CERTAIN INPROVEMENTS IN STEAM ENGINES
Year: 1873

page_text: LETTERS PATENT to John Ashworth, of Astley Bridge, near Bolton,
in the County of Lancaster, Cotton Spinner, for the Invention of
"CERTAIN INPROVEMENTS IN STEAM ENGINES."
Scaled the 16th January 1874, and dated the 15th November 1873.
PROVISIONAL SPECIFICATION left by the said John Ashworth at
the Office of the Commissioners of Patents, with his Petition, on
the 15th November 1873.
I, JOHN ASHWORTH, of Astley Bridge, near Bolton, in the County of
Lancaster, Cotton Spinner, do hereby declare the nature of the said
Invention for "CERTAIN IMPROVEMENTS IN STEAM ENGINES," to be as
follows:-
My Invention relates to the valve motion, and it consists in an
improved combination and arrangement of machinery for varying the
position of the expansion or cut-off valves, according to the load on the
engine.

page_text: The spindles of the cut-off valves are connected together by toothed
pinions, and the ends of the spindles are screwed through the ordinary
sliding block which is moved to and fro by an eccentric. As the
pinions revolve one screw is screwed into the sliding block, and the other
is unscrewed out of it. One of the pinions above referred to is driven
by a pinion fixed on a shaft which is turned round alternately in
opposite directions by a pair of friction discs acting alternately on a
pulley. The position of the friction discs is changed by the governor.
The friction pulley is attached to a bush to which a worm is fixed,
and this worm gears in a stationary rack, by this means the friction
pulley is moved to and fro over the face of the friction disc, and after
a certain number of revolutions in either direction the pulley is taken
beyond the edge of the disc.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Ashworth in the Great Seal Patent Office
on the 13th May 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
ASHWORTH, of Astley Bridge, near Bolton, in the County of Lancaster,
Cotton Spinner, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of November, in the
year of our Lord One thousand eight hundred and seventy-three, in
the thirty-fourth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said John Ashworth, Her
special licence, that I, the said John Ashworth, my executors,
administrators, and assigns, or such others as I, the said John
Ashworth, 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
"CERTAIN IMPROVEMENTS IN STEAM ENGINES," upon the condition (amongst
others) that I, the said John Ashworth, my executors or adminis-

page_text: trators, 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 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 I, the said John Ashworth, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement (that is to say) :-
My Invention relates to the valve motion and consists in an improved
combination and arrangement of machinery for varying the position
of the expansion or cut-off valves according to the load on the engine.
The spindles of the cut-off valves are connected together by toothed
pinions, and the ends of the spindles are screwed through the ordinary
sliding block, or through the bosses of the connecting wheels attached
to the sliding block, both of which are moved to and fro by an eccentric.
As the pinions revolve the spindles are moved in opposite directions, and
either more or less steam is admitted to the cylinder according to the
position of the governor. One of the pinions above referred to is driven
by a wheel fixed on a shaft which is turned round alternately in opposite
directions by a pair of friction discs acting alternately upon a pulley
attached to the said pinion shaft. The position of the friction discs is
changed by the governor.
And in order that my Invention may be fully understood and readily
carried into operation, I will proceed to describe the three accompanying
Sheets of Drawings, reference being had to the figures and letters marked
thereon.
On Sheet 1 Fig. 1 is an elevation of part of an ordinary horizontal
steam engine to which my improvements are applied, and Fig. 2 is a
plan of the same. a is part of the cylinder; b, the valve box;
c, c, the slide valves which are worked by the eccentric rod e¹ and
spindle c²; d, d, the cut-off valves worked by the eccentric rod & and
spindles &*
; e is the rod connected to the governor, and e³, e³, are a pair
of bevelled friction discs which act alternately on the friction pulley f.

page_text: keyed on the shaft f¹. The parts above enumerated are made in the
ordinary manner.
My improved cut-off motion which is shewn on an enlarged scale
in Figs. 3, 4, and 5, is made in the following manner:-The eccentric
rod d is connected to the sliding block h which is moved to and fro in
the stand i by the eccentric; this sliding block is somewhat similar to those
now is use but it is provided with bearings for the trunnions of the
pinion g, which is made with a square hole for the square end ƒ³ of
the shaft f¹ to which the friction pulley f is fixed, the two parts of the
shaft are connected together when required by the clutch box ƒª. The
sliding block h also supports the trunnions of the pinions d³ which gear
into each other, and which are screwed to fit the screws on the ends of
the spindles & connected to the cut-off valves d, d.
The mode of operation is as follows:-So long as the engine is working
at its proper speed the discs e¹, e³, remain out of contact with the friction
pulley fas shewn in Fig. 1, consequently the shaft f¹, f³, and pinion g
are not turned round, and the expansion valves d, d, remain at the
distance apart which is due to the load on the engine. When the
governor balls expand owing to the increased velocity of the engine the
disc e is raised into contact with the friction pulley f, thereby starting
the shaft f, fs, and pinion g which gears into the lower pinion d³, the
pinions d³ being thus turned round and in opposite directions cause one
of the screws ď³ to be screwed into one of the pinions d³, and the other
to be unscrewed out of the other; the cut-off valves are thus made to
approach or recede from each other, as the case may be, thereby cutting
off the steam earlier and admitting less steam to the cylinder. When
the engine is running too slow the disc e¹ comes in contact with the
friction pulley f and drives the shaft f¹, f³, in the contrary direction,
thereby moving the cut-off valves and increasing the amount of steam
admitted to the cylinder. By this means the position of the cut-off
valves is varied according to the load on the engine.
In Figs. 6, 7, and 8, I have shewn a modification of my Invention.
In this arrangement the sliding block h is moved to and fro as usual by
the ordinary cut-off eccentric rod d, and the spindles d³ of the cut-off
valves are screwed into the sliding block h, the square portions of the 3
spindles & pass through the pinions d³, the trunnions of which revolve

page_text: in the stationary bearing j. The shaft f¹ is driven as before by the
friction discs and pulley shewn in Figs. 1 and 2. As the pinion g'
revolves in one direction or the other according to the position of the
governor balls it causes one of the screws on the spindles & to be:
screwed into and the other to be unscrewed out of the sliding block,
thereby varying the position of the cut-off valves to admit more or less
steam to the cylinder in the manner above described.
On Sheet 2 Figs. 9, 10, and 11 represent another modification of my
Invention. In this arrangement the ends of the cut-off valve spindles d'
are screwed into the sliding block / which is moved to and fro by the
ordinary cut-off eccentric, and these spindles & are connected by the
long pinions d³, one of which is driven from the governor by the
pinion gas before described.
On Sheet 3 I have shewn a modification of my Invention applied to
an ordinary beam or vertical steam engine. Fig. 12 is an elevation of
the engine, and Fig. 13, a plan of the cylinder; Figs. 14 and 15 are
detached views of my improvements drawn full size. a is the cylinder;
b, the valve box; e, the rod from the governor connected to the conical
friction discs e¹, e, which act alternately on the friction pulley f as before
described; the horizontal shaft f¹ is connected to the vertical shaft ƒ³
by the bevel pinions f*, and the lower end of the shaft f³ is square and
passes through a square hole in the pinion g. The sliding block his
is moved up and down from the ordinary rocking shaft m to which the
lever is fixed, and to this lever is jointed the lower end of the
connecting rod k, the upper end of which is jointed to the cross head ²
which is connected to the sliding block h by the side rods h¹. The
pinion g works as before described in the pinion & as shewn in Figs. 14
and 15, and this pinion gears into the second pinion &³, both of which
serve as nuts for the screws on the cut-off valve spindles d³. The action
of these parts is similar to that described in reference to Sheet 1.
Having thus stated the nature of my Invention and described several
convenient modes of performing the same, I wish to remark that I do
not intend to limit myself to the details given, as the same may be
varied according to the peculiar construction of the steam engine to
which the improvements may be applied, I wish it also to be understood
that I make no claim to the combination of machinery connected to a

page_text: sliding block for varying the position of the cut-off valves, as such
combinations have before been used, but what I do claim is the
combination of the sliding block with the pinions & and d³, and
screwed spindles & connected to the cut-off valves for varying their
position according to the load on the engine, as shewn and described.
In witness whereof, I, the said John Ashworth, have hereto set
my hand and seal, this Twelfth day of May One thousand eight
hundred and seventy-four.