US Patent 7845046 Hand-held cordless vacuum cleaner

A hand-held vacuum cleaner with a container for the storage of dirt and debris therein. To provide improved efficiency and performance, the hand-held vacuum may employ a primary HEPA filter, a device for swirling a dirt and debris laden air flow and/or a mechanized filter cleaning device. Swirling may be employed to direct entrained dirt and debris in a desired direction relative to the container to slow the rate with which dirt and debris accumulates on the primary filter and/or to centrifugally remove dirt and debris from the air flow. Mechanized cleaning is employed to shake, scrape or otherwise remove accumulated dirt and debris from the primary filter.