US Patent 7891049 Deep cleaner with heat-retaining skirt

An upright extraction cleaning machine for cleaning a surface comprises a base assembly having a housing having at least one side wall and a rear wall extending toward the surface. A source of heated air is enclosed within the base assembly and the heated air is dischargeable through a bottom of the base assembly to the surface. At least one side wall skirt extends from the at least one side wall toward the surface, and a rear wall skirt extends from the rear wall toward the surface. The at least one side wall skirt and the rear wall skirt define an enclosed space beneath the base assembly for retaining heated air discharged from the base assembly against the surface.