Brushing – scrubbing – and general cleaning – Machines – With air blast or suction
Reexamination Certificate
2000-11-20
2003-07-15
Till, Terrence R. (Department: 1744)
Brushing, scrubbing, and general cleaning
Machines
With air blast or suction
C015S371000
Reexamination Certificate
active
06591448
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates generally to an extraction machine used for cleaning floor surfaces with a cleaning liquid and then extracting the liquid from the floor, and more particularly to such an extraction machine comprising an improved cleaning liquid recovery tool.
In extraction machines of conventional design as shown in
FIG. 1
, a solution tank contained within the machine housing dispenses a liquid cleaning solution onto the floor surface to be cleaned, such as a carpet. The cleaning solution is typically a premixed solution comprised of water and a liquid or powder cleaning agent. One or more spray nozzles of the extraction machine spray cleaning solution onto the carpet. The scrub brush, rotatably driven by a brush motor, then works the cleaning solution into the carpet to lift dirt from the carpet, temporarily leaving a dirty solution within the carpet.
The machine is self-propelled or moved manually to pass over the dirty solution so that a vacuum tool mounted on the machine moves over the portion of the carpet worked by the scrub brush. The vacuum tool comprises a hollow body with two elongate blades extending from the bottom of the body in spaced, generally parallel relationship, so that each blade forms a rough seal with the carpet (FIG.
2
). The vacuum tool provides a vacuum within a suction chamber, above the surface of the carpet, allowing the extraction of dirt and solution from the carpet. A vacuum pump driven by a vacuum motor creates a vacuum within a recovery tank, which communicates with the tool by means of a recovery line extending between the recovery tank and the tool. Suction created by the vacuum pump extracts the dirty cleaning solution from the carpet, resulting in a cleaned carpet. Dirty solution passes through the tool and recovery line into the recovery tank carried by the machine.
Conventional vacuum tool blades are formed from unitary pieces of hard material such as plastic. One disadvantage of using such a design is that when the blades encounter an uneven portion of the carpet, the blades lift from flatwise engagement with the carpet, creating air gaps and breaking the seal between the blades and the carpet. These air gaps degrade the effectiveness of the vacuum because they allow air to enter the suction chamber without extracting any dirty cleaning solution from the carpet. This increases how much cleaning solution residue remains in the carpet after cleaning, resulting in quicker resoiling of the carpet and longer drying time after cleaning. Another drawback of the conventional tool described above is the potential for damaging the tool should it strike a door threshold or other hard object. Damaging the recovery tool often further degrades the vacuum, exacerbating vacuum losses. Finally, a damaged vacuum blade on a conventional extraction machine requires replacing the entire blade, which is not cost effective when only a portion is damaged.
SUMMARY OF THE INVENTION
Among the several objects and features of an extraction machine of the present invention may be noted the provision of a recovery system that maintains a tight seal with the floor surface being cleaned over uneven portions of the floor surface; the provision of such a recovery system that improves the strength and effectiveness of the vacuum created beneath the tool; the provision of such a recovery system that more effectively removes dirty cleaning solution from a cleaning surface; the provision of such a recovery system that reduces the drying time of the floor surface; the provision of such a recovery system that reduces the likelihood of damage to the system when encountering door thresholds or other objects; the provision of such a recovery system that allows for easy replacement of damaged or worn system parts, including blade holders, blades and related parts; and the provision of an improved blade assembly and replacement blades therefor.
Generally, a recovery system of the present invention comprises a recovery tool movable over a floor surface. The tool has a body including an interior suction chamber in fluid communication with a source of vacuum. At least one elongate blade assembly is secured to the tool body and comprises a blade engageable with the floor surface to provide a seal between the blade and the floor surface. Cleaning solution and dirt are suctioned from the floor surface by the source of vacuum. The blade is substantially rigid to inhibit deformation of the blade during operation of the floor cleaning machine and is movable relative to the tool body such that the blade remains substantially in engagement with the floor surface while moving relative to the tool body to adapt to contours in the floor surface.
In a second embodiment of the present invention, a recovery system comprises a recovery tool comprising a blade generally as set forth above. The blade mounts resiliently on the tool for floating movement relative to the tool body so that the blade remains substantially in engagement with the floor surface while moving relative to the tool body to adapt to floor surface contours.
In a third embodiment of the present invention, a recovery system comprises a recovery tool comprising a blade generally as set forth above. The blade further comprises a plurality of blade segments independently secured to and resiliently mounted on the tool for floating movement of the individual segments with respect to the body and each other, further enabling the segments to conform to uneven floor surfaces.
The present invention is also directed to a blade assembly for use in a floor cleaning machine of the type including a dispensing system configured for dispensing a liquid cleaning solution onto a floor surface to facilitate the removal of dirt from the floor surface and a recovery system configured for recovering cleaning solution and dirt from the floor surface thereby leaving a cleaned floor surface. The blade assembly comprises an elongate blade having an upper portion and a floor engaging lower portion, and a holder for holding the blade for movement of the blade between an extended position and a retracted position. The assembly also includes a spring system mounted on the holder and engageable with the upper portion of the blade for biasing the blade to an extended position. Movement of the blade over an uneven contour of the floor surface moves the blade from the extended position upwardly toward a retracted position against the bias of the spring system to accommodate the uneven contour while maintaining a sealing engagement between the floor surface and the blade.
Another aspect of the present invention is directed to a blade which can be used on a floor cleaning machine of the type described above. The blade has an upper portion adapted to be held by a blade holder of the machine, and a lower portion engageable with the floor surface to be cleaned. The upper portion of the blade has an upward facing surface configured for engagement by a spring system on the blade holder to bias the blade in a downward direction toward the floor surface. The upper portion also has a downward facing surface engageable with the blade holder for limiting the downward movement of blade toward a floor surface.
The present invention is also directed to a cleaning machine comprising a recovery tool generally as set forth above. The cleaning machine is of the type comprising a main housing and at least one spray nozzle mounted on the main housing for spraying a cleaning solution onto a floor surface. The machine comprises a brush housing mounted on the main housing that includes at least one scrub brush for agitating a floor surface.
Other objects and features will become in part apparent and in part pointed out hereinafter.
REFERENCES:
patent: 965315 (1910-07-01), Moorhead
patent: 2516246 (1950-07-01), Norris
patent: 2677144 (1954-05-01), Parry
patent: 2842789 (1958-07-01), Wells
patent: 3107387 (1963-10-01), Katt
patent: 3324499 (1967-06-01), West
patent: 3605171 (1971-09-01), Candor et al.
patent: 3780398 (1973-12-01), Candor
patent: 419092
Eklund William R.
Fulghum Trent A.
Alto US Inc.
Blackwell Sanders Peper Martin LLP
Till Terrence R.
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