Note: Descriptions are shown in the official language in which they were submitted.
i~gzg75
BACKGROUND OF TIIE INVENTION
1. Field of the Invention
The present inven-tion is in -the field of high perform~
ance solenoid operated valves for controlling the flow of high
pressure air, and more particularly the invention relates to
waterproof, high performance solenoid valves which are adapted to
be submerged in sea water during operation or exposed to other
corrosive environments. The solenoid valve as described is
intended to be mounted on a high pressure airgun submerged in
water for controlling the firing of the airgun in carrying out
seismic exploration operations. The solenoid valve as described
can also be used for controlling airguns which a~e not submerged
and for controlling the sudden release of high pressure air or
other gases-for other purposes.
2. DescriPtion of the Prior Art
United States Letters Patent which would appear to
be pertinent to the present invention are as fol]ows:
3,588,039 - Stephen V. Chelminski and
Anthony J. Delano -
'ISolenoid Valve Structures and Systems"
4,210,222 - Paul Chelminski and Stephen
, V. Chelminski -
"Air Gun Monitoring Method and Apparatus"
4,240,518 - Stephen V. Chelminski -
"Method & Apparatus for Monitoring & Con~
trolling a Multiplicity of Air Guns for
Seismic Surveying"
U.S._ Patent No. 3,588,039 shows high performance
solenoid valves capable of withstanding high vibrational forces
and of being submerged in salt water, having an all stainless
steel magnetic circuit. The solenoid valves shown include a
plunger which together with a valve stem defines -the valve.
~ 7S
The plunger is selectively shaped to establish excellent pressure
balance Eor high performance reliabili-ty of the magnetic circuit,
while the plunger and associated operating parts can be ~uickly
and conveniently disassembled and reassembled wlthout injury
to the solenoid valve to remove dirt particles if any particles
should inadvertently en-ter through the supply line. The sole-
noid winding and its connecting leads are encased in the housing,
and its electrical contact pins or prongs are accessible in an
electrical male connector for engagement by contacts in an
electrical female connector at the end of an electrical cable
extending to the solenoid valve.
U.S. Patent No. 4,21~,222 describes the actual
instant of firing of an airgun being detected by a pressure
transducer in fluid communication with a shuttle-operating chamber
of the airgun for sensing the sudden surge in pressure occurring
therein. This transducer and the contact prongs of the solenoid
winding are connected to the electrical cable by inserting an
intermediate electrical plug between the contact prongs of the
solenoid winding and the female connector at the end of the
electrical cable extending to the solenoid valve.
U.S. Patent No. 4,240,518 describes the actual
....... _ .
instant of firing of the airgun being detected by a pressure
transducer located in the housing of the solenoid valve itself.
This transducer is shown grounded to -the housing of the solenoid
valve, so that it has only one lead connected to a contact
prong located near the pair of contact prongs of -the solenoid
winding and located near a grounding prong for the solenoid
housing. In another embodiment, -this transducer is shown
insulated from the housing so that the transducer has two leads
connected to a pair of contact prongs near the pair of contac-t
prongs for the solenoid winding~ The contact prongs of the
solenoid winding and the contact prong (or prongs) for the
~2~
. . ~
transducer lead (or leads) are engaged by a female connector at
the end of the electrical cable extending to the solenoid valve.
In these prior art solenoid valves there are
elastomeric seals, for example O-ring seals, engaged between the
electrical cable connector and -the nousing of the sol.enoid valve.
The purpose of such elastomeric seal is to prevent the entry
or penetration of seawater into the vicinity of -the electrical
contact region between the cable connector and the housing of
the solenoid valve. In this contact region the wires in the
cable are electrically joined through disengageable contacts
with the electrieal prongs (contacts) in the valve housing.
Such electrieal prongs (contacts) lead to the solenoid winding
for enabling an electrical signal to be sent from a remote
station through wires in the cable to the solenoid winding for
actuating the valve, for example for firing an airgun. From
the above discussion, it will be understood that there may also
be other eleetrical prongs (contaets) in this eontact region
which lead to a pressure transdueer for transmitting an elec-
triel signal through other wires in the cable to the remote
station for indicating the actual instant of firing of the air-
gun on which the solenoid valve may be mounted.
In the situation of an airgun submerged in water
and being repeatediy fired for carrying out seismic exploration
or surveying, the elastomerie seal associated with the electical
cable eonnector is subjected to a slight deflection each time
that the airgun is fired because of the powerful discharge
occurring from the airgun. This repeated slight deflection
of the seal occurring at each firing of the airgun tends to
cause a water pumping action allowing the water to creep past
the seal. Thus, sooner or later the seawater tends to reach
the region of the electrical eontaets and causes eleetrical
failure due to eorrosion problems.
In running a marine seismic exploration, the
survey ship may be towing fifty or more airguns in an array.
Thus, it will be unders-tood that the likelihood of corrosion
problems occurring is increased because of the relatively
large number of cable connectors involved. Moreover, the
hourly costs of marine seismic exploration are continuing to
rise. Therefore, any electrical failure caused by such
corrosion of connector contacts is a serious impediment and
economic problem for the operator of the survey ship.
SUM~AR~ OF THE INVENTION
It is an object of the present invention to overcome
these corrosion failure problems by providing a high perform-
ance solenoid valve system which is even more reliable elec-
trically than the prior art high performance solenoid valves.
In accordance with the present invention in one of
its aspects, the solenoid winding and the electrical cable are
formed as an integral waterproof electrical component or unit
which can be removed as a unit from the remainder of the sole-
noid valve. Thus, there are no detachable contacts to become
corroded.
Among the advantages of the present invention are
those resulting from the fact that the solenoid winding can be
removed as a unit and replaced in the solenoid valve without
disturbing the valve assembly and without dismoun-ting the
solenoid valve from its associated airgun.
In accordance with the present invention in another
of its aspects, the pressure transducer for detecting the actual
~L19Z17S
instant of firing of the airgun,often called the "time hreak"
transducer, is formed with i-ts elec-trical cable as an integral
waterproof component.
In accordance wi-th -the present invention in a
further of its aspects, the solenoid winding, its electrical
cable and an end portion of the corrosion resistant housing
of the solenoid valve are together formed as an integral
waterproof component or unit which can be removed from the
remainder of the solenoid valve. Moreover, this end portion
of the housing serves as means for removably securing the solenoid
winding in its operating position within the solenoid valve.
Another advantage of the foregoing integral
waterproof component including solenoid winding, electrical
cable and end portion of the housing is that this component
serves for removably securing the -time-break transducer in its
own operating position in the housing of the solenoid valve.
BRIEF DESC IPTION OF THE DRAWINGS
The various features, aspects, objects and
advantages of the present invention will in part be pointed
out in and will in part become understood from a consideration
of the following description in conjunction with the accompany-
ing drawings showing the best mode now contempla-ted by m~ for
carrying out this invention in practice. In these drawings,
like reference numbers indicate like elements or components
throughout the respective views, in which:
l~l9ZiL7~ ~
FIGURE 1 is a top plan view oE a solenoid valve
system embodying the present invention.
FIG. 2 is a side elevational view of the solenoid
valve system. A small portion of an airgun is indicated at
the bottom of FIG. 2 on which the solenoid valve is mounted.
FIG. 3 is an elevational sectional view of the
solenoid valve system as seen from the same~direction as in
FIG. 2. FIG. 3 is a section taken along the plane 3-3 in
FIG. 1.
FIG. 4 shows that the solenoid winding, its elec-
trical cable and a removable end of the housing are an integral
waterproof electrical component or unit. This advantageous
unitary electrical component is shown being removed from the
solenoid valve without disturbing the valve assembly and without
dismounting the solenoid valve from the airgun on which it is
mounted.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
.. ...... ,_
These four FIGURES show my presently preferred
embodiment of the invention. IJ1 effect, the invention provides
an overall solenoid valve system in which the solenoid winding
(sometimes called the "solenoid coil") and its electrical
cable and an end of the housing are integrated to form a single
waterproof component, namely, the electrical component of the
solenoid valve, This waterproof electrical component
can be removed as a uni-t from the remainder of the solenoid
valve which remains as a unit; namely, the operating
moving parts of the solenoid valve remain as a unit without
'S
being dis-turbed when the waterproof electrical componen-t is
removed and replaced. This novel concept of an overall
solenoid valve system will be most quickly understood by looking
at FIG. 4 which shows the whole system 7 separated into its
integral waterproof electrical component 8 and into its
mechanical components 9.
The solenoid valve 10 (FIGS. 2 and 3) i5 shown
mounted on the end portion 12 of an airgun. The manner in which
a solenoid valve 10 is used to trigger the firing of an airgun
will be unders-tood from the three pa-tents described above in
the background, and therefore will not be described here. This
solenoid valve 10 includes a main housing or base portion 14
(as seen most clearly in FIG. 4) which contains a valve assembly
16. The operating parts of the solenoid valve which move
during actuation are in this valve assembly 16, as will be
explained later. This solenoid valve 10 also includes a
removable top end portion of the housing or cover 18 which
integrally contains the solenoid winding 20. The main housing
14 defines an annular channel 22 (FIG. 4) encircling the valve
assembly 16, and this channel 22 is open and accessible toward
the top end of the main housing where the end portion or cover
18 of the housing is located during opera-tion. This cover 18
includes a downwardly extending boss 24 which is hollow to form
a thin cylindrical wall 26. The winding 20 and its bobbin (as
will be explained later) are potted within this thin cylindrical
wall 26 thereby forming an inverted cup of annular configuration
which fits snugly within the annular channel 22, as seen in
FIG. 3.
~9;i:~7~
The electrical cable firing line 27 (FIG. 3) for
-transmitting a signal for energizing the solenoid winding 20 for
firing -the airgun is dlrec-tly connec-tecl to the leads 28, 29 of
the winding 20. There are no intervening separatable electrical
contac-ts; in other words, a direct connection is made from
the insulated wires 31, 32 in the firing line cable 27 -to -the
leads 28 and 29. The solenoid winding or coil 20 is wound about
a bobbin 34 (FIG. 3) of dielectric material. The bobbin and
winding 34 and 20 are placed within -the thin cylindrical wall
26 with the cable wires 31, 32 and the adjacent end of the cable
located in a passageway 36 drilled in the housing cover 18.
There ls a nipple 38 welded at 39 onto the cover 18 with the
bore 40 of this nipple aligned with the upper end of the passage-
way 36. The firing line cable 27 extends up through the bore
of this nipple 38.
In order to form a waterproof, in-tegral unitary
elec-trical component 8 (FIG. 4), the solenoid winding 20, its
bobbin 3~ and its leads 28, 29 together with the wires 31, 32
are potted with epoxy pot-ting compound 42 within the cylindrical
wall 26 and wi-thin the passageway 26. In performing this
potting operation, these elements are first subjected to
vacuum for withdrawing air so that the epoxy potting material 42
fills all voids. This potting ma-terial 42 satura-tes -the
convolutions of the winding 20 for preventing the turns of the
coil from rubbing against each other and ex-tends down below
the lower flange of the bobbin and overlaps the edge of the wall
26 at 44 for providing a secure bond. This epoxy po-tting
material 42 when it sets is relatively rigid.
1 ~92~7~
¦ In order to complete the potting operation, the
upper portion of the passageway 36 and the bore 40 of the
nipple 38 are filled with polyurethane potting compound
46 which is more flexible than the epoxy material 42. The
advantage of using this more flexible potting material 46 is
that it accommodates any slight flexing between the cable 27
and nipple 38. It is noted that the nipple bore 40 is roughen-
ed, for example by a screw thread configuration, for providing
rough
a/surface area for strong holding and gripping of the poly-
urethane potting material 46.
In order to protect the firing line cable 27,
there is a tough, stiffly flexible sheath 48 placed around the
electrical cable. This protective sheath 48 is a commercially
available high pressure hose line containing strong, non-
metallic reinforcing fibers. The end of this protective sheath
48 is anchored by a commercially available mechanically crimped
hose coupling 50 to a commercially available fitting 52. This
hose fitting 52 is removably fastened to the niople 38 by a
coupling nut 54.
Thus, it will be understood that the electrical
component 8 (FIG. 41 is an integral waterproof unit. The
solenoid winding 20, together with its bobbin 34 potted
into the cylindrical wall 26, form an inverted annular cup
fitting snugly into and conveniently removable from the annular
channel 22 in the base component 9 of the solenoid valve. The
potted bobbin 34 and winding 20, together with the hollow
boss 24 (FIG. 4) define a socket 60 which fits snuyl~ around
the valve assembly 16.
119Zl~i ~
As shown in FIGS. 1 and 2, the base portion 14
of the housing is fastened to the airgun 12 by a pai,r of machine
screws 56 passing through a pair oE flanges 58 on opposite sides
of the base 14. The housing cover 18 is removably fastened to
the housing base 14 by four long machine screws 62 which
extena down into the airgun 12 and screw into the airaun.
Therefore, these four long screws 62 aid the two shorter screws
56 in securing the solenoid valve onto the airgun 12 during
operation. However, removal of the four screws 62 enables the
electrical component 8 (FIG. 4) to be removed as a unit as
indicated by the arrow 64, without disturbing the base component
9 nor its valve assembly 16 and without dismounting the base
housing 14 from the airgun 12. It is noted that the heads of
the machine screws 62 are neatly recessed relative to the top
surface of the housing cover 18, as seen in FIG. 2.
In order to removably hold a time-break transducer
sidewall of the
66 into a socket 68 in the/base housing 14, there is a 'U-shaped
slot 70 (FIG. 1) in the edge of the cover 18 providing clearance
for a tubular fitting 72. The lower end of this tubular fitting
72 has a flange 74 with an O-ring seal 76which ~its down into
the enlarged upper end of -the socket 68. There is also an
O-ring seal 78 around the lower end of the transducer 66. This
transducer may advantageously be of the type described and
claimed in U.S. Patent No. 4,286,687 - Augus-tus H. E'iske, Jr.,
assigned to the assignee of -the present applica-tion.
The leads 81, 82 of this transducex 66 are directly
connected to the wires 83, 84 of an electrical time-break sensor
cable 80 by permanently crimped electrical connectors 85, 86.
The leads 81/ 82, wires 83, 84 and the permanent connections 85,
~Z~7~i
86 are potted in the bore of the tu~ular fit-tiny 72 hy molded
rubber material 87. This rubber material ex-tends out as a
tapered s]eeve 88 over the end of the cable 70 for resisting
flexural stress. The bore of the fitting 72 is roughened,
as by a screw thread formation, for providing a strong holding
or gripping of the material 87. A passageway 89 provides fluid
communication with a region in the airgun in which a sudden
increase in pressure occurs in firing, as will be understood
from Patent Nos. ~,210,22 and 4,240,518 discussed in the back-
ground.
Pressurized gaseous fluid, usually compressed air,
is supplied to the solenoid valve 10 through a high pressure
supply line hose 90 connected to the housing cover 18 through
a fitting 92 screwed into a socket 94 in the top of the cover~
This solenoid valve 10 is of the dual action type as
described and claimed in Patent No. 4,240,518, namely, it can
produce a sudden flow from an inlet port to an outlet port upon
sudden energization and it can continuously shut off flow
from a supply port to the inlet port by continuous energization.
This solenoid valve 10 includes a supply port 96 (FIG. 3)
communicating with the supply line 90, an inlet port or chamber
98 communicating with the interior of the airgun and an outlet
port or trigger port 100, which also is in communication with
the interior of the airgun. This latter port 100 is suddenly
placed in communication with the inlet port 98 when the valve
assembly 16 is actua-ted by sudden energization of the solenoid
winding 20, thereby firing the airgun.
When -the solenoid winding 20 is de-energized,
pressurized gaseous fluid can flow from the supply port 96
through the solenoid valve assembly 16 to the inlet passage 98
1:~921L75
for supplying pressurized fluid to the equipment 12 beinc~
controlled by this solenoid valve system. In the event of
malfunction of the con-trolled equipment, this solenoid valve
system 7 can be used to shut off the supply of pressurized fluid
as explained in Patent No. 4,2~0,518. This shut off is obtained
by feeding a continuous flow of current through the winding 20.
While this continuous current is flowing, the valve assembly
16 is actuated by an additional sudden pulse of current through
the winding 20 and thereafter remains held in its actuated
condition by the continuous current.
The elements of the valve assembly 16 are essential-
ly identical to the elements shown in the valve mechanism in
FIGS. 4, 5 and 7-12 of U.S. Patent No. 4,240,518. These elements
of the valve assembly 10 will now briefly be pointed out. If the
reader wishes a full description of how these mechanical valve
elements function, attention is invited to the specification
of that patent. There is a valve stem 102 seated in the
105 held by a retainer
upper end of a plunger housing 10~ and held there by a retainer/
ring 106. A slidable plunger 107 encircles the stem 102 and
is urged downwardly into engagement with a seal 108 by springs
110 positioned in axially extending cavities in this plunger
107.
When the solenoid winding 20 is de-energized,
the plunger 107 engages the seal 106 for blocking communication
between the ports 98 and 100, while the supply port 96 communi-
cates with the port 98. When the solenoid winding 20 is
energized, the movable plunger 107 is electromagnetically drawn
upwardly against the force of the springs 1-lO, thereby
separating from the seal 108 for opening communication between
l~l9Z~7S
ports 98 and 100. While the plunger 107 is electromagneticall~
held upwardly, a lip 112 on the upper end of this plunger
engages a seal 114 for blocking communication between ports 96
and 98~ The materials used throughout this solenoid valve
system 7 are high-strength, corrosion-resistant materials of
high quality. In order to produce a strong magnetic field
through the plunger 107, the cover 18, base housing 14, top and
bottom portions of the plunger housing 104 and the plunger 107
are made of magnetically permeable, i.e. ferromagnetic, stain-
less steel. The thin cylindrical wall portion of the plunger
housing 104 adjacent to the plunger 107 is made of non-magnetic
stainless steel using the construction technique, as shown in
Patent No. 3,588,039.
The valve assembly 16 (FIG. 4) includes the
retainer 105,
following elements: plunger housing 104, valve stem 102,/ring
retainer 106, inlet-to-outlet blocking seal 108, springs 110,
supply-to-inlet blocking seal 114, and O-ring seals 115 and
117, seated in circumferential grooves in the valve stem 104.
The seal 115 provides a sliding seal against the bore of the
plunger 107.
This valve assembly 16 is removable from the lower
end of the base housing 14 when the base housing has been dis-
mounted from the airgun 12 or other equipment being controlledO
There is an in-ternal annular shoulder 118 in the base housing
14 located below the annular channel 22 and projecting inwardly,
and there is an external annular flange 119 on the plunger
housing 104. This flange 119 abuts up against the internal
shoulder 118 for retaining the whole valve assembly 16 in the
base housing 14 when the electrical component 8 is withdrawn
(arrow) 64 as shown in FIG. 4.
-14-
:119Z1L75
There are various other O-ring seals 120 as shown
in the drawing for providing sealing against the leakage of
high pressure gaseous fluid.
For convenience of description, the "top" and "hottom"
of the solenoid valve 10 have been described in relation to
the orientation as shown in the drawlngs. Similarly, for
convenience, the terms ;'top" and "bottom" and similar terms
of orientation may appear in certain claims. However, it is
to be understood that the solenoid valve described herein can
be used and actuated in any orientation relative to the earth's
gravitational field, and the claims are to be construed accord-
ingly.
From the foregoing, it will be understood -that the
solenoid valve system of the present invention is well suited
to provide the advantages set forth. It is to be understood
that all matter hereinbefore set forth or shown in the accompany-
ing drawings is to be interpreted as illustrative.
