摘要 |
A filter cartridge in a filter-in-filter design with an inner filter and an outer filter. A mechanism, for example crush ribs, connects an upper end plate of the outer filter and an upper end plate of the inner filter to prevent relative axial and radial movement therebetween when assembled. Relative axial or radial motion can create a rattling noise which is sometimes perceived as a low quality filter. The crush ribs are, for example, formed on an interior surface of the upper end plate of the outer filter, and the ribs engage an outer perimeter of the upper end plate of the inner filter. One or more of the ribs crush when the inner filter is installed into the outer filter to ensure tight axial and radial engagement between the filters. |