Valve actuating apparatus

A valve actuating apparatus for control of fluid flow that has a housing having a valve body with a first port and a second port that extend through the housing. In one embodiment the valve actuating apparatus also has a toggle valve assembly that includes an armature, at least one sealing surface connected to the armature, and a spring biasing the armature to a first position where the sealing surface closes the first port. The valve actuating apparatus further includes a solenoid assembly with an electromagnetic coil and a pole piece having a first leg and a second leg. The first leg is shorter than the second, and the first leg and the armature define an air gap when the armature is in the first position. The electromagnetic coil creates a magnetic field in the pole piece when it is electrically energized to attract the armature toward the first leg to a second position where the air gap is reduced.

BACKGROUND OF THE INVENTION

This invention relates to a toggle solenoid valve for controlling fluid flow through valve ports, and in particular, to a toggle solenoid valve having an electromagnetic pole piece and toggle assembly.

Solenoid valves commonly utilize either a plunger or a toggle-style assembly for valve actuation. It is believed that the plunger-style solenoids offer good power to force efficiencies but are difficult to design when trying to achieve minimum upsweep or dead volume. Toggle-style valves offer an alternative to minimize the upsweep or dead volume but may sacrifice the power to force efficiencies in the plunger-style solenoid valve.

Toggle-style solenoid valves typically utilize coils which are electromagnetically coupled to a pole piece or a core assembly and a moving armature. The armature is typically displaced or preloaded to a fixed gap using a spring element. The armature is then coupled through a membrane to a valve section typically having three ports: common, normally closed, and normally open. Alternatively, the valve can be configured with only two ports by omitting the center port. The armature serves as a poppet to the valves. Alternatively, the armature may have poppets connected to it. When the coils are energized, the armature moves or rotates to release the valve of the normally closed port and engage the valve on the normally open port. If the assembly includes a common port, the common port will be in communication through a pathway with the normally open port until the coil is energized and the armature moves, whereupon the common port will then be in communication with the normally closed port. It has been known to have the armature pivot around a fixed point when rotating upon actuation.

In a common arrangement, the armature will be biased by a coil spring providing the fixed gap between the armature/poppet and the normally open port and closing the normally closed port as is shown in U.S. Pat. Nos. 5,653,422 and 5,762,097.

It has also been known to provide a toggle-type valve that includes a pair of elastomeric support arms extending from a cover surrounding a rigid core as is shown in U.S. Pat. No. 6,394,136. The '136 Patent also discloses actuation arms, which are attached in a levered manner to the support arms. Moving the actuation arms provides a torque to the support arms for pivoting the toggle valve. The support arms, actuation arms, cover and a frame are all made of elastomeric material. All movement of the valve assembly in the '136 Patent is provided by movement of the actuation arms as opposed to the magnetic attraction of an armature and an opposing spring as shown in the '422 and '097 Patents.

SUMMARY OF THE INVENTION

In one embodiment, the invention includes a valve actuating apparatus for control of fluid flow that has a housing having a valve body with a first port and a second port that extend through the housing. The valve actuating apparatus also has a toggle valve assembly that includes an armature, at least one sealing surface connected to the armature, and a spring biasing the armature to a first position where the sealing surface closes the first port. The valve actuating apparatus further includes a solenoid assembly with an electromagnetic coil and a pole piece having a first leg and a second leg. The first leg is shorter than the second, and the first leg and the armature define an air gap when the armature is in the first position. The electromagnetic coil creates a magnetic field in the pole piece when it is electrically energized to attract the armature toward the first leg to a second position where the air gap is reduced.

When the armature is in the second position, the air gap may be eliminated with the armature in contact with the first leg of the pole portion. A second sealing surface may be included that closes the second port when the armature is in the second position. In this embodiment, the first sealing surface moves away from and opens the first port when the armature moves to the second position.

The valve actuating apparatus may also include a common port that is in communication with the second port when the armature is in the first position and that is in communication with the first port when the armature is in the second position.

The armature may be at least partially enclosed in an encapsulation medium, and the encapsulation medium may include a pair of integrally formed poppets. In one embodiment, one of the poppets is longer than the other, and the longer poppet closes the first port when the armature is in the first position. A diaphragm may be mounted to the poppets so that the diaphragm forms the sealing surface.

The spring may be at least partially encased by the encapsulation medium. The spring may include a pair of torsional force legs and a frame extending from the legs for mounting the spring to the housing.

In another embodiment a valve actuating apparatus for control of fluid flow is provided that includes a housing having a valve body including a first port and a second port that extend through the body. The valve actuating apparatus also has a toggle valve assembly that includes an armature, a first and second poppet connected to and extending from the armature, wherein the first poppet is longer than the second poppet, and a spring biasing the armature to a first position, such that the first poppet closes the first port. The valve actuating apparatus also has a solenoid assembly including an electromagnetic coil and a pole piece, the electromagnetic coil creates a magnetic field in the pole piece when it is electrically energized so as to attract the armature to a second position where the first port is open and the second port is closed. The second poppet may close the second port in the second position.

The valve actuating apparatus may also include a common port that is in communication with the second port when the armature is in the first position and that is in communication with the first port when the armature is in the second position.

The armature of the valve actuating apparatus may be at least partially enclosed in an encapsulation medium, and the poppets may be formed in the encapsulation medium. The valve actuating apparatus may also include a diaphragm mounted to at least one of the poppets to provide sealing surfaces against valve seats on the ports.

The spring of this embodiment may include torsional force legs, and at least a portion of the spring may be encased by the encapsulation medium. The spring may include a frame extending from the legs for securing the spring to the housing.

The pole piece of this embodiment of the valve actuating apparatus may include a first leg and a second leg, the first leg being shorter than the second leg. The armature and the first leg of the pole piece may define an air gap when the armature is in the first position, and the air gap may be reduced when the coil is energized.

An additional embodiment of a valve actuating apparatus for control of fluid flow is provided that includes a housing having a valve body that includes a first port and a second port wherein the ports extend through the housing. The valve actuating apparatus also has a toggle valve assembly that includes an armature, a spring having torsional force legs extending outwardly from the armature, and an encapsulation medium enclosing at least a portion of the armature. The spring provides a torsional force to bias the armature to a first position wherein the first port is closed. The valve actuating apparatus also has a solenoid assembly including an electromagnetic coil and a pole piece, and the electromagnetic coil creates a magnetic field in the pole piece when it is electrically energized to attract the armature to a second position, in which the first port is open.

The encapsulation medium may include a pair of integrally formed poppets, the first poppet being longer than the second poppet. The longer poppet may close the first port in the first position. A diaphragm may be mounted to at least one of the poppets to provide a sealing surface against a valve seat of one of the ports.

The spring may be made of metal alloy and include a frame to secure the spring to the housing.

The pole piece may include a pair of legs with a first leg being shorter than a second leg. The armature and the first leg may define an air gap when the armature is in the first position. The air gap may be reduced when the armature moves to the second position as the coil is energized.

Yet still another embodiment of a valve actuating apparatus for controlling fluid flow is provided that includes a housing having a valve body with a first port and a second port that extend through the housing. The valve actuating apparatus also has a toggle valve assembly with an armature. The armature is moveable between a first position and a second position, and when the armature is in the first position, the first port is closed, and when the armature is in the second position, the first port is open. The valve actuating apparatus also has a solenoid assembly that includes an electromagnetic coil and a pole piece. The pole piece may have a central portion located inside the coil and a pair of legs extending from the central portion with one of the legs being shorter than the other. The armature contacts only one of the legs while in the first position and contacts both of the legs while in the second position.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Now referring toFIGS. 1–5, a first embodiment of a valve actuating apparatus is designated generally as10. Valve actuating apparatus10includes a housing generally indicated as12, a solenoid assembly generally indicated as14and a toggle valve assembly generally indicated as16.

Housing12includes an upper portion20, an intermediate portion22, and a valve body24. Referring toFIGS. 4 and 5, the upper portion20includes a cavity25, wherein the solenoid assembly14is predominantly located. Intermediate portion22has a cavity26, wherein the toggle valve assembly16is predominantly located. The valve body24of housing12includes three ports or holes27a,27b, and27cfor passage of a fluid. Ports27aand27beach have a valve seat28aand28b, respectively. Ports27a,27b, and27cmay also contain counter bores29a,29b, and29c, respectively for receipt of fittings or O-rings to connect conduits (not shown) to carry a fluid (not shown) to and from the valve body.

The solenoid assembly14includes an electromagnetic coil30, electrical leads31(FIG. 2), and a pole piece generally indicated as32for transferring a magnetic field generated by the coil to the toggle valve assembly16. Electromagnetic coil30is of a standard design, as is well known to one skilled in the art, and is wound about a bobbin or spool generally indicated as35having a central through bore36and pair of outer flanges37a,37b(FIG. 3). The electrical leads31are connected to the electromagnetic coil30through the bobbin35.

Pole piece32includes a central core portion40and a pair of legs42a,42b(FIGS. 3–5). The central core portion40has a generally cylindrical configuration in the embodiment shown and includes mounting spindles43a,43b. The legs42a,42bof pole piece32have a generally L-shaped configuration, wherein each leg includes a first length44a,44b, and a second length45a,45b, respectively. Each of the first lengths44a,44binclude a hole46a,46b, respectively, for receipt of the respective mounting spindles43a,43bof central core portion40. In this embodiment, both the first length44aand the second length45aof leg42aare shorter than the respective first length44band second length45bof leg42b. In addition, in the embodiments shown, the second length45bof leg42bincludes a pivot area47extending along the width of length45b. Pole piece32also includes a bottom surface48aon the second length45aand bottom surfaces48band48con the second length45b. Bottom surfaces48band48cslope upward from the pivot area47, and bottom surface48ais sloped at the same inclination as bottom surface48b. When the solenoid is assembled, there is a space49between the ends of lengths45a,45b.

The toggle valve assembly16of valve actuating apparatus10includes an armature50of a ferromagnetic material, an encapsulation medium52, a spring54, and a diaphragm56. Armature54has a generally rectangular configuration and is predominantly enclosed on five sides with encapsulation medium52. Encapsulation medium52may be made from any suitable material such as thermoplastic polyester resin like Rynite®, which is available from Dupont. In this embodiment, the encapsulation medium includes a pair of integrally formed poppets58a,58bextending from a bottom wall59of the encapsulation medium. In this embodiment, poppet58ais longer than poppet58b. Each of the poppets58a,58b, includes a head60a,60b, respectively.

Now referring toFIG. 7, it can be seen that spring54includes an outer frame62, an inner frame64having a central opening65, and a pair of torsional force legs66a,66bconnecting the inner frame to the outer frame. In this embodiment of spring54, outer frame62and inner frame64each have a generally rectangular configuration, and the inner frame64is substantially concentric with the outer frame62. Additionally, the frames can pivot relative to one another about torsional force legs66a,66b. Of course, as the frames are pivoted relative to one another a torsional force is built up in torsional force legs66a,66b, which tends to bias the spring back to the flat position ofFIG. 7. Spring54may be made from a stainless steel alloy, as is well known, or other suitable spring material.

Diaphragm56is made from a suitable flexible material for sealing ports27aand27band includes sealing surfaces70a,70bfor mating with respective valve seats28a,28b(FIGS. 4 and 5). The diaphragm56also includes a connecting portion72and mounting cups74a,74bfor mounting the diaphragm to respective heads60a,60bof poppets58a,58b.

When assembled as shownFIGS. 4 and 5, the solenoid assembly14is mounted primarily in cavity25of the upper portion20of housing12as discussed above. The central core portion40of the pole piece32is located in and extends through bore36of bobbin35with the mounting spindles43a,43bextending beyond the respective flanges37a,37bof the bobbin. The legs42a,42bof the pole piece are mounted to the central core portion40with mounting spindles43a,43binserted in bores46a,46bof legs42a,42b, respectively. The second lengths45a,45bof the legs will be facing inward toward one another with the space49between the lengths.

The toggle valve assembly16is located predominately within the intermediate portion22of housing12as noted above. The inner frame64of spring54is mounted to the armature by being at least partially encased in the encapsulation medium52as shown inFIGS. 4–6. The spring is also mounted to housing12with the outer frame62held between the upper portion20and intermediate portion22of housing12. The diaphragm56is mounted to the toggle valve assembly16by snapping mounting cups74a,74bon the heads60a,60bof poppets58a,58b, respectively. The ends of the diaphragm are held between intermediate portion22of the housing12and the valve body24to seal the toggle valve assembly and solenoid assembly from the fluid. When the parts are assembled as above, the housing may be held together with bolts or screws (not shown) screwed into mating threaded holes (not shown) extending through the housing parts. Of course, clamps or other suitable means may also be used to secure the assembly together.

In operation, the armature will assume a first position as shown inFIG. 4when electromagnetic coil30is not energized and a second position as shown inFIG. 5when the coil30is energized. In the non-energized first position, spring54will bias the armature so that the longer poppet58aforces sealing surface70aof diaphragm56against valve seat28aof port27aand so that the upper surface of the armature is against surface48cof length45bof the pole piece. In this position, port27c, which serves as a common port, will be in open communication with port27bthrough a passage80aso that fluid may flow in either direction through ports27band27c. Port27awill be closed from fluid flow in this position since the sealing surface70ais pressed against the valve seat28a. Also, as can be seen inFIG. 4, in the first position, armature50is in contact with the second length45bof leg42b; however, an air gap82is present between the second length45aof leg42aand armature50.

When the electromagnetic coil30is energized from electricity received through electrically leads31, it will create a magnetic field, which will be transferred by pole piece32to armature50. The magnetic field will pull armature50against the second length45aof leg42aas shown inFIG. 5so that the air gap is eliminated and wherein the armature is in planar contact with bottom surfaces48aand48bof the pole piece. When moving to the position shown inFIG. 5, the armature will rotate and pivot about pivot area47of the second length45bof leg42b. The torsional force in torsional force legs66a,66bwill be increased when the armature rotates in this manner. Also, while the armature50is in the second position, poppet58awill have moved upward pulling sealing surface70aof diaphragm56away from valve seat28a. At the same time, the armature will force sealing surface70bof diaphragm56through poppet58bagainst valve seat28bof port27b. Accordingly, the common port27cwill now be in open communication with port27ato allow fluid to pass therebetween through passage80a.

When the coil is subsequently de-energized, the magnetic field in pole piece32holding the armature against leg42awill be eliminated. The torsional force in the pivot legs66a,66bof spring54will then bias the armature back to the first position shown inFIG. 4, opening port27band closing port27a.

An additional feature of the invention is the capability to achieve a proportional response or movement of the armature. Since the magnetic force, which is resisted by the toggle valve assembly16is proportional to the input current, it is possible to vary the current to achieve a variable force between the armature50and leg42aof pole piece32. This creates a proportional rotation of armature50resulting in a proportional orifice or opening between the diaphragm56and valve seats28aor28bof the valve body24. Of course, the proportional opening will allow for proportional flow wherein the flow through the valves is proportional to the current passed through the coil. The proportional control is possible in any of the embodiments disclosed herein.

An alternate embodiment valve actuating apparatus is shown generally indicated as110inFIGS. 8 and 9. Like numbers in the alternate embodiments represent like parts inFIGS. 1–7. In this embodiment, a valve body124of housing12includes ports127aand127bhaving respective valve seats128a,128b. Port127aextends higher than port127b, unlike ports27aand27bwhich are of equal height, so that valve seat128aextends above the valve seat128b. Also, the encapsulation medium52includes poppets158aand158b, which are of the same height in this embodiment unlike poppet58awhich is longer than poppet58b. This embodiment is assembled and functions in the same manner as the previous embodiment.

Now referring toFIGS. 10 and 11, a third embodiment of a valve actuating apparatus is shown generally indicated as210. Valve actuating apparatus210is a two-way valve having a valve body224in which the common port27chas been eliminated. As such, this valve actuating apparatus will either allow or prevent fluid flow, as compared to the embodiments inFIGS. 1–9in which the valve does not shut off fluid flow, but only directs whether the flow is through port27aor27b. To achieve the two-way valve, poppet58bhas been eliminated and a modified diaphragm256is used instead of diaphragm56. In this embodiment, when the coil is not energized as shown inFIG. 10, spring54biases poppet58adownward so that sealing surface70aof diaphragm256is pressed against valve seat28aclosing off port27aas with the first embodiment. However, since there is no common port, fluid is prevented from flowing through the valve in this position. When the electromagnetic coil30is energized as shown inFIG. 11, the armature pivots upward to contact leg42aand thereby draws the sealing surface70aaway from valve seat20a. At such time, fluid may then flow in either direction between ports27aand27bthrough a passage280aas there is no poppet to close off port27b.

Yet another embodiment of a valve actuating apparatus generally indicated as310is shown inFIGS. 12 and 13. This embodiment is similar to the embodiment ofFIGS. 10 and 11, wherein the common port has been eliminated from a valve body324, except that it conversely allows fluid to flow between ports27aand27bwhen the coil is not energized as shown inFIG. 12. Then, when the coil is energized as shown inFIG. 13, fluid flow is closed off. To accomplish this, poppet58ahas been eliminated so that in the normal state there is an open passage380abetween ports27aand27b. Then, when the coil is energized as shown inFIG. 13, the armature pivots about torsional force legs66aand66bso that poppet58bpushes sealing surface70bof a diaphragm356against valve seat28bto close the fluid flow.

While the invention has been taught with specific reference to the above embodiments, one skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention. For example, other springs may be substituted for the flat spring54such as coil springs. In addition, the spring may be manufactured from any suitable material other than a stainless steel alloy that provides the desired spring properties. Also, any suitable configuration may be used for the housing and the spring may be secured in a different manner. Additionally, any suitable shape may be used for the diaphragm, and the diaphragm made be made in two parts by eliminating the connecting portion. Also, the diaphragm may be attached in another suitable manner as opposed to the snap on design shown such as using an adhesive. It would also be possible to eliminate the diaphragm all together if the poppet is made of a material that provides a sufficient sealing surface against the valve seats.

It should also be appreciated that other configurations may be possible for a two-way valve wherein port27cis maintained and either port27aor27bis eliminated. Of course, the design of the encapsulation medium52and diaphragm56may be altered as shown inFIGS. 10–13or remain as shown inFIGS. 4–5and8–9for the two-way valve. It should also be realized that the location of the common port27ccan be located anywhere in the valve body on either three-way or two-way valves so long as there is a path for fluid flow to ports27aand/or27b.

Additionally, other solenoid configurations may be used such as having the coil assembled in a vertical orientation. Other designs for the pole piece may also be used instead of the L-shaped legs. Alternately, the legs may have the second lengths connected to one another with a step providing the difference in height, or the second lengths may be connected and have a varying slope that facilitates the desired operation.

Also, the armature need not contact the pole piece. There may be an intervening part that does not interfere with the magnetic field, or there may be some small air gap remaining. In addition, when the coil is energized, the armature may pivot without coming into contact with leg42a. The described embodiments are, therefore, to be considered in all respects only as illustrative and not restrictive. As such, the scope of the invention is indicated and limited only by the claims rather than by the description or drawings.