The foregoing and other aspects of the present invention will become apparent to those skilled in the art to which the present invention relates upon reading the following description with reference to the accompanying drawings, in which:
Example embodiments that incorporate one or more aspects of the present invention are described and illustrated in the drawings. These illustrated examples are not intended to be a limitation on the present invention. For example, one or more aspects of the present invention can be utilized in other embodiments and even other types of devices. Moreover, certain terminology is used herein for convenience only and is not to be taken as a limitation on the present invention. Still further, in the drawings, the same reference numerals are employed for designating the same elements.
Aspects of various known pilot-operated valve assemblies may be modified to incorporate one or more aspects of the present invention. Moreover, pilot-operated valve assemblies including aspects of the present invention described herein may also incorporate one or more features of known pilot-operated valves. For example the pilot-operated valve disclosed in U.S. Pat. No. 4,450,869 that issued on May 29, 1984 is incorporated by reference in its entirety and can be modified to include one or more aspects of the present invention. Still further, pilot-operated valves including aspects of the present invention described herein may also include one or more features of the pilot-operated valve disclosed in U.S. Pat. No. 4,450,869. In another example, the pilot-operated valve disclosed in U.S. Pat. No. 3,215,163 that issued on Nov. 2, 1965 is incorporated by reference in its entirety and can also be modified to include one or more aspects of the present invention. Still further, pilot-operated valves including aspects of the present invention described herein may also include one or more features of the pilot-operated valve disclosed in U.S. Pat. No. 3,215,163. Furthermore,
By way of illustration,
The slide assembly 112 can include a spool member 131 formed with a seal retaining groove 132 in which a first elastomeric seal 133 is mounted. Such seal 133 can be a high clearance seal which is capable of providing a fluid tight dynamic seal between relatively spaced or high clearance parts. A similar second elastomeric seal 138 can be mounted in the body member 113 against the apertured wall 121 and can be biased by the coil spring 139 toward such position. As shown, the second seal 138 can be fixed against movement with respect to the body member 113 and provides a fluid tight seal between the body member 113 and a cylindrical outer surface 141 of the spool member 131. Various seals and seal profiles may be used for the first and second elastomeric seals. For instance, as shown, the seals can comprise a U-shaped O-ring type seal. In further examples, the seals can comprise a “K-type” seal although other seal types may be used in further examples.
A balanced valving assembly 142 can be located within a crossbore 143 of the spool member 131. The crossbore 143 is configured to receive a floating valve member 144 and a floating reaction member 146 that are urged in opposite directions by a central coil spring 147. As shown in
A central passage 169 extends along the spool member 131 from the right end thereof, as viewed in
A lock pin 172 can also be provided to extend through a side bore 173 into the body member 113 and operates, when extended, to mechanically lock the spool member 131 in one or the other of its operative positions. The lock pin 172 can be retracted by a mechanism (not illustrated) to allow valve operation. The end 174 of the lock pin 172 can be formed with a conical shape and such conical end extends radially inward beyond the periphery of a land 176 of the spool member 131. When the lock pin 172 is in the illustrated position, the spool cannot shift to the right even when operating pressure is supplied to the central port 171. However, when the lock pin 172 is retracted while pressure is supplied to the central port 171, the spool member 131 shifts to the right from the illustrated position to the second operative position. If the lock pin 172 is again extended, the lock pin 172 can retain the spool member 131 in the second operative position until the lock pin 172 is retracted again, even if control pressure is removed from the central port 171.
As shown, the edges of the land 176 can be radiused so that a sharp edge does not engage the conical end 174. The conical end 174 of the lock pin 172 in combination with the radiused land 176 can reduce the force required to retract the lock pin 172 even when the spool member 131 is biased to shift to the left or the right.
It should also be noted that substantial radial clearance can be provided between the various portions of the spool member 131 and adjacent portions of the body member 113. Since there are no significant pressure-induced forces tending to radially displace the spool member 131, the spool can be effectively centered by the two seals 133 and 138. Consequently, rubbing contact between the spool member 131 and the body member 113 can be reduced or eliminated to reduce or eliminate wear between the parts. Example pilot-operated valves 100 can therefore be designed to substantially limit sliding or rubbing contact at the interface between the seal 133 and a cylindrical wall 137 of the end cap 114, the interface between the seal 138 and the cylindrical outer surface 141 of the spool member 131, the interface between the floating valve member 144 and a second surface 274 of a valve plate 270, and the interface between the curved surface 150 and the body member 113.
Although a wide range of materials may be used, the spool member 131 and the end cap 114 can be formed of steel which may be nickel-plated to provide a wear-resistant, good sealing surface for the dynamic seals. The body member 113, on the other hand, can be formed from a die casting of aluminum, aluminum alloy, relatively light-weight, relatively inexpensive, or other material since the body member 113 is not subject to metal-to-metal wear contact. In further examples, substantially all of the parts of the pilot-operated valve 100 can be formed with corrosion-resistant material to minimize any corrosion concerns.
Further, since high clearances are provided between the moving parts in example valves, malfunctions caused by the presence of dust, dirt, or other contamination can be virtually eliminated and the pilot-operated valve can properly function even when substantial amounts of contamination are present. The pilot-operated valve 100 can also include one or more exhaust ports, such as those illustrated and discussed with respect to FIG. 6 in U.S. Pat. No. 4,450,869.
The manifold assembly 200 includes a manifold body 210 including a bottom surface 221. The manifold body 210 can be provided with a plurality of ports for connecting the pilot-operated valve 100 to the associated system. For instance, the manifold body 210 can include at least one supply port to connect to a supply line. As shown in
As further shown in
The illustrated manifold body 210 can also include a first control port 250 and a second control port 260 that can each include a respective threaded portion 251, 261 configured to be coupled with a corresponding control line. In the illustrated example, the control ports 250, 260 can be located on opposite sides 214, 216 of the manifold body 210 although it is contemplated that the control ports may be located at different locations of the manifold body in further examples. Moreover, as illustrated, the first control port 250 and the second control port 260 can each comprise a single port. Providing a single port can simplify installation of the pilot-operated valve 100 in certain applications where only a single control port location for each control port 250, 260 is required.
Although not shown, it is contemplated one or both of the first control port 250 and the second control port 260 can each comprise plurality of control ports. For instance, the first control port 250 can comprise two or more ports in fluid communication with one another and located on opposite sides 214, 216 or other locations of the manifold body 210. In addition or alternatively, the second control port 260 can likewise comprise two or more ports in fluid communication with one another and located on opposite sides 214, 216 or other locations of the manifold body 210. Providing one or both of the control ports 250, 260 as a plurality of control ports can be beneficial in certain applications, for example, to facilitate installation of the pilot-operated valve 100 in a plurality of alternative positions. Moreover, if one or both of the first and second control ports 250, 260 comprise a plurality of control ports, unused ports may be plugged with an end cap or other arrangement.
As illustrated in
As further shown in
In one example, the manifold body 210 may include a plate cavity 280 recessed from the bottom surface 221 and at least partially defined by a cavity surface 282. The manifold assembly 200 can also include a valve plate 270 configured to be positioned within the plate cavity 280. The valve plate 270 can include a first surface 272 facing the cavity surface 282 and a second surface 274 facing away from the first surface 272. In the illustrated example, the first surface 272 of the valve plate 270 and the cavity surface 282 of the plate cavity 280 are both substantially planar although other configurations may be provided in further examples. Moreover, the first surface 272 may be substantially parallel to the first surface 272. As shown in
In another example, the plate cavity 280 can include a depth “D” (see
The valve plate 270 can further include a first aperture 278a extending through the first surface 272 and the second surface 274 of the valve plate 270. Likewise, the valve plate 270 can further include a second aperture 278b extending through the first surface 272 and the second surface 274.
The valve plate 270 can be configured to be keyed within the plate cavity 280 in at least one selected orientation. For example, the plate cavity 280 can include a peripheral surface portion 284 that can have a peripheral shape that is geometrically similar to the peripheral shape of a peripheral surface portion 276 of the valve plate 270. Providing the peripheral surface portions 284, 276 that have geometrically similar shapes can help appropriately align and maintain the position of the valve plate 270 with respect to the manifold body 210. In one example, the at least one selected orientation includes a single orientation wherein the valve plate can only be keyed in the plate cavity in a single orientation. Providing a valve plate that can only be keyed into the valve cavity in a single orientation can force alignment between the first and second apertures 278a, 278b and the respective first and second openings 256, 266.
In the illustrated example, due to the oblong symmetrical geometric shape of the valve plate 270 and corresponding valve plate cavity 280, the at least one selected orientation can include a first orientation and a second orientation, although more than two orientations may be provided in further examples. As shown, in the first orientation, a first aperture 278a of the valve plate 270 is aligned with the first opening 256 of the manifold body 210 and a second aperture 278b if the valve plate 270 is aligned with the second opening 266 of the manifold body 210. In the second orientation, the first aperture 278a of the valve plate 270 is aligned with the second opening 266 of the manifold body 210 and the second aperture 278b of the valve plate 270 is aligned with the first opening 256 of the manifold body 210. Thus, as shown, the valve plate 270 may be installed with either aperture 278a, 278b aligned with either opening 256, 266.
As shown, the first opening 256 and the second opening 266 extend through the cavity surface 282. In one example, at least one seal can be configured to provide a first fluid tight seal between the first aperture 278a and the first opening 256 and configured to provide a second fluid tight seal between the second aperture 278b and the second opening 266. In one example, the fluid tight seal comprises a single seal although two or more seals may be provided in further examples. For instance, as shown, the at least one seal comprises a first seal 258 and a second seal 268. The first opening 256 can be provided with the first seal 258 to provide a first fluid tight seal between the first aperture 278a and the first opening 256. Likewise, the second opening 266 can be provided with the second seal 268 to provide a second fluid tight seal between the second aperture 278b and the second opening 266. Although a wide variety of seals and/or materials may be used, the illustrated example includes seals 258, 268 comprising elastomeric O-ring seals seated within countersunk portions of the respective openings 256, 266 in the cavity surface 282 of the plate cavity 280.
In another example, the manifold supply opening 248 can extend through the bottom surface 221 of the manifold body 210 although the manifold supply opening can extend through the cavity surface 282 in further examples. The manifold supply opening 248 can be provided with a seal 249 to facilitate a fluid tight seal between the manifold supply opening 248 and a supply opening 120 in the body member 113. Although a wide variety of seals and/or materials may be used, the illustrated example includes a seal 249 comprising an elastomeric O-ring seal seated within a countersunk portion of the manifold supply opening 248 in the bottom 220 of the manifold body 210.
The manifold body 210 and the valve plate 270 may be formed in a wide variety of ways and from a wide variety of materials. The valve plate 270 can include a material that is harder than a material of the manifold body 210. The valve plate 270 can also include a material that has a higher wear resistance than a material of the manifold body 210. For instance, the manifold body 210 can be formed from as a casting from aluminum or an aluminum alloy or other material. In further examples, the valve plate 270 can be stainless steel, ceramic, or other suitable corrosion and wear-resistant material. Moreover, the second surface 274 can be polished, such as with a lapping technique, to obtain a smooth surface to maintain a sealing interface between the valve plate 270 and the floating valve member 144 as the floating valve member 144 reciprocates between, and aligns with, the first and second apertures 278a, 278b of the valve plate 270. In further examples, one or both of the apertures 278a, 278b may be provided with a rounded opening portion 279a, 279b to reduce potential wearing of the floating valve member 144 that might otherwise occur from burs or sharp corners associated with the apertures 278a, 278b.
An example method of assembling the manifold assembly 200 and mounting the manifold assembly 200 to the body assembly 110 will now be described. In one example, the manifold body 210 can be turned over as shown in
Once assembled, manifold assembly 200 can then be turned over and mounted to the body assembly 110. Referencing
One example of operating the pilot-operated valve 100 will now be described. Referencing
When operating pressure is supplied to the central port 171 through a pilot valve (not illustrated), the left side of the spool member 131 is pressurized as well as the right side. Since the effective area of the left end of the spool member 131 is greater than the effective area of the right end of the spool member 131, a fluid pressure-induced force is exerted on the spool member 131, tending to shift the spool member 131 to the right, from the position illustrated in
In the illustrated embodiment, the first seal 133 is mounted on the spool member 131 while the second seal 138 is mounted on the body member 113. Such a combination can provide a maximum differential area for valve operation within a relatively small space. In instances in which greater space is available, it may be desirable to provide both of the seals on the body member so that the end cap 114 need not be formed of wear-resistant material.
Example pilot-operated valves can be fabricate with a substantial amount of the valve structure formed of lightweight, corrosion-resistant aluminum, aluminum alloy, or other light-weight and/or inexpensive material, which need not be subjected to sliding wear. Further, a significant number of the valve parts can be formed as castings, eliminating costs associated with substantial and expensive machining techniques. As the spool member 131 can be suspended with substantial clearance by the seals, the spool member 131 can be designed such that it does not rub against the aluminum or other light-weight material parts, thereby eliminating metal-to-metal sliding wear and providing a structure which can function satisfactorily even when substantial amounts of contamination are introduced into the valve. Further, the pilot-operated valve can be provided with large ports and large clearances to permit contaminants to be flushed out of the valve to prevent excessive accumulations thereof.
Furthermore, example pilot-operated valves 100 can comprise a relatively complex manifold body that can be die cast or the like in an inexpensive manner. The valve plate 270 can also be fabricated from stainless steel, ceramic or other material to provide a wear-resistant, corrosion-resistant interface surface for the floating valve member 144. In further examples, providing the manifold with a plate cavity 280 to receive the valve plate 270 together with seals 258, 268 can provide a simple way of mounting the valve plate 270 with respect to the manifold body 210 and the body member 113 while providing reliable sealing between each aperture 278a, 278b of the valve plate 270 and the manifold body 210. In still further examples, the size of the valve plate 270 can be reduced such that it is not interact with the manifold supply opening 248. Reducing the size of the valve plate 270 can reduce the overall costs of producing the manifold assembly 200 since less material is necessary to produce the valve plate 270 and the costs of providing a seal between each aperture 278a, 278b of the valve plate 270 and manifold body 210 can be reduced. Moreover, in further examples, the valve plate 270 can be arranged such that it does not interact with the manifold supply opening 248 to reduce potential leak points.
The invention has been described with reference to the example embodiments described above. Modifications and alterations will occur to others upon a reading and understanding of this specification. Examples embodiments incorporating one or more aspects of the invention are intended to include all such modifications and alterations insofar as they come within the scope of the appended claims.
This application claims the benefit of U.S. Provisional Application No. 60/847,425, filed Sep. 27, 2006, the entire disclosure of which is hereby incorporated herein by reference.
Number | Date | Country | |
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60847425 | Sep 2006 | US |