The subject matter of the present disclosure broadly relates to the art of gas spring devices and, more particularly, to a gas spring piston that includes one or more partial bellows support areas for supporting a portion of a flexible wall and a gas spring assembly including the same.
The subject matter of the present disclosure finds particular application and use in conjunction with suspension systems of wheeled vehicles, and will be shown and described herein with particular reference thereto. However, it is to be appreciated that the present exemplary embodiments are also amenable to use in other applications and environments. For example, the subject matter of the present disclosure could be used in operative association with structural supports, height adjusting systems and/or actuators associated with industrial machinery, components thereof and/or other such equipment on which lateral load conditions may be encountered. Accordingly, the subject matter of the present disclosure is not intended to be limited to use associated with vehicle suspensions and it is to be understood that the embodiments shown and described herein are merely exemplary.
Gas spring assemblies of various kinds and constructions are well known and commonly used in vehicle suspension systems, industrial machinery as well as other equipment and devices to provide dynamic load support between sprung and unsprung masses associated therewith. A typical gas spring assembly includes two opposing end members with a flexible wall or sleeve secured between the two end members that at least partially define a spring chamber. A quantity of pressurized gas, usually air, is contained within the spring chamber and acts on the spaced end members as well as opposing portions of the flexible wall to support the load of the sprung mass or a force that is otherwise applied to the gas spring assembly.
It is commonly understood that gas spring assemblies are well suited for supporting loads acting axially (i.e., longitudinally between the opposed end members thereof), but that only a minimal lateral load, if any, can be supported by a typical gas spring assembly. Thus, applications that are normally identified as being well suited for the use of gas spring assemblies primarily involve the transfer of axially applied loads. As a result, there is a considerable body of art that is directed to arrangements for securing the gas spring assembly to a corresponding structural member in a way that provides sufficient axial support. Such arrangements commonly include the use of threaded fasteners, fixed mounting studs with threaded nuts and/or snap together-type connections.
It has been recognized, however, that in some applications the action of the gas spring assembly itself can generate lateral load conditions on one or more of the end members thereof. For example, in an application in which one end member is disposed at and/or moved through an angle relative to the other end member, the flexible wall is urged outwardly toward the open end of the included angle between the end members. This action can generate a lateral load acting on one or both of the end members. Unfortunately, many known securement arrangements, having been designed to withstand axially-applied loads, as discussed above, are less well suited for use under lateral or shear loads. Therefore, a need exists for an improved arrangement for engaging an end member of a gas spring assembly with a corresponding structural member such that the interface can withstand the aforementioned lateral load conditions, such as may be encountered by a vehicle suspension system, for example.
Various arrangements have been proposed to overcome the above-described difficulties. One example of such an arrangement is shown in U.S. Pat. No. 5,342,139, which discloses an attachment device for mounting an end member of an air spring assembly on a corresponding support component. Another example of such an arrangement is shown in U.S. Pat. No. 6,752,407, which discloses a multi-component and mounting plate arrangement for securing an air spring along a structural component. Still another example of such an arrangement is shown in U.S. Pat. No. 6,945,548, which discloses a spacer that is adapted to engage the air spring assembly and includes a winged portion that engages a slot in the corresponding structural component. Yet another example of such an arrangement is shown in U.S. Patent Application Publication No. 2006/0055094, which discloses an air spring with end members having snap-in attachments for engaging the corresponding structural members.
While the above-described arrangements have met with some degree of success, numerous difficulties and/or disadvantages have been identified with the same, which have undesirably impacted the widespread adoption and use of the same. Such difficulties and/or disadvantages include the use of additional components, such as extra fasteners, retention pins, mounting brackets and/or other components, which undesirably increase inventory and production costs and can also raise installation and maintenance issues. What's more, certain design configurations, such as snap-in type designs, for example, may be insufficiently robust to withstand both the axial and lateral load conditions, particularly those associated with heavy-duty applications. Furthermore, some known arrangements utilize features that extend radially-outwardly beyond the periphery of at least a portion of the gas spring assembly, which can result in space constraints for other components.
Additionally, attachment and/or other features of suspension components of vehicles are often disposed within approximately the same area in which a gas spring assembly of a suspension system also resides. As such, accommodations are often provided on one or more components of gas spring assemblies to help avoid interference with the attachment and/or other features while permitting the component of the gas spring assembly to be mounted or otherwise secured to a suspension component in that same area.
Such accommodations are commonly used in association with gas spring assemblies of the rolling lobe-type, which typically include a piston that has an outer side wall and flexible sleeve that is secured along the piston such that a lobe formed thereby can roll along the outer side wall as the gas spring assembly undergoes displacement. As one example of such an accommodation, the outer side wall of the piston can be supported or otherwise disposed in vertically spaced relation to the associated structural component along which the piston is secured. This accommodation can be accomplished in any suitable manner. For example, the piston of the gas spring assembly can include a bottom or end wall that the abuttingly engages the associated structural component with the nearest end of the outer side wall being disposed in spaced relation to the bottom wall. As another example, a spacer or other suitable component can be positioned and secured between the piston of the gas spring assembly and the associated structural component to space the end of the outer side wall a distance from the associated structural component.
In any case, such an accommodation often results in a gap or space being formed between the end of the outer side wall of the piston and the associated structural component to which the gas spring assembly is mounted. Under certain circumstances and conditions of operation of the gas spring assembly, the lobe of the flexible sleeve can begin to roll off of the edge of the outer side wall and into the aforementioned gap or space. Such situations are generally undesirable, as the same can result in decreased performance (e.g., a reduction in spring rate) of the gas spring assembly. Additionally, it has been recognized that as the gap or space increases in size, even greater decreases in performance can occur.
Therefore, it is believed desirable to develop a piston and gas spring assembly using the same that overcomes the foregoing and other issues and disadvantages.