Patent Application
20050268425
The invention relates generally to a surface cleaning apparatus. More particularly, the invention relates to a self-contained surface cleaner that effectively scrubs a surface with a pressurized fluid, and reclaims the contaminants loosened from a surface during the cleaning thereof.
A variety of industrial-strength surface cleaners are known in the prior art. In general, a pressurized cleaning fluid is sprayed onto a surface to loosen dirt, rubber, oil, grease, etc., that has been deposited on the surface during the use thereof. The loosened dirt and other contaminants are then vacuumed. Some surface cleaners filter out the dirt and other contaminants in order to reuse the cleaning fluid. Specific examples of prior art surface cleaners are noted below.
U.S. Pat. No. 3,959,010 discloses a surface cleaner having a spray/vacuum head attached to the front of a tractor and having mechanical systems mounted on a towed trailer. The spray/vacuum head has spray nozzles mounted in separate fore and aft compartments thereof. A central compartment positioned between the fore and aft compartments defines a vacuum chamber. Holes are provided in a bottom wall of the vacuum chamber adjacent the surface to be cleaned. Air vortexes are created at the holes as the vacuum is drawn therethrough.
U.S. Pat. No. 4,845,801 discloses a surface cleaning vehicle having a forward-mounted low-pressure sprayer, an aft-mounted high-pressure sprayer head and vacuum head mounted aft of the high-pressure sprayer for vacuuming up liquid and loose debris.
U.S. Pat. No. 5,331,713 discloses a surface cleaning vehicle having a front-mounted sprayer followed immediately by rotating brush heads. A squeegee and vacuuming assembly is mounted at the aft portion of the vehicle to vacuum up cleaning liquid and debris.
U.S. Pat. Nos. 5,287,589, 5,469,597 and 5,979,012 disclose surface cleaners having vehicle-mounted mechanical systems coupled by long hoses to either walk-behind cleaning heads or individual spray and vacuum wands. The walk-behind cleaning heads or wands must be manually moved/manipulated while the vehicle is frequently moved to a suitable support distance.
The Applicant's prior U.S. Pat. No. 6,381,801 discloses a self-propelled surface cleaning vehicle having a high-pressure sprayer to spray cleaning fluid or water to loosen dirt, rubber, oil, grease, paint, surface coatings, rust, etc., which has been deposited or formed on the surface. This cleaner reclaims the fluid and removed contaminants, and recycles the fluid to be used again.
However, each of these prior art surface cleaners are relatively large to accommodate the fluid storage, reclamation and recycling equipment. The need exists for a surface cleaner which is not as large and cumbersome as known cleaners and which is even more effective in reclaiming the contaminants removed from the surface being cleaned.
Accordingly, the present invention may provide a surface cleaner having improved cleaning capabilities with a reduced size for cleaning hard flat industrial surfaces such as ship decks, airport runways, streets, parking surfaces and industrial floors.
The present invention may also provide a surface cleaner that is totally self-contained and mobile.
The present invention may further provide a surface cleaner that can be operated by a single person.
The present invention may be used to remove debris and contaminants from a surface, or to remove rust, paint or other surface coatings.
The present invention may provide a surface cleaner that effectively scrubs a surface without the use of brushes or other types of surface-contacting scrubbing devices.
The present invention may still further provide a self-propelled surface cleaner that is easy to maneuver on a surface to be cleaned.
The present invention may also provide a surface cleaner that traps loosened surface contaminants in order to prevent any toxic exposure to the environment.
Other advantages of the present invention will become more obvious hereinafter in the specification and drawings.
Referring now to the drawings, and more particularly to
Surface cleaner 10 includes a self-propelled vehicle having a frame 12, a drive train coupled to frame 12 that includes a transmission 14 coupled to rear wheels 18 (as shown) and/or front wheels 16. The drive system 15 is outline in the indicated dashed lines in
Combustion-engine motor 24 can be any motor that runs on a combustible fuel such as gasoline, diesel fuel, propane gas, etc. The transmission 14 may be any device which translates power to the driving wheels, such as a conventional mechanical transmission, electric motor, hydraulic motor, gas (air) motor, etc., or combinations thereof.
In one embodiment of the drive train 15, an electric motor 22 can be powered by one or more batteries 28 or by a DC current-producing alternator 30. More specifically, alternator 30 is coupled mechanically to combustion-engine motor 24 and electrically to a switch 32 that is selectively positioned to couple either batteries 28 or alternator 30 to electric motor 22. In this way, even if batteries 28 run low during the cleaning operation, power for electric motor 22 can simply be switched over to alternator 30 which is turned by combustion-engine 24. An AC voltage generator 38 is also mechanically coupled to combustion-engine motor 24 to produce an AC voltage for use by various electrically-powered elements onboard surface cleaner 10 as will be explained further below.
A cleaning head 40 is mounted to surface cleaner 10 by means of, for example, an arm 42 pivotally attached to frame 12 at pivot point 44. Arm 42 can be manually pivoted or pivoted via a motorized force to raise/lower cleaning head 40 and set a forward-to-rear pitch angle of cleaning head 40 relative to surface 100.
Cleaning head 40 is defined by an inverted tray shape having a top or deck 46 and a peripheral side skirt 48 that extends down from deck 46 when cleaning head 40 is positioned over surface 100 as shown. In use, when cleaning head 40 is placed in contact with surface 100, (i.e., a sealing band 70 contacts surface 100), a cleaning volume 50 is defined by the volume of air space bounded by deck 46 on its top, skirt 48 (to include band 70) on its sides and surface 100 at its bottom. Preferably at the forward portion of cleaning head 40, one or more vent ports 54 are provided. Preferably at the rear portion of cleaning head 40, one or more vacuum ports 56 are provided. By way of convention, the terms “forward” and “rear” as used herein are relative to normal forward motion of surface cleaner 10, i.e., front wheels 16 leading back wheels 18.
Ports 54 and 56 are preferably formed in deck 46 and allow outside air to communicate with cleaning volume 50. The area defined by ports 54 should be approximately equal to the area defined by port(s) 56. However, the shape or number of ports 54 or 56 is not a limitation of the present invention. An open-ended prior duct 60 can be attached to deck 46 to effectively extend the height at which each port 54 communicates with the outside air. The function of duct 60 will be explained below.
Alternatively, the skirt 48 may comprise a series of brushes or bristles, and the spaces between the brushes/bristles may function as the vent ports 54.
Referring additionally to
Alternatively, as shown in
As mentioned above, attached to the lower periphery of skirt 48 is a band 70 of flexible material that forms a seal with surface 100. Band 70 is a strong but flexible material that can withstand abrasion forces developed as cleaning head 40 moves over surface 100. A material that performed well in testing of surface cleaner 10 is a multi-layered material having alternating layers of rubber and nylon. This material is available commercially from a variety of rubber manufacturers such as B.F. Goodrich and Goodyear.
Referring now to
Attached to the forward end of cleaning head 40 are a plurality of spaced-apart wheel assemblies, one of which is illustrated in
Coupled to cleaning head 40 are a fluid delivery system and a vacuum system, both of which are mounted on frame 12. Alternatively, the fluid delivery system and/or vacuum system may be mounted on a separate trailer. Referring again to
One advantage of mounting the fluid delivery system 90 and vacuum system 92 on a separate trailer is that the surface cleaner could then also be easily used with conventional water or other cleaning liquid delivery and vacuum systems mounted on another trailer. Thus, either delivery and vacuum system could be used depending on the conditions and choice of the user. The trailer with mounted fluid delivery system and vacuum system 92 may be pulled behind the driven surface cleaner, thus allowing the surface cleaner to be very versatile and mobile.
Fluid delivery system 90 includes a storage tank 902 which can be baffled at 904 to prevent/minimize sloshing forces when surface cleaner 10 is moving. A high-pressure pump 906 is coupled to tank 902 to draw fluid therefrom and pump same under high pressure to spindles 62A/64A. Although not shown for clarity of illustration, pump 906 is typically a mechanically-driven pump that would be coupled to combustion-engine motor 24 as would be well understood in the art.
The pressurized fluid is supplied at 901 to nozzles 66A/66B and 68A/68B via spindle 62A/arm 62 and spindle 64A/arm 64, respectively. Each arm rotates within cleaning volume 50 as fluid is sprayed onto surface 100.
Vacuum system 92 includes a vacuum 920 having its blowing vent side vented at 922 and its suction side coupled to a vacuum tank 924. Vacuum tank 924 is a sealed tank ported at 926 and 928. Ports 926 and 928 should define approximately equal areas. Port 928 has a larger-particle filter 930 coupled thereto. Filter 930 resides in the air space of vacuum tank 924, and will be explained further below. Port 926 is coupled via hose 942 to vacuum port(s) 56.
The present surface cleaner 10 most notably differs from prior surface cleaners by the type of cleaning fluid which is used. While the prior surface cleaners use water or some other cleaner comprising mostly water, the present invention uses a cleaning fluid having a very low boiling point, and which evaporates very quickly when exposed to outside atmospheric conditions. The preferred cleaning fluid of the present invention is nitrogen, although other fluids may be used. Nitrogen is preferred because it is readily available and economical, non-toxic to the environment, and does not pose any fire, explosive, toxic or other hazard to an operator.
The term “fluid” or “cleaning fluid” as used throughout this specification is defined as encompassing any material either in a liquid or gaseous state. These terms are also defined to encompass those materials, such as carbon dioxide, which evaporate directly from a solid state to a gaseous state. Such materials may be stored in a solid state, but in use are in a gaseous state; it is assumed that when stored at least some part of the material is in a gaseous state, or in other words in fluid form.
Preferably, the cleaning fluid is stored in a liquid state, under pressure in tank 902. The cleaning fluid is maintained under pressure until the cleaning fluid is sprayed from nozzles 66A/66B and 68A/68B. As the cleaning fluid exits the nozzles 66A/66B and 68A/68B it is quickly subjected to atmospheric conditions and begins to evaporate. The cleaning fluid contacts the surface 100 in a liquid state at a very cold temperature. For example, liquid nitrogen has a boiling point of −195.8° C. under atmospheric pressure at sea level. Any contaminants on the surface 100 are almost instantaneously frozen (flash frozen). The combination of the very cold temperature and force at which the cleaning fluid strikes the surface causes the contaminants to lift from the surface 100 and break into small particles, which become entrained in the cleaning fluid and incoming air mixture 202.
In operation, surface cleaner 10 has tank 902 filled with cleaning fluid and may be driven to a site to be cleaned. When driving to a site, switch 26 will normally be positioned to couple combustion-engine 24 to transmission 14. Once surface cleaner 10 is in position to begin cleaning, switch 26 is positioned so that electric motor 22 OR hydraulic pump 23 is coupled to transmission 14. Combustion-engine motor 24 continues running to turn alternator 30 and generator 38, as well as provide the mechanical drive for elements such as pump 906. Cleaning head 40 is lowered onto surface 100 with its front-to-rear and side-to-side pitch being set to accommodate surface 100. Systems 90 and 92 are turned on and surface cleaner 10 is driven over surface 100.
The cleaning fluid under pressure is sprayed from nozzles 66A/66B and 68A/68B on rotating arms 62 and 64, respectively, between ports 54 and 56 as described above. The cold, pressurized fluid loosens solid debris and other contaminants from surface 100. A vacuum force created by vacuum system 92 is applied through hose 942 to port(s) 56. The suction force from this vacuum draws outside air into cleaning volume 50 via duct(s) 60. The use of ducts 60 prevent fluid sprayed into cleaning volume 50 from escaping therefrom via port(s) 54. The resulting fluid flow into and through cleaning volume 50 is illustrated at 200. By placing port(s) 54 and 56 at the respective forward and rear portions of cleaning volume 50, a high-pressure fluid flow is drawn over surface 100 in the area where high-pressure cleaning fluid is being sprayed. This large area of high-pressure fluid flow serves to not only pick up the loosened debris/contaminants, but also frees debris/contaminants partially loosened by the high-pressure cleaning fluid spray. Placing ports 54 and 56 in the top of cleaning volume 50 (i.e., in deck 46) has the further advantage of allowing the downward rush of air passing through duct(s) 60 and port(s) 54 to strike surface 100 to aid in loosening contaminants from surface 100. The resulting mixture 202 of fluid, air and loosened debris/contaminants is drawn into hose 942 and delivered to vacuum tank 924.
Mixture 202 is filtered by particle filter(s) 930 where solid particles and liquids are trapped and retained in the tank 924. Preferably, the tank 924 has a horizontally extending screen 923 on which solid particles will collect and liquids may pass through to collect in the lower portion of the tank 924 where the collected liquids may be drained through a drain port 925. The filtered fluid, which is now all in a gaseous state, and air mixture are vented at 922 to the outside atmosphere.
At the drain port 925 there may be provided a valve 935. The valve may be a three-way valve having a first position in which the valve 935 is closed, a second position in which the valve 935 directly discharges the liquid collected in the lower portion of the tank 924, and a third position in which the liquid is directed through a filtering process. In this further liquid filtering process the liquid passes through pump 934 and one or more filters 938. The filtered liquid could then also be passed through an oil separator 940 if necessary. The relative positions of the pump 934 and the valve 935 may also be switched so that the pump 934 is used regardless of whether the liquid is being directly discharged from the tank 924 or filtered.
During the cleaning process, surface cleaner 10 is driven under the power of electric motor 22 or hydraulic motor 33 because of the smoother delivery of power to transmission 14 as compared to combustion-engine motor 24. For optimum cleaning, cleaning head 40 should move at a relatively constant speed over surface 100. This constraint is simplified for an operator by powering transmission 14 via electric motor 22. For greater precision, a consistent speed could be maintained automatically by use of speed control 36. Furthermore, optimum cleaning is obtained by assuring that cleaning head 40 is positioned over each area of surface 100 for a certain period of time. This is achieved by not driving surface cleaner 10 to quickly over surface 100. Once again, while this quality control measure can be left up to the operator, speed limiter 34 can be coupled to transmission 14 during the cleaning operation to assure that the maximum (optimum cleaning) speed for a particular surface is not exceeded. For safety reasons, the use of speed limiter 34 may be preferred to speed control 36.
Liquid nitrogen may be stored and maintained in tank 902 under 80 pounds per square inch (psi) of pressure. The liquid nitrogen is sprayed out of the nozzles 66A/66B and 68A/68B at up to 55,000 psi. Most cleaning operations will require the cleaning fluid be sprayed at between 3,000 and 6,000 psi. Removal of paint and other coatings may require that the cleaning fluid be sprayed at higher pressures.
A typical cleaning operation would require approximately 400 gallons of liquid nitrogen for each hour of operation, for a 72″ path covered by the cleaning head 40. This amount of liquid nitrogen would be enough to clean approximately 20,000 to 25,000 square feet of a surface 100.
In contrast, a similar surface cleaner using pressured water would require approximately 800 gallons of water for each hour of operation which additionally would need to be filtered, stored before and after use, and further reclaimed and recycled. The surface cleaner 10 of the present invention thus may be made much smaller and lighter, and may even be made small enough so that it may be incorporated into a user-propelled package for smaller cleaner operations.
Furthermore, a separate cleaning head 40 and wheel assembly 80 having a smaller cleaning path may be incorporated into a smaller package, easily maneuvered by a user, and operatively connected to the fluid delivery system 90 and vacuum system 92 by hoses. This would allow a user to clean hard to reach places with the smaller surface cleaner package which are not accessible to a larger self-contained surface cleaner package.
Larger, self-propelled surface cleaners 10 may also incorporate a fluid condenser 905 into the fluid delivery system 90 which continuously refills and maintains liquid nitrogen or other fluid in the tank 902.
The advantages of the present invention are numerous. Improved surface cleaning is achieved by a uniquely-designed cleaning head that uses both a high pressure cleaning fluid and a uniquely directed vacuum flow to remove the maximum amount of debris/contaminants from a surface using only a very cold and highly pressurized fluid having a very low point. The surface cleaner is self-contained and may be self-propelled so that it can be efficiently operated by one person. There is no contaminated cleaning water which needs to be reclaimed for reuse. Further, since the spray/vacuum operation is contained within a single cleaning head, there is no toxic runoff generated by the cleaning operation. The surface cleaner can be propelled smoothly by an electric or hydraulic motor for optimum cleaning while simultaneously using a combustion-engine motor to charge batteries and drive various mechanical systems. The overall weight, size and complexity of the surface cleaner is greatly reduced.
Although the invention has been described relative to a specific embodiment thereof, there are numerous variations and modifications that will be readily apparent to those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described.
| Number | Date | Country | |
|---|---|---|---|
| 60563684 | Apr 2004 | US |
