HK1195603A - Multi-port normally open modular valve with thread-in seat - Google Patents

Description

Multi-port normally-open superposition valve with threaded base

Technical Field

The present disclosure relates to a solenoid operated poppet valve.

Background

This section provides background information related to the present disclosure, which is not necessarily prior art.

Solenoid operated valves, such as poppet valves and the like, are known which provide fluid control, such as compressed air, in operating accessories such as sorters, packaging machines, food processors, and the like. These valves can run millions of cycles. To maintain the solenoid operated valve in the closed position when the solenoid is de-energized, a biasing member, such as a spring, is used. It is known, for example in U.S. patent 4,598,736 to chord, that fluid pressure can be balanced within the valve to reduce the electromagnetic force required to move the valve member between the closed and open positions.

In known valves, direct access to the valve seat region is generally not possible. Known valve designs require disassembly of the entire valve or replacement of the entire valve when wear occurs to the valve components or the base. Valve designs with snap-fit components are known that provide easier access to the valve assembly by the user, but which do not provide the flexibility to change the operational characteristics of the valve.

Disclosure of Invention

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

According to several aspects, a normally-on electromagnetically-operated superposition valve includes an electromagnet having a coil and a pole piece. The valve body portion is detachably connected to the electromagnet. The armature/valve member in the valve body portion includes a threaded end shank. The threaded poppet valve/valve member includes a threaded portion that engages the threaded end shank to retain the threaded poppet valve/valve member on the armature/valve member. The valve ring is disposed on the threaded poppet/valve member. A biasing member acts on the armature/valve member for normally biasing the valve ring out of contact with a valve seat surface formed in the valve body portion to establish a normally open position of the overlying valve.

According to other aspects, a normally-on electromagnetically-operated superposition valve includes an electromagnet having a coil and a pole piece. The valve body portion is detachably connected to the electromagnet. An armature/valve member having a male tang is slidably disposed in the electromagnet and valve body portion. The threaded poppet valve/valve member has an internally threaded portion that engages the male threaded end shank to retain the threaded poppet valve/valve member on the armature/valve member. A valve ring of elastomeric material is retained on the threaded poppet/valve member. The cylindrical tube portion receives the stem portion of the armature/valve member. The biasing member acts on the armature/valve member to normally bias the valve ring out of contact with a valve seat surface formed on the valve body portion to define a normally open valve position of the overlying valve.

According to another aspect, a normally-on electromagnetically-operated superposition valve includes an electromagnet receiving a coil and a pole piece. A valve body portion of polymeric material is removably connected to the electromagnet. An armature/valve member having a male threaded end shank and stem is slidably disposed in the stacked valve. The threaded poppet valve/valve member has an internally threaded portion that engages the male threaded end shank to retain the threaded poppet valve/valve member on the armature/valve member. A valve ring of elastomeric material is disposed on the threaded poppet/valve member. The cylindrical tube portion receives the stem portion of the armature/valve member. A seal of resilient material is located in a groove formed in the stem portion to form a fluid barrier between the stem portion and the inner wall of the inner bore of the cylindrical tube portion.

Further areas of applicability of the present invention will become apparent from the description provided hereinafter. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

Drawings

The drawings described herein are for illustrative purposes only of several selected embodiments and are not intended to illustrate all possible implementations or to limit the scope of the present disclosure.

FIG. 1 is a top front perspective view of a multi-port normally open superposition valve of the present invention;

FIG. 2 is a top view of the stack valve of FIG. 1;

FIG. 3 is a front cross-sectional view of region 3 of FIG. 2;

FIG. 4 is a front cross-sectional view of area 4 of FIG. 3, showing the superposition valve in a normally-open position;

FIG. 5 is a front cross-sectional view similar to FIG. 4, further showing the superposition valve in a closed position;

FIG. 6 is a front cross-sectional view similar to FIG. 3, further showing the stacking valve installed in the manifold assembly;

FIG. 7 is a front cross-sectional view similar to FIG. 3 of the three-way, multi-port, normally-open, superposition valve of the present invention;

FIG. 8 is a front cross-sectional view similar to FIG. 6 showing a three-way superposition valve installed in the manifold assembly.

Corresponding parts are designated by corresponding reference numerals throughout the several views.

Detailed Description

Example embodiments are now described more fully with reference to the accompanying drawings.

Referring to fig. 1, a multi-port normally closed overlap-and-add valve 10 includes an electromagnet 12 removably connected to a polymeric material valve portion 14. A threaded poppet/valve member 16 is removably attached to the free end of the valve portion 14 of the stacked valve 10. An end cap 18 is attached to the electromagnet 12, the end cap 18 having a connection port 20, the connection port 20 having a plurality of electrical connectors 22, 24 for providing power to operate the electromagnet 12. The electromagnet 12 comprises an electromagnet vessel 26, the electromagnet vessel 26 housing an electromagnet assembly as shown in figure 2. Valve portion 14 is provided with a first seal 28 and a second seal 30, such as an O-ring or D-ring. The first and second seals 28, 30 are positioned opposite one another about a valve inlet 32, the function of which will be further described in fig. 6.

Referring to fig. 2, the superposition valve 10 may include end cap planes 34, 36 disposed opposite each other to assist in mounting the superposition valve 10. The electrical connectors 22, 24 are axially aligned with respect to the electromagnet 12 so that the stacked valve 10 is electrically connected within the spatial envelope of the end cap 18. This minimizes the spatial envelope of the stack valve 10 to most fully align a plurality of other stack valves in a side-to-side relationship in a configuration such as a manifold assembly, as shown and described in greater detail in fig. 6.

Referring to fig. 3 and 1, the components of the electromagnetic assembly 37 in the electromagnet 12 include an electromagnetic coil 38, the electromagnetic coil 38 being within a bobbin 40. When energized, the electromagnetic coil 38 generates a magnetic field that acts on an axially adjustable, but generally fixed, pole piece 42. The pole piece 42 includes a threaded end 44 that engages a threaded hole 45 of the electromagnetic vessel 26, allowing the axial position of the pole piece 42 to be manually adjusted by rotating the pole piece 42. The pole piece 42 may also include an axial bore 48, the axial bore 48 providing an exhaust passage through the pole piece 42. When the stacked valve 10 is in the normally open position shown, a gap 50 is provided between the pole piece 42 and the combined armature/valve member 52. The clearance provided by the gap 50 allows the armature/valve member 52 to be displaced from the normally open position to the closed position. The armature/valve member 52 and the pole piece 42 are coaxially aligned along a longitudinal central axis 54 of the stacked valve 10 and are independently displaceable relative to the longitudinal central axis 54 of the stacked valve 10. The magnetic field generated by energizing the electromagnetic coil 38 acts through the pole piece 42 to axially displace the armature/valve member 52 in the first direction "a" and coaxially with respect to the longitudinal central axis 54 from the illustrated normally-on, lower position, thereby closing the superimposed valve 10. Thus requiring continuous operation of the solenoid 38 to maintain the overlap valve 10 in the valve closed position.

The armature/valve member 52 is slidably guided within a cylinder sleeve 56 located in the spool 40. The flange 58 is integrally connected with the cylinder liner 56 and is disposed in a transverse direction with respect to the cylinder liner 56. The flange 58 is secured between a spool end wall 60 and a resilient material seal 62, such as an O-ring. The biasing force of the seal 62 maintains the position of the flange 58 and thus the position of the spool 40 when the seal 62 is partially compressed in contact with the first body end 64 of the valve portion 14. Also, an end seal 66, such as an O-ring or D-ring, is provided on the outwardly extending body flange 68, the function of which will be described with reference to FIG. 6. The first body end 64 of the valve portion 14 is removably coupled to the electromagnetic vessel 26 using a threaded connection 70. The first and second seals 28, 30 are retained in first and second grooves 72, 74, respectively, formed in mutually opposed ends of the valve portion 14. A first slot 72 is formed in the first body end 64 and a second slot 74 is formed in the second body end 76.

A biasing member 78, such as a compression spring, in direct contact with the flange 58 normally provides a biasing force acting in a second direction "B" opposite the first direction "a" to place the armature/valve member 52 in the normally open position shown. The armature/valve member 52 includes a valve member portion 80 located primarily in the valve portion 14, the valve member portion 80 being threadably coupled to a tubular portion 82 of the threaded poppet valve/valve member 16. According to several aspects, the valve portion 14 is made of a polymeric material, reducing the weight and cost of the stacked valve 10. The tubular portion 82 and the valve member portion 80 are each positioned in a fluid passageway 84 of the valve portion 14 and are thus exposed to a fluid, such as water, air, or pneumatic fluid, that superimposes the operational controls of the valve 10. The elastomeric valve ring 86 is retained between a first ring retainer 88 and a second ring retainer 89, the first 88 and second 89 ring retainers extending radially outwardly from an integral portion of the threaded poppet/valve member 16. The valve ring 86 is used in the valve closed position (shown in FIG. 5) to isolate fluid in the valve inlet "C" from the valve outlet "D". In the valve open position shown, fluid in valve inlet "C" is in communication with valve outlet "D".

Referring to fig. 4 and 3, the biasing member 78 is concentrically disposed about the armature/valve member 52 with a first end in direct contact with the flange surface 90 of the flange 58 and a second end in direct contact with the piston 92. The piston 92 is an integral part of the armature/valve member 52, is slidably disposed in a piston cylinder portion 94 of the valve portion 14, and is slidably displaceable in first and second directions "a" and "B". The biasing force of the biasing member 78 is generally used to move the piston 92 and thereby the armature/valve member 52 in the second direction "B". An elastomeric seal 96 is provided in a sealing ring 98 of the piston 92, the elastomeric seal 96 slidably contacting a bore wall 100 of the piston cylinder portion 94, thereby preventing fluid in the valve inlet "C" from flowing to the solenoid components of the stacked valve 10 in the solenoid can 26. When the superimposed valve 10 is in the normally open position shown, the end face 102 of the inwardly extending wall 104 of the valve portion 14 directly contacts a compressible seal 103 disposed on the piston 92.

An open channel 106 formed through the wall 104 provides clearance for a stem portion 108 of the armature/valve member 52 to extend to the valve inlet "C". The diameter "E" of the stem portion 108 is sized to slidably fit within a cylindrical tube portion 110 of the threaded poppet/valve member 16. An elastomeric seal 112, such as an O-ring or D-ring, is disposed in a receiving groove 113 formed in the circular stem portion 108, the elastomeric seal 112 providing a fluid boundary seal against an inner wall 114 of an inner bore 115 of the cylindrical tube portion 110. The seal 112 thus serves to prevent fluid from flowing out of the overlap valve 10 through the bore 115 and out of the inlet "C". The cylindrical tube portion 110 of the threaded poppet/valve member 16 is sized to slidably fit within the smallest diameter portion 116 of the inlet "C".

The armature/valve member 52 further includes an end shank 118 having male threads 120. The male threads 120 mate with female threads 122 in an internally threaded portion 124 of the threaded poppet/valve member 16. The longitudinal position of the threaded poppet/valve member 16 relative to the longitudinal central axis 54 may be adjusted by axially rotating the threaded poppet/valve member 16 relative to the male threads 120. The valve ring 86 is retained on the threaded poppet/valve member 16 by direct contact with a flange face 125 of an end flange 126 integrally provided with the threaded poppet/valve member 16, and conversely, directly contacts an annular surface 128 of a second ring retainer 89 integrally provided with the threaded poppet/valve member 16. Thus, when the armature/valve member 52 is displaced in the first and second directions "a" and "B", the valve ring 86 is retained between the end flange 126 and the ring surface 128.

In the normally open valve position shown, the piston 92 of the armature/valve member 52 is held in direct contact with the compressible seal 103 by the biasing force of the biasing member 78. The biasing force causes the planar contact surface 130 of the valve ring 86 to move away from the valve seat surface 132 formed in the valve portion 14 by a seat clearance distance "F" to open a fluid passageway 134 between the valve inlet "C" and outlet passageway 136, defining the valve outlet "D".

As previously mentioned, the seat clearance distance "F" can be adjusted by axially rotating the threaded poppet valve/valve member 16 relative to the male threads 120 of the armature/valve member 52 to increase or decrease the seat clearance distance "F". The valve open/close time and/or valve stroke may also be controlled by the seat clearance distance "F". Because the threaded poppet/valve member 16 is accessible to an operator of the overlap valve 10, the seat clearance distance "F" can be adjusted whenever the overlap valve 10 is not in an installed position. As the valve ring 86 wears over time and use, the threaded poppet/valve member 16 may be axially adjusted in the first direction "a" to accommodate the wear, or removed in a second direction "B" coaxial with the longitudinal central axis 54 and replaced with a new threaded poppet/valve member 16 or a new valve ring 86 by displacement in the first direction "a".

Referring to fig. 5 and 3-4, the superposition valve 10 is in the valve-closed position when the electromagnetic coil 38 is energized, pulling the armature/valve member 52 in the first direction "a" and simultaneously compressing the biasing member 78. The inwardly extending wall 104 is remote from and not in contact with the compressible seal 103. The valve inlet "C" is isolated from the valve outlet "D" when the planar contact surface 130 of the valve ring 86 directly contacts a valve seat surface 132 formed in the valve portion 14. As previously mentioned, the superposition valve 10 is in the valve-closed position whenever the solenoid 38 is energized. When the electromagnetic coil 38 is de-energized, the biasing force of the biasing member 78 returns the armature/valve member 52 and the threaded poppet/valve member 16 in the second direction "B" to the valve open position shown in FIGS. 3-4.

Referring to fig. 6 and 3-5, in a typical installation, a two-way version of the stacking valve 10 shows the stacking valve 10 installed in the manifold 140. The stack valve 10 is inserted through the aperture and held in place by the pressure plate 142. The pressure plate 142 directly contacts the manifold 140 and partially compresses the end seal 66, thereby providing a biasing force to maintain the stacked valve 10 in the fully installed position shown. The valve portion 14 is inserted in direct contact with the bore wall 144 of the main chamber 146 of the manifold 140 and is sealed by the first seal 28. The second body end 76 of the valve portion 14 is slidably inserted into direct contact with the bore wall 148 of the second chamber 150 of the header 140 and sealed by the second seal 30. The free end 152 of the valve portion 14 directly contacts the end wall 154 of the second chamber 150, fixing the installed position of the stacked valve 10. The threaded poppet/valve member 16 is mounted within the passage 156 of the manifold 140 and is free to displace axially therein. When the superimposing valve 10 is in the normally open position shown, the inlet "C" is in communication with the inlet connection port 158 of the header 140 and the outlet "D" is in communication with the outlet connection port 160 of the header 140.

Referring to fig. 7 and 1 and 3-6, the three-way version of the normally-open superposition valve 162 contains many of the same electromagnetic components as the superposition valve 10. The components of the electromagnetic assembly in the electromagnetic section 12' are substantially identical and therefore will not be discussed here. A valve portion 164 of polymeric material is threaded into solenoid portion 12'. A gap similar to gap 50 is similarly provided between the pole piece and the combined armature/valve member 166 when the overlap valve 162 is in the normally open position shown. The gap creates a clearance that allows the armature/valve member 166 to be displaced from the normally open position to the closed position.

Similar to the armature/valve member 52, the armature/valve member 166 is normally biased by a biasing member 168, the biasing member 168 being in direct contact with a radially extending piston 170 integrally disposed with the armature/valve member 166. The piston 170 is slidably guided in an upper or first body portion 172 of the valve portion 164. A lower or second body portion 174 is integrally disposed with and extends away from the first body portion 172 and further includes a body end portion 176. A cartridge assembly 178 is removably connected to the body end portion 176. The pocket member 178 includes a snap pocket portion 180 formed of a polymeric material, the snap pocket portion 180 integrally including first and second barbs 182, 184 disposed opposite one another, the first and second barbs 182, 184 being mounted to deflect toward the body end portion 176 and then snap outwardly toward the body end portion 176. When the overlap valve 162 is in the assembled but uninstalled position, a gap "G" is formed between the snap pocket portion 180 and the body end portion 176 due to the biasing force of the biasing member 168. When the overlap valve 168 is installed in the header as shown in fig. 8, the gap "G" is substantially eliminated.

The armature/valve member 166 further includes a stem portion 186 integrally extending from the piston 170, with a first radial flange 188 extending outwardly from the stem portion 170. A first valve ring 190 of elastomeric material is supported by the first radial flange 188. In the illustrated valve open position, the first valve ring 190 is separated from a first seating surface 192 formed in the second body portion 174 by a ring gap "H". The armature/valve member 166 also includes a valve member portion 194, the valve member portion 194 functioning similarly to the valve member portion 80, primarily located in the valve portion 164, including a male-threaded end shank 196 to threadably couple to an internally threaded tubular portion 198 of a threaded poppet/valve member portion 200 of the cartridge assembly 178. According to several aspects, the snap pocket portion 180 is made of a polymer material, reducing the weight and cost of the stacked valve 10. A seal 202, such as an O-ring or D-ring, is disposed in the threaded poppet/valve member portion 200, the seal 202 sealing the cylindrical end 204 of the snap pocket portion 180 when the threaded poppet/valve member portion 200 is slidably inserted into the snap pocket portion 180.

The poppet/valve member portion 200 also includes a second radial flange 205, the second radial flange 205 supporting a second valve ring 206 of elastomeric material. In the valve open position, the second valve ring 206 abuts against a second seating surface 208 formed in the snap pocket portion 180. The male threaded end shank 196 is threadably coupled to an internally threaded tubular portion 198 of a threaded poppet/valve member portion 200, allowing axial adjustment of the threaded poppet/valve member 200 by rotating the threaded poppet/valve member portion 200. When the stack valve 162 is in the assembled, but uninstalled position, the ring gap "H" is adjusted accordingly.

Referring to fig. 8 and 3-7, in a typical installation, the three-way version of the overlap valve 162 shows the overlap valve 162 installed in the manifold 210. The stack valve 162 is inserted through an aperture in the platen 212 and held by the platen 212. The pressure plate 212 directly contacts the manifold 210 and partially compresses the end seal 66' to provide a biasing force to maintain the stacked valve 162 in the fully installed position shown. The installation of the overlap valve 162 is substantially similar to the installation of the overlap valve 10 in the manifold 140. The free end of the valve portion 164 directly contacts the end wall of the second chamber of the header 210, fixing the mounting position of the overlap valve 162. The threaded poppet/valve member 200 and the snap-in cartridge portion 180 are mounted within the channel of the manifold 210, within which the threaded poppet/valve member 200 is axially displaceable for adjustment. To allow axial displacement of the poppet/valve member 200, the manifold 210 is provided with an exhaust passage 220, aligned with the poppet/valve member 200, open to the atmosphere. When the overlap valve 162 is in the normally open position shown, the inlet "J" is in communication with the inlet connection port 214 of the header 210 and the outlet "L" is in communication with the outlet connection port 218 of the header 210. Exhaust port "K" is in communication with exhaust connection port 216 and is isolated from inlet "J" and outlet "L" when the valve is normally open. The overlap valve 162 can also be used in the closed position, using port "J" as the exhaust port and port "K" as the inlet port.

The above-described embodiments as examples are intended to convey the disclosure in depth to those skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods to provide a thorough understanding of the present disclosure. It will be apparent to those skilled in the art that the specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some embodiments, well-known processes, well-known device structures, and well-known techniques are not described in detail.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting in any way. As used herein, a description of a singular form may include a plural form unless the context clearly dictates otherwise. The terms "comprises," "comprising," "including," and "having," and the like, are intended to be inclusive and mean that there may be additional features, integers, steps, operations, elements, and/or components included, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes and operations described herein do not have to be performed in the particular order discussed or illustrated herein, unless an order of performance is specifically indicated. It is understood that additional or alternative steps may be used.

When an element or layer is referred to as being "on … …", "engaged to", "connected to" or "coupled to" another element or layer, it can be directly on, engaged, connected or coupled to the other element or layer, but intervening elements or layers may also be present. In contrast, when the term "directly" is used, there may be no intervening elements or layers. Other words describing the relationship between elements should also be construed accordingly (e.g., "between" and "directly between … …," "adjacent" and "directly adjacent," etc.). As used herein, "and/or" includes any one or more of the associated items and all combinations thereof.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. As used herein, terms such as "first," "second," and other numerical terms do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the embodiments.

As used herein, relative spatial terms, such as "inner," "outer," "lower," "below," "lower," "above," "upper," and the like, are used in a descriptive sense to describe one element or feature as compared to another element or feature. Relative spatial terms may encompass other orientations than the orientation depicted in the figures when the apparatus is in actual use or operation. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, examples of the term "below" may include both an orientation of above and below. The device may also be otherwise oriented (rotated 90 degrees or at other orientations) and the spatial terminology may be adjusted accordingly.

The foregoing description of the embodiments has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Certain elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in an embodiment even if not specifically shown or described herein. In other embodiments, variations in many aspects are possible. Such variations are not to be regarded as a departure from the disclosure and are intended to be included within the scope of the disclosure.

Claims (25)

1. A normally-on, solenoid-operated, stack valve comprising:

an electromagnet receiving the coil and the pole piece;

a valve body portion connected to the electromagnet;

an armature/valve member having a threaded end shank at the valve body portion;

a threaded poppet/valve member having:

a threaded portion engaged with the threaded end shank to retain the threaded poppet/valve member on the armature/valve member; and

a valve collar disposed on the threaded poppet/valve member; and

a biasing member acting on the armature/valve member to normally bias the valve ring out of contact with a valve seat surface formed on the valve body portion to define a normally open valve position of the overlying valve.

2. A normally-on electromagnetically-operated superposition valve according to claim 1, wherein the electromagnet further comprises a bobbin supporting the coil and into which the pole piece is slidably inserted.

3. A normally-on electromagnetically-operated superposition valve according to claim 2, wherein the pole piece is movably arranged in the bobbin; and further comprising engaging the pole piece to a threaded end of the electromagnet to allow selection of an axial position of the pole piece by rotation of the pole piece relative to the threaded end.

4. A normally-on, solenoid-operated, stacked valve as defined in claim 1, wherein the threaded poppet/valve member includes a cylindrical tube portion for slidably receiving a stem portion of the armature/valve member, the stem portion being positioned adjacent the end shank.

5. A normally open solenoid operated overlap valve according to claim 4 wherein the stem portion includes a seal slidingly contacting the inner wall of the cylindrical tube portion to prevent fluid in the overlap valve from exiting through the threaded end shank of the armature/valve member.

6. A normally-on, solenoid-operated, stacked valve as defined in claim 1, wherein the armature/valve member is slidably disposed in the electromagnet and the valve body portion and is displaceable under a magnetic field toward the pole piece in a downward direction when the coil is energized to generate the magnetic field; the magnetic field acts on the armature/valve member and the pole piece to compress the biasing member until the valve ring of the threaded poppet valve/valve member contacts the valve seat surface to define the valve closed position.

7. A normally-on, solenoid-operated, overlap-add valve as claimed in claim 1, wherein the overlap-add valve is a two-way valve.

8. A normally-on solenoid-operated overlap-add valve according to claim 1, wherein the overlap-add valve is a three-way valve providing a threaded poppet/valve member having a snap-in pocket portion and a threaded pocket portion.

9. A normally-on, solenoid-operated, overlap-add valve as set forth in claim 1, wherein the snap-pocket portion includes first and second barbs disposed opposite one another to engage the snap-pocket portion to the valve body portion.

10. A normally-on solenoid-operated overlap valve according to claim 1, further comprising a manifold having an aperture for insertion of the overlap valve and an aperture end face, wherein the valve body portion directly contacts the seat end face of the aperture end face.

11. A normally-on, solenoid-operated, superposition valve according to claim 1, wherein the threaded poppet/valve member comprises first and second ring retainers with said valve ring therebetween.

12. A normally-on, solenoid-operated, superposition valve according to claim 1, wherein in the normally-on position, the valve annulus is spaced from the valve seat surface, thereby defining a seat clearance distance; the seat clearance distance is adjusted by axially displacing the threaded poppet valve/valve member by rotating the threaded poppet valve/valve member relative to the end shank of the armature/valve member.

13. A normally-on electromagnetically-operated overlap valve as claimed in claim 1, wherein the valve body portion is made of a polymer material.

14. A normally-on, solenoid-operated, superimposed valve as claimed in claim 1, wherein the threaded poppet/valve member is made of a polymeric material and the valve ring is made of an elastomeric material.

15. A normally-on, solenoid-operated, overlap-add valve, comprising:

an electromagnet receiving the coil and the pole piece;

a valve body portion made of a polymer material detachably connected to the electromagnet;

an armature/valve member slidably disposed in the overlying valve, having a male threaded end shank;

a threaded poppet/valve member made of a polymeric material having:

an internally threaded portion engaged with the male tang to retain the threaded poppet valve/valve member on the armature/valve member;

a valve ring of elastomeric material disposed on the threaded poppet/valve member; and

a cylindrical tube portion into which the stem portion of the armature/valve member is inserted; and

a biasing member acting on the armature/valve member to normally bias the valve ring out of contact with a valve seat surface formed on the valve body portion to define a normally open valve position of the overlying valve.

16. A normally-on, solenoid-operated, overlap-add valve as set forth in claim 15, wherein the armature/valve member is slidably disposed in the electromagnet and the valve body portion and is displaceable toward the pole piece by a magnetic field generated by energization of the coil.

17. A normally-on, solenoid-operated, overlap-add valve as set forth in claim 16, wherein the armature/valve member comprises a piston slidably disposed in a piston cylinder portion of the valve body portion.

18. A normally-on electromagnetically-operated overlap valve as claimed in claim 17, wherein a valve seal is supported on the piston, the piston slidably contacting a bore wall of the cylinder portion of the piston, the valve seal isolating fluid in the overlap valve from the electromagnet.

19. A normally-on, solenoid-operated, overlap-add valve as set forth in claim 17, wherein the biasing member is located between and in contact with the flanges of the piston and cylinder liner to axially guide the armature/valve member.

20. A normally open solenoid operated overlap valve according to claim 15, wherein the stem portion is located proximate the end shank.

21. A normally-on, solenoid-operated, overlap-add valve as set forth in claim 15, wherein the diameter of the stem portion is sized to slidably fit within the cylindrical tube portion.

22. A normally-on, solenoid-operated, overlap-add valve, comprising:

an electromagnet receiving the coil and the pole piece;

a valve body portion made of a polymer material detachably connected to the electromagnet;

an armature/valve member slidably disposed in the overlying valve, having a male threaded end shank and a stem portion;

a threaded poppet/valve member made of a polymeric material having:

an internally threaded portion engaged with the male threaded end shank to adjustably position the threaded poppet/valve member on the armature/valve member;

a valve ring of elastomeric material disposed on the threaded poppet/valve member; and

a cylindrical tube portion into which the stem portion of the armature/valve member is inserted; and

a seal made of an elastomeric material located in a groove formed in the stem portion forms a fluid barrier between the stem portion and the inner wall of the inner bore of the cylindrical tube portion.

23. A normally-on solenoid operated overlap valve as claimed in claim 22, further comprising a biasing member acting on the armature/valve member to normally bias the valve annulus out of contact with a valve seat surface formed on the valve body portion to define a normally-on position of the overlap valve.

24. A normally-on, solenoid-operated, overlap-add valve as set forth in claim 22, wherein the armature/valve member further comprises a piston integrally connected therewith, the piston being slidably disposed in a piston bore of the valve body portion.

25. A normally-on electromagnetically-operated superposition valve according to claim 22, wherein the axial position of the pole piece is adjusted by using a thread formed on the pole piece to axially move the pole piece relative to the electromagnet; axial movement of the pole piece causes a gap to be formed between the pole piece and the armature/valve member, thereby defining the valve stroke distance.