Note: Descriptions are shown in the official language in which they were submitted.
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METHOD AND SEALING VALVE UNIT FOR
CONTROLLING FLUID FLOW THROUGH A PASSAGE
Background of the Invention
This invention relates generally to methods and
sealing valve units for controlling the flow of fluid
through a passage defined by the interior surface of a
tubular casing, and more particularly to methods and
sealing valve units for inhibiting particulate material
in the fluid from adversely affecting operation of the
sealing valve unit.
Recent improvements in the methods of balancing
a pneumatic wheel assembly and reducing the radial and
lateral force variations within the wheel assembly under
varying load conditions include the introduction of
particulate or pulverulent material into a tire. One
such method is disclosed in U.S Pat. No. 5,073,217,
The particulate material is mixed with
pressurized fluid, such as air,
and injected into the wheel assembly through the tire
valve stem by a suitable injecting device, such as the _
device shown and described in U.S. Patent Nos. 5,386,857
and 5,472,023, One well-known particulate material is a
polymeric synthetic plastic material sold by
International Marketing, Inc. under the trademark
irEQUAL.°
The particulate material is injected into the
tire of the wheel assembly with the valve core (e. g.,
sealing valve) absent from the valve stem, such as in a
new tire prior to installation of the valve core or in an
older tire where the valve core has been removed from the
valve stem, to allow free flow of the material into the
tire. The tire is typically inflated or at least
partially inflated during injection of the material into
the tire. After injecting the material into the tire,
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the valve core is installed into the valve stem and the
tire is inflated to the desired inflation pressure.
The valve core is a standard sealing valve used
for controlling the flow of fluid through a passage
defined by the interior surface of a tubular casing, such
as the valve stem passage of the valve stem. A valve
portion of the valve core opens and closes relative to a
stationary valve seat in the passage to control fluid
flow through the passage. It is important to the
operation of the valve core that the valve and its
associated valve seat remain free of particulate
material. However, when the valve is opened to release
pressurized fluid from the tire or to check the tire
pressure, the above described particulate material may be
drawn into the valve core and adversely affect operation
of the valve core components, as by preventing the valve
from fully closing against the valve seat, resulting in
fluid continually leaking from the tire. It~is also not
uncommon for tires to contain other particulate matter
such as dust, dirt, or particles of rubber which have
dislodged from the interior bead of the tire_during use
of the wheel assembly. These particles may also be drawn
into the valve core and adversely affect operation of the
valve core components.
To reduce this risk, it is known to provide a
valve stem having a movable filter element permanently
enclosed within the valve stem between the valve core and
the interior of the tire so that fluid is allowed to flow
through the filter element while particulate material is
retained within the tire and inhibited from reaching the
valve core. For example, the valve stem shown and
described in U.S. Pat. No. 5,479,975 includes such a filter.
While this valve stem is quite useful, users of
particulate material such as EQUAL may desire a method of
removably installing a stationary filter into common or
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standard valve stems already used in the industry rather
than replacing the valve stems with those having
permanently installed filters.
The use of valve cores or other similar sealing
' S valves to control fluid flow through the passage of a
casing is known in other industries as well. For
example, valve cores are used to control fluid flow
through utility lines, automotive, residential and
commercial air conditioning units, carbonated beverage
machines, and other apparatus in which it is necessary to
control fluid flow through a tubular casing. It is
equally important to the operation of valve cores used in
these applications that the valve and its associated
valve seat remain free of particulate material.
Backcrround of the Invention
Among the several objects and features of the
present invention may be noted the provision of a sealing
valve unit in which a sealing valve and a filter element
are constructed for simultaneous installation in and
removal from a passage of a tubular casing; the provision
of such a sealing valve unit in which the filter element
can be installed in or removed from the tubular casing
passage without removing or replacing the tubular casing;
the provision of such a sealing valve unit which reduces
the risk of mishandling, dropping and losing the filter
element; the provision of such a sealing valve unit which
requires no additional structure in the passage for
retaining the filter in the passage; the provision of
such a sealing valve unit which is easy to install in the
passage; the provision of such a sealing valve unit which
. is easy to assemble using standard, currently available
sealing valves; and the provision of such a sealing valve
unit which inhibits particulate material from flowing
into the valve portion of the sealing valve.
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Further among the objects and features of the
present invention may be noted the provision of a tool
for efficiently and reliably inserting a filter element
into a tire valve stem without disconnecting the valve
stem from the tire; the provision of such a tool which is
used to assemble a valve assembly that inhibits
particulate material from flowing into a sealing valve;
the provision of such a tool which is mechanically
simple; the provision of such a tool which further allows
the introduction of particulate material into the tire
before the filter is inserted into the valve stem,
without disconnecting the tool from the valve stem; and
the provision of such a tool which further allows
installation of a sealing valve into the valve stem after
insertion of the filter, without disconnecting the tool
from the valve stem.
Still further among the objects and features of
the present invention may be noted the provision of a
method for inhibiting the escape of particulate matter
through a valve assembly of a pneumatic wheel assembly;
the provision of a method for inserting a filter into a
tire valve stem which can be carried out quickly and
simply; the provision of such a method which permits both
introduction of particulate material into the tire and
insertion of the filter into the valve stem using a
single tool; the provision of such a method which further
permits installation of the valve core in the valve stem
after insertion of the filter using the single tool.
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According to one aspect of the present invention,
there is provided a sealing valve unit for controlling the
flow of fluid through a passage defined by the interior
surface of a tubular casing, the sealing valve unit having
inner and outer ends and being adapted to be inserted, inner
end first, in an inward direction into the passage of the
tubular casing, said sealing valve unit comprising: a valve
body having a longitudinal axis and a longitudinal bore
therethrough, said valve body being formed for releasable
connection to the tubular casing when the valve body is
inserted into the passage of the tubular casing to a
position in which the longitudinal axis of the body is
generally coaxial with the passage; a valve seat on the
valve body; a sealing assembly comprising a sealing device
adapted for sealing engagement with the valve seat, the
sealing device being movable in an inward direction with
respect to the valve seat from a closed sealing position in
which the sealing device sealingly engages the valve seat to
block fluid flow through the bore in the valve body to an
open position in which the sealing device is spaced from the
valve seat to permit fluid flow through the bore; and a
filter element adjacent the inner end of the sealing valve
unit configured for substantially preventing passage of
particulate matter of a size capable of interfering with
movement of the sealing device to its closed sealing
position; said valve body, sealing assembly and filter
element being so constructed that they are held in assembly
with one another independent of the tubular casing so that
they can be simultaneously installed as a single unit in the
tubular casing passage and simultaneously removed as a
single unit from the tubular casing passage.
According to another aspect of the present
invention, there is provided a sealing valve unit for
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controlling the flow of fluid through a passage in a tubular
casing having an internal shoulder, the sealing valve unit
having inner and outer ends and being adapted to be
inserted, inner end first, in an inward direction into the
passage of the tubular casing, said sealing valve unit
comprising: a valve body having a longitudinal axis and a
longitudinal bore therethrough, said valve body being formed
for releasable connection to the tubular casing when the
valve body is inserted into the passage of the tubular
casing to a position in which the longitudinal axis of the
body is generally coaxial with the passage; a valve seat on
the valve body; a sealing assembly comprising a sealing
device adapted for sealing engagement with the valve seat,
the sealing device being movable in an inward direction with
respect to the valve seat from a closed sealing position in
which the sealing device sealingly engages the valve seat to
block fluid flow through the bore in the valve body to an
open position in which the sealing device is spaced from the
valve seat to permit fluid flow through the bore; and a
filter assembly adjacent the inner end of the sealing valve
unit sized and configured for engaging the internal shoulder
of the casing so that substantially all of the fluid flowing
through the passage passes through the filter assembly, the
filter assembly including a filter element configured for
substantially preventing passage of particulate matter of a
size capable of interfering with movement of the sealing
device to its closed sealing position; said valve body,
sealing assembly and filter assembly being so constructed
that they are held in assembly with one another independent
of the tubular casing so that they can be simultaneously
installed as a single unit in the tubular casing passage and
simultaneously removed as a single unit from the tubular
casing passage.
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According to a further aspect of the present
invention, there is provided a method for inhibiting the
escape of particulate matter through a valve assembly of a
pneumatic wheel assembly, said wheel assembly defining an
enclosed interior volume for holding fluid under pressure,
said valve assembly comprising a valve stem having a passage
therethrough for permitting fluid under pressure to be
introduced into said interior volume, said passage having an
inlet end accessible from outside the wheel assembly and an
outlet end adjacent said interior volume, said method
comprising the steps of: inserting a filter element in the
valve stem passage while the valve stem is connected to the
wheel assembly, said filter element being configured to
substantially prevent the passage of particulate matter
while allowing the passage of pressurized fluid; and
installing a sealing valve in the valve stem passage after
insertion of the filter element, the sealing valve being
movable between an open position for allowing pressurized
fluid to flow through said passage and a closed sealing
position, the sealing valve being positioned between the
inlet end of the passage and the filter whereby the filter
functions to substantially prevent particulate matter from
inside the interior volume of the wheel assembly from
interfering with the sealing closure of the sealing valve.
According to a yet another aspect of the present
invention, there is provided a method for inhibiting the
escape of particulate matter through a valve assembly of a
pneumatic wheel assembly, said wheel assembly defining an
enclosed interior volume for holding fluid under pressure,
said valve assembly having a valve stem with a passage
therethrough for permitting fluid under pressure to be
introduced into said interior volume, said passage having an
inlet end accessible from outside the wheel assembly and an
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outlet end adjacent said interior volume, said method
comprising the steps of: affixing a filter element to a
sealing valve, and installing the sealing valve with the
filter element affixed thereto into the valve stem passage,
the sealing valve being movable between an open position for
allowing air under pressure to flow through said passage and
a closed sealing position, the filter element being
configured to substantially prevent particulate matter from
inside the interior volume of the wheel assembly from
interfering with the sealing closure of the sealing valve.
According to a further aspect of the present
invention, there is provided a valve assembly for use in
combination with a pneumatic wheel assembly comprising a
circular rim for attachment to a rotatable hub of a vehicle,
and an annular tire attached to the rim, the rim and tire
defining an interior volume capable of being pressurized to
support the vehicle, the valve assembly permitting fluid to
enter said interior volume and selectively preventing fluid
from exiting said wheel assembly, the valve assembly
comprising: a valve stem having an internal passage
therethrough for communicating with the interior volume of
the wheel assembly to permit fluid to enter and exit the
wheel assembly, the internal passage having inlet and outlet
ends, and means for attachment of the valve stem to the
wheel assembly so that the inlet end of said passage is
accessible from outside the wheel assembly and the outlet
end of the passage is adjacent the interior volume of the
wheel assembly; a sealing valve positioned within the valve
stem passage for movement between an open position for
allowing fluid under pressure to flow through said passage
and a closed sealing position; and a filter element fixedly
positioned within the valve stem passage, the filter element
being configured for substantially preventing passage of
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particulate matter of a size capable of interfering with
movement of the sealing valve to its closed sealing
position.
Other objects and features will become in part
apparent and in part pointed out hereinafter.
Brief Description of the Drawings
Fig. 1 is a perspective of a tool of the present
invention connected to the valve stem of a pneumatic wheel
assembly;
Fig. 2 is a perspective of the tool of Fig. 1;
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Figs. 3A-D are fragmented cross sectional views
taken along the line 3-3 of Fig. 2 at four different
stages of operation of the tool;
Fig. 4 is a fragmented cross sectional view
' 5 taken along the line 4-4 of Fig. 2; and
Fig. 5 is a cross sectional view of a valve
assembly;
Fig. 6 is a perspective of a sealing valve of
the present invention with a filter element attached
thereto;
Fig. 7 is a perspective view of the sealing
valve of Fig. 6 with a sealing device of the sealing
valve moved to an open position, a portion of the filter
element being removed to show an end of the sealing
device;
Fig. 8 is a schematic of a sealing valve
similar to the sealing valve of Fig. 6 with the filter
element shown in section;
Fig. 9 is a schematic of the sealing valve of
Fig. 8 installed in a valve stem, with the filter element
and valve stem shown in section;
Fig. 10 is a schematic of a second embodiment
of a sealing valve of the present invention with a filter
assembly attached thereto, the filter assembly being
shown in section;
Fig. 11 is a schematic of a third embodiment of
a sealing valve of the present invention with a filter
assembly attached thereto, the filter assembly being
shown in section;
Fig. 12 is a schematic of the sealing valve of
Fig. 10 installed in a valve stem, with the filter
assembly and valve stem shown in section;
Fig. 13 is a schematic of the sealing valve of
Fig. 11 installed in a valve stem, with the filter
assembly and valve stem shown in section;
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Fig. 14 is an enlarged perspective of a sealing
valve of the valve assembly of Fig. 5;
Fig. 15 is a fragmentary schematic showing a
fourth embodiment of a sealing valve of the present
invention, with a filter assembly and valve stem shown in
section;
Fig. 16 is a fragmentary schematic showing a
fifth embodiment of a sealing valve of the present
invention with a filter assembly shown in section;
Fig. 17 is a fragmentary schematic of the
sealing valve of Fig. 16 shown installed in a valve stem,
the filter assembly and valve stem being shown in
section; and
Fig. 18 is a fragmentary schematic showing a
sixth embodiment of a sealing valve of the present
invention with a filter assembly, the sealing valve being
installed in a valve stem with the filter assembly and
valve stem being shown in section.
Corresponding parts are designated by
corresponding numerals throughout the several views of
the drawings.
Description of the Preferred Embodiment
Referring first to Fig. 1, a tool for inserting
a filter element into a valve assembly of a tire is
indicated in its entirety by the reference numeral 21.
The tool 21 is shown connected to a pneumatic wheel
assembly, indicated generally as W, which comprises a rim
R and pneumatic tire T mounted on the rim. The rim R and
tire T define an interior volume V within the wheel
assembly W for holding pressurized fluid. A valve
assembly, indicated generally as 23, is attached to the
wheel assembly W in communication with the interior
volume V for selectively allowing the flow of pressurized
fluid in and out of the interior to inflate or deflate
the tire T.
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In the various drawings of the invention, the
valve assembly 23 is oriented generally upright or
' vertical, and for the purpose of describing the invention
as illustrated in the drawings the terms "upper" and
"lower" are used in referring to the various components
and operations of the valve assembly. However, it is to
be understood that the valve assembly 23 may be oriented
other than vertically and that the components and
operations of the valve assembly may broadly be referred
to using the terms "outer" and "inner," respectively.
The valve assembly 23 (Fig. 5) comprises a
valve stem, indicated generally as 25, and a sealing
valve, such as a valve core, indicated generally as 27,
seated within the valve stem. The valve stem 25 is a
substantially tubular casing having a first or lower end
29 adapted for attachment to the wheel assembly W in
communication with the interior volume V, and a second or
upper end 31 accessible from outside the wheel assembly.
The ends 29, 31 of the valve stem 25 are open such that
the interior surface of the stem defines a valve stem
passage 33 in communication with the interior volume V of
the tire to allow entry and exit of pressurized fluid
into and out of the wheel assembly W. The valve stem
passage has a central longitudinal axis X as shown in
Fig. 5. The upper end 31 of the valve stem 25 is
externally threaded for engagement by a closure cap (not
shown) or other suitable connector, and is also
internally threaded for engagement with the valve core 27
to secure the valve core within the stem.
The valve stem 25 has an internal annular
shoulder adjacent its lower end defining a filter seat
35, the function of which is described further herein.
However, valve stems not having this filter seat 35 are
. contemplated to be within the scope of this invention.
Additionally, the present invention is not limited to any
particular valve stem material, shape, size or method of
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attachment to the wheel assembly, and it is contemplated
that the valve stem 25 may be configured for use with
motorcycle tires, automobile tires, light and heavy duty
truck tires, aircraft tires and other tires for which
valve stems are commonly used, without departing from the
scope of this invention.
4~lith reference to Fig. 14, the sealing valve
27, or valve core, of the present invention has a lower
end 201 and an upper end 203 and is adapted for being
inserted, lower end first, in a downward direction into
the valve stem passage 33. The valve core 27 comprises a
stationary valve body, generally indicated at 205, having
a longitudinal axis X'. The valve body 205 is threaded
at an upper end 207 for releasable connection to the
valve stem 25 so that the valve body 205 is held against
longitudinal movement relative to the valve stem. The
valve body 205 has a longitudinal bore 209 therethrough
extending along its longitudinal axis X'. The valve body
205 is connected to the valve stem 25 in coaxial
relationship with the valve stem passage 33 so that the
longitudinal axis X' of the valve body is generally
coincident with the central longitudinal axis X of the
valve stem passage (Fig. 5).
A lower end of the valve body 205 surrounding
the longitudinal bore 209 defines an annular valve seat
37 positioned in the valve stem passage 33 in coaxial
relationship therewith. An annular sealing member 39
around the valve body 205 is engageable with the valve
stem 25 so that fluid flowing within the valve stem
passage 33 is directed through the longitudinal bore 209
in the valve body. The threaded upper end 207 of the
valve body 205 is preferably rotatable with respect to
the remainder of the valve body, and has an external
surface formed with opposing flats 47 for reasons which
will become apparent herein.
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The valve core 27 also includes a sealing
assembly, generally indicated at 211, adapted for
longitudinal movement in the valve stem passage 33
relative to the valve body 205 for controlling the flow
' 5 of fluid through the longitudinal bore 209 of the valve
body. The sealing assembly 211 comprises a sealing
device, indicated generally as 213, adapted for movement
along the longitudinal axis X of the valve stem passage
33 between a closed sealing position in which the sealing
device sealingly engages the valve seat 37 to block flow
through the longitudinal bore 209 in the valve body 205,
and an open position in which the sealing device is
spaced from the valve seat to allow pressurized fluid to
flow through the longitudinal bore, and an actuator pin,
such as a valve pin 43, connected to the sealing device
for use in moving the sealing device to its open
position. A spring (not shown) disposed in the valve
body 205 biases the sealing device 213 toward its closed
sealing position.
Still referring to Fig. 14, the sealing device
213 comprises a sealing element 215, preferably
constructed of rubber or other suitable material, seated
in a generally cup-shaped sealing element carrier 217. A
crimping member 220 is integrally formed with the sealing
element carrier 217 and extends down from the carrier.
The valve pin 43 extends up from the sealing device 213
through the longitudinal bore 209 in the valve body 205
beyond the threaded upper end 207 of the valve body. An
upper end 221 of the valve pin 43 is accessible for being
pushed downward relative to the valve body 205 and valve
stem 25 against the bias of the spring for moving the
sealing device 213 to its open position.
A lower portion 42 (not shown in Fig. 14 but
shown extended beyond the crimping member 220 in Fig. 8)
of the pin 43 extends down through the sealing element
carrier 217 and crimping member 220, with the lower
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portion of the pin and the crimping member being
generally co-terminal and together defining a shaft,
generally indicated at 219, having a lower end 223. The
crimping member 220 is preferably crimped by suitable
5 crimping means (not shown) into secure engagement with
the lower portion 42 of the valve pin 43 for connecting
the sealing device 213 to the valve pin to define the
sealing assembly 211. As shown in Figs. 8 and 9, the
lower portion 42 of the valve pin 43 may instead extend
10 substantially down beyond the end of the crimping member
220 so that the shaft 219 extends further downward
away from the carrier 217.
With reference to Figs. 2 and 3A, the tool 21
of the present invention generally comprises a body 51
having a handle 53, a valve stem connector, indicated
generally as 55, a fluid inlet 57, a filter insertion
inlet 59, a filter loading assembly, indicated generally
as 61, a valve core insertion inlet 63, a plunger
assembly, indicated generally as 65, and a selector
valve, indicated generally as 67, rotatably mounted on
the body for selectively configuring the tool to perform
various operations while the tool is connected to the
valve stem 25. For example, the tool 21 of the preferred
embodiment is used for injecting particulate or
pulverulent material into the interior volume V of the
wheel assembly W, inserting a filter element 71 into the
valve stem 25, and then installing the valve core 27 into
the valve stem. The tool 21 shown in Fig. 2 is
approximately 6.965 inches in length measured along the
handle and body, 9.325 inches in depth measured along the
valve stem connector and plunger assembly, and 1 inch in
width. However, these dimensions may vary depending on
the particular type of wheel assembly W and valve stem 25
for which the tool 21 is used.
The body 51 is preferably a unitary piece
constructed of suitable material, such as plastic, brass,
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aluminum or steel, but it may be fabricated from multiple
parts or other materials and be within the scope of this
' invention. The handle 53 extends outward from the body
51 to provide a means for grasping the tool 21 while
connecting the tool to the valve stem 25 and performing
the various operations. The handle 53 is preferably
ergonomically configured to provide for comfortable
grasping of the handle by the operator of the tool 21.
The body 51 has a generally cylindrical opening 69
extending laterally therethrough for receiving the
selector valve 67, the purpose of which will be described
later. Various passages (Figs. 3A-D), such as a fluid
passage 75, a filter passage 77, a plunger passage 79, a
valve core passage 81 and an outlet passage 83 (broadly
an "outlet") extend outward from the opening 69 in the
body 51 of the tool 21 to allow communication between the
opening and the various components located about the
periphery of the body and handle 53, as will be
described.
The outlet passage 83 (Figs. 3A-D) in the body
is in direct alignment with a central longitudinal axis X
of the valve stem passage 33 when the tool 21 is
connected to the valve stem 25 to provide communication
between the opening 69 in the body 51 and the valve stem
passage. The valve stem connector 55 is preferably a
quick disconnect coupler that allows for quick releasing
engagement of the tool 21 with the valve stem 25. This
connector 55 includes a trigger 87 pivotally connected to
the tool 21 in spaced relationship with the handle 53 so
that the trigger may be squeezed using the same hand that
grasps the handle of the tool. A suitable spring clamp
89 is connected to the trigger 87 and is operable to
engage the valve stem 25 releasably to connect the tool
21 to the stem. For example, squeezing the trigger 87
moves the spring clamp 89 away from the valve stem 25 to
allow the connector 55 to be placed over the valve stem.
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Releasing the trigger 87 allows the spring clamp 89 to
move under its own spring force into engagement with the
valve stem 25 to releasably connect the tool 21 to the
stem. Construction and operation of this type of
connector is commonly known in the art, as disclosed in
U.S. Pat. No. 4,276,898, and is described herein only for
the purpose of providing a means for connecting the tool
to the tire valve assembly. Other connecting means, such
as those commonly know in the art for connecting gas or
liquid supply lines, may be used without departing from
the scope of this invention.
As best seen in Figs. 3A-D, the fluid passage
75 extends through the body 51 and handle 53 to allow
communication between the opening 69 in the body and the
fluid inlet 57. A connector 91 is attached to the end of
the handle 53 at the fluid inlet 57 for connection with a
source of fluid. The fluid being defined herein as gas
(such as air, nitrogen, or other suitable gases commonly
uses for inflating the tire of a wheel assembly), liquid,
or a mixture of gas or liquid under pressure and a
particulate or pulverulent material. The particulate
material is preferably a fine powder used for balancing
the wheel assembly W and reducing the radial and lateral
force variations within the wheel assembly under varying
load conditions, such as the material described in U.S
Pat. No. 5,073,217
One such particulate material is a polymeric
synthetic plastic material sold by International
Marketing, Inc. under the trademark "EQUAL." The fluid
source is preferably an injection device which mixes
pressurized gas with the particulate material and injects
the mixture into the interior volume V of the wheel
assembly W, such as the injection device shown and
described in U.S_ Patent Nos. 5.386,857 and 5.472,023,
It is
understood, however, that the connector 91 may be
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connected to other fluid sources, whether or not
particulate in nature, without departing from the scope
of this invention.
The filter passage 77 provides communication
between the opening 69 in the body 51 and the filter
insertion inlet 59 and is sized for receiving the filter
element 71. A tubular guide 101 extends outward from the
body.51 in registry with the filter insertion inlet for
properly guiding the filter element into the filter
passage. The filter element 71 is preferably a screen
woven of suitable material such as stainless steel, cloth
or nylon, and has a mesh sized to prevent particulate
material in the interior volume V of the wheel assembly W
large enough to interfere with proper operation of the
valve core 27 from passing into the valve stem passage
33, while causing little interruption in the rate of
fluid flow through the valve stem passage. For example,
the mesh size should preferably range from about 5
microns to 100 microns, and is more preferably about 40-
50 microns. As shown in Figs. 3A-D, the filter element
71 is generally cup-shaped (e. g., a hollow cylinder
having a closed end 93), the closed end being in the path
of fluid flowing through the valve stem passage 33. The
diameter of the filter element 71 is slightly less than
the diameter of the valve stem passage 33 so that the
element seats tightly within the passage against the
filter seat 35. Because of the small mesh size, the
filter element 71 is sufficiently rigid or stiff to hold
its shape upon insertion into the valve stem 25.
The filter element 71 is preferably pre-formed
into its cup shape, but it may also be formed as it is
inserted into the body 51 through the filter insertion
inlet 59. Moreover, rather than using a screen-type
element, the filter element 71 may be constructed of
sintered materials, such as sintered stainless steel,
sintered magnesium, sintered manganese and other sintered
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materials formed using known powdered metallurgical
processes, or other porous media commonly used for
filtering particulate material. The filter element 71
may also be spherical, disc shaped, or other suitable
shapes without departing from the scope of this
invention. It is also contemplated, as will be described
later herein, that the filter element 71 may be affixed
to the valve core 27 such as by bonding or other suitable
means so that the combined filter element and valve core
define a sealing valve unit to be inserted into the
filter insertion inlet 59 for delivery through the filter
passage 77 toward the opening 69 in the body 51.
Still referring to Figs 3A-D, the filter
loading assembly 61 is removable from the body 51 to
allow loading of the filter element 71 into the filter
passage 77 through the filter insertion inlet 59. The
assembly 61 is then replaceable on the body 51 for
pushing the filter element 71 toward the opening 69 in
the body. The assembly 61 comprises a generally
cylindric cap 95 having a closed top and an open bottom.
A coil spring 97 in the cap 95 pushes against a seat 99
adjacent the open end of the cap adapted for contact with
the tubular guide 101. The seat 99 and guide 101 are
sized slightly smaller than the cap 95 to allow
telescoping sliding movement of the cap relative to the
seat and guide. The guide 101 acts as a reaction surface
for the seat 99 for compressing the spring 97 as the cap
95 is pushed down over the seat and guide. A push rod or
ram 103 is connected to the top of the cap 95 and extends
through the seat 99 and guide 101 into the filter passage
77 in the body 51, with the ram being sufficiently long
so that a free end 104 of the ram extends substantially
into the opening 69 in the body when the spring 97 is
compressed. The seat 99 is engageable with a shoulder on
the ram 103 to hold the seat and spring 97 in assembly
with the ram and within the cap 95.
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In the preferred embodiment, the diameter of
the free end 104 of the ram 103 is sized slightly smaller
than the diameter of the filter element 71 so that the
ram seats within the open end of the cup-shaped filter
5 element for pushing the element toward the opening 69 in
the body 51. It is contemplated that other suitable
means for urging the filter element 71 through the
passage 77 toward the opening 69 in the body 51 may be
used without departing from the scope of this invention.
10 The plunger passage 79 provides communication
between the opening 69 in the body 51 and the plunger
assembly 65, and is aligned with the central longitudinal
axis X of the valve stem passage 33. As seen in Figs.
3A-D, the plunger assembly 65 includes a guide tube 105
15 attached to the body 51 and extending outward from the
body in alignment with the plunger passage 79, and a
plunger 107 adapted for reciprocating movement in the
guide tube 105 through a forward stroke in which a
working end or head i09 of the plunger passes through the
opening 69 in the body 51 through the outlet passage 83
into the valve stem passage 33, and a reverse stroke in
which the head of the plunger is retracted into the
plunger passage or entirely into the guide tube. The
plunger 107 is preferably sufficiently long to extend
into the valve stem passage 33 upon moving through its
forward stroke. A cap 117 is mounted over the top of the
guide tube 105 to secure the plunger 107 within the tube.
It is understood that the plunger assembly 65 may be
flexible, so that the plunger assembly need not be
aligned with the central longitudinal axis X of the valve
stem passage 33, without departing from the scope of this
invention, as long as the head 109 of the plunger 107 is
adapted for movement into the valve stem passage.
The head 109 of the plunger 107 is sized
slightly smaller than the diameter of the filter element
71 for seating within the open end of the cup-shaped
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16
filter element to push the element into the valve stem
passage 33. The head 109 is also preferably forked to
fit over the flats 47 of the valve core insert 45. The
plunger 107 is rotatable on its axis for screwing the
valve core 27 into the valve stem 25. A disc-shaped knob
111 is mounted on the opposite (tail) end 113 of the
plunger 107 for ease of handling and manipulating the
plunger. An annular stop 114 is attached to the plunger
107 for movement within the guide tube 105. The stop 114
is sized larger than the openings in the guide tube 105
through which the plunger 107 extends so that the stop
limits the forward stroke of the plunger into the valve
stem passage 33, thereby limiting the depth of insertion
of the filter element 71 into the passage. A suitable O-
ring 115 seated in an annular groove in the stop 114
provides a seal between the stop and the guide tube 105
to prevent pressurized fluid from escaping the interior
volume V of the wheel assembly W while the plunger 107 is
in use, thereby maintaining the pressure within the wheel
assembly.
While the plunger passage 79 is shown and
described as extending toward the opening 69 in the body
51, it is contemplated that the plunger passage may
extend through the body so that the plunger passage is in
direct registry with the valve stem passage and that the
filter passage may be in direct registry with the plunger
passage so that a filter element received in the filter
passage may be loaded directly into the plunger passage
and pushed by the plunger through the plunger passage
into the valve stem passage.
The valve core passage 81 provides
communication between the opening 69 in the body 51 and
the valve core insertion inlet 63 for delivery of a valve
core 27 toward the opening. If necessary, the valve core
27 may be pushed toward the opening 69 using the filter
loading assembly 61 described above. It is contemplated
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17
that the valve core 27 may be received in the filter
passage 77 rather than a valve core passage 81 without
departing from the scope of this invention.
With reference to Fig. 4, the selector valve 67
(broadly, "moving means" or "means for moving the filter
element 71 into registry with the plunger passage 79 and
the valve stem passage 33") is rotatably mounted in the
opening 69 in the body 51 for selectively performing the
various operations of the tool 21. The selector valve 67
is generally cylindrical and is preferably of two-piece
construction having a cylindrical core 119 constructed of
brass or other suitable metal, and a sleeve 121
constructed of teflon or other suitable sealing, low-
friction material surrounding the circumference of the
core. The diameter of the selector valve 67 is slightly
smaller than the diameter of the opening 69 in the body
51 so that the selector valve fits tightly in the
opening. For example, the selector valve shown in Fig. 4
is about 1.25 inches in diameter. However, the diameter
of the selector valve 67 may vary depending on the size
of the tool 21 and the diameter of the opening 69 in the
body 51. The teflon sleeve 121 seals the selector valve
against the body while allowing rotation of the selector
valve 67 relative to the body 51 about a rotational axis
Y extending laterally with respect to the body. As shown
in Fig. 3D, this axis Y is offset from the longitudinal
axis X of the valve stem passage 33 by a distance D,
although it is contemplated that the rotational axis of
the selector valve 67 may intersect the longitudinal axis
of the valve stem passage without departing from the
scope of this invention.
The selector valve 67 is secured within the
opening 69 in the body 51 by snap-rings 123 (Fig. 4)
fitted into annular grooves 125 in the body 51 on each
side of the selector valve. A non-metallic washer 127 is
placed between each snap-ring 123, which is typically
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constructed of metal, and the selector valve 67 to
prevent the core of the valve from rubbing against the
snap-ring as the valve is rotated. It is understood,
however, that means other than snap-rings 123 and washers
127 may be used for rotatably securing the selector valve
67 within the opening 69 in the body 51 without departing
from the scope of this invention, as long as the valve is
free to rotate relative to the opening about its
rotational axis Y. Rotation of the selector valve 67
within the opening 69 in the body 51 between pre-
determined settings is affected by a lever 129 fitted
over a stub shaft 131 extending outward from one side of
the selector valve.
Two passages or bores 133, 135 extend through
the selector valve 67 and are adapted for selective
registry with the various passages 75, 77, 79, 81, 83
extending within the body 51 as the selector valve is
rotated between its different settings (Figs. 3A-D). The
body 51 or the selector valve 67 may have stop limits
(not shown) to assure proper positioning of the valve
bores 133, 135 in registry with the passages 75, 77, 79,
81, 83. As shown in Figs. 3A-D, the selector valve bores
133, 135 are completely separate from each other, there
being no communication between the bores. The bores 133,
135 are also angled relative to one another and are
directed along chords of the selector valve 67 so that
neither bore extends through the rotational axis Y of the
selector valve. For example, in the preferred embodiment
these bores 133, 135 are angled approximately 45-50
degrees with respect to each other. However, the
relative angle may vary according to the location of the
various passages 75, 77, 79, 81, 83 within the body.
Operation of the tool 21 according to the
method of the present invention will now be described
with reference to Figs. 3A-D. The pressure within the
interior volume V of the wheel assembly W is adjusted
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19
such that the tire T, whether new or used, is partially
inflated, as for example, to less than one-half of its
rated pressure. As shown in Fig. 3A, the tool 21 is
releasably connected to the valve stem 25 by grasping the
handle 53 and squeezing the trigger 87 of the valve stem
connector 55, placing the connector over the valve stem,
and then releasing the trigger to allow the spring clamp
89 to move under its own spring force into releasable
engagement with the valve stem to secure the tool on the
stem. The plunger 107 is initially retracted so that the
head 109 of the plunger is withdrawn into the guide tube
105 or plunger passage 79, and the selector valve 67 is
positioned in a first setting in which the first bore 133
of the selector valve is in registry with the outlet
passage 83 and the fluid passage 75 of the body 51 to
provide communication between the valve stem passage 33
and the fluid source. A mixture of particulate material
and pressurized gas is then injected into the fluid inlet
57 and directed through the fluid passage 75 , the first
bore 133 and the outlet passage 83 for injection through
the valve stem passage 33 into the interior volume V of
the wheel assembly W. After injection of the particulate
material into the interior volume V, pressurized gas is
delivered to the fluid inlet 57 and directed through the
valve stem passage 33 into the interior volume V of the
wheel assembly W to inflate the tire R to the desired
pressure.
With the selector valve 67 still positioned in
this first setting, the second bore 135 in the selector
valve is in registry with the filter passage 77. The
filter loading assembly 61 is removed from the body 51
and a filter element 71 is loaded into the passage
through the filter insertion inlet 59. The assembly 61
is then replaced over the inlet 59 with the free end 104
of the ram 103 extending into the filter passage 77 and
seating within the open end of the cup-shaped filter
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element 71. The cap 95 of the assembly 61 is pushed down
over the guide 101 toward the body 51 whereby the ram 103
pushes the filter element 71 into the second bore 135 in
the selector valve 67. Compression of the coil spring 97
5 caused by pushing the cap 95 down over the guide 101
biases the cap away from the body 51 so that when the cap
is released, the ram 103 retracts out of the second bore
135. The other end of the second bore 135 is closed by
the body 51 so that the filter element 71 is retained
10 within this bore as shown in Fig. 3A until the selector
valve 67 is rotated to another setting.
With the filter element 71 loaded in the second
bore 135 in the selector valve 67, the lever 129 is then
used to rotate the selector valve to a second setting, as
15 best seen in Fig. 3B, in which the first bore 133 is no
longer in registry with the fluid passage 75 and outlet
passage 83 of the body 51, thus preventing the escape of
gas from the interior volume V of the wheel assembly W
through the fluid passage, and in which the second
20 selector valve bore 135, in which the filter element 71
is loaded, is aligned with the central longitudinal axis
X of the valve stem passage 33 in registry with the
plunger passage 79 and the outlet passage 83. In this
setting, the open end of the cup-shaped filter element 71
preferably faces the head 109 of the plunger 107. The
plunger 107 is pushed forward in the guide tube 105 to
move the head 109 of the plunger into the second bore 135
to seat within the open end of the cup-shaped filter
element 71. Further forward movement of the plunger 107
pushes the filter element 71 through the aligned outlet
passage 83 and into the valve stem passage 33 until the
filter element seats against the filter seat 35 within
the valve stem 25. The plunger 107 is then pulled back
through a return stroke to move the head 109 of the
plunger back into the plunger passage 79 (or into the
guide tube 101). Where the valve stem 25 does not have a
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21
filter seat 35, it is contemplated that the top of the
guide tube I05 will limit the forward stroke of the
plunger 107 and hence limit the depth of insertion of the
filter element 71 into the valve stem passage 33, whereby
the tight fit of the filter element against the interior
of the valve stem will act to secure the element within
the valve stem passage.
The next step is to rotate the selector valve
67, via the lever 129, to a third setting (Fig. 3C) in
which the second bore 135 is in registry with the valve
core passage 81. A valve core 27 is loaded into the
valve core passage 81 through the valve core insertion
inlet 63 and is pushed into the second bore 135 in the
selector valve 67 as shown in Fig. 3C. If necessary, the
filter loading assembly 61 may be used within the valve
core passage 81 to push the valve core 27 into the second
bore 135. The opposing end of the second bore 135 is
closed by the body 51 so that the valve core 27 is
retained within the second bore until the selector valve
67 is moved to a different setting.
Referring now to Fig. 3D, with the valve core
27 loaded in the second bore 135 of the selector valve
67, the lever 129 is used to rotate the valve back to its
second setting to re-align the second bore in registry
with the outlet passage 83 and plunger passage 79. The
plunger 107 is then moved through its forward stroke to
push the valve core 27 into the valve stem passage 33.
The plunger 107 should be moved a distance sufficient to
cause the forked head 109 of the plunger to fit over the
flats 47 of the threaded insert 45 of the valve core 27,
at which point the plunger 107 is rotated about its axis
to screw the valve core into engagement with the internal
threads of the upper end 31 of the valve stem 25 for
securing the valve core within the valve stem passage 33.
With the valve core 27 and filter element 71 installed in
this manner, particulate material in the interior volume
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22
V of the wheel assembly W of a size capable of
interfering with proper operation of the valve core is
blocked by the filter element from flow through the valve
stem passage 33 while other fluid under pressure is
allowed to flow through the passage. The tool 21 is then
disconnected from the valve stem 25 by again squeezing
the trigger 87 of the valve stem connector 55 to move the
spring clamp 89 out of engagement with the valve stem,
and pulling the tool away from the stem.
While the tool 21 is described herein for
manual operation, it is contemplated that the various
operational components of the tool, including the lever
129 and the selector valve 67, the valve stem connector
55, the filter loading assembly 61 and plunger 107 may be
automatically operated for increasing the rate at which
filter elements can be inserted into wheel assemblies.
Additionally, only the outlet passage 83 in the body 51
need be aligned along the central longitudinal axis X of
the valve stem passage 33. The remaining passages 75,
77, 79, 81 and components may be located on the body 51
other than described herein without departing from the
scope of this invention. Moreover, while the selector
valve 67 is shown and described herein as rotating within
the body 51 and having a rotational axis Y perpendicular
to the body, numerous other selector valve embodiments
are contemplated to be within the scope of this
invention, such as a selector valve having a rotational
axis in the plane of the body, as long as the valve is
adapted for allowing fluid passage into the valve stem
passage 33 when moved to a first position, and for
preventing fluid passage in and out of the valve stem
passage when moved to another position during operation
of the other tool components.
Providing a filter passage 77 separate from the
plunger passage 79 allows the filter element 71 to be
installed into the valve stem passage 33 without
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23
disconnecting the tool 21 from the valve stem 25 and
without removing the plunger 107 from its guide tube 105,
thereby reducing the risk of losing the plunger, reducing
the loss of pressure within the interior volume V of the
wheel assembly W, and providing an efficient and reliable
tool for inserting the filter element 71 into the valve
stem passage 33. The mesh size of the filter element 71
is sized to inhibit particulate material from passing
into the valve stem passage 33 and potentially adversely
affecting operation of the valve core 27, thereby
reducing the risk of gas leakage from the interior volume
V of the wheel assembly W.
Additionally, the provision of the fluid
passage 75, the valve core passage 81 and the selector
valve 67 allow the user to selectively inject fluid under
pressure into the interior volume V of the wheel assembly
W, insert the filter element 71 into the valve stem
passage 33, and install the valve core 27, all without
disconnecting the tool from the valve stem, thus
increasing the efficiency of the tool 21. This is
particularly useful in the manufacture of new tires where
the valve core 27 has not yet been installed.
As discussed above, it is contemplated that the
filter element 71 may be attached to the valve core 27 so
that the valve core and filter element can be installed
in and removed from the valve stem passage 33 as a single
sealing valve unit, indicated generally as 72 in Figs. 6-
I3. Figs. 6-9 illustrate a first embodiment of a sealing
valve unit of the present invention. The lower end 223
of the shaft 219 of the sealing device 213 is enlarged,
preferably to have the shape of a frustum with a rounded
bottom (Fig. 7), or a generally spherical shape (Figs. 8
and 9), or other shapes such as a frustum with a flat
bottom, a semi-spherical or domed shape, a cylindric
shape, a disc shape or other suitable shape. The
enlarged end 223 is secured to the shaft 219 by suitable
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24
fastening means, such as by crimping the enlarged end
over the shaft into secure engagement therewith, although
it is contemplated that the enlarged end may be
integrally formed with the shaft. The maximum transverse
diameter of the enlarged lower end 223 of the shaft 219
is substantially greater than the diameter of the shaft,
but is also sufficiently less than the diameter of the
valve stem passage 33 to allow free longitudinal movement
of the enlarged end of the shaft within the passage along
the central longitudinal axis X of the valve stem
passage.
The filter element 71 is preferably a fine mesh
screen constructed of a suitable material as described
earlier. In this embodiment, the filter element 71 has
the general shape of a balloon, having an enlarged,
rounded body 301 and a narrowed neck 303. The filter
element 71 is open at its neck 303 and is adapted for
fitting onto the sealing device 213 over the enlarged end
223 of the shaft 219 so that the body 301 of the filter
element surrounds the enlarged end of the shaft and the
neck of the filter element encircles a portion of the
shaft outward of the enlarged end of the shaft. The
diameter of the neck 303 is preferably smaller than the
maximum transverse diameter of the body 301 of the filter
element 71, but larger than the diameter of the shaft
219. As seen best in Fig. 9, the enlarged body 301 of
the filter element 71 has a side portion 307 adapted to
engage the interior surface of the valve stem 25, and a
filtering end portion 305 adapted to extend generally
across the valve stem passage 33 below the side portion
307 of the filter element. When the body 301 of the
filter element 71 is unrestrained, it has a maximum
diameter greater than that of the valve stem passage 33
so that the side portion 307 of the filter element
fractionally engages the interior surface of the valve
stem 25 when the valve core 27 is installed in the
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passage. The filter element 71 is sufficiently flexible
to substantially conform to the interior surface of the
valve stem 25 as the filter element frictionally engages
the interior surface of the stem.
5 Referring to Fig. 6, the filter element 71 is
attached to the shaft 219 of the sealing device 213 by
retention means, generally indicated as 311, that secures
the neck 303 of the filter element in a position in which
the diameter of the neck is substantially smaller than
10 the maximum transverse diameter of the enlarged end 223
of the shaft 219. The retention means 311 is preferably
a band 313 constructed of metal or plastic which
encircles the neck 303 of the filter element 71 to hold
the filter element on the shaft 219. The band 313 is
15 adjustable to a diameter substantially less than the
maximum transverse diameter of the enlarged end 223 of
the shaft 219. Accordingly, the filter element 71 cannot
slip off the enlarged end 223 of the shaft 219, so that
the filter element is retained on the sealing device 213
20 to permit the valve body 205, sealing assembly 211 and
filter element 71 to be simultaneously installed in the
valve stem 25 and simultaneously removed from the valve
stem. In the illustrated embodiment of Figs. 6-9, the
filter element 71 and the band 313 together broadly
25 define a filter assembly, generally indicated at 70.
The band 313 of the filter assembly 70 is
preferably adjusted only to a diameter at which the
filter element 71 is loosely attached to the sealing
device 213 rather than tightly clamped thereto. This
permits longitudinal movement of the shaft 219 and its
associated enlarged end 223 relative to the filter
element 71 while the filter element is frictionally
engaged with the interior surface of the valve stem 25.
While the filter element 71 is generally flexible, it is
also sufficiently rigid to remain in a fixed position
relative to the valve stem 25 as the sealing device 213
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26
moves between its open and closed positions. The
enlarged body 301 of the filter element 71 is also
sufficiently long to allow movement of the shaft 219
within the filter element so that when the sealing device
213 is moved to its open position, as shown in Fig. 7,
the enlarged end 223 of the shaft 219 is adjacent the
filtering end portion 305 of the filter element, and in
the closed position, the enlarged end of the shaft is
adjacent the neck 303 of the filter element. However, it
is contemplated that the filter element 71 may be tightly
clamped to the sealing device 213 for conjoint movement
with the shaft in the passage 33, without departing from
the scope of this invention.
While the filter element 71 shown in Fig. 6 is
retained on the shaft 219 of the sealing device 213, it
is understood that the filter element may be retained on
the sealing element carrier 217 so that the entire shaft
is enclosed by the filter element. Moreover, the filter
element 71 may be retained on the valve body 205 so that
both the sealing element carrier 217 and shaft 219 are
movable within the filter element, without departing from
the scope of this invention. It is also understood that
means other than the band 313 may be used for retaining
the filter element 71 on the sealing device 213, such as
flexible cable (not shown) threaded through the mesh of
the filter element adjacent its neck 303 and pulled
taught to cinch the neck 303 of the filter element around
the shaft 219, or by folding portions of the neck 303 of
the filter element 71 over onto other portions of the
neck and welding these portions together to permanently
reduce the diameter of the neck. Moreover, the diameter
of the neck 303 of the filter element 71 may initially be
equal to the maximum transverse diameter of the body 301
of the filter element for ease of sliding the filter
element over the enlarged end 223 of the shaft 219,
without departing from the scope of this invention, as
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27
long as the filter element takes on the balloon shape
when the diameter of the neck of the filter element is
reduced and held in position by the retention means 311.
With reference to Fig. 9, the valve core 27 and
attached filter element 71 are installed in the passage
as a single sealing valve unit 72 by a suitable
installation tool, such as the tool 21 described above.
For example, in using this tool 21, the valve core 27,
comprising the valve body 205, sealing assembly 211, and
the attached filter element 71, are loaded into the
plunger passage 79, filter element first, as a single
unit in the manner described above relating to
installation of the valve core. As the sealing valve
unit 72 is plunged down into the valve stem passage 33 by
the plunger 107, the enlarged end 223 of the shaft 219
contacts the filtering end portion 305 of the enlarged
body 301 of the filter element 71 to push the filter
element down into the valve stem passage 33. The
flexibility of the filter element 71 allows the side
portion 307 of the enlarged body 301 of the filter
element 71 to conform to the interior surface of the
valve stem 33 in frictional engagement therewith so that
substantially all fluid flowing through the valve stem
passage 33 must pass through the filtering end portion
305 of the filter element 71. Once the unit 72 is fully
installed in the valve stem passage 33, the valve pin 43
is used to move the sealing device 213 between its open
and closed sealing positions. The frictional engagement
of the filter element 71 with the interior surface of the
valve stem 25 maintains the filter element 71 in a fixed
position in the passage 33 as the sealing device 213 is
moved between its open and closed positions. The
enlarged end 223 of the shaft 219 thus moves
longitudinally within the stationary filter element 71.
To remove the filter element 71 from the valve
stem passage 33, the valve body 205 is disconnected from
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28
the valve stem 25 and the valve core 27 is pulled upward
relative to the passage. As the enlarged end 223 of the
shaft 219 moves up out of the valve stem passage 33, it
abuts the band 313 and neck 303 of the filter element 71,
thereby pulling the band and filter element from the
valve stem simultaneously with the valve body 205 and
sealing assembly 211.
Figs. 10 and 12 illustrate a second embodiment
of a sealing valve unit 72. A filter assembly, generally
indicated at 70, comprises a spring seat 423 connected to
the lower end 223 of the shaft 219 of the sealing device
213, and the filter element 71. As shown in Fig. 10, the
spring seat 423 of the filter assembly 70 is generally
cylindrical, having a generally closed upper end 424 and
an open lower end 426 adapted for seating against the
internal annular shoulder 35 of the valve stem 25.
Notched portions 428 of the spring seat 423 facilitate
fluid flow through the valve stem passage 25. The closed
upper end 424 of the spring seat 423 has an opening
through which the shaft 219 extends. The lower end 223
of the shaft 219 is enlarged to a size substantially
greater than that of the opening so that the spring seat
423 cannot slide off of the lower end of the shaft,
thereby retaining the filter assembly 70 on the shaft.
The filter element 71 is constructed to have
the shape of a frustum, having a widened open end 415, a
side portion 407 and a narrowed filtering end portion
405. The widened open end 415 of the filter element 71
preferably faces up toward the valve body 25 of the valve
core 27. When the filter element 71 is unrestrained, the
side portion 407 of the filter element has a maximum
diameter greater than that of the valve stem passage 33
so that it fractionally engages the interior surface of
the valve stem 25 when the valve core 27 is installed in
the passage. The filtering end portion 405 of the filter
element 71 includes that portion of the filter element
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29
below the side portion 407 that engages the interior
surface of the valve stem 25, and is adapted to extend
generally across the valve stem passage 33. The filter
element 71 is sufficiently flexible to substantially
conform to the interior surface of the valve stem 25 as
the filter element frictionally engages the interior
surface of the stem.
The filter element 71 is preferably formed
initially from an annular mesh screen (not shown) cut
l0 along its radius to permit the filter element to be
placed around the shaft 219 of the sealing device 213
generally on the upper end of the spring seat 423. The
loose ends of the filter element 71 defined by the radial
cut are overlapped slightly and soldered together so that
the filter element cannot be removed from the shaft 219,
thereby retaining the filter element on the sealing
device 213. It is also contemplated that the filter
element 71 may be pre-formed in its frustum shape with a
central opening (not shown) formed therein so that the
filter element may be fitted onto the shaft 219 before
the spring seat 423 is connected to the shaft.
A spring 421 for biasing the sealing device 213
toward its closed sealing position is loosely retained on
the shaft 219 of the sealing device between the sealing
element carrier 217 and the upper end 424 of the spring
seat 423, whereby the filter element 71 is secured to the
sealing device by being clamped between the spring and
the spring seat. The spring (not shown) disposed in the
valve body 25 acts in conjunction with the spring 421
retained on the shaft 219 to further bias the sealing
device 213 to its closed position, although the spring in
the valve body may be omitted without departing from the
scope of this invention. As shown in Fig. 12, the spring
421 also urges the spring seat 423 and filter element 71
downward in the valve stem passage when the sealing
device is moved to its open position so that the spring
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seat remains stationary (along with the filter element)
in abutment against the internal annular shoulder 35 of
the valve stem 25. It is also contemplated that the
filter element 71 may be retained on the shaft 219
5 between the sealing element carrier 217 and the spring
421, without departing from the scope of this invention.
With further reference to Fig. 12, the sealing
valve unit 72 is installed in the valve stem passage 33
by a suitable installation tool, such as the tool 21
10 described above. For example, in using this tool 21, the
unit 72 is loaded into the plunger passage 79, filter
assembly first, in the manner described above. As the
unit 72 is plunged down into the valve stem passage 33 by
the plunger 107, the filter element 71, which is retained
15 between the spring seat 423 and the spring 421, is pushed
further down into the passage.
The flexibility of the filter element 71 allows
the side portion 407 to substantially conform to the
interior surface of the valve stem 25 in frictional
20 engagement therewith so that substantially all fluid
flowing through the passage must pass through the
filtering end portion 405 of the filter element. The
unit 72 is plunged down into the valve stem passage 33
until the spring seat 423 engages the internal annular
25 shoulder 35 of the valve stem 25 and the threaded upper
end 207 of the valve body 205 engages the internal
threads of the valve stem. Once the sealing valve unit
72 is fully installed in the valve stem passage 33, the
valve pin 43 is used to move the sealing device 213
30 between its open and closed sealing positions.
As the sealing device 213 moves to its open
position, the shaft 219 of the sealing device moves
downward relative to the spring seat 423 and filter
element 71. The sealing element carrier 217 compresses
the spring 421 between the carrier and the spring seat
423 so that the bias of the spring urges the spring seat
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31
downward in the valve stem passage 33 to hold the spring
seat in abutment with the internal annular shoulder 35 of
- the valve stem 25. The filter element 71 thus remains
stationary as the sealing device 213 is moved to its open
position, with the shaft 219 of the sealing device 213
moving longitudinally through the filtering end portion
405 of the stationary filter element 71 and the opening
in the upper end 424 of the spring seat 423.
To remove the filter element 71 from the valve
stem passage 33, the valve body 205 is disconnected from
the valve stem 25 and the sealing valve unit 72 is pulled
upward relative to the passage. The enlarged lower end
223 of the shaft 219 of the sealing device 213 abuts
against the upper end 424 of the spring seat 423 to pull
the spring seat and filter element 71 up out of the valve
stem passage 33, thereby removing the filter element from
the valve stem 25 simultaneously with the valve body 205
and sealing assembly 211.
Figs. 11 and 13 illustrate a third embodiment
of a sealing valve unit 72 of the present invention
similar to the second embodiment. The filter element 71
of the filter assembly 70 is generally cup-shaped, having
a generally cylindric side wall 507 or side portion, an
open end 515 and a filtering end portion 505 defined by
an end wall opposite the open end. The filter element 71
is adapted for fitting over the spring seat 423 so that a
body 501 (comprising the side wall 507 and filtering end
portion 505) of the filter element surrounds the spring
seat 423 and a neck 503 of the filter element adjacent
its open end 515 encircles a portion of the spring 421
retained on the shaft 219, above the spring seat. When
installed in the valve stem passage 33, the filtering end
portion 505 of the filter element 71 engages the internal
annual shoulder 35 of the valve stem 25, and the filter
element is held in a fixed position by the spring seat
423. The filtering end portion 505 is adapted to extend
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generally across the valve stem passage 33 so that
substantially all fluid flowing through the passage
passes through the filtering end portion of the filter
element 71.
The filter assembly also includes retention
means, generally indicated as 511, for attaching the
filter element 71 to the shaft 219 of the sealing device
213. The retention means 511 secures the neck 503 of the
filter element 71 in a position in which the diameter of
the neck is smaller than the maximum diameter of the
spring seat 423. In the illustrated embodiment, the
retention means 511 is a band 513 constructed of metal or
plastic which encircles the neck 503 of the filter
element 71 to hold the filter element on the shaft 219.
The band 513 is adjustable to a diameter substantially
less than the maximum diameter of the spring seat 423.
Accordingly, the filter element 71 cannot slip off over
the spring seat 423, so that the filter element is
retained on the sealing device 213 to permit the valve
body 205, sealing assembly 211 and filter element 71 to
be simultaneously installed in the valve stem 25 and
simultaneously removed from the valve stem.
The band 513 is preferably adjusted only to a
diameter at which the filter element 71 is loosely
attached to the sealing device 213 rather than tightly
clamped thereto. This permits longitudinal movement of
the shaft 219 and spring 421 relative to the filter
element 71 and spring seat 423 while the filter element
is maintained in a stationary position in the valve stem
passage 33 between the spring seat 423 and the internal
annular shoulder 35 of the valve stem 25.
While the filter element 71 shown in Fig. 11 is
retained on the shaft 219 of the sealing device 213, it
is understood that the filter element may be retained on
the valve body 205 so that both the sealing element
carrier 217 and shaft 219 are movable within the filter
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33
element, without departing from the scope of this
invention. It is also understood that means other than
- the band 513 may be used for retaining the filter element
71 on the sealing device 213, such as flexible cable (not
. 5 shown) threaded through the mesh of the filter element
adjacent its neck 503 and pulled taught to cinch the neck
of the filter element around the spring 421, or by
folding portions of the neck of the filter element over
onto other portions of the neck and welding these
portions together to permanently reduce the diameter of
the neck.
With reference to Fig. 13, the sealing valve
unit 72 of the third embodiment is installed in and
removed from the valve stem passage 33 in a manner
similar to the second embodiment. As the sealing valve
unit 72 is plunged into the valve stem passage 33, the
spring seat 423 pushes against the filtering end portion
505 of the filter element 71 to push the filter element
into the passage until it engages the internal annular
shoulder of the valve stem and the threaded upper end 207
of the valve body 205 engages the internal threads of the
valve stem 25.
Fig. 15 illustrates a fourth embodiment of a
sealing valve unit 72 of the present invention,
substantially similar to the third embodiment, with the
exception that the filter element 71 is attached directly
to the spring seat 423 by welding or other suitable
attachment methods.
Figs. 16 and 17 illustrate a fifth embodiment
of a sealing valve unit 72 similar to that of the second,
third and fourth embodiments except that the filter
assembly 70 comprises a filter housing 651 connected to
the lower end 223 of the shaft 219 and a filter element
71 disposed in the housing. The filter housing 651 is
generally cylindrical and has a passage 653 extending
therethrough between an upper end 624 and lower end 626
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of the housing. The lower end 626 of the filter housing
651 is sized for seating against the internal annular
shoulder 35 of the valve stem 25 when the unit 72 is
installed in the valve stem passage 33 so that
substantially all of the fluid flowing into and out of
the tire T through the valve stem passage passes through
the passage 653 in the filter housing. In the
illustrated embodiment, the filter housing passage 653 is
widened adjacent the lower end 626 of the housing 651 so
that its diameter is slightly larger than the diameter of
the valve stem passage 33 at the internal annular
shoulder 35 of the valve stem 25. The filter housing
passage 653 substantially narrows as it extends up toward
the upper end 624 of the housing 651, thereby defining an
internal annular shoulder 655 of the housing.
The filter element 71 is generally disc-shaped
and sized for fitting into the widened portion of the
housing passage 653 to seat generally against the
internal annular shoulder 655 of the filter housing 651.
The filter element 71 fractionally engages the interior
surface of the filter housing 651 to secure the filter
element in the housing. A retaining ring 657 sized for
frictional engagement with the interior surface of the
filter housing 651 is inserted in the widened portion of
the housing passage 653 to secure the filter element in
the passage between the ring and the internal annular
shoulder 655 of the housing. It is to be understood that
the filter element 71 may be secured in the housing 651
by means other than the ring 657, such as by welding the
element to the interior surface of the housing or other
suitable means, without departing from the scope of this
invention.
As shown in Fig. 17, the outer diameter of the
filter housing 651 is substantially less than the
diameter of the valve stem passage 33 so that an annular
gap 659 is defined between the exterior surface of the
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filter housing and the interior surface of the valve stem
25. An exterior annular groove 661 extends around the
filter housing and communicates with the gap 659.
Openings 663 in the filter housing 651 extend transverse
5 to the housing passage 653 and communicate with the
exterior annular groove 661 to provide fluid
communication between the filter housing passage and the
annular gap 659 in the valve stem passage 33. The
openings 663 are spaced substantially above the filter
10 element 71 so that fluid flowing out from the tire T is
filtered through the filter element before flowing out of
the housing 651 and to the sealing device 213.
The filter housing passage 653 tapers radially
inwardly and upwardly adjacent the upper end 624 of the
15 housing 651 to define a reduced diameter opening 665 at
the upper end of the housing. The shaft 219 extends
through the opening 665 and into the filter housing
passage 653. The lower end 223 of the shaft 219 is
enlarged to a size substantially greater than that of the
20 opening 665 at the upper end 624 of the housing 651 so
that the housing cannot slide off of the lower end of the
shaft, thereby connecting the housing to the shaft.
However, the enlarged lower end 223 of the shaft 219 is
sized smaller than the diameter of the filter housing
25 passage 653 to permit the shaft to move longitudinally
within the housing 651 as the sealing device 213 is moved
between its open and closed positions.
The spring 421 on the shaft extends between the
sealing element carrier 217 and the upper end 624 of the
30 filter housing 651 to bias the filter housing toward the
lower end 223 of the shaft 219 so that the housing
remains stationary against the internal annular shoulder
35 of the valve stem during movement of the sealing
device 213 between its open and closed sealing positions.
35 The spring 421 also biases the sealing device 213 to its
closed position. In the illustrated embodiment, the
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36
spring 421 seats loosely against the filter housing 651
and carrier 217, but it is contemplated that the spring
may be secured to the housing and/or to the sealing
element carrier without departing from the scope of this
invention. The spring disposed in the valve body 205
also biases the sealing device 213 to its closed
position, although this spring may be omitted without
departing from the scope of this invention.
With reference to Fig. 17, the sealing valve
unit 72 is installed in the valve stem passage 33 by a
suitable installation tool, such as the tool 21 described
above. For example, in using this tool 21, the sealing
valve unit 72 comprising the valve body 205, sealing
assembly 211 and filter assembly 70, is loaded into the
plunger passage 79, filter assembly first, as a single
unit in the manner described above. The plunger 107 is
used to push the unit 72 into the valve stem passage 33
until the lower end 626 of the filter housing 651 engages
the internal annular shoulder 35 of the valve stem 25 and
the threaded upper end 207 of the valve body 205 engages
the internal threads of the valve stem. Once the sealing
valve unit 72 is fully installed in the valve stem
passage 33, the valve pin 43 is used to move the sealing
device 213 between its open and closed sealing positions.
When the sealing device 213 is moved to its
open position, the shaft 219 of the sealing device moves
downward in the valve stem passage 33 relative to the
filter housing 651, with the lower end 223 of the shaft
moving within the housing. The sealing element carrier
217 compresses the spring 421 between the carrier 217 and
the upper end 624 of the housing 651 so that the bias of
the spring urges the filter housing downward in the valve
stem passage 33 to hold the housing stationary in
abutment with the internal annular shoulder 35 of the
valve stem 25. Fluid flowing out from the tire T flows
into the filter housing passage 653 adjacent the lower
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37
end 626 of the housing 651 and is filtered through the
filter element 71 disposed in the housing. The filtered
fluid then flows up through the filter housing passage
653, out of the housing 651 through the openings 663 and
into the valve stem passage 33 at the gap 659 between the
filter housing and the interior surface of the valve stem
25. The fluid then exits the valve stem 25 in a
conventional manner. Fluid flowing down through the
valve stem flows along a reverse path, e.g., into the
filter housing 651 via the openings 663, down through the
housing passage 653 and filter element 71 and into the
tire T.
To remove the filter assembly 70 from the valve
stem passage 33, the valve body 205 is disconnected from
the valve stem 25 and the sealing valve unit 72 is pulled
upward relative to the passage. The enlarged lower end
223 of the shaft 219 of the sealing device 213 engages
the upper end 624 of the filter housing 651 and pulls the
housing and filter element 71 up out of the valve stem
passage 33, thereby removing the filter element from the
valve stem 25 simultaneously with the valve body 205 and
sealing assembly 211.
Fig. 18 illustrates a sixth embodiment similar
to the fifth embodiment in which the filter assembly 70
comprises the filter housing 651 and the filter element
71 disposed in the filter housing. In this sixth
embodiment, the annular groove 661 and openings 663
(Figs. 16 and 17) are omitted, eliminating the need for
the gap 659 between the filter housing 651 and the
interior surface of the valve stem 25. Thus, while the
outer diameter of the filter housing 651 shown in Fig. 18
is less than the diameter of the valve stem passage 33,
the filter housing outer diameter may increased without
departing from the scope of this invention, as long as
,the filter housing is capable of movement within the
valve stem passage 33 for engagement with the internal
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38
annular shoulder 35 of the valve stem 25.
In replacement of the annular groove 651 and
openings 653 of the fifth embodiment, the filter housing
651 of this sixth embodiment has a pair of opposing flats
781 adjacent its upper end 624, and an opening 783
extending between the flats to provide fluid
communication between the filter housing passage 653 and
the valve stem passage 33. The upper end 624 of the
filter housing 651 is generally flat, and includes the
opening 665 through which the shaft 219 extends. The
spring 421 seats loosely on the upper end 624 of the
filter housing 651.
When the sealing device 213 of this sixth
embodiment is moved to its open position, the shaft 219
of the sealing device moves downward in the valve stem
passage 33 relative to the filter housing 651, with the
lower end 223 of the shaft moving within the housing.
The sealing element carrier 217 compresses the spring 421
between the carrier 217 and the upper end 624 of the
housing 651 so that the bias of the spring urges the
filter housing downward in the valve stem passage 33 to
hold the housing stationary in abutment with the internal
annular shoulder 35 of the valve stem 25. Fluid flowing
out from the tire T flows into the filter housing passage
653 adjacent the lower end 626 of the housing 651 and is
filtered through the filter element 71 disposed in the
housing. The filtered fluid then flows up through the
filter housing passage 653 and out of the housing 651
(and into the valve stem passage 33) through the opening
783 extending between the flats 781 adjacent the upper
end 624 of the housing. The fluid then exits the valve
stem 25 in a conventional manner. Fluid flowing down
through the valve stem flows along a reverse path, e.g.,
into the filter housing 651 via the opening 783, down
through the housing passage 653 and filter element 71 and
into the tire T.
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While the sealing valve units 72 of Figs. 6-17
are shown and described for use in controlling fluid flow
through the valve stem 25 of a pneumatic wheel assembly
W, it is contemplated that these units may be used in any
number of other tubular casings having an interior
surface defining a fluid passage without departing from
the scope of this invention. For example, valve cores
are used to control fluid flow through utility lines,
automotive, residential and commercial air conditioning
units, carbonated beverage machines, and other apparatus
in which it is necessary to control fluid flow through a
casing. The valve cores currently used in these
apparatus may be replaced by the sealing valve units of
the present. The passages defined by these apparatus are
generally quite small, such that the valve core and
filter element installed in these passages must be
correspondingly small. For example, the filter elements
shown in the embodiments of this invention are preferably
in the range of 0.1 - 0.2 inches in diameter. However,
by using the disclosed mesh size of the filter element,
the rate of fluid flow through the passage is generally
unaffected by installation of the filter element in the
passage.
It will be observed from the foregoing that
affixing or otherwise attaching the filter element 71 to
the valve core 27 satisfies various objectives of the
present invention and offers other advantageous results.
For example, because the filter element 71 is installable
simultaneously with the valve core 27 as a single unit,
the separate filter insertion steps of the method
described above with respect to the filter insertion tool
may be omitted. Accordingly, the filter passage 77 and
filter loading assembly 61 of the tool may also be
omitted, thus simplifying construction and operation of
the tool. In addition, the valve core 27 and filter
element 71 can be removed from the valve stem passage 33
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and replaced without the additional cost and effort
associated with replacing the valve stem 25.
Since the filter element 71 is retained on the
valve core 27, the risk of dropping and losing the filter
5 element 71 is reduced. Allowing for simultaneous removal
of the filter element 71 and valve core 27 from the valve
stem passage 33 also negates the need for a separate
filter element removing tool. Moreover, because the
filter element is secured in a stationary position by the
10 components of the valve assembly, such as by the filter
element 71 fractionally engaging the interior surface of
the valve stem 25, or by the spring 421 urging the filter
to a stationary position, no additional structure or
mechanical device is required in the valve stem (or other
15 tubular casing) for installing the filter element in the
valve stem and maintaining the filter element in a fixed
position in the passage 33, thus providing for easy
installation of the valve core 27 and filter element in
the passage.
20 In particular, the sealing valve unit 72 of the
first embodiment (Figs. 6-9), in which the spring (not
shown) of the valve core 27 is contained in the valve
body 205 so that a spring seat and internal shoulder 35
for seating the spring seat are not required, can be
25 installed into any passage in which control of the fluid
flow through the passage is desired.
As various changes could be made in the above
constructions and methods without departing from the
scope of the invention, it is intended that all matter
30 contained in the above description or shown in the
accompanying drawings shall be interpreted as
illustrative and not in a limiting sense.
