CERTAIN IMPROVEMENTS IN STEAM ENGINES
Year: 1862

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PROVISIONAL SPECIFICATION left by Edward Kenworthy Dutton at the
Office of the Commissioners of Patents, with his Petition, on
23rd July 1862.
I, EDWARD KENWORTHY DUTTON, of Stretford, in the County of Lancaster,
Mechanical Draughtsman, do hereby declare the nature of the said Invention
for "CERTAIN IMPROVEMENTS IN STEAM ENGINES," to be as follows:-
My Invention relates principally to that portion of the steam engine
generally known as the slide valve, and to apparatus connected therewith, and
consists, firstly, in admitting the steam to the inside of the valve through a
port" in the valve face usually cast on the cylinder, the said port, by pre-
ference, corresponding in position to the ordinary exhaust port, the "exhaust
steam" passing into the valve box. The valve may be of a similar form to
that ordinarily used for "high-pressure" engines, suitably furnished with a
plate on the back or other equivalent to keep it to the face on the cylinder,
or it may consist of a block or plate with a port through its centre sliding
between an adjustable plate and the "valve face," constituting what is known
as an equilibrum valve; the plate on the back of the valve sustaining the
pressure of the steam.
The second part of my Invention is designed principally for the purpose of
saving a portion of the steam usually lost in the passages between the ends
of the cylinder and the valve, and the improvement consists in making the
valve sufficiently long to discharge the steam into ports formed at or near.

page_text: each end of the cylinder, the steam being admitted to the centre of the valve
from a port or ports in the "valve face," and thence through passages cast or
formed in the valve to the cylinder ports through openings or cross passages
at each end of the valve, which said cross passages, together with the opening
in the centre of the valve, are open through from front to back, and are closed
at the back by a plate or plates, between which and the "valve face" the
valve slides; the said plate or plates being adjusted in distance from the
"valve face" by means of screws or bolts and nuts, springs being added to
sustain the pressure of the steam, if preferred. The exhaust steam may either
be allowed to pass into the valve box, or it may be conducted to openings in
the "valve face" through passages formed in the valve, or partly in the valve
and partly in the adjustable plate, in which case the valve box may be opened
for the adjustment or inspection of the valve during the working of the
engine.
The third part of my Invention consists in a novel method of "cutting off
the steam" from the cylinder at any portion of the "stroke" when working
expansively. For this purpose I form the longitudinal steam passages in the
valve described as the second part of my Invention, or in a modification
thereof of a cylindrical form, a hollow cylinder being fitted into each end, so
as to slide easily, the steam passing through the sliding cylinders on its way
to the "cross passages." The cylinders are attached to a rod working, by
preference, through the "valve rod" (made hollow for that purpose), which is
connected at the end outside the valve box to one arm of a "bell-crank lever," the
other arm of which is connected by means of a rod with another lever, which
is operated upon at the proper times by a suitable motion attached to the
working parts of the engine, the effect being to cause the "hollow cylindlers" to
slide in the valve at each end alternately a sufficient distance to close the cross
passages at the end of the valve towards which the cylinders are moved,
thus shutting off the steam from the main cylinder. I prefer to attach the
fulcrum of the "crank lever," immediately connected with the expansion valvo
rod, to the rod working the slide valve, so that the movement of the slide valvo
does not interfere with the action of the expansion valve, both valves moving
together until such time as the steam is required to be cut off. The expansion
valve rod may be screwed at each end, and the "cut-off" cylinders mounted
upon it in such a manner that they may be adjusted from the outside of th
valve box by turning the said rod in either direction. The expansion valve i
described above as being cylindrical, but it may be made of a quadrilateral o
any other section than cylindrical, if preferred. The expansion valve may b
actuated by a suitably formed cam placed on the "crank shaft," and furnishe

page_text: with a "worm " and "worm wheel," or other equivalent for the purpose of
regulating the expansion, or by the following novel arrangement :-To one
end of a lever actuating the "bell-crank lever" on the valve rod is attached
an antifriction roller or stud, which is operated upon alternately by two
inclines or "tappits" carried by a sliding bar or frame, which is caused to
reciprocate by being connected to a reciprocating portion of the engine, or
to a crank, eccentric, or cam on the engine shaft. One of the inclines is
reversed with regard to the other, so that as they come in contact with the
roller or "bowl" on the lever, the said roller is alternately moved in opposite
directions a distance sufficient to cut-off the steam. The inclines turn on
centres, so as to yield to the roller when moving back, and may be fitted to
slide in the frame, so as to "cut off" at any portion of the stroke of the piston.
In another arrangement the inclines may be mounted upon screws connected
together with gearing, or upon racks worked by a pinion, a handle or hand
wheel being fixed upon one of the screws, or upon the rack pinion shaft, by
which arrangement the inclines may be moved in oposite directions, and the
amount of expansion thereby regulated whilst the engine is in motion. The
amount of expansion may be indicated on a scale attached to or marked upon
the bar or frame by an index moving with one of the inclines.
The forth part of my Invention consists in a novel construction of regu-
lating or diminishing valve for steam engines and other purposes. In a
cylinder furnished at the sides with the necessary passages for the entry and
exit of the steam two hollow cylinders are fitted to slide easily, and are
connected to pistons fitted into the covers at the ends of the cylinder in such
a manner that each inner cylinder moves in unison with the piston farthest
from itself, the steam being admitted between the inner ends of the cylinders,
and passing through them in contrary directions to the exit passages acting on
the pistons to close the valve, a weight equivalent to the pressure of steam
required being applied to the outer ends of the pistons, and tending to open
the valve, the action of the two forces effecting the reduction of the pressure
of the steam, as is well understood.