Patent Application
20060055094
The present invention relates generally to suspension systems, and more particularly to an air spring mount used in a suspension system.
Air spring mounts are commonly used in the suspension systems for Class 8 trucks to mount cabs and trailers to their respective chassis. Conventional air spring mounts include a flexible elastomeric member, typically in the form of a tube or sleeve, that is crimped, swaged or otherwise secured to a support plate such that the elastomeric member and support plate create a pressurizable chamber. The chamber can be filled with pressurized air, or alternatively, air can be selectively expelled from the chamber to adjust the height and stiffness of the mount relative to a desired supported load. This tunability of air spring mounts is particularly advantageous when the loads supported by the mounts vary significantly, such as the different loadings created, for example, by empty and fully loaded trailers of Class 8 trucks.
It is known in the art to provide a snap-in-place attachment on the support plates to facilitate installation of an air spring mount in a desired application. The snap-in-place attachment typically includes resilient fingers with barbs for engaging a hole formed through a corresponding bracket provided on the vehicle. One conventional air spring mount utilizes two fingers disposed on opposite sides of a mounting stud to facilitate installation. While this type of mount is easy to install, the oppositely disposed fingers do not provide resistance to lateral loading of the mount in a direction perpendicular to the aligned fingers. Under such loading, whether dynamic or static, the air spring mount can “pop out” of the installation. Such loading may be due to misalignment of components or to an overturning moment applied to the mounted structure during aggressive maneuvering or crash conditions.
Another conventional air spring mount utilizes four fingers, with pairs of the fingers disposed on opposite sides of the mounting stud. This particular snap-in configuration requires more expensive tooling due to the increased number of fingers needed for the attachment. Moreover, the greater number of fingers on the attachment requires each finger to be smaller for a given size mounting configuration. Another drawback of conventional snap-in-place mounting attachments for air spring mounts is that control of the deflection of the fingers toward the mounting stud is typically unrestricted. The fingers simply bottom out against the stud. This can cause severe loading of the fingers and can lead to fracture or cause the mount to pop out of the mounting bracket. A need therefore exists for an air spring mount having a snap-in-place attachment that overcomes these and other drawbacks of the prior art.
The present invention provides an air spring mount having a snap-in-place attachment that facilitates ready installation while providing increased resistance to inadvertent detachment of the mount from a mounting plate and minimizing manufacturing costs. In one embodiment, an air spring mount according to the present invention includes at least one support plate and an elastomeric member coupled to the support plate to define a pressurizable chamber. A snap-in-place attachment is disposed on the support plate and includes a mounting stud projecting substantially perpendicularly from the support plate. Three resilient fingers project from the support plate, adjacent the mounting stud, and are spaced peripherally around the stud. The fingers have radially outwardly projecting barbs disposed on terminal ends of the fingers for engaging a mounting bracket after the stud and resilient fingers of the attachment have been inserted through a hole formed in the mounting bracket.
In another embodiment, an air spring mount of the present invention includes recesses associated with each finger. The recesses extend axially along the stud such that the fingers can be flexed within the recesses in directions toward the stud. The recesses may be defined by axially extending slots formed in the stud, or by pairs of spaced walls extending radially outwardly from the stud.
The features and objectives of the present invention will become more readily apparent from the following Detailed Description taken in conjunction with the accompanying drawings.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the invention.
Referring now to
With continued reference to
In one embodiment, the support plates 12, 14, including the resilient fingers, are formed from polymeric material such as injection molded plastic, for example. Alternatively, the support plates may be formed as a composite construction wherein the resilient fingers are polymeric but other parts of the support plates 12, 14 are formed from metal. It will be recognized, however, that the support plates may be formed completely from metal or other materials suitable to secure the air spring 10 to the mounting brackets 20, 22.
Once the air spring mount 10 is installed, the deflection of each resilient finger 32a, 32b, 32c; 34a, 34b, 34c due to relative motion between the mounting brackets 20, 22 and the attachment is controlled by respective recesses associated with each finger and extending axially along the studs 16, 18. As shown most clearly in
In another embodiment, the recesses are defined by pairs of spaced walls 52, 54 extending radially outwardly from the mounting stud 18, as depicted in
While the present invention has been illustrated by the description of one or more embodiments thereof, and while the embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of Applicant's general inventive concept.
