Fasteners are often used to connect a plastic component to another component in various types of assemblies, especially automotive assemblies. However, the fastener must usually be loaded to an extent that would cause the plastic component to quickly deform, fracture or creep over time, thereby reducing the load carried by the fastener. As such, a metal compression limiter (sometimes simply referred to as a bushing or insert) is commonly used in assemblies in which a compressive load is applied to a plastic component. The compression limiter strengthens the plastic component and resists the load applied by the fastener. Therefore, the integrity of the plastic is not compromised and the compression limiter reduces creep of the plastic component.
Typically, a compression limiter has a tubular shape with an outer surface that engages the plastic component. The inner surface of the compression limiter defines a passageway that accommodates the fastener. Most simple compression limiters do not include additional features; as such, the compression limiter may fall out of the plastic component during manufacturing if the compression limiter is inserted by overmolding or press-fitting. To address this problem, some compression limiters include retaining features to provide a more secure connection to the plastic component. For example, some compression limiters include a flanged end that engages a surface of the plastic component outside the hole. Other designs include perforations into which the plastic component flows during an overmolding process.
However, the retention features of the aforementioned designs typically require additional processing steps that significantly increase the overall manufacturing time, and therefore cost, of the compression limiter. For example, some compression limiters are perforated by a punch and then moved to another tooling assembly to be rolled into a cylindrical shape. Considering the limitations of previous designs, a need exists for an improved compression limiter that is easily manufactured.
USPTO Backgrounds
USPTO Backgrounds