relative positions of the lugs
aforesaid and also the angle of the lever correspondingly.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 3
filed by the said Max Eyth in the Great Seal Patent Office on the
3rd February 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MAX EYTH,
of the Steam Plough Works, Leeds, in the County of York, Engineer,
send greeting.
3

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of August, in- the year
of our Lord One' thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Max Eyth, Her special licence that
I, the said Max Eyth, my executors, administrators, and assigns, or
such others as I, the said Max Eyth, my 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 STEAM ENGINES,'
upon the condition (amongst others) that I, the said Max Eyth, my
executors or administrators, by an instrument in writing under my, or
their,. or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, 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.
39
NOW KNOW YE, that I, the said Max Eyth, 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 :-
This Invention has for its object improvements in steam engines. In
steam engines in which a slide valve is employed I replace the ordinary
link motion by an arrangement which is less complicated, less costly,
and less liable to wear and tear. For this purpose I mount a cylindrical
block on the crank shaft of the engine. The axial line of the block is
inclined to that of the shaft, and the block is divided longitudinally. The
block is able to slide along the shaft, but it is prevented from rotating
upon it by a key passed through the shaft and projecting between the
two parts of the block. A plate or ring at either end of the block holds.
its two halves or parts together. The excentric or tumbler which by.
means of an excentric rod gives motion to the valve is mounted upon
the block. The two projecting ends of the aforesaid key are firmly
fixed to the tumbler, and prevent by this means any lateral movement
of the tumbler, and compel it to revolve with the shaft. When the
block is moved along the shaft it slides through the tumbler, and in

page_text: and the excentric rod is fastened to it. By means of a fork (such as
is shown in Figures 4 and 5), the cylinder c may be moved along the
shaft in one direction or the other, and thus the throw of the excentric
is varied or reversed, and a corresponding change effected in the amount
of expansion or the direction of motion of the engine.
Figure 4 is a side view, and Figure 5 a horizontal section of the
apparatus as it is applied to double cylinder engines in which the
cylinders are parallel the one to the other. In this case the excentric
strap g has two forked ends g¹ and 9²; the end g¹ is jointed directly
to a rod h, which is also connected with the stem of the slide valve of
one of the cylinders, whilst the other end g² is jointed to the lever arm i
on the axis ; is another arm on the same axis. The parts i, , and ³,.
thus form together a bell crank or a two-armed lever with the arms at
right angles or nearly so. To the arm is connected the rod h² passing
to the stem of the slide valve of the other cylinder. The angle between
the ends and g² is the same as the angle of the cranks, usually a right
angle; k is a double fork embracing studs upon a belt / encircling the
ring e, and by it the ring and the divided cylinder may be moved along
the shaft and held in any desired position.
In these arrangements it will be remarked that the sliding part c by
which the throw of the valve is varied and reversed being of cylindrical
form it is easily fitted by lathe work both to the tumbler and to the
shaft.
It will also be observed that the method above described of working.
the slide valves belonging to both the cylinders of a double cylinder
engine is applicable independently of the apparatus for varying and
reversing the motion of the valves, which is shown in the same Figures
with it.
Having thus described the nature of my said Invention, and the
manner of performing the same, I would have it understood that I claim
as my improvements in steam engines the general arrangement of
apparatus substantially as described.
I also claim the combination of the oblique divided cylinder c, the
tumbler f, and the key b, substantially as described.
I also claim the construction of double cylinder engines in such
manner that the slide valves of the two cylinders are both controlled by
the same excentric from which two motions are taken at an angle the

page_text: one to the other corresponding to the angle at which the cranks are set,
these motions as they are transmitted to the valves being brought
parallel to each other by means of a bell-crank lever or an equivalent
instrument or instruments, substantially as described.
In witness whereof, I, the said Max Eyth, have hereunto set my
hand and seal, this 28th day of January, in the year of our Lord
One thousand eight hundred and seventy-one.
MAX EYTH. (L.S.)