Note: Descriptions are shown in the official language in which they were submitted.
~313~73
NE~nL~ ~At.V~ ~AT
nackground of the Invention
The present invention relates generally to improvements in
needle valves, and more particularly, but not by way of limita-
tion, to tlle construction of seats that receive the needle of the
valve.
A known type of valves is one in which a frusto-conical valve
member, or needle, is mounted on a valve body for axial movement
along a valve closure axis into, and out of, a frusto-conical
valve seat cavity. Flow passages, opening into the valve seat
cavity, are formed in the valve body so that the valve can be
closed by inserting the needle into the valve seat cavity and
opened by withdrawing the needle from the valve seat cavity.
In many cases, the valve seat cavity is formed in a valve
seat that is situated in a chamber formed in the valve body and
openings are formed through the wall of the valve seat to extend
the flow passages into the valve seat cavity. The valve seat, in
such case, is provided with a locking system of some type so that
the openings through the walls of the valve seat are maintained
in alignment with the portions of the flow passage that extend
through the valve body.
A problem that has occurred with valves of this type is that
the valve member ten~s to expand the valve seat when the valve is
closed, because of the frusto-conical shapes of the valve member
and the valve seat cavity, and the openings formed through the
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~3~73
seat to extend the flow passage9 of the valve into the valve seat
cavity weaken port~on~ o the valve 8eat at the location at whlch
sealing of valve seat cavity is effected to close the valve.
Should the valve member be forcefully inserted into the valve
seat cavity, as will often happen when the user closes the valve,
the valve seat has a tendency to break at the openings formed at
the wall thereof with result that the valve will leak.
Summary of the Invention
The present invention overcomes this problem by providing a
valve seat with weak points displaced away from the openings into
the valve seat cavity that will cause any breakage of the valve
seat to occur at a non-critical location. In particular, at
least one groove is formed in the valve seat to intersect and
extend away from the valve seat cavity to provide a weak point
along which breakage of the valve seat will occur should a user
force the valve member into the valve seat cavity with excessive
force during the closing of the valve. The groove is positioned
between the openings and extends parallel to the longitudinal
axis of the valve seat cavity so that, should the valve seat
break along the groove, portions of the valve seat surrounding
the openings into the valve seat cavity will remain intact
permitting a seal between the valve member and valve seat and
between the valve seat and valve body in the vicinity of the
openings and the flow passages through the valve body so that the
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~3~3173
:eakage of the valve seat wlll not affect the efflc~cy of the
valve member in closing the valve.
In several of the embodlments of the invention, two grooves
are formed in the valve seat wall, the two grooves being
positioned in diametr~c opposition across the valve seat cavity.
In two of these embodiments, anti-rotation tabs are formed on the
lower end of the valve seat to maintain the openings through the
valve seat wall in alignment with flow passages formed in the
valve body. In the third of these embodiments, the valve seat
has the general form of a rectangular parallelepiped that can be
place in a mating valve chamber to maintain the openings through
the valve seat wall in alignment with the flow passages in the
valve body. In two other embodiments of the invention, the valve
seat is molded as two side-by-side halves that are connected
together by a web so that planar surfaces on two halves adjacent
the web will form the groove when the valve seat is folded to
form a tubular structure into which the valve member will fit.
In one of these embodiments, the web is formed on outer surfaces
of two halves so that the web forms a projection when the two
halves are folded together and such projection can be used to
prevent rotation of the valve seat in the valve body. In the
second of these two embodiments, the web is formed on planar
surfaces that are abutted when the valve seat is folded into the
tubular structure and an anti-rotation tab on the lower end of
the valve seat is used to prevent rotation of the valve seat in
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the valve b~dy. In a final embodlment of the lnventlon a5
described herein, a cut ls Eormed through the valve seat wall
across the valve seat cavity fr~m the groove ~o that portions of
the valve seat positioned radially outwardly of the groove form a
S spring that provides the valve seat with an expans~on capabil~ty
that tends to prevent brea~age of the valve seat when the valve
member is forced into the valve seat cavity. Rotatlon of the
valve seat in this embodiment of the invention can conveniently
be prevented by forming a notch in a flange that extends about
the upper end of the valve seat to receive a pin that is mounted
on the valve body.
An object of the present invention is to provide a valve
seat for a needle valve that will suffer no loss of sealing
capability should the valve member be urged to forcefully into
the valve seat when the valve is closed.
Another object of the invention is to limit maintenance
requirements of valves by providing a valve seat that will seal a
valve though the valve seat has been damaged by fixing the form
that such damage can take.
Other objects, features and advantages of the present
invention will become clear from the following detailed
description of the preferred embodiment of the invention when
read in conjunction with the drawings and appended claims.
~313~73
_ief Descript1on of the Draw~ngs
~ igure 1 i9 a ragmentary, slde elevatlonal cross-sect1on ~f
a needle valve including one preferred embodi~ent of a valve
seat constructed in accordance with the present invention.
Figure 2 is a fragmentary cross-section of the valve shown in
Figure 1 taken along line 2-2 of Figure 1.
Figure 3 is a fragmentary cross-section of the valve shown in
Figure 1 taken along line 3-3 o~ Figure 1.
Figure 4 is a plan view of the of the valve seat shown in
Figure 1.
Figure 5 is a bottom view of the valve seat shown in Figure
4.
Figure 6 is a cross-section of the valve seat shown in Figure
4 taken along line 6-6 of Figure 4.
Figure 7 i9 a plan view of a second embodiment of the valve
seat of the present invention, usable in the needle valve shown
in Figure 1, illustrating the valve seat as the valve seat is
molded.
Figure 8 is a side elevational view of the valve seat shown
in Figure 7 and illustrating the valve seat in the as-molded
configuration.
Figure 9 is a plan view of the valve seat shown in Figure 7
showing the valve seat in a folded configuration.
Figure 10 is a fragmentary, side elevational cross-section of
a needle valve adapted to receive a third embodiment of a valve
seat constructed in accordance with the present invention.
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3173
Figure 11 i8 a fragmentary cross-9ect10n of the body of the
needle valve shown ln ~lgure 10 taken along line 11-11 of ~igure
10 .
Figure 12 is a plan view of the third embodiment of the valve
seat.
Figure 13 is a bottom view of the third embodiment of the
valve seat.
Figure 14 is a cross-section of the third embodiment of the
valve seat taXen along line 14-14 of Figure 12.
Figure lS is a fragmentary, side elevational cross-section of
a needle valve adapted to receive a fourth embodiment of a valve
seat constructed in accordance with the present invention.
Figure 16 is a fragmentary cross-section of the body of a
needle valve shown in Figure 15 taken along line 16-16 of Figure
lS 15.
Figure 17 is a plan view of the fourth embodiment of the
valve seat.
Figure 18 is a cross-section of the fourth embodiment of the
valve seat taken along lines 18-18 of Figure 17.
Figure 19 is a fragmentary, side elevational cross-section of
the body of a needle valve adapted to receive a fifth embodiment
of a valve seat constructed in accordance with the present
invention.
Figure 20 is a cross-section of the needle valve body shown
in Figure 19 taken along line 20-20 of Figure 19.
~313173
Figure 21 i8 a s~de elevatlonal vlew of the fifth embod~ment
o~ the valve seat showing the valve seat in an as-mol~ed
configurat~on.
Figure 22 is a plan vlew and partial cut-away of the fifth
S embodiment of the valve seat showing the valve seat in an
as-molded configuration.
Figure 23 is a plan view and partial cut-away of the fifth
embodiment of the valve seat showing the valve seat in a folded
configuration.
Figure 24 is a side elevational view of the fifth embodiment
of the valve seat showing the valve seat in a folded
configuration.
Figure 25 is a fragmentary, side elevational cross-section of
the body of a needle valve adapted to receive a sixth embodiment
of a valve seat constructed in accordance with the present
invention.
Figure 26 is a fragmentary cross-section of the needle valve
body shown in Figure 25 taken along line 26-26 of Figure 25.
Figure 27 is a plan view of the sixth embodiment of the valve
seat.
Figure 28 is a cross-section in side elevation of the sixth
embodiment of the valve seat taken along line 28-28 of Figure 7.
Description of Figures 1 through 6
~ eferring first to Figures 1 and 2, shown therein and
designated by the general reference numeral 30 is a needle valve
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that includes a valve ~eat 32 constructed ln accordance with the
present invention. The valve 30 lnclu~e8 ~ valve body 34 ~n
which the valve seat 32 ls positioned and Pigure 3 has heen
included to more particularly point out features of the valve
body 34 that are utilized in the positioning of the valve seat 32
in the valve 30. Figures 4-6 more particularly illustrate the
construction of the valve seat 32.
As indicated by Figures 1-3, the valve body 34 is preferably
constructed in the form of a rectangular block having a blinfl
hole 36 formed in a transverse side 38 thereof, portions of the
hole 36 adjacent the side 38 being threaded so that a bonnet 40,
having a threaded portion near the lower end 42 thereof, can be
screwed into the hole 36 to close the valve 30 at the transverse
side 38. The valve bonnet 40 extends only partially into the
blind hole 36 so that portions of the hole 36 below the end 42 of
the bonnet 40 form a valve chamber 44 in which the valve seat 32
is inserted when the valve 30 is assembled. Fluid communication
into and out of the valve chamber 44 is provided by a flow
passage 46 that intersects opposite sides of the valve chamber 44
and extends longitudinally through the valve body 34.
As shown in Figures 1-3, the lower end 48 of the blind hole
36 is flat with the exception of a pilot hole 50 and two canted
grooves 52 and 54 that intersect the pilot hole 50 and slope
upwardly therefrom along a line that parallels the axis 56 of the
flow passage 46. A shoulder 58 is formed circumferentially about
portions of the hole 36 that are adjacent the lower end 42 of
1~13173
.,
the bonnet 40 when the v~lve 30 is ~s9embled ~o th~t ~ flange 60
formed on the valve seat 32 can be cl~mped between the lower e~d
42 of the valve bonnet 40 and the shoulder 58 when the valve 30
is assembled. The bonnet 40 has a bore 62 formed therethrough in
a concentric arrangement with the threads near the lower end of
the bonnet 40 and portions of the bore 62 are threaded to receive
threaded portions of an operating member 64 that supports a
frusto-conical valve member 66 for axial movement into and out of
the valve chamber 44 along a valve member closure axis 68 that
extends coaxially with the hole 36 and transversely to the flow
passage 46.
The valve seat 32 is generally tubular in form, the valve
seat having a wall portion 70 that extends circumferentially
about a frusto-conical valve cavity 72 that intersects opposite
first and second ends, 74 and 76 respectively, of the wall
portion 70 and extends therebetween. The outer peripheral
surface 78 of the wall portion 70 of the valve seat 32 is
cylindrical, is centered along the longitudinal axis 80 (Figure
6) of the valve seat cavity 72, and is shaped to mate with the
valve chamber 44 in the valve body 34 so that, when the valve
seat 32 is positioned in the valve chamber 44 as shown in Figure
1, movement of the valve member 66 along the valve closure axis
68 will cause the valve member 66 to enter or leave the valve
seat cavity 72. Coaxial openings 82 and 84 are formed through
the valve seat wall portion 70 perpendicularly to the
longitudinal axis of the valve seat cavity 72 to intersect both
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1~13173
the outer perlpheral ~urface 78 o~ the w~ll portlon 70 and the
cavlty 72 thereby providing fluid ~ommunicat~on into the valve
seat cavity 72 along an axis transverse to the longitudinal ax1s
80. The valve seat 32 further comprises a pair of anti-rotation
S tabs 86 and 88 that are formed on the second end 76 of the valve
seat wall portion 70 along a line that parallels the common axis
gO (Pigure 6) of the openings 82 and 84. Thus, the valve seat 32
can be mounted in the valve chamber 44 with the second end 76 of
the wall portion 70 abutting the lower end 48 of the hole 60 and
the first end 74 of the valve seat wall portion 70 abutting the
lower end 42 of the valve bonnet and with the anti-rotation tabs
86 and 88 disposed in the grooves 52 and 54, respectively, formed
in the lower end 48 of the blind hole 36 to position the valve
seat 32 in the valve chamber 44 with the opening~s 82 and 84
aligned with the flow passage 46 of the valve body 34 and the
anti-rotation tabs 86 and &8 will co-act with the grooves 52 and
54 to maintain the alignment of the openings 82 and 84 with the
flow passage 46. Accordingly, the valve 30 can be opened by
turning the operating member 64 to withdraw the valve member 66
along the valve closure axis 68 from the valve seat cavity 72 and
the valve 30 can be closed by turning the operating member 64 to
move the valve member 66 into the valve seat cavity 72 to block
fluid flow between the openings 82 and 84.
The valve seat 32 is constructed of an organic polymer; for
2S example, polytetrafluoroethylene so that the valve seat 32 is
capable of undergoing a small degree of expansion when the valve
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~ 313173
member 66 i8 moved ~nto the valve seat cavlty 72 and such
expansion of the valve seat 32 18 utillzed to prevent leakage of
the valve ~0 when the valve 30 1g closed. That ls, the valve
member h6 will mate tightly with the valve seat cavity 72 to
prevent leakage about the valve member 66 when the valve member
66 is forced into the cavity 72 to expand the valve seat 32 and
the expansion of the valve seat 32 causes portions of the valve
seat 32 about the openings 82 and 84 to tightly engage adjacent
portions of the valve chamber 44; that is, portions of the valve
chamber 44 that are intersected by the flow passage 46, to
prevent leakage of the valve about the valve seat 32.
As will be appreciated by those skilled in the art, the
forcing of the valve member 66 into the valve seat cavity 72 to
expand the valve seat 32 and seal the valve 30 against fluid flow
can result in breakage of the valve seat 32. Moreover, such
breakage is most likely to occur at the openings 82 and 84 since
the openings 82 and 84 tend to weaken the wall portion 70 of the
valve seat 32. Should breakage of the valve seat 32 occur at the
openings 82 and 84, the break will very often provide a leakage
path through the valve seat 32 that will cause the valve 30 to
leak when closed. In the practice of the invention, such a
leakage path is prevented by causing any breakage of the valve
seat 32 that might occur to be confined to plane that bisects the
valve seat 32 perpendicularly to the common axis 90 of the
25 openings 82 and 84 through the wall portion 70 of the valve seat
32. To this end, the valve seat 32 is provided with a first
. . .
73
groove 92 that ~ formed ln the wAll port~on 70 to ~ntersect and
extend radially away from the valve seat cavity 72. The groove~
92 is positioned between the openings 82 and 84 as particularly
shown in Figure 6 and extends parallel to the longitudinal axis
80 of the valve seat cavity 72 throughout the length of the valve
seat cavity 72. In one preferred embodiment of the invention, a
second groove 94 is similarly formed in the wall portion 70 to
intersect and radially extend away from the valve seat cavity 72
across the valve seat cavity 72 from the groove 92.
Operation of Figures 1 through 6
The operation of the valve 30 to open and close the flow
passage 46 to fluid flow through the valve 30 is conventional.
That is, to close the valve 30, the valve member 66 is moved
along the valve closure axis 68 into the valve seat cavity 72 to
lS engage the frusto-conical surface defining the valve seat cavity
72 and obstruct fluid flow between the openings 82 and 84
through the wall portion 70 of t~e valve seat 32. Since the
valve seat 32 is expanded to form a seal with the valve chamber
44 when the valve member 66 is forced into the valve seat cavity
72, the valve 30 will be sealed against fluid flow by the
insertion of the valve member 66 into the valve seat cavity 72.
To open the valve 30, the operating member 64 need only be turned
to withdraw the valve member 66 partially from the valve seat
cavity 72.
.,
`- 1313173
Should the valve member 66 be drlven too ti9htly lnto the
valve seat cavity 72, when the valve 30 i5 closed, excesnive
strains can be set up ln the wall portion 70 of the valve seat 32
with the result that the valve seat 32 can break. The grooves 92
and 94 weaken the wall portion 70 of the valve seat 32 so that
such breakage, if it occurs, will occur along a plane that i9
displaced away from the openings 82 and 84 so that no loss of
sealing capability will occur for the valve 30 as the result of
such breakage. Rather, the two resulting portions of the valve
seat 32 will remain held in place within the valve chamber 44 and
will act independently to each provide a seal both to the valve
member 66 and to portions of the valve chamber 44 that are
intersected by the flow passage 46. It will be noted that the
provision of the grooves 92 and 94 thus can effect an extended
lifetime for the valve seat 32. That is, should the valve seat
32 take a set that will require the valve member 66 to be
increasingly forcefully urged into the valve seat cavity 72,
increasing the likelihood of breakage of the valve seat 32, the
confinement of any breakage of the valve seat 32 that might occur
to portions of the valve seat 32 which do not enter into the
sealing of the valve 30 will permit the valve 30 to be used
without loss of closure and sealing capability for an extended
period beyond any breakage of the valve seat 32 that might occur.
Description of Figures 7 through 9
Figures 7-9 illustrate a second embodiment of a valve seat,
designated by the numeral 32A, that has the selected breakage
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,
`
'~
1313173
characterl~tlcs of the valve 8eat 32. The valve seat 32A ~s
sultable for use ln a valve having a valve body that i5 identl~al
to the valve body 34, a valve bonnet that is identical to the
valve bonnet 40, and a valve ~ember that is identical to the
valve member 66 so that the valve seat 32~ can be emplaced in a
needle valve which, with the exception of the valve seat, i8
identical to the valve 30 shown in Figures 1-3.
The valve seat 32A is constructed of an elastomeric material
that can be folded without causing breakage of the valve seat 32A
to facilitate molding of the valve seat 32A. In particular, the
valve seat 32A is comprised of two semi-tubular halves 96 and 98
that each have a semi-cylindrical surface, 100 and 102 for the
halves 96 and 98 respectively, and a planar sllrface, 104 and 106
for the halves 96 and 98 respectively, that can be abutted, as
shown in Figure 9 to form the valve seat 32A into a cylindrical
structure similar to the valve seat 32. A web 108 is integrally
molded with the halves 96 and 98, the web 108 being positioned
partially on the planar surface l04 and partially on the planar
surface 106 adjacent the first end 74 of the valve seat 32a so
that the web 108 can be folded to bring the two planar surfaces
104 and 106 into a substantially abutting relationship. Once the
valve seat 32a has been so folded, portions of the planar
surfaces 104 and 106 form two sides of the groove 92 that
characterizes the valve seat of the present invention to provide
the breakage plane for the valve seat 32A and the web 108, at
which breakage occurs, forms the end of such groove. A cut 107
--`` 1313173
is formed through the wall portlon of the valve seat 32~ that 1s
formed by the two halves 96 and 98 so that the valve ~eat 32~ ~
will have the same preferred breakage location characteristics as
the valve seat 32. In order to form the valve seat cavity ln the
valve seat 32A that is to receive the valve member 66,
depressions 110 and 112 are formed ln the planar surfaceY 104 and
106 to extend between the first end 74 of the valve seat 32A and
the second end 76 thereof and the depressions 110, 112 are each
provided with a semi-circular cross-section that narrows toward
the second end 76 of the valve seat 32A so that a frusto-conical
cavity will be formed within the interior of the valve seat 32A
when the web 108 is folded to oppose the planar surface 104 to
the planar surface 106. Anti-rotation tabs, 86 and 88, that are
identical to the anti-rotation tabs of the valve seat 32
and, accordingly, identically numbered are formed on the second
end of the valve seat 32A, the anti-rotation tab 86 being formed
on the half 96 and the anti-rotation tab 116 being formed on the
half 98 so that the valve seat 32A will not rotate in the valve
body 34 in which the valve seat 32A may be disposed. The
openings 82 and 84 are formed through the lialves 96 and 98 above
the tabs 86 and 88 so that the openings will he disposed in a
coaxial relationship when the valve seat 32A is formed into the
final configuration thereof as shown in Figure 9. The valve seat
32A operates in the same manner as the valve seat 32.
Description of Figures 10 through 14
Figures 10 and 11 illustrate a modification of the valve body
of a valve that receives the valve seat of the present invention
~` ~
.
``" 1~13173
so that the valve body will receive a modlfled ~orm of such valve
seat. As shown ln Figures 10 and 11, the blind hole 36 that is
formed in the valve body, designated 34B in Figure 10, has a
tapered portion 122 near the lower end thereof. Correspondingly,
the valve seat, designated 32B, that is received in the valve
body 34B has a frusto-conical outer peripheral surface 124 that
is centered on the longitudinal axis 80 of the frusto-conical
valve seat cavity 72 with which the valve seat 32B is provided
to receive the valve member 66. The preferred breakage position
characteristics of the valve seat 32B are provided by grooves 92
and 94 that intersect the valve seat cavity 128 and extend
radially away therefrom in the same manner such characteristics
are provided for the valve seat 34, and the brea~age plane so
provided for the valve seat 32B is positioned between the
openings 82 and 84 that provide fluid communication into the valve
seat cavity 72. In order to prevent rotation of the valve seat
32B in the valve chamber formed by the tapered portion 122 of the
blind hole 36 of the valve body 34B, depressions 134 and 136 are
formed in the lower end 140 of the blind hole 36 and anti-rotation
tabs 86B and 88B, shaped slightly differently from the tabs 86
and 88 as shown, are formed on the second, or lower end 76 of the
valve seat 32B to enter the depressions 134 and 136 when the
valve seat 32B is mounted in the valve body 34B. In order that
the preferred breakage plane of the valve seat 32B defined by the
first and second grooves 92 and 94 will be positioned away from the
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openin~s n2 and 34 throuqh the v~lve seAt 3~, the ~epre~lon~
134 and 136 are formed along a line parallel~ng the axis 56 of
the flow pas~age through the valve body 34n and the anti-rotatlon
tahs 86~, 88n are formed along a line paralleling the common axis
of the openings 82 and 84 into the valve seat cavity 72. The
grooves 92, 94 are then formed along a plane that is
perpendicular to the axis 90 so that any breaka~e o~ the valve
seat 32~ that might occur will occur at portions of the valve
seat 32B that do not enter into the sealing of a valve in which
the valve seat 32B might be ~ounted. ~oth the valve that receive
the valve seat 3?.n and the valve seat 32b operate in the same
manner as the valve 30 and the valve seat 32.
Description of Figures 15 through 18
Figures 15 and 16 illustrate another embodiment of a valve
body that receives a valve seat which includes ther preferred
breakage characteristics of the valve seat of the present invention
and Figures 17 and 18 illustrate such other Preferred embodiment
of the valve seat. The valve body, such modification, designated
34C in Figures 15 and 16, differs from the valve body 34 in that
the valve cha~ber 44 formed in the valve body 34C to receive the
valve seat, designated 32C in Figures 15, 17 and 18, has a non-
circular cross-section as is Particularly shown in ~igure 16.
Correspondingly, the valve seat 32C has the general form of a
rectanqular parallelepiped having two parallel faces 15n, 15~,
corresponding to the ends 74 and 76 of the valve seat 32, that
.... . - .. ..
73
are intersected by the valve se~ cavlty 72. The openlngs 82 and
84 that provlde fluld communicatlon into the valve seat cavlty
72 are formed coaxially to lntersect the valve seat cavlty 72 and
to parallel sides 156 and l5R that are perpendicular to the sides
150 and 152. The first and second grooves 92 and 94 that provide
the valve seat 32C with the preferred breakage location
characteristic, away from the locations of the openings 82 and 84
are then formed near the two remaining sides 160 and 162 of the
valve seat 32C, the grooves 92 and 94 extending radially away
from the valve seat cavity 72 between the openings 82 and 84
toward the sides 160 and 162 respectively. Since the valve seat
32C has a substantially square cross-section perpendicular to the
longitudinal axis 80 of.the valve seat cavity 72 and since the
valve chamber 44 formed in the valve body 34C similarly has a
square cross-section, no additional means, such as the
anti-rotation tabs formed on previously described embodiments of
the valve seat, need be provided to maintain alignment between
the openings 82, 84 into the valve seat cavity 72 and the flow
passage 46 formed through the valve body 34C. Both the valve
having the valve body 34C and the valve seat 32C operate in the
same manner as the valve 30 and the valve seat 32.
Description of Figures 19 through 24
Figures 21-24 illustrate another preferred embodiment of a
valve seat, designated 32D, constructed in accordance with the
present invention and Figures 19 and 20 show a further
modification of a valve seat body, designated 34D, to receive
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the valve seat 32n. Llke th~ valve seat 32A, the valve seat 32D
is constructed of a resilient elastomer so that the valve seat
32D can be molded in the form of two semi-tubular, side-by-side
halves 166 and 168 connected together by a web 170, as
illustrated in Figures 21 and 22, and subsquently folded at the
web 170 to form the seat 32D into a tubular structure having a
frusto-conical valve seat cavity formed by two co-acting
depressions 172, 174 molded into planar surfaces 176, 178 formed
on the halves 166, 168 respectively. Thus, as in the case of the
valve seat 3.~, the groove 9~ that provides the preferred
breakage location characteristics for the valve seat 32D is
formed by portions by the planar surfaces 176 and 178 and the web
170 as indicated at 180 in Figure 23.
The valve seat 32D differs from the valve seat 32A in the
: lS placement of the web 170 on the halves 166 and 168, permitting
the anti-rotation tabs 114, 116 of the valve seat 32A to be
eliminated from the valve seat 32D. As can be seen in Figures 22
and 23, the web 170 is formed on the outer semi-cylindrical
surfaces 180, 182 of the valve seat halves 176, 178 respectively,
so that the web 170 will protrude from one side of the otherwise
cylindrical surface of the valve seat wall portion 184, formed by
folding the valve seat 32D from the as-molded configuration, to
form a radially projecting locking tab as shown in Figures 23 and
24. Correspondingly, the valve seat body 34D is provided with a
niche 186 formed in the wall of the valve chamber 44 to one side
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~ '
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13~73
of the flow passage 46 to rece1ve the folded web 170 and align
the openings 82, 84 formed throu~h the valve seat halves 166, 168
respectively with the open~ngs of the flow passage 46 into the
valve chamber 44. A valve having a valve body constructed in the
manner of the valve body 34D and containing a valve seat 32n
operates in the same manner as the valve 30 to include the manner
of breakage of the valve seat 32D should such breakage occur.
Description of Fi~ures 25 through 28
-
Figures 27 and 28 illustrate yet another embodiment of a
valve seat, designated 32E, constructed in accordance with the
present invention and Figures 25 and 26 illustrate the body,
designated 34E, of a valve similar to the valve 30 that receives
the valve seat 32E. Like the valve seat 32, the valve seat 32E
has a wall portion 70 that extends circumferentially about a
frusto-con;cal valve seat cavity 72 that extends on a conver(3ing
taper from a first end 74 of the wall portion 70 to a second end
76 thereof. However, the valve seat 32E does not include
anti-rotation tabs similar to the anti-rotation tabs 86 and 88 of
the valve seat 32; rather, the orientation of the valve seat 32E
2~ about the valve closure axis 68 is maintained constant in a
different way which will now be described.
Referring first to Figures 25 and 26, it is seen that the
valve chamber 44 is, as in the case of the valve chamber 44 of
the valve body 34, substantially cylindrical. However, a groove
200 is formed in one side of the valve chamber 44, between the
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openings of the Elow passage 46 therelnto, the groove 200
becoming a hole 2n2 at the floor 204 of the valve cha~ber 44
formed by the lower end of the blind hole 36 by means of which
the valve chamber 44 is formed. The groove 200 is formed with
su~ficient depth and the hole 202 is posltioned so that a pin
inserted into the hole 202 will be completely dispose~ within the
groove 200 in a non-interfering relationship with the wall
portion 70 of the valve seat 32E except for a flange 206 that is
formed about the first end 74 of the valve seat 32E to be
received in a shoulder 208 that i~s formed in the hlind hole 36 at
the upper end of the valve chamber 44. A notch 210 is formed in
the flange 206, between the openings 82 and 84, so that the valve
seat 32E can be oriented within the valve chamber 44 via a pin
(not shown) inserted into a hole 202 and a groove 2n0 to extend
alongside the wall portion 70 of the valve seat 32E and through
the notch 210 in the flange 206 formed on the valve seat 32E. A
groove 92, extending from the valve seat cavity to provide the
preferred breakage position characteristics of the valve seat
32E, is then positioned in radial alignment with the notch 210
and both the notch 210 and groove 92 extend parallel to the
longitudinal axis 80 of the valve seat cavity 72 as shown in
Figure 28. Opposite the groove 92, a cut 216 is formed through
the valve seat wall portion 70 to similarly parallel the
longitudinal axis 80 of the valve seat cavity 72. The formation
of the cut 216, in combination with the manner in which the
groove 92 is formed, provides an additional advantage to the
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to the valve seat 32E. In part1culAr, the groove 92 extends away
from the valve ~eat cavity 72 and is formed nearly through the
valve seat wall portion 70 so that only a thin web ~s left
between portions of the valve seat 32 at opposite sides of the
groove 92 and cut 216. Such web, lndicated at 218 in Figure 28
provides the valve seat 32E with a spring expan.sion capability
that tends to limit breakage of the valve seat 32E by forceful
urging of valve member 66 into the valve seat cavity 194 while,
at the same time, limiting the e~eect of breakage should it occur
in the same manner that the effect of breakage is limited in the
valve seats 32-32D. The operation of a valve including a valve
body constructed in the manner of the valve body 34E and
including a valve seat constructed in the manner of the valve
seat 32E is substantially the same as the operation of the valve
30 and valve seat 32 differing only in the additional
anti-breakage characteristic of the valve 32E provided by the web
218.
It is clear that the present invention is well adapted to
carry out the object and attain the ends and advantages mentioned
as well as those inherent therein while presently preferred
embodiments of the invention have been described for purposes of
this disclosure, numerous changes may be made which will readily
suggest themselves to those skilled in the art and which are
encompassed within the spirit of the invention disclosed and is
defined in the appended claims.
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