IMPROVEMENTS IN BALANCED SLIDE VALVES
Year: 1875

page_text: LETTERS PATENT to Georgo Haseltine, of the "International Patent
Office," Southampton Buildings, London, Doctor of Laws, for
the Invention of "IMPROVEMENTS IN BALANCED SLIDE VALVES."-A.
communication from abroad by Edward Tilden Smythe, of the City
and State of New York, United States of America.
COMPLETE SPECIFICATION filed by the said George Haseltine at the
Office of the Commissioners of Patents, with bis Petition and
Declaration, on the 4th February 1875, 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 greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
BALANCED SLIDE VALVES," 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 Declaration that it has
been communicated to me from abroad by Edward Tilden Smythe,
of the City and State of New York, United States of America.

page_text: NOW KNOW YE, that I, the said George Haseltine, do hereby
declare that the following Complete Specification, under my hand and
seal, 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.
This Invention relates to improvements in balanced slide valves, and
consists mainly in the combination with a slide valve proper of a pecu-
liarly constructed balance or frame, which is adapted to rise vertically
when steam is introduced into the chest, and press upon the upper side
of the latter for the purpose of excluding the steam from the upper side
of the valve, by which means an excess of downward pressure is pre-
vented, and the valve is properly balanced in its movements.

page_text: two of which, d³, communicate with the outer chamber of the valve
between the partitions d'and the outer walls, and the last of which ď
communicates with the central chamber, as shown.
E represents the balance or frame of rectangular form, which is
adapted to fit snugly in the upper recess or chamber of the valve D, and
move freely therein in a vertical direction, the same being provided with
suitable packing e inserted in a proper groove for the purpose of making
the joint steam-tight. e¹, e¹, Figures 1 and 2, represent ears projecting
inward from the ends of the frame, and resting upon the outer ends of
the levers; F and e' is an outwardly projecting flange extending about
the entire frame, as shown; e³ represents a groove formed in the upper
face of the frame E at a proper distance from its outer edge, which is
connected to the upper chamber of the valve by the short grooves or
flanges e', Figure 1.
F, F, represent bent levers of identical construction adapted in width
and length to occupy the entire chamber of the valve D, as shown. The
ends of the long arms of these levers bear against each other, and form
a close joint, while the ends of the short arms rest beneath the ears e¹ of
the frame E, as shown.
G, Figures 2, 2, a, b, c, represents a bridge piece or plate provided
with an opening g and a reed or clastic valve g¹. This plate is located
over the central opening d³ in the horizontal diaphragm d, as shown in
Figures 2 and 3.
The operation of the said valve is as follows:-When steam is
admittted to the chest it exerts a downward pressure upon the flanges d',
Figure 3, of the valve D, and holds the same to its seat. A portion,
entering also between the upper portion of the valve and the plate O,
exerts a pressure upon the levers F, F, and depressing the long arms
thereof raises the balance or frame E against the plate O, and effectually
cuts off the further entrance of steam. The balance or frame is retained
in this position while the steam pressure exists in the chest by the
pressure exerted beneath its flange e². The steam which has passed in
between the upper face of the frame and the plate C is conveyed away
by the action of the exhaust through the central chamber X and the
opening g in the bridge piece G to the exhaust chamber x¹, the elastic
valve g¹ preventing any flow of steam from the exhaust chamber into
the chamber of the valve. Any leakage which may occur between the
plate C and the frame E also is conveyed away by means of the

page_text: grooves e³, et, and the openings d³, d², d³. When steam is shut off from
the chest the frame or balance being unsupported will fall and cover
the holes d³, ď².
In consequence of the falling of the frame the valve is free to rise
from its seat to prevent vacuum obstruction when the piston is working
without steam.
In the modified form of valve, shown in Figures 4, 5, 6, 7, 8, and 9,
the construction differs from the construction previously described
mainly in the following particulars :-First, the frame or balance, which
was described as being made of a single piece, is constructed in sections;
and, secondly, the levers for elevating the frame or balance are dispensed
with, and in their stead elevators of peculiar construction, which are
acted on directly by the steam, are employed.
A represents the bottom plate of the usual construction; B, the top
plate; and C, the intermediate plate, which in this case is represented as
made in one piece with the top plate B.
D represents the said slide valve provided with the horizontal
diaphragm, having the openings d, d', and the longitudinal partitions d³,
Figures 7 and 9, united at the ends by the blocks d³, having the over-
hanging ears or flanges d', Figures 5 and 8, the inner wall d³, and the
outer wall do, as shown.
E, Figures 5, 5a, and 5b, represents the balance or frame constructed
in four similar sections, which are provided with a vertical web or plate e
adapted to rest in the recess between the outer and inner walls d³, d³,
and to move freely therein in a vertical direction and the horizontal web
or plate e¹ projecting inward, as shown. e³ represents a groove in the
upper face of the plate e¹, which is connected by the passages e³, e³, with
the chamber within the valve.
F, F, Figures 5 and 5c represent the elevators constructed of a
suitable block cut away upon the lower face, as shown in Figure 5, to
permit the entrance of steam beneath it, and provided above with a
transverse bar or plate ƒ projecting beneath the sections of the balance
or frame E, as shown.
G, Figures 4, 5, and 5d, represents a retaining plate or bar bent near
its ends at right angles, as shown, and provided with the angle open-
ings 9, 9, and which is adapted to rest between tho elevator blocks, and
guide them in their vertical movement,

page_text: The operation of this valve is as follows:-Steam being admitted to
the chest passes between the upper surface of the valve and the plate Ơ
down through the openings g in the plate G beneath the blocks F, and
consequently in elevating them raises also the balance or frame E against
the plate C, and prevents the further entrance of steam.
The balance may be retained in this position by the steam entering
openings x, x, Figure 7, at the corners of the valves, and bearing
against the lower edges of the vertical plate e of the balance E, or by
pressure upon a projecting flange, as previously described. The steam
which has entered the chamber of the valve is drawn off by the exhaust
through the opening d. Any leakage of steam between the valve and
the plate e is conducted by the groove e² and its passages e³ to the
chamber, and thence drawn off by the exhaust. Any steam also, which
may penetrate into the spaces adjacent to the elevators, may be drawn off
through the passages d', d. By making the frame in sections it is
adapted to adjust itself more perfectly than would otherwise be prac-
ticable against the plate C, and the packing of the sides may be dispensed
with.
Having thus fully described the said Invention as communicated to
me by my foreign correspondent, and the manner of performing the
same, I wish it understood that I claim,—
First. The novel combination herein described, and illustrated in
Figures 1, 2, and 3 of the Drawing.
Second. The novel combinations herein described, and illustrated in
Figures 4, 5, 6, 7, 8, and 9 of the Drawing.
In witness whereof, I, the said George Haseltine, have hereunto
set my hand and seal, this Third day of February, in the
year of our Lord One thousand eight hundred and seventy-
five.
GEORGE HASELTINE. (L.S.)
Witness,
HENRY JAMES NOONE.