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Patent Abstract
A miniature solenoid valve including a housing defining an axial
passage with a valve seat formed integral with the housing and including
a minute flow orifice in fluidic communication with the axial passage.
A magnetic actuator is positioned within the axial passage and is
adapted for reciprocating movement along an actuation axis. A valve
element is engagable with the integrally formed valve seat to substantially
prevent flow through the minute flow orifice in response to displacement
of the magnetic actuator along the actuation axis. In another embodiment,
a connection element is formed integral with the housing and is
configured for sealing engagement with a pressurized flow source
to supply flow to the flow orifice. In a further embodiment, the
housing defines a closed end and an open end, with a pole piece
engaged with the valve housing and including a transverse portion
covering the open end of the valve housing.
Patent Claims
What is claimed is:
1. A miniature electrically operated solenoid valve, comprising:
a valve housing defining an axial passage extending generally along
an actuation axis; a valve seat formed integral with said valve
housing and including a minute flow orifice in fluidic communication
with said axial passage; a magnetic actuator positioned within said
axial passage of said valve housing and adapted for reciprocating
movement along said actuation axis; and a valve element engagable
with said valve seat to substantially prevent flow through said
minute flow orifice in response to displacement of said magnetic
actuator along said actuation axis.
2. The solenoid valve of claim 1, wherein a portion of said minute
flow orifice has a diameter no greater than about 0.025 inches.
3. The solenoid valve of claim 2, wherein said portion of said
minute flow orifice has a diameter no greater than about 0.011 inches.
4. The solenoid valve of claim 3, wherein said portion of said
minute flow orifice has a diameter no greater than about 0.004 inches.
5. The solenoid valve of claim 1, wherein said valve seat comprises
a raised portion of said valve housing arranged generally along
said actuation axis.
6. The solenoid valve of claim 5, wherein said valve element is
compressed against said raised portion of said valve housing to
substantially prevent flow through said minute flow orifice.
7. The solenoid valve of claim 5, wherein said raised portion of
said valve housing includes a substantially planar end surface and
a tapered side surface extending about said substantially planar
end surface, said flow orifice opening onto said substantially planar
end surface.
8. The solenoid valve of claim 5, wherein said raised portion of
said valve housing protrudes into said axial passage.
9. The solenoid valve of claim 1, wherein said valve housing includes
an end wall defining a surface protrusion positioned generally along
said actuation axis and extending into said axial passage, said
valve element being compressed against said surface protrusion to
substantially prevent flow through said minute flow orifice.
10. The solenoid valve of claim 1, wherein said valve housing is
formed of a molded material with said valve seat molded directly
into said valve housing.
11. The solenoid valve of claim 10, wherein said minute flow orifice
is molded directly into said valve housing.
12. The solenoid valve of claim 1, further comprising a vent opening
in fluidic communication with said axial passage of said valve housing,
said vent opening directing flow from said valve housing upon disengagement
of said valve element from said valve seat.
13. The solenoid valve of claim 12, wherein said vent opening is
sized and shaped to provide a predetermined flow pattern exiting
said valve housing.
14. The solenoid valve of claim 13, wherein said predetermined
flow pattern comprises a narrowly concentrated flow stream.
15. The solenoid valve of claim 13, wherein said predetermined
flow pattern comprises a widely dispersed flow stream.
16. The solenoid valve of claim 12, wherein said vent opening is
positioned axially opposite said minute flow orifice, said magnetic
actuator configured to provide axial flow between said minute flow
orifice and said vent opening.
17. The solenoid valve of claim 16, wherein at least one of said
magnetic actuator and said valve housing defines an axial passageway
for conveying said axial flow between said minute flow orifice and
said vent opening.
18. The solenoid valve of claim 17, wherein said magnetic actuator
defines an outer cross section sized smaller than an inner cross
section of said axial passage of said valve housing to provide said
axial passageway for conveying said axial flow between said minute
flow orifice and said vent opening.
19. The solenoid valve of claim 18, wherein said outer cross section
of said magnetic actuator and said inner cross section of said axial
passage are each substantially circular and wherein said axial passageway
comprises a circumferential passageway.
20. The solenoid valve of claim 1, wherein said axial passage of
said valve housing defines an open end arranged axially opposite
said valve seat; and further comprising a cap member positioned
to cover said open end of said axial passage.
21. The solenoid valve of claim 20, wherein said cap member defines
a vent opening in fluidic communication with said axial passage
of said valve housing, said vent opening directing flow from said
valve housing upon disengagement of said valve element from said
valve seat.
22. The solenoid valve of claim 20, further comprising a pole piece
member engaged with said valve housing and including an axial portion
extending along at least a portion of said axial passage and a transverse
portion positioned adjacent said open end of said axial passage,
said transverse portion defining said cap member.
23. The solenoid valve of claim 22, wherein said transverse portion
of said cap member includes a protrusion extending through said
open end and into said axial passage.
24. The solenoid valve of claim 23, wherein said protrusion includes
an inwardly tapered annular side surface to facilitate sealing engagement
with said open end of said valve housing.
25. The solenoid valve of claim 1, further comprising a pole piece
member configured for self-engagement to said valve housing.
26. The solenoid valve of claim 25, wherein said self-engagement
of said pole piece member to said valve housing comprises a snap
fit.
27. The solenoid valve of claim 1, wherein said valve element comprises
a valve seal member formed of a resilient material.
28. The solenoid valve of claim 27, wherein said valve seal member
and said magnetic actuator comprise separate structural elements.
29. The solenoid valve of claim 28, wherein said valve seal member
floats relative to said magnetic actuator.
30. The solenoid valve of claim 1, further comprising a biasing
member co-acting with said actuator member to urge said actuator
member against said valve seat to substantially prevent flow through
said minute flow orifice.
31. The solenoid valve of claim 30, wherein said biasing member
comprises a washer-type spring.
32. The solenoid valve of claim 1, further comprising a connection
element formed integral with said valve housing and configured for
sealing engagement with a pressurized flow source to supply flow
to said minute flow orifice.
33. The solenoid valve of claim 32, wherein said connection element
comprises a quick-disconnect connection.
34. The solenoid valve of claim 33, wherein said connection element
comprises a boot-type connection element configured for non-threaded
sealing engagement with said pressurized flow source.
35. A method of forming a miniature electrically operated solenoid
valve, comprising: molding a valve housing to include an axial passage
extending generally along an actuation axis and a valve seat formed
integral with the valve housing, the valve seat defining a minute
flow orifice in fluidic communication with the axial passage; providing
a magnetic actuator positioned within the axial passage of the valve
housing for reciprocating movement along the actuation axis; and
providing a valve element engagable with the valve seat to substantially
prevent flow through the minute flow orifice in response to displacement
of the magnetic actuator along the actuation axis.
36. The method of claim 35, wherein the molding of the valve housing
includes forming a raised portion extending from an end wall of
the valve housing and into the axial passage to form the valve seat.
37. The method of claim 35, wherein the molding of the valve housing
includes forming the minute flow orifice valve through an end wall
of the valve housing.
38. The method of claim 35, wherein the molding of the valve housing
includes providing the axial passage with an open end positioned
axially opposite the valve seat; and further comprising providing
a pole piece member engaged with the valve housing and including
an axial portion extending along at least a portion of the axial
passage and a transverse portion positioned to cover the open end
of the valve housing.
39. The method of claim 35, wherein the molding of the valve housing
includes providing a connection element formed integral with the
valve housing and configured for sealing engagement with a pressurized
flow source to supply flow to the minute flow orifice.
40. A miniature electrically operated solenoid valve, comprising:
a valve housing defining an axial passage extending generally along
an actuation axis, said valve housing defining a closed end and
an open end positioned axially opposite said closed end; a magnetic
actuator positioned within said axial passage of said valve housing
and adapted for reciprocating movement along said actuation axis;
a valve element engagable with a valve seat defining a minute flow
orifice to substantially prevent flow through said minute flow orifice
in response to displacement of said magnetic actuator along said
actuation axis; and a pole piece engaged with said valve housing
and including an axial portion extending along at least a portion
of said axial passage and a transverse portion covering said open
end of said valve housing.
41. The solenoid valve of claim 40, wherein said transverse portion
of said pole piece defines a vent opening in fluidic communication
with said axial passage of said valve housing, said vent opening
directing flow from said valve housing upon disengagement of said
valve element from said valve seat.
42. The solenoid valve of claim 41, wherein said transverse portion
of said pole piece includes a protrusion extending through said
open end of said valve housing and into said axial passage to facilitate
sealing engagement with said open end of said valve housing.
43. The solenoid valve of claim 42, wherein said protrusion includes
an inwardly tapered annular side surface to facilitate said sealing
engagement with said open end of said valve housing.
44. The solenoid valve of claim 40, wherein said valve seat is
formed integral with said closed end of said valve housing.
45. A miniature electrically operated solenoid valve, comprising:
a valve housing defining an axial passage extending generally along
an actuation axis and a flow orifice in fluidic communication with
said axial passage; a connection element formed integral with said
valve housing and configured for sealing engagement with a pressurized
flow source to supply flow to said flow orifice; a magnetic actuator
positioned within said axial passage of said valve housing and adapted
for reciprocating movement along said actuation axis; and a valve
element engagable with a valve seat to substantially prevent flow
through said flow orifice in response to displacement of said magnetic
actuator along said actuation axis.
46. The solenoid valve of claim 45, wherein said connection element
comprises a quick-disconnect connection engagable with said pressurized
flow source.
47. The solenoid valve of claim 45, wherein said connection element
comprises a boot-type connection element configured for non-threaded
engagement with said pressurized flow source.
48. The solenoid valve of claim 45, further comprising a seal member
engaged between said connection element and said pressurized flow
source to provide for said sealing engagement with said pressurized
fluid source.
49. The solenoid valve of claim 48, wherein said connection element
defines an inner retention groove sized to receive and retain said
seal member therein.
50. The solenoid valve of claim 49, wherein said pressurized flow
source comprises a pressurized canister including a stem portion
positioned within an interior region of said seal member to provide
for said sealing engagement with said pressurized fluid source.
51. The solenoid valve of claim 45, wherein said pressurized fluid
source includes a valve mechanism; and wherein engagement of said
pressurized fluid source with said connection element automatically
opens said valve mechanism to supply flow to said flow orifice.
52. The solenoid valve of claim 45, wherein said valve housing
is formed of a molded material with said connection element molded
directly with said valve housing.
53. The solenoid valve of claim 52, wherein said valve seat is
molded directly into said valve housing.
54. The solenoid valve of claim 45, wherein said valve seat comprises
a raised portion of said valve housing arranged generally along
said actuation axis and defining said flow orifice, said valve element
being compressed against said raised portion of said valve housing
to substantially prevent flow through said flow orifice.
55. The solenoid valve of claim 45, wherein said valve housing
defines a closed end and an open end positioned axially opposite
said closed end; and further comprising a pole piece engaged with
said valve housing and including an axial portion extending along
at least a portion of said axial passage and a transverse portion
covering said open end of said valve housing.
Patent Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of Provisional
Application Ser. No. 60/530,569 filed on Dec. 18, 2003, the contents
of which are hereby incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of
electrically operated solenoid valves, and more particularly relates
to a miniature electrically operated solenoid valve.
BACKGROUND OF THE INVENTION
[0003] Electrically operated solenoid valves are used in a wide
variety of automotive and industrial applications to control the
flow of a gas or fluid. An electrically operated solenoid valve
is generally comprised of an electrical coil which, when energized,
produces an electromagnetic field that is utilized to perform some
function. In the case of a solenoid valve actuator, the electromagnetic
field is utilized to displace an actuator member along an actuation
axis. The actuator member is in turn operatively engaged with a
valve mechanism such that axial displacement of the actuator member
correspondingly engages/disengages a portion of the valve mechanism
to control the flow of a gas or fluid therethrough.
[0004] In some instances, the use of electrically operated solenoids
is desired to control minute flow volumes of gases or fluids. However,
precise and accurate control of minute quantities of fluid volumes
is difficult to achieve. Additionally, controlling minute flow volumes
requires the use of relatively small solenoid and valve components.
Manufacture miniature solenoid valve components and assembling such
components into a physically small package can be both expensive
and time consuming.
[0005] Thus, there is a general need in the industry to provide
an improved miniature electrically operated solenoid valve. The
present invention meets this need and provides other benefits and
advantages in a novel and unobvious manner.
SUMMARY OF THE INVENTION
[0006] The present invention relates generally to a miniature electrically
operated solenoid valve for controlling minute flow volumes of gases
or fluids. While the actual nature of the invention covered herein
can only be determined with reference to the claims appended hereto,
certain forms of the invention that are characteristic of the preferred
embodiments disclosed herein are described briefly as follows.
[0007] In one form of the present invention, a miniature electrically
operated solenoid valve is provided which includes a valve housing
and a valve seat formed integral therewith and defining a minute
flow orifice.
[0008] In another form of the present invention, a method of forming
a miniature electrically operated solenoid valve is provided which
includes molding a valve housing with a valve seat formed integral
therewith and defining a minute flow orifice.
[0009] In another form of the present invention, a miniature electrically
operated solenoid valve is provided which includes a valve housing
defining an axial passage having a closed end and an open end, and
a pole piece engaged with the valve housing and including an axial
portion extending along at least a portion of the axial passage
and a transverse portion covering the open end of the valve housing.
[0010] In another form of the present invention, a miniature electrically
operated solenoid valve is provided which includes a valve housing
defining a flow orifice, and a connection element formed integral
with the valve housing and configured for sealing engagement with
a pressurized flow source to supply flow to the flow orifice.
[0011] It is one object of the present invention to provide an
improved miniature electrically operated solenoid valve.
[0012] Further objects, features, advantages, benefits, and further
aspects of the present invention will become apparent from the drawings
and description contained herein.
BRIEF DESCRIPTION OF THE FIGURES
[0013] FIG. 1 is side view of a miniature electrically operated
solenoid valve according to one form of the present invention.
[0014] FIG. 2 is a first end view of the solenoid valve illustrated
in FIG. 1.
[0015] FIG. 3 is a second end view of the solenoid valve illustrated
in FIG. 1.
[0016] FIG. 4 is a cross-sectional view of the solenoid valve illustrated
in FIG. 1.
[0017] FIG. 5 is an exploded cross-sectional view of the solenoid
valve illustrated in FIG. 4.
[0018] FIG. 6 is a partial cross-sectional view of the proximal
end portion of a miniature electrically operated solenoid valve
according to another form of the present invention which is adapted
for sealing engagement with a pressurized source of gas or fluid.
DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0019] For the purposes of promoting an understanding of the principles
of the invention, reference will now be made to the embodiments
illustrated in the drawings and specific language will be used to
describe the same. It will nevertheless be understood that no limitation
of the scope of the invention is hereby intended, such alterations
and further modifications in the illustrated devices, and such further
applications of the principles of the invention as illustrated herein
being contemplated as would normally occur to one skilled in the
art to which the invention relates.
[0020] Referring to FIGS. 1-5, shown therein is a miniature electrically
operated solenoid valve 10 according to one form of the present
invention. The solenoid valve 10 extends along a longitudinal axis
L and is generally comprised of a housing 12, a pole piece or yoke
member 14, an energizing coil 16, an actuator member 18, a valve
seal member 20 and a biasing member 22. One or more electrical conductors
or leads (not shown) extend from the energizing coil 16 and are
electrically connected to a controller or power source (not shown)
adapted to electronically control operation of the solenoid valve
10, the details of which would be apparent to one of skill-in the
art and therefore need not be discussed herein. The solenoid valve
10 may be operated via a conventional power source and/or via battery
power.
[0021] As will be discussed in greater detail below, the biasing
member 22 exerts an axial biasing force against the actuator member
18 which in turn compresses the valve seal member 20 against a valve
seat (formed integral with the housing 12) to hold the solenoid
valve 10 in a normally closed position. However, activation of the
energizing coil 16 exerts a magnetic force onto the actuator member
18 to overcome the biasing force exerted by the biasing member 20
which in turn pulls the valve seal member 20 away from the valve
seat to switch the solenoid valve 10 to an open position. Further
details regarding the operation of the solenoid valve 10 will be
described in greater detail below.
[0022] The housing 12 has a proximal end portion 12a and a distal
end portion 12b and is preferably formed of a non-magnetic material
including, for example, a plastic or polymeric material such as
a virgin Nylon material, or any other non-magnetic material that
would occur to one of skill in the art. In one embodiment of the
invention, the housing 12 is formed via a molding process, as disclosed
in U.S. Pat. No. 6,086,042 to Scott et al., the contents of which
are hereby incorporated by reference in their entirety. In the illustrated
embodiment of the invention, the housing 12 includes a generally
cylindrical side wall 30 defining an inner surface 31 and a proximal
end wall 32, with the side wall 30 and the end wall 32 cooperating
to define an interior region or axial passage 34 (FIG. 5) having
an open distal end 35 (FIG. 5).
[0023] A flow orifice 36 extends through the proximal end wall
32 in communication with the axial passage 34. A pressurized gas
or fluid source (not show) is positioned in communication with the
flow orifice 36 to provide gas or fluid flow through the flow orifice
36 and into the axial passage 34. As will be discussed in greater
detail below, in one embodiment of the invention, the solenoid valve
10 includes an integral connection portion that provides for sealing
engagement between the valve housing 12 and a pressurized gas/fluid
source. However, it should be understood that other types of connections
between the gas/fluid source and the valve housing 12 are also contemplated
including, for example, a threaded connection, a quick disconnect
connection, a bayonet-type connection, or any other suitable means
for connecting a pressurized gas/fluid source and the valve housing
12.
[0024] As shown in FIG. 5, the flow orifice 36 includes an inwardly
tapered inlet portion 36a extending from the outer surface of the
end wall 32, an axial portion 36b extending through the end wall
32, and an outwardly tapered portion 36c extending to the inner
surface of the end wall 32. In one embodiment of the invention,
the axial portion 36b of the flow orifice 36 has a diameter of less
than about 0.025 inches. In another embodiment, the axial portion
36b of the flow orifice 36 has a diameter of less than about 0.011
inches. In a specific embodiment, the axial portion 36b of the flow
orifice 36 has a diameter of about 0.010 inches. In another specific
embodiment, the axial portion 36b of the flow orifice 36 has a diameter
of about 0.004 inches. It should be understood that other specific
embodiments are also contemplated wherein the axial portion 36b
of the flow orifice 36 has other select sizes. It should also be
understood that providing the flow orifice 36 with a particular
size and/or configuration controls the amount of gas/fluid passing
therethrough and entering into and through the solenoid valve 10.
[0025] The inner surface of the end wall 32 includes a raised central
portion or protrusion 40 extending into the axial passage 34 of
the housing 12 and with the flow orifice 36 extending therethrough.
In a preferred embodiment of the invention, the protrusion 40 is
formed integral with the end wall 32 of the housing 12. In the illustrated
embodiment, the raised central portion 40 includes an inwardly tapered
annular side surface 42 and a relatively flat end surface 44, with
the flow orifice 36 opening onto the flat end surface 44. As will
be discussed below, the central protrusion 40 serves as a valve
seat and the flat end surface 44 as a valve seat face against which
the valve seal member 20 is engaged to prevent flow through the
flow orifice 36.
[0026] The housing 12 also includes a pair of annular ribs or flanges
50a, 50b extending outwardly from the side wall 30 and defining
a bobbin portion 52 for receiving the energizing coil 16. The annular
flange 50b includes a pair of anchor portions 54 for anchoring a
corresponding pair of engaging members 56 to the housing 12. In
the illustrated embodiment, the anchor members 56 are threaded studs
or posts that are formed integral with the housing 12 and adapted
for engaging the solenoid valve 10 to another structure or a substrate.
However, other configurations are also contemplated. The energizing
coil 16 is comprised of an electrically conductive wire wound about
the bobbin portion 52 of the housing 12 between the annular flanges
50a, 50b. In one embodiment, the energizing coil 16 is formed of
copper wire. However, other types of wire are also contemplated
for use in association with the present invention. One or more electrical
terminals or lead supports (not shown) may be provided to connect
electrical lead wires to the energizing coil 16.
[0027] The pole piece or yoke member 14 is formed of a magnetically
responsive material, such as, for example, a soft magnetic steel
material, low carbon steel, cold rolled steel, stainless steel,
or any other magnetically responsive material that would occur to
one of skill in the art. In the illustrated embodiment of the invention,
the pole piece member 14 also serves as the support frame for the
solenoid valve 10 and is generally configured as a U-shaped bracket
having a central portion 60, a proximal portion 62 and a distal
portion 64. Although a particular embodiment of the pole piece member
14 has been illustrated and described herein, it should be understood
that other types and configurations of pole pieces are also contemplated
as falling within the scope of the present invention.
[0028] The central portion 60 of the pole piece member 14 runs
axially along the length of the bobbin portion 52 of the housing
12 and the energizing coil 16. The proximal portion 62 includes
a transverse flange 66 extending generally along the bobbin flange
50a and an annular collar 68 at least partially surrounding the
proximal portion of the housing 12. The distal portion 64 includes
a transverse flange 70 extending generally along the bobbin flange
50b and a cap member or disc-shaped protrusion 72 extending axially
from the transverse flange 70 in proximal direction. The disc-shaped
protrusion 72 is sized and shaped for insertion into the distal
portion of the axial passage 34 in the housing 12 to close off the
open distal end 35. The protrusion 72 includes an inwardly tapered
annular side wall 74 to facilitate insertion of the protrusion 72
into the distal portion of the axial passage 34 and to aid in sealing
off the open distal end 35.
[0029] A vent opening 76 extends through the transverse flange
70 and the disc-shaped protrusion 72 in communication with the axial
passage 34. The vent opening 76 is positioned generally along the
longitudinal axis L and includes an axial portion 76a extending
from the inner surface of the protrusion 72 and a countersunk portion
76b extending from the outer surface of the transverse flange 70.
The vent opening 76 serves to provide a flow path for gas or fluid
exiting the solenoid valve 10. Although a specific configuration
of the vent opening 76 has been illustrated and described herein,
it should be understood that other shapes, sizes and/or configurations
of the vent opening 76 are also contemplated as falling within the
scope of the present invention. It should also be understood that
by varying the shape, size and/or configuration of the vent opening
76, different types of spray or flow patterns may be produced to
satisfy the particular requirements of the solenoid valve 10. For
example, in some applications of the solenoid valve 10, a concentrated
flow stream or jet may be desired. In other applications, a dispersed
flow stream or mist may be desired. As should be appreciated, varying
the parameters associated with the vent opening 76 can be used to
produce a particular flow or spray pattern exiting the solenoid
valve 10.
[0030] As should also be appreciated, the pole piece member 14
comprises an integrated structure that serves multiple functions
including, for example, use as a component in the magnetic circuit,
as a frame member to provide structural support to the solenoid
valve 10, and as a cap member to seal off the open distal end 35
of the housing 12. As should also be appreciated, the use of a single
piece structure to perform multiple functions tends to reduce manufacturing
and assembly costs, particularly when dealing with miniature components.
Initially, the seal member 18, the plunger 18 and the biasing member
22 are all inserted within the axial passage 30 of the housing 12.
Additionally, the pole piece member 14 is assembled with the housing
12 by aligning the bobbin portion 52 of the housing 12 between the
transverse flanges 66, 70 and transversely displacing the pole piece
14 until the axial protrusion 72 snaps into the open distal end
35 of the axial passage 34 and the annular collar 68 is positioned
about the proximal portion of the housing 12. Although the pole
piece member 14 is configured to self-engage the housing 12, it
should be understood that the pole piece member 14 may be secured
to the housing 12 via various means for attachment including, for
example, fasteners, pins, an adhesive, or any other suitable method
of attachment.
[0031] The actuator member 18 is formed of a magnetically responsive
material, such as, for example, a soft magnetic steel material,
cold rolled steel, low carbon steel, stainless steel, or any other
magnetically responsive material that would occur to one of skill
in the art. In one embodiment of the invention, the actuator member
18 comprises a magnetic plunger 18 disposed within the axial passage
34 of the housing 12 and adapted for reciprocating axial movement
therein. However, it should be understood that other types and configurations
of actuator members are also contemplated as falling within the
scope of the present invention. In the illustrated embodiment, the
plunger 18 has a generally circular outer cross section that correspond
to the size and shape to the inner cross section of the axial passage
34. In this manner, the plunger 18 may be operatively guided along
the axial passage 34. It should be understood, however, that other
shapes and configurations of the plunger 18 are also contemplated,
including, for example, a rectangular configuration, a hexagonal
configuration, or any other configuration that would occur to one
of skill in the art.
[0032] In one embodiment of the invention, the clearance between
the outer surface 19 of the plunger 18 and the inner surface 31
of the housing side wall 30 provides a circumferential passageway
extending along the longitudinal axis L for conveying fluid flow
from the inlet flow orifice 36 to the vent opening 76. However,
in an alternative embodiment, the plunger 18 may be provided with
a hexagonal outer cross section so as to form a number of axially-extending
fluid flow passageways between the outer surface of the plunger
and the inner surface 31 of the housing side wall 30. In another
alternative embodiment, the plunger may define a number of fluid
channels broached or notched into the exterior surface of the plunger
and extending axially along the longitudinal axis L. In yet another
alternative embodiment, the plunger may define a number of fluid
passages extending axially through an interior portion of the plunger.
Other configurations of flow passages or channels defined by the
plunger 18 and/or the housing side wall 30 are also contemplated
as would occur to one of ordinary skill in the art for conveying
fluid flow from the inlet flow orifice 36 to the vent opening 76.
[0033] As should be appreciated, activation of the energizing coil
16 generates an electromagnetic force which is exerted onto the
plunger 18 to axially displace the plunger 18 along the passage
34 in the direction of arrow A (away from the valve seat 40) to
open the solenoid valve 10. As should also be appreciated, deactivation
of the energizing coil 16 removes the electromagnetic force exerted
onto the plunger 18 which allows axial displacement of the plunger
18 along the passage 34 in the direction of arrow B (toward the
valve seat 40) to close the solenoid valve 10, the details of which
will be discussed below. The magnetic plunger 18 is therefore adapted
for reciprocating movement along the longitudinal axis L in the
direction of arrows A and B to correspondingly open and close the
solenoid valve 10.
[0034] The valve seal member 20 is positioned between the proximal
end 18a of the plunger 18 and the integral valve seat 40. In one
embodiment of the invention, the valve seal member 20 comprises
a pad of material formed of a resilient material such as, for example,
a rubber or polymeric material. In a specific embodiment, the valve
seal member 20 is formed of Nitrile (Buna-N). However, it should
be understood that the other configurations of valve seal members
and/or the use of other types of materials are also contemplated
as falling within the scope of the present invention. In one embodiment,
the valve seal member 20 is not attached to the proximal end 18a
of the plunger 18. Instead, the valve seal member 20 is lifted off
of the valve seat 40 via fluid flow pressure when the plunger 18
is displaced in the direction of arrow A upon activation of the
energizing coil 16. However, in another embodiment of the invention,
the valve seal member 20 may be securely attached to the proximal
end 18a of the plunger 18 such as, for example, by an adhesive material
or via one or more fasteners.
[0035] The biasing member 22 is positioned between the distal end
18b of the plunger 18 and the axial protrusion 72 defined by the
distal portion 64 of the pole piece 14. In one embodiment of the
invention, the biasing member 22 comprises a spring. In the illustrated
embodiment, the biasing member 22 comprises a flat washer-type spring
formed of a metallic material such as, for example, stainless steel,
cold rolled steel, or any other suitable material that would occur
to one of ordinary skill in the art. However, it should be understood
that other types and configurations of biasing devices are also
contemplated including, for example, an elastically deformable element
or other types and configurations of springs including, for example,
a coil spring. As should be appreciated, a sufficient amount of
clearance is provided between the spring washer 22 and the axial
portion 76a of the vent opening 76 to permit fluid flow into and
through the vent opening 76. However, other configurations for permitting
fluid flow into and through the vent opening 76 are also contemplated
such as, for example, providing one or more fluid flow apertures
extending through the spring washer 22.
[0036] Although not specifically illustrated in FIGS. 1-5, the
solenoid valve 10 may be at least partially encased within an encapsulation
material to shield and protect the solenoid valve components from
the surrounding external environment (e.g., to provide protection
against exposure to moisture, contaminants, corrosive substances
or other elements which might otherwise adversely affect operation
of the solenoid valve 10). Further details regarding encapsulation
found in U.S. Pat. No. 6,086,042 to Scott et al, the contents of
which have been incorporated herein by reference.
[0037] In operation, with the energizing coil 16 de-energized,
the biasing member 22 exerts a biasing force onto the plunger 18
in the direction of arrow B to urge the valve seal member 20 into
engagement with the valve seat 40 to provide a pressure tight seal
therebetween. In this position, the valve seal member 20 engages
the valve seal face 44 to seal off and prevent flow through the
flow orifice 36. However, when the coil 16 is energized, an electromagnetic
force acts upon the plunger 18 to overcome the biasing force of
biasing member 22 and displace the plunger 18 in the direction of
arrow A. As a result, the valve seal member 20 disengages the valve
seat 40 to thereby permit flow through the fluid orifice 36 and
into the axial passages 34.
[0038] As should be appreciated, fluid flow through the orifice
36 is continued until the coil 16 is de-energized to allow the biasing
member 22 to urge the plunger 18 into engagement with the valve
seat 44 to once again prevent flow through the flow orifice 36.
As should also be appreciated, the quantity of flow through the
flow orifice 36 and into the axial passage 30 of the solenoid valve
10 can be accurately and precisely controlled by varying the duration
the valve is open (e.g., the period of time in which the valve seal
member 20 is displaced from the valve seat 40). As should further
be appreciated, very low levels of flow through the solenoid valve
10 are possible due to the uniquely small size of the flow orifice
36. Small flow orifice sizes provide an increased level of flow
volume control and more precise and accurate control over the flow.
Additionally, the flow volume and flow rate through the solenoid
valve can be adjusted via the selection of an appropriately sized
flow orifice 36 and/or by varying the time that the solenoid valve
remains in the open or activated position. As should further be
appreciated, the larger the size of the flow orifice 36, the shorter
the time period in which the solenoid valve 10 must remain open
to achieve a desired flow volume. Shorter activation time periods
result in less energy consumption to drive the solenoid valve 10,
thereby possibly resulting in increased battery life if powered
in that manner.
[0039] Referring to FIG. 6, shown therein is the proximal portion
of a solenoid valve 100 according to another form of the present
invention. The solenoid valve 100 is similar to the solenoid valve
10 illustrated and described above, with like features being designated
with the same reference numerals and with the plunger 18 and the
valve seal member 20 removed for clarity. However, unlike the solenoid
valve 10, the solenoid valve 100 includes a connection portion 102
extending from the proximal end 12a of the valve housing 12 that
provides for sealing engagement with a pressurized gas/fluid source
200.
[0040] In the illustrated embodiment, the source 200 is configured
as a supply canister 202 having a stem portion 204 extending therefrom
for delivering a pressurized gas to the solenoid valve 10. The source
200 operates in a manner similar to an aerosol-type can wherein
axial displacement of the stem portion 204 toward the canister 202
opens an internal valve mechanism which in turn allows a pressurized
gas or fluid to flow from the stem portion 204. However, is should
be understood that other types and configuration of gas/fluid sources
are also contemplated, and that the scope of the present invention
is in no way limited to the type and configuration of gas/fluid
source used in association with the present invention.
[0041] In the illustrated embodiment of the invention, the connection
portion 102 is generally comprised of a boot or sleeve portion 104
and a seal member 106 positioned within the boot portion 104. In
one embodiment, the boot portion 104 is formed integral with the
valve housing 12. In a specific embodiment, the valve housing 12
and the boot portion 104 are molded together to form a single piece,
unitary structure. However, other means for engaging the boot portion
104 with the proximal portion 12a of the housing 12 are also contemplated
such as, for example, by threading engagement, by welding or by
any other suitable attachment techniques.
[0042] In the illustrated embodiment of the invention, the boot
portion 104 has a substantially cylindrical configuration including
a sidewall 110 defining an axial passage 112. The axial passage
112 includes a stem receiving portion 114 adjacent the valve housing
end wall 32 that is sized and shaped to receive the step portion
204 of the air/fluid source 200 therein to properly position the
stem portion 204 relative to the inlet flow orifice 36. Although
the distal end of the stem portion 204 is shown as abutting the
valve housing end wall 32, it should be understood that this is
not necessarily required to provide for sealing engagement between
the valve housing 12 and the gas/fluid source 200. Additionally,
although the stem portion 204 is shown as being snuggly received
within the receiving portion 114 of the axial passage 112, it should
be understood that this is not necessarily required to provide for
sealing engagement between the valve housing 12 and the gas/fluid
source 200.
[0043] The axial passage 112 also includes a seal receiving portion
116 that is sized and shaped to receive the seal member 106 therein.
In the illustrated embodiment, the seal member 106 is retained within
a groove formed between an annular shoulder 120 and a retention
element 122 in the form of an annular lip or flange extending inwardly
into the axial passage 112. However, it should be understood that
other means for retaining the seal member 106 within the boot portion
104 are also contemplated such as, for example, by sonic welding,
an adhesive, or by any other suitable retaining/securing technique
know to those of skill in the art.
[0044] In one embodiment, the seal member 106 comprises a pad of
material formed of a resilient material such as, for example, a
rubber or polymeric material. In a specific embodiment, the seal
member 106 is formed of Nitrile (Buna-N). However, it should be
understood that the use of other types of materials is also contemplated
as falling within the scope of the present invention. In the illustrated
embodiment, the seal member 106 has a circular shape defining a
central opening therethrough and including an outer surface 130
and an inner surface 132 extending about the central opening. The
outer surface 130 has an outer diameter substantially equal to the
inner diameter of the seal receiving portion 116 of the axial passage
112. The inner surface 132 has an inner diameter somewhat less than
the outer diameter of the stem portion 204 of the fluid source 200.
As a result, insertion of the stem portion 204 through the central
opening in the seal member 106 results in tight sealing engagement
between the seal member 106 and the stem portion 204. Additionally,
since the inner diameter of the seal member 106 is less than the
outer diameter of the stem portion 204, the wall of the seal member
106 is outwardly deformed to provide for tight sealing engagement
between the seal member 106 and the connection portion 102 of the
solenoid valve 100.
[0045] As discussed above, the gas/fluid source 200 operates in
a manner similar to an aerosol-type can wherein axial displacement
of the stem portion 204 toward the canister 202 opens an internal
valve mechanism (not shown) which allows a pressurized gas or fluid
to flow from the stem portion 204 and into the inlet flow orifice
36 of the solenoid valve 100. Sealing engagement between the stem
portion 204 and the seal 106 and the seal 106 and the boot portion
104 prevents the escape of pressurized gas or fluid and ensure that
all of the gas or fluid is conveyed through the inlet flow orifice
36 upon opening of the solenoid valve 100.
[0046] In one embodiment of the invention, the proximal portion
126 of the boot 104 is configured to engage the canister 202 in
such a manner as to maintain the internal valve mechanism of the
gas/fluid source 200 in an open position to provide a constant supply
of pressured gas or fluid to the solenoid valve 100. In the illustrated
embodiment, the proximal portion 126 of the boot 104 is positioned
in abutment against an alignment surface 206 of the canister 202
to maintain proper alignment of the stem portion 202 relative to
the solenoid valve 100 and to maintain the internal valve mechanism
in an open position. However, it should be understood that other
means for engaging the boot 104 to the canister 202 are also contemplated
as would occur to one of ordinary skill in the art, and that a particular
interface between the boot 104 and the canister 202 is not essential
to practicing the present invention.
[0047] As should be appreciated, the unique configuration of the
miniature solenoid valve 100 which includes an integral boot portion
104 and seal member 106 provides for a high integrity sealing arrangement
with a gas/fluid source. As should also be appreciated, the sealing
arrangement provided by the solenoid valve 100 uses a minimal number
of components, thereby tending to reduce manufacturing and assembly
costs, particularly when dealing with miniature components.
[0048] While the invention has been illustrated and described in
detail in the drawings and foregoing description, the same is to
be considered as illustrative and not restrictive in character,
it being understood that only the preferred embodiments have been
shown and described and that all changes and modifications that
come within the spirit of the invention are desired to be protected. |