Year: 1895

page_text: We, JOHN ADAM SMITH, JAMES HART. and ABRAHAM WILKINSON, all of
No. 305 McConaughy Street, Johnstown, Pa, U.S.A., Inventors, do hereby
declare the nature of this invention to be as follows
-
This invention relates to steam, hydraulic, and similar valves of the class known
as balanced valves, and the objects in view are to provide a piston-valve in which
the pressure of the fluid prevents the packing mngs from expanding into the
moving part or piston, and at the same time secure a balanced pressure upon the
piston.
The invention comprises a valve casing, preferably cylindrical in constructio
and provided at each end with a cap, one having a stuffing-box and aperture for
the valve-stem. An exterior duct connects the opposite ends of the casing with
the exhaust port. The mlet port taps the casing at its centre. The cylinder ports
aic arranged on opposite sides of the inlet port The inner surface of the casing
18 channelled at those parts opposite the inlet, cylinder ports, and ends of the
exterior duct, and through these channels the steain or fluid entering or leaving
the casing passes entirely around the bore of the casing
Within the casing, and extending the length thereof, is a cylindrical bushing
provided, opposite each of the openings in the casing, with an annular series of
perforations. This bushing is preferably constructed of sections suitably united
and having packing-rings between them.
A cylindrical piston reciprocates within the bushing and 18 connected for operation
with the valve-stem The ends of the piston are closed by heads formed upon the
valve-stem. The heads project within the piston so as to leave an open ended
portion thereof at each end. This portion has perforations through it which
communicate alternately with the exterior duct and exhaust when the piston
reciprocates
Dated this 10th day of May 1895.
W. 11. MUNNS,
Agent for Applicants.
We, JOHN ADAM SMITH, JAMES HART, and ABRAHAM WILKINSON all of
No. 305 McConaughy Street, Johnstown, Pn, U.S A., Inventors, do hereby
declare the nature of this invention and in what manner the same
performed, to be particularly described and ascertained in and by the following
statement.-
18 to
Our invention relates to steam, hydraulic and sumilat valves, of the class known
as balanced valves, and the objects in view are to provide a piston valve m which
the pressure of the fluid prevents the packing rings from expanding into the ports
of the moving part or piston, and at the same time secure a balanced pressure upon
the piston.

page_text: Toutages of the invention will appeal in the following
descuption, and novel features thereof will be particularly pointed out in the
appended claims
In the drawings.
Fig. 1 is a vertical central section of a valve embodying our invention, the eaine
being constructed for use in connection with a double-acting cylinder. Fig. 2 is a
similar section at ught angles to the plane of Fig. 1, shewing the piston in its
depressed position
Fig. 3. is a view of the bushing cylinder, detached
Fig. 4 is a view of the piston.
Sula numerals of reference indicate corresponding parts in all the figures of
the diawings.
1 designates the valve casing preferably cylindrical in construction, which is
provided at one end with a cap 2 and at the opposite end with a cap 3 perforated
for the stem 4, a stuffing box 5 being arranged in the cap 3 Communicating with
opposite ends of the easing is an exterior duct 6, with which connects the exhaust
port 7, and tapping the easing at its centre is the inlet port 8 and upon opposite
sides thereof the cylinder parts 9. The inner surface of the casing in communt-
ention with the inlet port is channeled as shown at 10, in communication with the
cylinder ports is channeled as shewn at 11, and in communication with the terminals
of the duet 6 is channelled as shewn at 12, whereby fluid entering or leaving the
casing through either of the said openings passes cutirely around the bore of the
casing.
Arranged in the casing and extending from one of the end caps to the other, is
the Indrical bushing 13, provided opposite each of the openings in the casing
with an annular series of perforations or ports, those opposite the inlet port being
designated at 14, those opposite the cylinder ports at 15, and those opposite the
ends of the exterior duct at 16. Communicating severally with these annular
series of perforations are the channels 17, formed by cutting away the inner su face
of the bushing upon opposite sides of the pei fotations
The bushing is preferably sectional in constinction, the joints between the
sections being arranged between the planes of the various ports, and the terminals
of the sections being fitted with interposed packing ungs 18, grooved as shewn
at 19 and fitted upon the reduced extremities of the sections
Arianged to icciprocate within the bushing, and connected for operation with
the stem 4, is the cylindrical piston 20, having closed extremities The ends of
the piston are closed by heads 21, arranged in contact with annular shoulders 22
formed in the inner surface of the same, and being held in place by a shoulder 23
on the stem bearing against one head and a removable nut 24, threaded upon the
extremity of the stem and beating against the other head. The shoulders 22, o
the seats against which the heads abut are set back from the ends of the shell of
the piston, and the projecting hollow portions 25 are provided with annular series
of perforations 26 to communicate, successively, with the counter boned portions of
the bushing and hence with the terminal ports of the exterior duct. The shell is
further provided, at intervals, with annular cues of ports 27 and 28, which are
adapted to commumente, respectively, with the counterbore of the ports in
communication with one of the cylinder ports
port
With the parts in the position shewn in Fig. 1, the live steam or other actuating
fluid, enters through the inlet part, and after "passing through the openings in the
bushing enters the bore of the shell and thence passes through the upper cylinder
It is obvious that the pressure within the shell is balanced. The exhaust
Buid escaping from the cylinder, passes through the other cylinder port, and
through the perforations in the extension at the lower end of the shell, theuce into
the connecting duct, and out through the exhaust port. This exhaust fluid, owing
to the said duit, bears with cqual force upon opposite ends of the piston thereby
balancing that element. When the position of the piston is reversed, as shown in
Fig. 2, the conditions are reversed accordingly, and the steam after entering the

page_text: shell passes through the other cylinder port, while the exhaust fluid escapes through
the upper cylinder port, and through the perforations in the extension of the upper
end of the shell, to the exterior duct, and theuce to the exhaust port.
From the above description it will be seen that the pressure of the fluid is from
the interior of the shell outward, and hence as the ports of the shell pass the
packing rings the latter are expanded and thus prevented from entering or
crowding into the latter. Thus the packing rings are relieved from excessive wear
and leakage is prevented.
The pressure of the terminal caps of the casing upon the ends of the bushing
bolds the latter in place, and when necessary to replace the packing rings one of
the caps may be removed and the sections of the bushing withdrawn.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same 18 to be performed 1 declare that what we
claim 13
(1) The combination of a casing having open ends, an exterior duct connecting
the ends of the bore thereof, an inlet and a cylinder port, a sectional bushing
arranged in the casing and provided with perforations communicating with
the openings in the shell of the casing, caps fitted in the ends of the casing and
bearing against the ends of the bushing, packing rings, interposed between the
sections of the bushing, and a cylindrical terminally closed piston arranged i
the bushing and provided with ports to register with said inlet and cylinder ports,
substantially as specified
(2) The combination of a casing having an exterior duct connecting its
extremities, and inlet and cylinder poits, said casing being counterbored in
communication with the ports and the terminals of the duct, a sectional bushing
provided with ports and counterbores in communication with the openings in the
casing, packing rings arranged between sections of the bushing, and a piston
cylindrical in construction, provided with annular series of ports adapted to register
with the counterbores in the bushing substantially as specified.
(3) The combination of a casing provided with inlet and cylinder ports,
communicating with counter-boree, and an exterior duct connecting the onds of the
casing and also communicating with counter-bores a sectional bushing provided
with ports and counter-bores, packing rings inter posed between the sections of
the bushing, and a hollow piston having closed extremities and intermediate ports
adapted to register with the inlet and cylinder ports, and also provided with
hollow extensions having openings to register with the counter-bores communi-
cating with the ends of the said duct, substantially as specified.
(5) The combination of a casing provided with inlet and cylinder ports,
cominumicating with counter-bores, and an exterior duct connecting the ends of
the casing and also communicating with counter-bores, n sectional bushing provided
with annular series of ports, packing rings arranged between the sections of the
bushing, and a piston having a cylindrical shell provided with intermediate ports
and terminal ports, and having interior annular seats, perforated heads fitting said
seats, and a stern having a shoulder to engage one of the heads and a out
engaging the other head, said seats boing set in from the extremities of the shell,
between the intermediate and the terminal ports, substantially as specified.
Dated thus 13th day of February 1896
W. IT MUNNS,
Agent for Applicants.