Patent Application
20070125975
The present disclosure relates to valve assemblies, and more particularly, to a reinforced valve assembly for use with gaseous fluids.
It is generally well known in the art to have a gas valve assembly that includes a combination of a valve body, a valve member, and a rotatable valve stem to control the flow of a fuel, or other gas, from an inlet source to an outlet. Contemporary gas valve assemblies are increasing in popularity and are being used with various appliances, such as gas ranges, outdoor barbecues, camp stoves, etc. The valve stems are typically made of brass or steel and currently have between a 0.25 and 0.35 inch outside diameter valve stem.
In some gas valve assemblies, the valve stem can have an undesirable wobble movement between the valve stem and the valve body. While it may not be unsafe, wobbling movement of the stem is undesired as it may negatively impact product appearance and a consumer's impression of quality. The present teachings provide a cost effective reinforced gas valve assembly having increased valve stem rigidity.
In various embodiments, the present disclosure provides a gas valve assembly including a main valve body having a first port, a second port, and a fluid passage providing fluid communication between the first and second ports. A valve member is disposed within the main valve body and configured to selectively permit fluid flow between the first and second ports. A valve stem is secured to the main valve body adjacent the valve member and configured for coordinated rotational movement with the valve member. A reinforcement member is coupled to the valve assembly and configured for restricting radial movement of the valve stem.
The present disclosure also provides a method of restricting radial movement of a valve stem of a gas valve assembly. The method includes aligning a valve stem with a valve member disposed in a cavity of a main valve body. The valve stem is secured to the valve body with a retaining cover plate having an upstanding collar and the valve stem is configured for coordinated rotational movement with the valve member. The method further includes extending a fulcrum point of the valve stem using a reinforcement member operable to restrict radial movement of the valve stem.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
Typical gas supply systems include a plurality of gas valves, manifolds, air/fuel mixing tubes, and burner units. Referring to
In various embodiments, the first and second ports 24, 26 may be integral extensions of the main valve body 22. The main valve body 22 is preferably made of a metal material, such as brass, steel, or aluminum, by appropriate casting, forging, or other forming methods. It should be appreciated that the main valve body 22 may be configured differently to accommodate various types of inlet 24 and outlet 26 configurations as well as mounting arrangements. For example, while the figures depict the inlet 24 and outlet 26 ports generally perpendicular to one another, it is contemplated that their spatial relationship may be parallel to one another and may include a wide array of alternate variations.
Various ports, passages, and bores may be formed in the main valve body 22 using casting or drilling operations known to one skilled in the art. The ports may be shaped having flattened regions 32 and provided with apertures 34 as desired. As illustrated, certain ports and other areas may be provided with one or more threaded portions 36 for connection to various manifolds, gas tubing, and other connecting devices. Appropriate recessed areas may also be provided to house gaskets or other sealing members (not shown).
A fully assembled reinforced gas valve assembly 20 will preferably include a detachable control knob (not shown) to rotate the valve stem 28. The main valve body 22 may provide a bore 38, or cavity, for receiving a valve member 30 or other valve components. The valve components may include any of several valve components as known in the art operable to selectively control fluid flow between the first and second ports 24, 26. It is appreciated by one skilled in the art, however, that the use of an annular tapered component may provide numerous advantages as compared to other valve designs. In particular, there is added flexibility in providing a desired control as well as simple manufacture. Additionally, if the valve member 30 wears over time, it will continue to provide an adequate seal between various ports disposed in the bore 38. Thus, in various embodiments, the bore 38 may be configured to retain an annular plug type valve member that provides selective fluid communication between the first and second ports 24, 26. A plug type valve member preferably has a body portion that is generally cylindrical or conical in shape such that the exterior of the body portion matches the interior of the bore 38 in the valve body 22. Typically, the valve member 30 includes at least one radially extending aperture 40, configured for positioning in selective alignment and providing fluid communication to the second port 26.
Once assembled, the valve stem 28 is disposed adjacent to the valve member 30 for coordinated rotational movement with the valve member 30 within the bore 38 of the main valve body 22. As shown in
In various embodiments, a biasing member such as a spring 48 may be provided in the bore 38 of the main valve body 22 to coordinate with the valve stem 28 such that the valve stem 28 must be depressed prior to rotating the valve member 30 out from the off position. A suitable spring seat or stop means, such as a locking clip, may be provided so as to not over compress the spring. The valve stem 28 may be provided with a base section having at least one tab-type locking mechanism. It should be appreciated that the interior of the retaining cover plate 42 may be configured with numerous stops, notches, tangs, or protrusions that may limit rotation of the valve member 30, thereby allowing the valve stem 28 to be locked at different positions, such as low, medium, and high. This particular embodiment allows for multiple operating conditions by simple rotation of a valve stem 28. In this instance, the valve stem would have to be slightly depressed in order to move the valve stem from the various locked positions. For example, once a locking tab is out of a safety notch, the valve stem 28 may be freely rotated from the lowest setting to a fully open position.
In various embodiments, the valve stem has a generally circular cross-section in an area 50 adjacent to the valve body to match and correspond with the shoulder region 46 of the retaining cover plate 42. Once assembled, a portion 52 of the exposed valve stem 28 keeps the generally circular cross-section while the remainder of the valve stem 28 may define a cut-out section 54 extending a remaining length of the valve stem 28. In certain embodiments the valve stem 28 may include a flattened portion (not shown) that partially extends a length of the valve stem 28 and would be disposed at a location between the circular cross-section 52 and the cut-out section 54. In other embodiments, the entire cut-out section 54 may be flattened, and not cut-out to provide increased torque strength while still providing an anti-rotation feature to minimize any misalignment between the valve stem 28 and a control knob or optional ignition switch (not shown).
Due in part to the manufacturing process, the assembled valve stem 28 and collar 46 may have an annular space between them, which may result in radial displacement of the assembled valve stem 28 within the collar 46. This displacement may be measured by what is referred to in the industry as Full Indicator Movement (FIM). FIM is the deviation from perfect form of a part surface (e.g., the valve stem) detected by full displacement of the part on a datum axis, using a dial indicator. FIM is generally defined as the total movement of a dial indicator, or comparable measuring device, applied normal or perpendicular to a surface, and its value describes the displacement of a measured surface from a selected surface as shown on a dial indicator. By reducing an FIM tolerance, one can reduce any wobble, or radial displacement of the valve stem 28 with respect to the collar 46. A part meeting an FIM tolerance means that as the part is radially displaced, a dial indicator can be held against the surface, and the total deviation (which includes both the plus and minus deviation) cannot exceed the given number.
In various embodiments, the teachings of the present disclosure include the use of a reinforcement member, such as a cap bushing 56, which is coupled to the valve and configured for restricting radial movement of the valve stem 28, for example, by extending a fulcrum point 58 of the valve stem 28 away from the valve body 22 and reducing an average FIM tolerance. The cap bushing 56 may be coupled to at least a portion of one or both of the valve stem 28 and the collar 46 of the cover plate 42. In various embodiments, the use of a reinforcement member reduces the average FIM tolerance of from about 0.04 inches down to an average of about 0.01 inches, or less, as measured at a distance of about 1.75 inches from the main valve body inlet using a one pound force parallel to the indicator measurement.
As shown in
In various embodiments, the reinforcement member 56 may be press-fit onto the valve assembly 20. As with most press-fit installations, generally a small amount of metal may be displaced due to the compressive forces applied, thus enabling the components to fit tightly together. In various embodiments, the cover plate 42 is hardened steel and the reinforcement member 56 is made of brass, such that it is preferred that the collar 46 of the cover plate 42 displace a portion of the inside diameter of the reinforcement member 56 to form a generally permanent union. The union should be provided with enough press-fit to couple the reinforcement member 56 with the collar 46, but not too much so as to compress the internal clearance of the collar 46.
In other embodiments, the reinforcement member may be mechanically joined to the valve, for example by welding or crimping, or fastened to the valve with the use of a screw, or otherwise secured. Still other alternate methods for installing the reinforcement bushing 56 with press-fit security may involve the use of metal to metal adhesive.
In various embodiments, an optional control means may also be provided for fine-tune adjustments to a rate of fluid flow for valve assemblies that are equipped with specific flow settings, such as high and low. As is known in the art, one control means includes an adjustment plug (not shown) rotatably disposed in the valve member 30. Preferably, an adjustment feature of the plug is accessible through the aperture 66 of the valve stem 28 by using an instrument such as a thin bladed screw driver. This feature allows for adjustment of the flow through at least one of the first and second ports 24, 26.
The present disclosure also provides a method of restricting radial movement of a valve stem 28 of a gas valve assembly 20. The method includes aligning a valve stem 28 with a valve member 30 disposed in a cavity 38 of a main valve body 22. The valve stem 28 is secured to the valve body 22 with a retaining cover plate 42 having an upstanding collar 46 and the valve stem 28 is configured for coordinated rotational movement with the valve member 30. The method further includes extending a fulcrum point 58 of the valve stem 28 using a reinforcement member 56 operable to restrict radial movement of the valve stem 28 with respect to the valve assembly 20. In various embodiments, extending the fulcrum point 58 of the valve stem 28 may include securing the reinforcement member 56 over the valve stem 28 by press-fitting or mechanically fastening the reinforcement member 56 with an exterior portion 47 of the upstanding collar 46 as previously described. In various embodiments, extending the fulcrum point 58 of the valve stem lowers an average FIM tolerance of the valve stem to about 0.01 inches as measured at a distance of about 1.75 inches from the main valve body inlet using a one pound force parallel to the indicator measurement.
The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the gist of the disclosure are intended to be within the scope of the claims. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.
