Note: Descriptions are shown in the official language in which they were submitted.
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Background of the Invention
A. Field of the Invention
The present invention relates generally to valves for controlling
the flow of fluid in a fluid system and particularly to an improved poppet
stem guide for controlling the movement and location of a poppe~ stem in a
chec~ or relief valve.
B. Description of the Prior Art
Chec~ valves or relief valves are well known devices for controlling
the flow of fluid in a fluid system. One common characteristic of many prior
art check valves is their relatively complex and thus expensive ContrUCtiQn.
Examples of typical prior art chec~ valves are the devices disclosed in
United States Patent No. 2~9~641J 3,288,167, 3,334,659, and 3,473,561.
One component of these prior art check valves that adds substantial
cost both in material and assembly is the poppet guide. One such guide is
disclosed in United States Patent No. 3,800,824. Poppet guides serve to guide
and locate the poppet within the check valve while minimizing flow restric-
tion. Typically, prior art guides are fabricated from material that is
substantial in cost and expensive to assemble within the check valve and are
often subject to jamming after short periods of use.
Summary of the Invention
The present invention is directed to a valve for controlling fluid ;~
flow in a fluid system, comprising an elongated body including an internal
bore and a fluid inlet and a fluid outlet in fluid communication with the ~
bore. There is a valve seat in said bore, and a valve element is adapted ~ -
to move longitudinally in the bore and to engage the valve seat in the valve
closed condition. The valve element includes a valve stem.
Means are provided for guiding the longitudinal mo~ement of the
valve stem in the bore, the guiding means including a continuous annular
flexible rim adapted to be inserted in the bore and to be frictionally en-
gaged thereby. A guide hub is provided for encircling the stem, and at
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least one radial web extends from the hub to the rim. The rim has a prede-
termined effective outer diameter that is larger than the effective inner
diameter of the bore prior to insertion of the guiding means into the bore
to define an interEerence fit therebetween, the engagement between the bore
and the rim cooperating to deform the rim inwardly in a posit;on spaced
angularly from the bore, and the at least one radial web acts to retain the
guiding means against movement relative to the bore.
Valves having a guide in accordance with th0 present invention have
many advantages. As compared to prior art valves, they are simple, and re-
latively inexpensive~ both in terms o~ material cost and assembly. The
guide is held against movement relative to the valve, and the stem is held
against rotation relative to the guide~ thereby minimizing wear and prolong-
ing the life of the valve. Sufficient clearance is provided between the
guide hub and th^ stem to minimize the possibility of particulate matter
jamming therebetween. And, the guide itself provides for streamlined fluid
flow therethrough. ;~
Brief Description of the Drawing
Figure 1 is a cut-away perspec~ive view of a first valve including
a poppet guide constructed in accordance with the principles of the present
invention;
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FIG. 2 is a view taken along line 2-2 of FIG. l;
FIG. 3 is a second valve including a poppet guide con- ;
structed in accordance with the principles of the present invention;
and
FIG. 4 is an enlarged end view of an embodiment of the
poppet guide of the present invention.
Description of the Preferred Embodiments
While this invention is susceptible of embodiment in
n~any different forms, there is shown in the drawings and will
herein be described in detail a preferred embodiment in accordance
with the present invention, and with the understanding that the
present disclosure is to be considered as an exempli~ication of
the principles of the invention and is not intended to limit the
invention to the specific embodiments illustrated and described.
Having reference to the drawing and initially to FIGS. 1,
2, and 4I there is illustrated a new and improved check valve
and poppet guide constructed in accordance with the principles of
~he present invention. The check valve is designated as a whole
by the reference numeral 10 and is used to control the flow of
fluid in a fluid system, and specifically, t~ allow unidirectional
flow in the fluid system. The check ~alve 10 includes a novel
poppet guide that functions to guide a poppet stem within
the check valve 10. ~;
The check valve 10 includes a body 12 having an inlet 14
and an outlet 16. The inlet 14 and the outlet 16 are threaded
to allow the valve 10 to be easily coupled to a pipeline or similar
fluid system. Defined between the inlet 14 and the outlet 16
and within the body 12 is an elongated bore 18 through which fluid
flows when the valve 10 is open. The body 12 includes an annular
valve seat 20 defined on the inner peripheral surface of the
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bore 18. The check valve lO further includes a poppet 22 for for~ing
a fluid-tight sealing engagement with the valve seat 20. Poppet 22
is preferably formed of an elastomeric material. When the poppet
22 is positioned in sealed engagement with the valve seat 20,back
flow of fluid through the check valve is prevented. When the
poppet 22 is in an open position spaced from and out of sealiny
engagement with the valve seat 20, flow of 1uid through the
check valve lO from the inlet 14 through the outlet 16 is permitted.
A poppet stem generally desi~,ated by reference numeral 24
extends longitudinally through the bore 18 and is secured to the
poppet 22. The poppet stem 24 is of a polygonal configuration in
cross sectionl and in the embodiment illustrated, is of a square
cross-sectional configuration having flat sides 25. The poppet
stem 24 is utilized to control the movement of the poppet 22 with
respect to the valve seat 20. The poppet stem 24 may be connected
to the poppet 22 by any suitable means, such as, by having an upper
flattened portion 25a embrace a metal stiffening element 26, and molding the
poppet around the end of the poppet stem incl~lLng the stiffening el~t 26.
The poppet stem 24 includes a threaded end portion 28
~or receiving a threaded lock nut 30. The lock nut 30 serves as
a lower limit, or shoulder, for one end of a compression spring 32,
and the opposite end of spring 32 hears against a poppet guide 34,
to be hereafter described in detailO The compression spring 32
provides the necessary bias to maintain the poppet 22 in sealing
engagement with the valve seat 20. When force exerted by the
pressure of the fluid in the check valve 10 against the under~
surface of the poppet 22 exceeds the opposing bias force provided
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by the compression spring 32, the poppet 22 disengages from the
valve seat 20 to permit fluid to flow through the check valve lO,
and such fluid flow will con~inue so long as the fluid pressure
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at the inlet siae of the check valve exceeds the bias of spring 32.
The bias force imparted by the compression spring 32 may be
adjusted by varying the longitudinal position of the threaded nut
30 on the threaded end portion 28 of the valve s~em 24. Thus,
the operation of ~he check valve 10 can be easily adjusted to
permit fluid flow at any desired fluid pressure.
In accordance with an important feature of the presen~
invention, poppet guide 34 provides for both positioning the poppet
stem 24 within the bore 18 of the check valve 10, and for
controlling the movemPnt of the stem 24 along a longitudinal axis
coincident with the central longitudinal axis of the bore 18.
Guide 34 is formed of a flexible smooth surface bearing material,
such as, D~LRIN. In addition, poppet guide 34 prevents rotation
of the poppet 22 and the stem 24 relative to the body 12 of the
check valve 10. By controlling the position and movement of the
poppet stem 2~, the poppet guide 34 controls the position and
movement of the poppet 22 to cause the poppet 22 to engage the
valve seat 20 in a proper alignment. And, by pre~enting the valve
stem from rotating relative to the valve body, wear resulting from
excessive movement is minimized, thus prolonging the useful life
of the valve.
In accordance with an important advantage o the present ;~
invention, and as can be best seen from FIG. 4~ the poppet guide 34
includes a thin resilient rim 36 of a tapered cross section to
define a fluid flow passage that is streamlined, i.e., progressively
increasing in size, to reduce the flow resi~tance of the rim 36.
The poppet guide 34 also includes a cylindrical hub 38 that i5
coaxial with the rim 36, and hub 38 includes on its inner peripheral
surface one or more lugs 40 that extend along a portion of the
entire length of the hub 38.
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Th~ hub 38 and rim 36 are joined ~nd spaced from
each other by radially extending webs or ~pokes 42 that are of
a cross-sectional configuration substantially similar to that
: of the rim 36 so as to further streamline the fluid flow passages
and reduce resistance to flow through the guide 34 and along the
bore 18. In a most preferred embodiment, both surfaces of rim 36
and webs 42 are uniformly tapered.
The stem guide 34 in its entirety is fabricated, by
molding, or the like, from material that allows some deformation
of the rim 36 during assembly of the guide 34 into the check
valve 10. The guide 34 is of a diameter relative to the diameter of a machined
intermediate p~rtion of the bore 18 such that once the guide 34 is positioned
within the bore 18, it remains slightly compressed, thereby producing
a force that assists the interference fit of the guide 34 in the
bore 18 in holding the guide 34 within the machinedportion of the borel8.
To prevent the guide from rotating within the check
valve 10, the pairs of circumferentially space~ axially extending
lugs or projections 44 defined on the outer peripheral surface
of the rim 36. In the preferred embodiment illustrated, the lugs
44 are located approximately at a point on the rim 36 diametrically
opposed to the point of intersection of the webs 42 with the
rim 36. This location of the lugs 44 allows maxim~ deformation
of the rim 36 if force is applied at or near the lugs 44, as when
the guide is inserted in the valve body. ~:
To maintain the valve guide 34 within the check valve 10,
the valve 10 includes legs or ribs 46 defined on the inner :~
peripheral surface of the bore 18. To assemble the poppet guide 34
in the check valve 10, the poppet guide 34 is positioned within
the inlet 14 of the check valve 10 by moving the guide
34 longitudinally within the bore 18 so that the outer periphery
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of rim 36 between the projections 44 engages the apex of the
legs 46. The apex of the legs 46 defines a cylindrical area
of a diameter slightly less than the diameter of the outer
periphery of the rim 36. Accordingly, as the poppet guide
34 is moved further into the machined intermediate portion of
bore 18, ribs 46 exert an inward compressive orce, and a slight
inward deformation of the rim 36 at the interface of the rim
~ 36 and the legs 46 occurs. Once the poppet guide 34 is
; fully positioned within the machined portion of bore 18, the
downstream end of the valve guide 34 abu~s against a shoulder
48 machîned within bore 18.
Once assembled, ther~ is a significant force due to the
deformation of the rim 36 holding the valve guide 34 in position.
This force, together with ~he confining action of ribs 44, is
sufficient to prevent movement of the valve guide 34 by the swirl-
ing motion or in~luence of fluid flowing through the check valve
10. Consequently, wear due to rotation of the valve guide 34,
within the machined portion of bore 18, as is prevalent in prior
art valve guides, is prevented.
To complete the assembly of the check valve 10, the poppet
stem 24 is inserted axially into the hub 38 such that the lugs
40 face the sides 25 of the poppet stem 24, and spring 32 is ~ ;
positioned around the valve stem 24, with one end seated ;~
within a set of grooves 50 defined in the webs 42 of the valve
guide 34. The other end of the spring 32 seats against the lock
nut 30 once ik is threaded on the end 28 of the stem 24. The
inner diameter of ~he hub 38 is slightly larger than the transverse
dimension of the valve stem 24, such that the valve stem 24 may
move freely in a longitudinal direction within the intermediate
portion of bore 18 and the hub 38 without interference. This allows
free movement of the poppet 22 under the influence of fluid pressure
and the spring 32 and reduces the likelihood of jamming of the
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stem 24 within the hub 38 due to sand, or other particulate
matter that may be entrained in the fluid. Rotation of the stem
24, however, is prevented due to the engagement of the lugs 40
with the sides 25 of the stem 24.
The poppet guid~ 34 may also be used in a second type of
check valve, such as the check valve 110 illustrated in FIG. 3.
The check valve 110 is of the type that may be used at the inlet
of a fluid system and includes a screen 111 that is secured to
the inlet 114 of the check valve 110 to filter or screen particles
and prevent their entry into the fluid system.
The check valve llG includes a body 112 having an inlet
114 at one end and an outlet 116 at the other end. The inlet 114
is externally threaded to allow the attachment of the screen 111.
The outlet 116 is internally threaded to allow coupling to the
1uid system, such as a pipe line.
The check valve 110 also includes an internal bore 118
and a valve seat 120 substantially similar to the corresponding
components of the check valve 10. ~he check valve 110 further
includes a poppet 122 ~or forming a fluid-tight sealing engagement
with the seat 120. In a sealed engagement, the poppet 122 and
the valve seat 120 prevent flow of fluid from the outlet 116 to
the inlet 114 of the check valve 110. In a non-sealing engagement~
or when disengaged, the poppet 122 and the valve seat 120 permit
the flow of 1uid through the check valve 110
A poppet stem 124 is securely attached to the poppet 122
and extends longitudinally through the bore 118 of the check valve ~ ~;
lln and into screen 111. In a manner substantially similar to the poppet stem 24.
the check valve 10, the poppet stem 124 is utilized to control ;-~
the movement of the poppet 122 with respect to the valve eat 12O
The poppet stem 124 is connected to the poppet 122 in any suitable
manner, such as by molding the poppet about an enlarged
stiffener 126 at the end of the stem. :
The poppet stem 124 is polygonal in configuration
and includes sides 125 that, in a preferred embodiment, may be
of a configuration substantially similar to the valve stem 24.
The poppet stem 124 also includes a threaded end 128 to which
a lock nut 130 may be threaded to serve as a shoulder for the
spring 132 once the spring 132 is mounted around the stem 124.
The check valve 110 differs from the check valve 10 ~ :
~10 in that the check valve 110 does not include cast legs or : :~
ribs 46, but rather the inlet 114 is of a diameter slightly ~:
smaller than the diameter of the poppet guide 34. Consequently,
to assemble the valve guide 34 in the check valve 110, the
valve guide 34 is press-fitted, or pushed, into the inlet 114
against ~e shoulderin a manner such that the lugs 44 on the outer
peripheral surface of the rim 36 engage the inn~r peripheral : :
surface of the inlet 114 slightly deforming the rim 36. This . ;
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slight deformation provides a holding force imparted to the : ;
inner peripheral surface of the inlet 114 resulting in a
securement of the poppet guide 34 within the inlet 114 with
sufficient force to prevent movement o the poppet guide 34
~ as a result of the swirling motion of fluid flowing through the :~
: check valve 110.
To complete the assembly of the check valve 110, poppet :~
stem is inserted through the poppet with the lugs 40 engaging
surface 125, and spring 132 is positioned so that one end of
the spring 132 engages the slots 50 defined on the webs 42.
The lock nut 130 may then be threaded on the end 128 to serve
as a shoulder for the other end of the spring 132. The screen
111 may then be threaded on the external threads defined on the
inlet 114.
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During operation of the check valve 110 the poppet
stem 124 may slide longitudinally relative to the hub 38 and in
a direction toward the outlet 116, The lugs 40, prevent rotation
of the stem 124 within the bore 118.
In view of the above teachings, it may be understood
that the poppet guide 34 due to its flexible material and ease
of manufacture is easily assembled within several different
types of check valves, such as the check valves 10 and 110, and
is less subject to wear since it cannot be rotated within the
check valve due to the influence of the swirling motion of
~luid. Many modifications and variations of the pre6ent
invention are possible in light of the above teachings. Thus,
it is to be understood that, within the scope of the appended
claims, the invention may be practiced otherwise as specifically
described.
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