Vacuum cleaner with noise reduction recesses

2) A vacuum cleaner that has:

• a removable debris collection tank;
• two or more recesses that are on a bottom of the collection tank;
• wall segments on the recesses that inhibit both fore-and-back movement of debris within the collection tank and side-to-side movement of debris within the collection tank;
• and
• one or more raised sections that extend through the recesses, divide the recesses into multiple recess sections, and inhibit both fore-and-aft movement of debris within the recesses and side-to-side movement of debris within the recesses.

12) A vacuum cleaner that has:

• a removable debris collection tank with corners that join generally planar lateral sides of the tank;
• two or more recesses that are on a bottom of the tank;
• wall segments on the recesses that inhibit both fore-and-aft movement of debris within the collection tank and side-to-side movement of debris within the collection tank;
• and
• one or more raised sections that extend through the recesses, divide the recesses into multiple recess sections, and have inner and outer wall segments that, when viewed from above, curve convexly away from central portions of the bottom of the collection tank.