IMPROVEMENTS IN WORKING THE VALVES OF STEAM ENGINES
Year: 1856

page_text: LETTERS PATENT to James Mash, of the City of Manchester, in the
County of Lancaster, Engineer, for the Invention of "IMPROVEMENTS IN
WORKING THE VALVES OF STEAM ENGINES"
PROVISIONAL SPECIFICATION left by the said James Mash at the
'Office of the Commissioners of Patents, with his Petition, on the 81st
January 1856:
را
I, JAMES MASH, of the City of Manchester, in the County of Lancashire,
Engineer, do hereby declare the nature of the said Invention for IMPROVE-
MENTS IN WORKING THE VALVES OF STEAM ENGINES, to be as follows:-
My Invention of improvements consists in working or actuating the slide
and other like descriptions of valves of steam engines, by which the distribution
of the steam is effected in such manner, that the supply of steam to the
cylinder may be cut off or suspended at variable portions of the length of the
stroke of the piston as desired.
Figure 1 represents my improved motion (as one modification) as applied to
an ordinary beam steam engine. The excentric. A is fixed upon the crank
shaft B, so as to have its greatest or full throw, with respect to the valve, .when
the piston is at the end and beginning of its stroke. The excentric strap or
lever C is suspended at its back end by the link D from a. fixed stud-E; the
other or front end carries a block capable of moving in the link F, which is

page_text: suspended by the links K and L, K-being jointed to the regulating lever M,
and L to the expansion bell crank lever N, moving on the fixed stud O; the
other arm is connected by the rod P to the excentric lever. The slotted link F
also carries the rod G to the valve. The action is thus: the eccentric in
moving round carries down the front end of the excentric lever, the block on
which moving down the slotted link, will, by its inclination, draw the link and
the rod, and thereby moving the valve, opens the port for the supply of steam
to the cylinder, at the same time the rod P moves the expansion bell crank N,
and link L alters the inclination of the slotted link, and causes a receeding
action on the valve, which will close the port earlier than would be otherwise
done. By the regulating handle the relative inclination of the slotted link is
adjusted, and the period of cut-off of the steam by the valve determined. By
this modification the movement of the engine can be reversed by simply
reversing the relative inclination of the slotted link.
Figure 2 represents a modification as applied to a similar engine, the
excentric being fixed on the crank shaft in the ordinary position. The end of
the excentric rod is attached to the slotted link, which is suspended by links,
as before. The block traversing the slotted link is carried by the lever to
which the valve is attached. The inclination of the slotted link, as before
stated, determines the period of cut-off and amount of expansion of the
steam.
Figure 3 shows a modification applied to a vertical oscillating cylinder
engine. The traverse of the block in the slotted link is here obtained by the
oscillation of the cylinder.
My approved motion may be adapted and applied to engines where the
ordinary link motion is employed. The governor or other regulator of the
engine may be connected, so as to render the motion self-regulating.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Mash in the Great Seal Patent Office on the
81st July 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
MASI, of the City of Manchester, in the County of Lancaster, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirty-first day of January, in the year of our Lord

page_text: One thousand eight hundred and fifty-six; in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said James Mash, Her special license that I, the said James Mash, my
executors, administrators, and assigns, or such others as I, the said James
Mash, 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 WORKING THE
VALVES OF STEAM ENGINES, upon the condition (amongst others) that I, the
said James Mash, by an instrument in writing under my hand and seal, 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said James Mash, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, that is to say :-
My Invention of improvements relate to the working and actuating the
valves or other distributors or regulators of steam in steam engines, as slide
valves, valves known as D valves, piston valves, or other distributors or
regulators of steam, having sliding or continuous actions or movements, and
consists in working and actuating these or any of them by new and improved
arrangements, or combinations of excentrics or cranks, with other mechanical
parts, wholly or in part, and imparting to the valves or other distributors or
regulators of steam, actions or movements different from the actions or move-
ments usually or hitherto communicated or imparted to these descriptions of
valves, or other distributors or regulators of steam, by any previous arrange-
ments or combinations of mechanical parts which derive their actions or move-
ments or parts of them from the rotary movements of excentrics or cranks.
One important feature in my Invention is, that the actions or movements
imparted to the valves or other distributors.or regulators of steam approaches
very nearly to that of intermittent actions or movements imparted by cams.
And these actions or movements are, that relatively quicker movements or
greater rates of velocities than is usually the case are imparted to the valves
or other distributors or regulators of steam, just before and during the opening
of the steam ports for the admission of steam to the cylinders, and also just
before and during the opening of the exhaust ports for the emission of the

page_text: steam therefrom, and that relatively slower movements or less rates of velocities
are imparted after the closing of the steam ports.
Another important feature in my Invention, when in-proper and effective
connection and communication with the governors of steam engines, is; that
the closing of the steam ports by the valves or other distributors or regulators
of steam is caused to take place at proportionately earlier or later periods of
the strokes of the pistons of the engines, dependent upon variations of the rates
of velocities of the engines, and this is effected without affecting the closing or
the opening of the exhaust ports for the compression or the emission of the
steam from the cyl to any considerable extent. Still it is not absolutely
essential that my improvements should be used and employed in connection
and in combination with the governors of steam engines, as when not so
employed the adjustment may be regulated, when required, by the attendant.
In some of the modifications of which my Invention is susceptible, and which
I sometimes use and employ, another important feature presents itself, as
particularly usefull, and adapted to those classes of steam engines in which it is
desireable or necessary that the directions of rotation of the crank shafts should
sometimes be reversed, as locomotive engines, marine engines, and pit winding
engines, for example; and this means of reversing I obtain simply by. reversing
or altering the relative positions of portions or parts of the mechanical arrange-
ments, the effect of which is to reverse the actions or movements of the valves
or other distributors or regulators of the steam, and so to reverse the arrange-
ments of the distributions of the steam:
1
In some modifications of my Invention another important feature presents
itself, more particularly applicable to steam engines which are subject to work
and operate under variable loads or resistances, or with variable general rates
of speed. This feature is, the facility which exists in these particular modi-
fications of varying and altering the general positions of the valves or other
distributors or regulators of the steam, so as to alter and vary what is technically
known as the lead of the valve.
I
..
I will proceed to explain the accompanying Drawings, and describe more
minutely my 'Invention. One modification of it is shown in Figure 1, where it
is represented as adapted and applied to an ordinary beam steam engine.
The connecting rod, crank, and shaft here shown are of the ordinary and
usual construction, and therefore form no part of my Invention.
Upon the crank shaft B is secured the excentric A, in such a position as to
have its greatest or full throw or traverse, or nearly so, with relation to the
valve worked or actuated by it, when the piston of the engine is at the end of
or beginning of its strokes (or what is technically) or at the centres. The
•

page_text: excentric strap or lever C is suspended at its back end by the link D from the
stud E, fixed to the standard E'; the other or front end carries a block, capable
of moving or sliding in the slotted link F, suspended by the links Kand L,
the link K being jointed to the regulating lever M; and the link L.to the
expansion lever N. Both the levers move upon the fixed stud O. The other
arm of the expansion lever N is connected. by the rod P to the excentric
lever C; the slotted link F also carries one end of the rod G, the other end of
which is connected, by any old and convenient means; to the valve. The
regulating lever M may be connected to, and its position adjusted and regulated
by the governor Q; this connection may be made in any convenient manner,
as the mode of doing so forms no part of my Invention; but the method I here
show is that which I at present prefer to make use of: The second arm.of the
regulating lever M is formed of a worm segment, into which gears a worm
upon the worm shaft R; the other end of this shaft carries the bevil wheel S,
gearing into two bevilled wheels 'loosely upon the rod of the governors The
inside of the bosses of these two wheels are formed conical, to receive the cones
attached by rods to the arms of the governor, and when the action of the
governor brings the one or the other of the cones into close contact and. gear,
the worm shaft will be caused to rotate the one way or the other, and through
the worm segment move the regulating lever, and so adjust the action of
working of the slotted link F, by which the point or time of closing the steam
ports will be determined; when there is no connection with the governor,
then the regulating lever may have a handle attached, and a means provided
for securing it in any desired position, so as to be adjustable at pleasure, or it
may be fixed in any determined position. The action of this modification of
my Invention is thus :-The excentric, in moving round in the direction of the
arrow from the position shown, carries downward the front end of the excentric
lever, and the block upon the end of which, moving in the slot of the slotted
link, will, by reason of the relative inclination of that link, draw the link and
the rod attached to it, and communicating to the valve towards the excentric,
and thereby act upon and move the valve; at the same time the rod P moves
the expansion lever so as to alter and vary the inclination of the slotted link,.
and thereby effect the action and movement of the valve, and by causing a
receding action, close the steam port earlier than would otherwise be done.
The general adjustment of the relative angle of inclination of the slotted link
can be made and effected by the engine attendant by moving the handle U
round in either direction. The lead of the valve may be altered or readjusted
by the stud E being moved and again fixed in another part of the slot of the
standard E', so as to alter & vary the relative inclination of the link D, the

page_text: amount of such in either direction determining the amount of alteration of the
lead, whether greater or less than before.
Figure 2 represents a modification as applied to a similar engine with the
excentric fixed upon the crank shaft in the usual manner and position. The
end of the excentric rod is attached to the slotted link, which is suspended and
connected by links. The block traversing the slotted link is carried by the lever,
to which the valve is usually attached, the adjustable inclination of the slotted
link, as before, determining the period of closing of the steam ports.
Figure 3 represents a modification adapted and applied to a vertical oscillating
cylinder engine. The slotted link is attached to the excentric rod, and the
movement of the block within its slot is obtained from the oscillation of the
cylinder, the block being mounted upon a lever attached or connected to the
valve, as usual.
In those modifications where it may be desirable to be enabled to reverse
the directions of rotations of the crank shafts of the engines, it is effected simply
by reversing the relative angles of inclinations of the slotted links.
I will here observe, that though I show & describe some modifications of
my Invention, still I do not confine myself thereto, as other modifications or
parts may be employed.
In witness whereof, I, the said James Mash, have hereunto set my
hand and seal, this Twenty-sixth day of July, in the year of our Lord
One thousand eight hundred and fifty-six.
JAMES MASH. (L.S.)