IMPROVEMENTS RELATING TO THE SLIDE VALVES OF STEAM ENGINES
Year: 1874

page_text: LETTERS PATENT to George Haseltine, of the "International Patent
•
Office," Southampton Buildings, London, Doctor of Laws, for the
Invention of "IMPROVEMENTS RELATING TO THE SLIDE VALVES OF STEAM
ENGINES." A communication from abroad by Samuel Frederick
Hodge, of Detroit, Michigan, United States of America, Machinist.
COMPLETE SPECIFICATION filed by George Haseltine at the Office of
the Commissioners of Patents, with his Petition and Declaration on
the 29th December 1874, pursuant to the 9th Section of the Patent
Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
HASELTINE, of the "International Patent Office," Southampton Buildings,
London, Doctor of Laws, send grecting.
-
WHEREAS I am in possession of an. Invention for "IMPROVEMENTS
RELATING TO THE SLIDE VALVES OF STEAM ENGINES," and have petitioned
Her Majesty to grant unto me, my executors, administrators, and
assigns, Her Royal Letters Patent for the same, and have made solemn

page_text: Declaration that it has been communicated to me from abroad by Samuel
Frederick Hodge, of Detroit, Michigan, United States of America,
Machinist.
NOW KNOW YE, that I, the said George Haseltine, do hereby declaro
that the following Complete Specification, under my hand and scal,
fully describes and ascertains the nature of the said Invention, and in
what manner the same is to be performed, in and by the following
statement, reference being had to the accompanying Drawing, forming
a part of this Specification.
The object of this Invention is to construct a steam valve which can
be easily applied to any of the steam engines in common use, as well as
to new engines, in place of the valves heretofore employed, whereby the
steam is economized and an easy action of the piston secured. The
main principle of its operation is effecting periodically the introduction
by means of a single valve and ordinary ports of a portion of the
exhaust steam into the ends of the cylinder behind the piston and using
such steam in the backward and forward strokes of the piston as a steam
cushion; and the said Invention consists in the construction of the valve
and in its combination with the other parts of the engine to effect that
purpose, as I will now proceed to describe.

page_text: such relation to the bridge that whenever either steam port C or D is
entirely closed, the exhaust is at that moment partially open, in other
words whenever the exhaust is wholly closed, as in Figure 2, the passage
from one end of the cylinder to the other is open, as at a, a¹, and
whenever the port E for the exhaust or dead steam is wholly or partially
open, as shown in Figures 1, 3, and 4, the port D for the live steam is
cither closed, as shown in Figure 3, to cut off the steam, or open, as
shown in Figures 1 and 4, to admit steam to thic piston.
.
In Figure 1 the piston B is supposed to have made a partial move-
ment to the left, and the valve F has been moved by its mover far
enough to open the port D, and admit live steam from the steam chest
into the cylinder, and to allow the live steam port C and the exhaust
steam port E to be in full communication. As the piston continues its
movement to tho left and arrives at a certain position, the valve F is then
moved to the right, and in its movement cuts off the live steam at the
port D for an instant, without entirely closing the exhaust, as indicated
in Figure 3, and the piston still moving to the left, and the valvo still
moving to the right, the valve the next instant assumes the position
shewn in Figure 2, and cuts off the live steam from the chest, and
completely closes the exhaust passage E, and leaves small communi-
cations as at a, a¹, with the segmental passage G, and thereby establishes
a communication between the two ends of the piston cylinder, as
indicated by the arrows in Figure 2. In an instant more the valve has
moved far enough to cut off the communication of passago C, with the
cxhaust passage E, and to confine all the remaining exhaust or dead
steam in the left hand end of the cylinder, where it forms a cushion for
the finishing stroke of the piston, thus serving to assist in arresting its
movement without unnecessary and injurious jarring. The piston is now
ready to return to the right, the valve moves on to the right opening,
the port C to the live steam in the chest, and putting the ports D, E,
into communication, the live steam rushing in through the port C,
finds the left hand end of the cylinder already full of steam, and is
therefore ready to exert at once its whole force upon the piston,
which moves immediately toward the right, the operation of all the
parts upon the return stroke being the reverse of that already
described. In the section Figure 3, the piston head is shewn as it
appears, when it has almost completed its stroke toward the right, the
valve D being closed so that the steam in that end of the cylinder forms
a cushion.

page_text: In constructing the valve the bridge o may be supported by a bolt or
bolts extending from it up through the back of the valve, the said bolts
being screwed or otherwise fastened to the valve and bridge in any
manner that may be preferred. This valve while adapted to all new
engines of the forms in common use, can also bo casily applied to old
engines, it being only necessary to remove their valves, insert the bridge
o between the ends of the steam space to cover the exhaust, and if
required elongate the steam space in the face of the valve, so that it will
leave the communications a, a', between the ends of the cylinder open
when in the position shown in Figure 2.
The effects of this construction which has been subjected to the most
complete practical tests, are to greatly decrease the expenditure of the
steam, to increase the power, and to make the engine run smoothly
and easily, and therefore wear much longer than when constructed as
heretofore.
Having thus fully described the said Invention as communicated to
me by my foreign correspondent, and the manner of performing the
samc, I wish it understood that I claim a slide valve F, having an
exhaust steam passage in it, communicating with the live steam ports
of the steam cylinder, and constructed and operated to establish
periodically, a communication between the chambers at the ends of the
cylinder, at the front and rear of the piston, and to admit at cach
stroke a portion of the exhaust steam into the cylinder, and confine the
same to make it serve as a cushion to the piston in its backward and
forward strokes; said valve also being constructed and operated
to admit the live steam, and exhaust the dead steam as occasion requires
as above described.
In witness whereof, I, the said George Haseltine, have hereunto
set my hand and seal, this Twenty-ninth day of December, in tho
year of our Lord One thousand eight hundred and seventy-
Witness,
HY. JA. NOONE.
GEORGE HASELTINE. (L.S.)