US Patent 7272870 Secondary introduction of fluid into vacuum system

An apparatus and method for minimizing the accumulation of soil and debris within a vacuum system of a surface maintenance machine is disclosed. A secondary fluid, such as pressurized cleaning solution, is sprayed into the vacuum system in order to reduce soil and debris accumulation within the vacuum system without applying additional fluid to a floor surface. In one embodiment of the invention, pressurized fluid is introduced directly into the vacuum extractor tool of a surface cleaning machine in order to dislodge accumulated debris on surfaces therein. A method of minimizing the accumulation of soil and debris within the vacuum system is also disclosed. The invention is applicable to a variety of portable and vehicle-based floor cleaning machines.