US Patent 8051531 Cleaning appliance

A cleaning appliance such as a vacuum cleaner includes a main body housing a motor and fan unit for generating a fluid flow. The main body also houses a removable pre-motor filter located upstream of the motor and fan and a removable post-motor filter located downstream of the motor and fan. It is beneficial to permit the user to be able to monitor the condition of both the pre-motor filter and the post-motor filter, and to remove and replace them as required, and so access to both filters may be provided. It is more important that the user checks the pre-motor filter as it gets dirtier than the post-motor filter. Therefore, the post-motor filter is not accessible or removable from the main body until the pre-motor filter is removed from the main body, by removing its housing.