This invention relates to vacuum extraction cleaning machines. More particularly, the instant invention relates to carpet cleaning machines which spray a cleaning solution upon an area to be cleaned and simultaneously vacuum extract dirt and used cleaning solution therefrom.
In the prior art a variety of machines and equipment exists for cleaning carpets and the like by vacuum extraction. For example, machines of this nature generally employ a hand tool which is moved back and forth over an area to be cleaned. The apparatus sprays a cleaning solution on the area to be cleaned, while at the same time vacuum extracting dirty solution and dirt. Lines coupled between the cleaning machine and the hand tool deliver vacuum and spraying solution to the tool. Many different varieties of this basic concept are known in the prior art. For example, the concept is illustrated in the following U.S. Pat. Nos.: 3,496,592; 3,711,891; 3,812,552; 3,896,521; 3,909,197; and 3,436,787.
Prior art carpet cleaning machine typically employ a separate pump for mixing water with concentrated chemical cleaner stored within the machine. Use of such pumps increases cost and complexity, while simultaneously reducing reliability. Moreover, typical prior art extraction cleaning machines normally include a storage area or device for temporarily storing recovered dirt-laden chemical solution. Such holding tanks usually include manually actuable drain means for manual draining at periodic intervals. The use of such apparatus necessitates regular routine maintenance checks, which drive up the overall cost of the system resulting in increased cost ultimately born by the consumer.