Shaped Diaphragm with Retaining Feature

A valve diaphragm for a pneumatic valve includes a diaphragm body having an annular shape defining an inner diameter and an outer diameter. The diaphragm body includes a conical portion extending radially inward from the outer diameter toward the inner diameter and a curved portion extending between the conical portion and the inner diameter.

DETAILED DESCRIPTION OF THE INVENTION

For purposes of the description hereinafter, spatial orientation terms, as used, shall relate to the referenced embodiment as it is oriented in the accompanying drawing figures or otherwise described in the following detailed description. However, it is to be understood that the embodiments described hereinafter may assume many alternative variations and configurations. It is also to be understood that the specific components, devices, and features illustrated in the accompanying drawing figures and described herein are simply exemplary and should not be considered as limiting.

With reference toFIGS. 2-9, a pneumatic valve100that includes a shaped valve diaphragm50is shown in accordance with one embodiment. As shown inFIGS. 2,3, and9, the pneumatic valve100includes a valve body101having an exterior surface102and at least one chamber103defined therein that extends into the valve body101from the exterior surface102such that the at least one chamber103is in fluid communication with an exterior of the valve body101prior to assembly of the pneumatic valve100. The valve body101also includes a retaining groove104defined in the exterior surface102and the pneumatic valve100also includes a top plate105. The retaining groove104and the top plate105are provided for maintaining the engagement between the valve body101and the shaped valve diaphragm50. The top plate105may also be provided to define a control volume120of the pneumatic valve100, as will be discussed in further detail below.

The pneumatic valve100also includes at least one piston assembly110. As shown inFIGS. 3,4, and9, the piston assembly110may include a piston head111and a stem113depending from the piston head111. The piston head111also includes a circumferential retaining channel112defined therein for maintaining the engagement between the piston head111and the valve diaphragm50. The at least one piston assembly110is movably disposed within the at least one chamber103of the valve body101. In particular, as shown inFIGS. 3 and 9, the at least one piston assembly110is installed into the valve body101such that the piston head111is at least partially disposed within the at least one chamber103of the valve body101while the stem113is slidably received in the valve body101in accordance with principles known to those having ordinary skill in the art. The installed position of the piston head111with respect to the valve body101is demonstrated by phantom lines shown inFIG. 9. The pneumatic valve100also includes at least one valve diaphragm50connected to the piston head111of the at least one piston assembly110and to the exterior surface102of the valve body101.

According to another embodiment, the pneumatic valve100includes two corresponding chambers103, piston assemblies110, and valve diaphragms50, though it is to be appreciated that the pneumatic valve100may be provided with fewer or more such assemblies depending on the configuration of the pneumatic valve100and the operational requirements of the valve100. Further, as shown inFIG. 2, the exterior surface102is shown to be the top surface of the valve body101, and the piston assembly110and the valve diaphragm50are oriented upward with respect to the valve body101. However, it is to be appreciated that the valve body101may be configured in a variety of ways such that the piston assembly110and the valve diaphragm50may be oriented sideways or upside down with respect to the valve body101. Further, it is to be appreciated that the pneumatic valve100may be of any type having a configuration of the type described above with a chamber103, piston assembly110, and valve diaphragm50. According to a particular embodiment, the pneumatic valve100is a pneumatic control valve or the pneumatic portion of an electronic relay valve used in connection with a railway car or locomotive.

As shown inFIGS. 5-9, the shaped valve diaphragm50includes a diaphragm body51having an annular shape defining an inner diameter52and an outer diameter53. In particular, the inner diameter52is connected to the piston head111of the piston assembly110, as shown inFIGS. 2-4and9, and the outer diameter53is connected to the exterior surface102of the valve body101, as shown inFIGS. 2,3, and9. According to a particular embodiment, the diaphragm body51is molded from a rubber material. However, it is to be appreciated that the diaphragm body51may be formed of any suitably compliant material that will bend and flex in the manner described herein.

The diaphragm body51includes a conical portion54extending radially inward from the outer diameter53toward the inner diameter52and a curved portion55extending radially between the conical portion54and the inner diameter52. The diaphragm body51may further include a flat portion56that extends radially outward from the inner diameter52to the curved portion55. In an alternative configuration, the flat portion56may be replaced with another curved portion having a reverse curvature to the curved portion55, or the curved portion55may extend all the way to the inner diameter52. The diaphragm body51may also further include a second curved portion57that extends radially between the conical portion54and the outer diameter53such that the outer diameter53extends radially outward from the end of the conical portion54to engage the groove104defined in the external surface102of the valve body101, as shown inFIG. 9.

The diaphragm body51also includes an interior surface58that defines an interior59of the diaphragm body51and an exterior surface60that defines an exterior of the diaphragm body51. As shown inFIG. 8, the curved portion55is curved with a radius R about a center of curvature C defined in the interior59of the diaphragm body51. In other words, the curved portion55is formed with a concave curvature with respect to the interior59of the diaphragm body51. As shown inFIGS. 3 and 9, the diaphragm body51is oriented with respect to the valve body101such that the interior59of the diaphragm body51is in fluid communication with the at least one chamber103. In this manner, the interior surface58of the diaphragm body51is oriented toward an output pressure feedback volume130that is at least partially defined by the interior59of the diaphragm body51and the chamber103of the valve body101. The exterior surface60of the diaphragm body51, meanwhile, is oriented toward a control volume120that is at least partially defined by the exterior of the diaphragm body51and an exterior of the valve body101. In other words, the control volume120is defined over the diaphragm body51and outside of the valve body101, as shown inFIGS. 3 and 9. As shown inFIG. 9in accordance with a particular embodiment of the invention, the control volume120is defined by the exterior surface60of the diaphragm body51and the top plate105, a portion of which is depicted inFIG. 9with cross-hatching and phantom lines, extending over the exterior surface102of the valve body101, as well as the piston assembly110and the valve diaphragm50. It is to be appreciated, therefore, that the top plate105may be a solenoid plate of a pneumatic relay or control valve.

With reference toFIG. 9, the diaphragm body51is formed with an internal resilient bias that causes the diaphragm body51to flex in a consistent manner, particularly a uniform and unvarying manner, that forms a bent portion B extending “up” from the output pressure feedback volume130(or the interior59of the diaphragm body51) toward the control volume120(or the exterior of the diaphragm body51) when the piston assembly110is assembled into the valve body101. When this occurs, the piston head111becomes at least partially disposed within the chamber103such that the inner diameter52of the diaphragm body51comes to be disposed vertically adjacent to the outer diameter53of the diaphragm body51in the sense that the inner diameter52is pressed by the piston head111in a direction toward the level of the outer diameter53, thus causing the diaphragm body51to flex or “roll” in the manner discussed below. This particular configuration of the piston head111and the diaphragm body51at the installed height with respect to the valve body101is shown in phantom lines inFIG. 9juxtaposed with the configuration of the piston head111and the diaphragm body51at the piston assembly free height with respect to the valve body101shown in solid lines. It is to be appreciated that the installed height of the piston head111and the inner diameter52of the diaphragm body51may be varied with respect to the valve body101such that inner diameter52of the diaphragm body51is “vertically” spaced from the outer diameter53to a greater degree than shown inFIG. 9or such that the inner diameter52and the outer diameter53are fully aligned. The terms “vertically adjacent” and “adjacent” as used herein throughout this specification are intended to encompass all such variations in the position of the inner diameter52of the diaphragm body51with respect to the outer diameter53so long as the inner diameter52is pressed in the direction toward the outer diameter53so as to cause the diaphragm body51to flex or “roll” in the manner described below.

As shown inFIG. 9, the diaphragm body51is formed with the internal resilient bias, particularly caused by the shaped configuration of the conical portion54and the curved portion55of the diaphragm body51, which ensures that the diaphragm body51“rolls” or flexes into the proper shape, i.e., forms the bent portion B, when installed in order to create the proper control volume120in relay and control valve operations. In other words, the cross-sectional shape of the diaphragm body51is configured such that the diaphragm body51will consistently, or always, flex or “roll” in the same fashion towards the control volume120when installed so that the control volume120is uniformly defined and can be accurately determined among a plurality of pneumatic valves100without resorting to disassembly of the pneumatic valve100to determine the condition of the valve diaphragm50.

With further reference to FIGS.3and5-9, the diaphragm body51further includes a retaining bead61formed at the inner diameter52. Likewise, the diaphragm body51also includes a retaining bead62formed at the outer diameter53. According to a particular embodiment, the inner retaining bead61and the outer retaining bead62have the same shape or geometric configuration. The retaining bead61at the inner diameter52is disposed within the retaining channel112formed in the piston head111of the piston assembly110in order to maintain the engagement between the inner diameter52of the diaphragm body51and the piston head111.

The retaining bead62at the outer diameter53is disposed within the retaining groove104formed in the exterior surface102of the valve body101. As shown inFIG. 9, the top plate105can be extended toward the exterior surface102of the valve body101to engage and/or attach to the exterior surface102over the groove104and the retaining bead62at the outer diameter53of the diaphragm body51in order to clamp the retaining bead62within the retaining groove104. Accordingly, the retaining bead62at the outer diameter53is disposed within the retaining groove104and clamped by the top plate105in order to maintain the engagement between the outer diameter53of the diaphragm body51and the valve body101.

Accordingly, the inner retaining bead61and the outer retaining bead62provide molded-in retaining features to the diaphragm body51that ensure that both the inner diameter52and the outer diameter53of the diaphragm body51are properly engaged with the piston head111and the valve body101, and ensure proper and uniform clamping as well as to prevent pinching of the diaphragm body51due to the diaphragm body51popping out of the retaining channel112in the piston head111or the retaining groove104in the exterior surface102of the valve body101. To that end, the inner retaining bead61and the outer retaining bead62may include respective semicircular protrusions63,64formed thereon. The semicircular protrusions63,64will tend to be compressed when engaged by the piston head111or the plate105so as to further clamp the inner retaining bead61within the retaining channel112and the outer retaining bead62between the retaining groove104and the plate105.

Further, the outer retaining bead62may be configured with a greater surface area at an outer face65of the retaining bead62and may also be configured to substantially fill the retaining groove104. This geometry coupled with a slight interference dimensioning scheme between the outer retaining bead62and the retaining groove104creates additional friction between the outer face65of the outer retaining bead62and the mating wall of the retaining groove104, and retains the diaphragm body51within the groove104as the piston assembly110is pushed into the chamber103of the valve body101during assembly of the pneumatic valve100and fastening of the top plate105to the valve body101. Further, the outer retaining bead62may be formed with a thickness T (shown inFIG. 8), including the semicircular protrusion64, which conforms to the thickness of retaining grooves104of existing valve bodies101in order to ensure that the outer retaining bead62is properly clamped when the valve diaphragm50is installed on a pneumatic valve100manufactured according to current design standards. In other words, the outer retaining bead62is designed to ensure that the valve diaphragm50is backwards compatible with existing pneumatic valves100. It is to be appreciated that a similar geometry may be provided to the inner retaining bead61of the diaphragm body51as well.

In accordance with yet another particular embodiment, the valve diaphragm50is formed with a molded diaphragm body51of rubber or similar compliant material. The diaphragm body51, including the conical portion54, curved portion55, flat portion56, second curved portion57, inner retaining bead61, and outer retaining bead62, may be molded as a single integral, continuous, and monolithic piece. It is to be appreciated, however, that the valve diaphragm50may be formed according to a variety of techniques and methods. For instance, the various portions of the diaphragm body51may be separately formed and then assembled by fasteners or adhesives or integrated via welding or similar techniques. Or portions of the diaphragm body51may be co-molded of different materials or in different stages according to methods and techniques known to those of ordinary skill in the art.

While embodiments of a shaped valve diaphragm for a pneumatic valve were provided in the foregoing description, those skilled in the art may make modifications and alterations to these embodiments without departing from the scope and spirit of the invention. Accordingly, the foregoing description is intended to be illustrative rather than restrictive. The invention described hereinabove is defined by the appended claims and all changes to the invention that fall within the meaning and the range of equivalency of the claims are to be embraced within their scope.