IMPROVEMENTS IN STEAM ENGINES
Year: 1868

page_text: LETTERS PATENT to William Tasker, the younger, of the Waterloo
Iron Works, near Andover, in the County of Hants, for the
Invention of "IMPROVEMENTS IN STEAM ENGINES."
Sealed the 3rd November 1868, and dated the 13th May 1868..
PROVISIONAL SPECIFICATION left by the said William Tásker at
the Office of the Commissioners of Patents, with his Petition, on
the 13th May 1868..
I, WILLIAM TASKER, the younger, of the Waterloo Iron Works,.
near Andover, in the County of Hants, do hereby declare the nature
of my said Invention for "IMPROVEMENTS IN STEAM ENGINES," to be as.
follows:-
The object of this Invention is to regulate the supply of steam (or-
vapour) passing into the cylinder or cylinders of steam engines by
altering the travel of the valve or valves, which will also enable the
steam to be given to or cut off from the engine at any required period.
during the stroke.

page_text: In carrying out this Invention two or more eccentrics are employed
placed within or upon each other so that they can be moved backwards
or forwards separately or at the same time, making the sheave round
which the eccentric strap works more or less eccentric, and thus
regulates the travel of the valve or valves and consequently the admission
of the steam. The eccentrics may be fastened in any adjusted position
to an ordinary disc or reversing plate by bolts, screws, or any other
convenient means..
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Tasker in the Great Seal Patent Office
on the 12th November 1868..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
TASKER, the younger, of the Waterloo Iron Works, near Andover, in
the County of Hants, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of May, in the year
of our Lord One thousand eight hundred and sixty-eight, in the
thirty-first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Tasker, the younger, Her
special license that I, the said William Tasker, the younger, my
executors, administrators, and assigns, or such others as I, the said
William Tasker, the younger, my executors, administrators, or 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 William Tasker, the
younger, 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 immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Tasker, the younger, do
hereby declare the nature of my said Invention, and in what manner

page_text: the same is to be performed, to be particularly described and ascertained
in and by the following statement reference being had to the accom-
panying Drawings and to the letters and figures marked thereon, that
is to say:-
My said Invention relates to certain improvements in portable and
other steam engines whereby great economy in the consumption of
fuel and water is effected, and consists essentially of an arrangement
for enabling the travel of the valve or valves of steam engines to be
altered or adjusted at pleasure so as to vary the opening of the steam
ports and thereby regulate the supply of steam passing into the cylinder,
whilst at the same time the engine is enabled to cut off the steam at
any point required during the stroke.
In carrying out my Invention I employ two or more eccentrics
placed and working either one within another or one on another with
a view to making the outer sheave of the combined eccentrics more
or less eccentric, and thus regulating the travel of the valve or valves
accordingly. The eccentrics may be fastened to an ordinary reversing
disc or plate by bolts, screws, or any other convenient fastening.
And in order that my said Invention may be fully understood I
shall now proceed more particularly to describe the same, and for that
purpose shall refer to the several Figures on the annexed Sheet of
Drawings, the same letters of reference indicating corresponding parts
in all the Figures.
Figure 1 of my Drawings is a side elevation showing part of the
crank shaft with my improved adjustable eccentric and an ordinary
reversing disc or reversing plate fitted thereon; Figure 2 is an end
clevation of the same; Figure 3 is an ordinary reversing disc or plate
detached; Figure 4 is a detached side elevation of the smaller eccentric
which works within the larger eccentric, shown also detached in side
clevation at Figure 5.
In these Figures A represents the crank shaft; B, the large eccentric
within which works the small eccentric C; D, is the ordinary reversing
disc or plate by which the eccentrics are maintained in their adjusted
position, as herein-after explained, by means of the bolt E and nut F.
The mode I prefer to adopt for altering and adjusting the eccentric A.
is as follows:-At various distances on the outer edge of the smaller

page_text: eccentric C several semicircular or other shaped notches a, b, c, are
cut, the said distances being determined according as it is required to
cut off the steam or to close the port at ,,, or any other point
of the stroke. On the inner edge of the larger eccentric A other
correspondingly shaped notches d, e, f, are made at various distances
according to the relative size of the two eccentrics. The bore of the
larger eccentric is such that the smaller fits it so as to enable the two
to be turned on or round the crank shaft independently of each other.
In adjusting the eccentric a notch in the smaller one C is turned
opposite to the corresponding notch in the larger eccentric, and the
two eccentrics are held together by a pin E or other convenient
fastening passing through them both and through a hole g in the
reversing disc D, the said pin or bolt being fixed as shown in Figure 1
by a nut or otherwise. A greater or less number of notches in both
or either of the eccentrics may be made if required.
This Invention is of the greatest importance for agricultural engines,
which are required to work at different times under very different
loads. For example it may be required at one time to drive a threshing
machine and straw elevator, which will require the full power of the
engine, whilst on another occasion it is simply required to work a chaff
cutter or root pulper only, in which latter case a small portion of the
power of the engine only is required. Under these and other similar
circumstances the following advantages will be obtained, videlicit :-
First. By means of my adjustable eccentric I regulate the supply of
steam passing into the cylinder according to the amount of power
required to be exerted, the alteration being made in the size of the
steam port instead of opening or shutting the stop or starting valve
as is usually done, and by these means I avoid what is usually known
as wiredrawing the steam.
Second. By shutting the port at any point or time required during
the stroke I work the steam expansively in relation to the amount of
power required.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used
or carried into effect, I would observe in conclusion that what I
consider to be novel and original, and therefore claim as the Invention
secured to me by the herein-before in part recited Letters Patent is,
the combination of two or more adjustable eccentrics working one within

page_text: another or one on another and secured in any adjusted position on
the crank shaft by any convenient mechanical arrangement, substantially
as and for the purpose herein-before described.
In witness whereof, I, the said William Tasker, the younger,
have to this my Specification set my hand and seal, the
Eleventh day of November, One thousand eight hundred and
sixty-eight.
WILLIAM TASKER, JUN. (L.S.)