Application apparatus for multiple solution cleaner

[0001] This patent application is a continuation-in-part of U.S. patent application Ser. No. 09/812,503, originally filed on Mar. 20, 2001, and issued as U.S. Pat. No. 6,554,207 on Apr. 29, 2003, which in turn originally claimed priority based upon Provisional Patent application No. 60/190,106, filed on Mar. 20, 2000.

[0002] The current invention relates to an apparatus which combines two or more separate reactive solutions within a base unit, with or without additional heating of the combined solution, for presentation to a cleaning applicator connected to the base unit for remote application to a surface to be cleaned.

[0003] The use of cleaning agents to remove soil, oils, and other stains from textiles in the form of carpet and upholstery is well known. The vast majority of these cleaning agents are composed of soaps and other detergents which are generally referred to as surfactants. A surfactant is defined as a synthetic, water soluble, amphipathic molecule which has a large non-polar hydrocarbon end and a polar end. Typically, a composition of this kind is premixed by adding the components to a common solution tank beforehand, where they are mixed and held until they are applied to the textile surface by an applicator.

[0004] Other compositions derive their cleaning properties from the fact that they are self-carbonating. Their components may be held in separate containers and are mixed to produce carbon dioxide immediately before they are applied to the surface to be cleaned. Some compositions are mixed directly on the surface to be cleaned. Each component may be pre-heated before mixing or the combination may be heated after mixing, in order to increase solution reactivity. One example of such self-carbonating cleaners is found in U.S. Pat. No. 5,244,468, issued on Sep. 14, 1993, to Harris, in which a solution consisting of a carbonate salt, an acid, and urea is prepared in a single pressurized container at a gauge pressure of from about 0.5 to 15 atmospheres. Another example is found in U.S. Pat. No. 5,718,729, issued on Feb. 17, 1998, to Harris, in which a carbonate salt solution and an acid solution are separately heated and both directly applied to a textile surface where they react to form a carbonating solution which effervesces and cleans the textile fibers. Still another example is found in U.S. Pat. No. 5,624,465, issued on Apr. 29, 1997, to Harris, in which separate solutions of a carbonate salt and an acid are heated at ambient pressure and combined to produce a carbonating cleaning solution. U.S. Pat. No. 6,126,697, issued on Oct. 3, 2000, to Ebberts, describes combining two different carbonate salts and an acid under pressure to produce a carbonating cleaning solution.

[0005] Many types of application systems have been developed for preparing these multiple component solutions and then applying the prepared solution to various types of textiles. Such preparation by a base unit may consist of heating the components of the solution (either separately or together after mixing), mixing the components, adding optional agents, and pumping the solution to the applicator under pressure. Application by an applicator may consist of bringing the solution into close proximity to the textile or surface to be cleaned; adding specialty preparations such as scents or disinfectants; spraying the solution onto the fabric or surface as a fine spray or sheet of liquid; removal of excess liquid after it has been in contact with the textile or surface; or scrubbing the textile surface while the solution is on the surface by means of brushes which are activated either manually, by the pressure of the cleaning solution, or by means of motors. Applicators featuring various combinations of these activities have been developed by many different manufacturers.

[0006] Those application systems adapted for application of a single, premixed solution use a system of centrifugal or diaphragm pumps contained in the base unit to deliver the prepared solution to the applicator. Many such systems have a Y connection in the line containing the prepared solution, which allows two technicians to use the same prepared solution and work from the same base unit at the same time; however, several different systems must be employed when each technician requires use of a different prepared solution. Other types of application systems produce a prepared solution by combining multiple cleaning solution components at the job site and applying the result under pressure to the textile surface.

[0007] One system for the preparation and application of a multiple component cleaner is described in U.S. Pat. No. 5,593,091, issued Jan. 14, 1997, to Harris. It describes an application system consisting of a base unit for heating two or more solutions and presenting each heated solution in a separate line under pressure to an applicator, where each line is connected to a common mixing chamber in the proximal end of the applicator. Each container is adapted for holding a heated solution at a desired temperature. One or more pumps are used for the delivery of the solution from each container through separate lines to the applicator. The solutions are mixed in a mixing chamber which features special baffles for thorough agitation and mixing of the components to ensure complete reaction between the components to produce carbonation. The resulting carbonated prepared solution is applied to a textile surface through a manifold in the distal end of the applicator which is immediately proximate to the textile surface.

[0008] Another, much older, mixing and spraying apparatus is found in U.S. Pat. No. 748,971, issued on Jan. 5, 1904, to Millspaugh, which describes a system consisting of a pair of air-tight tanks holding different liquids, an air pump having free connection with both tanks so as to exert equal pressures on the two liquids, outlet hoses from each tank having a junction to a common discharge pipe, and a means for regulating the flow of each liquid by inserting one of a set of disks having different diameter holes into the flow. Proportional mixing of the liquids is accomplished by using disks with dissimilar holes. Hand controlled valves are provided between each system component for cutting off the flow of liquid, with a check valve being provided in common air pump line to prevent backflow into the air pump.

[0009] However, it has been found that these systems and methods for combining multiple component solutions for cleaning textiles, with or without preheating the component solutions, have certain disadvantages. First, it can be necessary to change out containers so that a prepared solution containing different components may be used in the base unit. This is necessary when, for example, a strong cleaning solution for use on commercial carpets must be replaced by a different solution for cleaning fine upholstery fabric that would be susceptible to heat damage, fading, shrinkage or discoloration. Sometimes the application system must be completely drained and purged to ensure no residue of the previous solution remains in the recirculating hoses, injectors, mixing chamber, applicator, etc. Such a drain and purge operation would be necessary when changing, for example, from a detergent to a solvent. This is done for either because a small amount of the detergent residue may damage some upholstery fabrics or because a mixture of detergent and solvent will solidify and thus plug the pumps, hoses, and applicators. This drain and purge process can be time consuming and removes the application system from service.

[0010] Second, those existing systems which generally employ a heating and/or pressurization process for the component containers are cumbersome and complicated. A pump in the base unit is used to pump a liquid solution, either a component to be mixed or a premixed solution, from its container for presentation under pressure to the applicator. Two separate pumps are generally used when two containers are involved where the solutions contained therein must be kept separate until they are mixed. For example, self-carbonating cleaners requiring mixture of a strong acidic solution and a strong carbonate salt solution held in two separate containers must be kept separate and mixed under certain conditions to take advantage of the self-carbonating action which results. However, it is difficult to maintain a consistent, equal pressurization from two separate pumps because of variations in manufacture and wear of the pumps over time. The problem is further compounded when one or both of the component solutions must be heated. Each component solution is heated separately and then pumped to the mixing chamber. In order to heat the separate components, each solution is recirculated through heating elements and held in a non-pressurized container. These pumps work independently and when demand is required at the applicator, each component solution is pumped from the container to the applicator by its respective pump. The carbonating effect and the pH level of the prepared cleaner depend upon the two solutions being equally metered. Getting both pumps to pump solution equally, over time, has proven to be a major handicap and liability to such systems.

[0011] Third, existing systems require the use of special, custom containers containing heaters and connections. The method of heating component solutions is often cumbersome. The containers may contain heating units consisting of a simple element or a series of coils through which the solution passes, the coils being a part of the container itself. Such containers are generally more difficult to obtain since they are specialized and not commonly used, and they are sold at higher prices from single sources because of their uniqueness. Some systems may require recirculating lines to keep each of the solutions at a constant temperature, whereby the recirculating lines extend from the container in the base unit to the applicator where a portion of the solution is expended, with the remainder being circulated back again to the base unit for reheating, thus doubling the hose structure and making the system cumbersome and awkward for the technician to manipulate. Excessive hoses are especially troublesome in a residential setting where they may knock or overturn household objects.

[0012] Fourth, the placement of the mixing means in the applicator, such as is done in U.S. Pat. No. 5,593,091, precludes the base unit from being used with certain types of applicators. A number of third party manufacturers make applicators having only a single input line. In order to use a base unit built for preparation of a multiple component cleaner, a third accessory for mixing the two components would be necessary in order to use an applicator having a single input line. Therefore, a base unit without a mixing means precludes the use of single line applicators, and it would be desirable to provide a base unit which could accept a broad range of applicators in order to adapt the base unit for more uses.

[0013] Therefore, what is needed is a general purpose base unit having the following properties:

[0014] 1. capability of being rapidly drained and purged when changing from one solution to a different solution.

[0015] 2. equal pressurization of all component containers by use of a single, common pressurization source.

[0016] 3. a simple method of heating component solutions which does not require special heating means for containers nor recirculation hoses.

[0017] 4. capability of being used with a wide range of different applicators, each applicator requiring either dual input lines or a single input line.

[0018] 5. independent use of the containers in the system by separate applicators.

[0019] It would further be desirable to construct such an application system from standard, off-the-shelf parts which are inexpensive and easily obtainable.

[0020] It is therefore an object of the present invention to provide a means for mixing two or more separate solutions in separate containers for presentation of the mixture to an applicator to clean a surface.

[0021] It is a further object of this invention to provide an application system whereby the contents of a plurality of containers are combined in equal volumetric amounts in an unheated environment for application to a soiled textile surface.

[0022] It is a further object of this invention to enable two or more workers to utilize the same application system where each worker requires the same prepared cleaning solution resulting from the mixture of two or more separate components.

[0023] It is a further object of this invention to enable two or more workers to utilize the same application system where each worker requires use of a different single, premixed solution contained in a container of the system.

[0024] It is a further object of this invention to provide a method of delivery that will assure equal pressure will be maintained in all lines and applicators, thus ensuring a consistent and safe mixture of chemicals and solutions.

[0025] It is a further object of this invention to provide an application system which provides cleaning product under pressure through use of a single compressor applying equal pressure to all containers in the system.

[0026] It is a further object of this invention to provide a prepared cleaning solution which is heated without use of special containers.

[0027] It is a further object of this invention to provide heated component solutions by means of individual inline heaters for each component solution.

[0028] It is a further object of this invention to provide an application system whereby solution containers can be easily and efficiently changed without undue effort required to clean and purge the application system.

[0029] It is a further object of this invention to provide a compact application system that two or more technicians can use simultaneously on different textiles and at different locations.

[0030] It is a further object of this invention to provide a compact application system that permits two or more technicians to use different solutions in different tanks independently and simultaneously.

[0031] It is a further object of this invention to provide an application system that may be assembled from standard parts for more economical use and maintenance.

[0032] It is a further object of this invention to provide a means whereby self carbonated cleaning compounds, such as the compound described in U.S. Pat. No. 6,126,697, comprised as two separate solutions and stored in different containers, may be mixed upon demand in such a manner that the mixed solution remains in the system, under pressure, preserving the carbonating effect to a high degree, even when the pressure is released in other parts of the system, or the solution tanks are removed and replaced or the compressor is disconnected.

[0033] It is a further object of this invention to provide an adjustable means for varying the composition of the prepared solution by controlling the contribution of the two component solutions to the prepared solution.

[0034] To achieve the foregoing objects, and in accordance with the purpose of the invention as broadly described herein, the present invention provides a cleaning apparatus serving to proportionately combine different solutions into a prepared solution for application to a surface to be cleaned. It may be configured with an integral applicator or else configured for use with a number of single- and dual-line applicators available in the commercial marketplace.

[0035] In accordance with the present invention, an apparatus is provided that may comprise a plurality of standard containers capable of maintaining a liquid solution under pressure and mounted on a mobile base for easy transportation from place to place. The solutions held by the containers may be supplied under pressure to a mixing means, normally comprising a standard tee connector commonly found in most supply houses, for a one-to-one mixture of the solutions. Mixing of two component solutions may be accomplished by supplying each solution under pressure to input ports of the tee with the resulting mixed solution flowing out of an output port. This arrangement provides thorough mixing of the component solutions without use of special baffles or manifolds in the mixing means.

[0036] In accordance with another aspect of the present invention, the mobile base may comprise a dolly upon which the apparatus may be mounted for easy movement from room to room in a house; such an embodiment would allow the apparatus to be self contained for easy portability.

[0037] In accordance with another aspect of the present invention, the mobile base may also comprise a vehicle such as a truck or van, within which portions of the apparatus may be mounted. In such an embodiment, hoses may extend from the applicator back to the vehicle so that only that it is necessary only to move a portion of the apparatus, such as for example the applicator, into the area to be cleaned. Such an embodiment would reduce the necessity of having a large amount of equipment in the area to be cleaned.

[0038] In accordance with another aspect of the present invention, the mobile base may be bifurcated so that portions of the apparatus may be mounted on a dolly and portions of the apparatus may be mounted within a vehicle, the portions connected by means of extended hoses.

[0039] In accordance with another aspect of the present invention, the mixing means may also comprise a valve having multiple input ports and a single output port, where the valve may selectively control the proportion of the solutions to be mixed to produce the prepared solution.

[0040] In accordance with another aspect of the present invention, a flow regulator valve may be used between the outlet valve of a container and the mixing means in order to control the amount of a component liquid provided to the prepared solution from that container.

[0041] The prior objects and advantages of the invention will become evident upon examination of the following detailed description presented in conjunction with the drawings, in which:

[0042] FIG. 1 shows an a schematic diagram of an embodiment of the invention illustrating a representative interconnection of constituents of the application apparatus for preparing and mixing a multiple component cleaning solution;

[0043] FIG. 2 shows the front view of an embodiment of the invention, wherein the mobile base is shown as a dolly; and

[0044] FIG. 3 shows the rear view of an embodiment of the invention, wherein the mobile base is shown as a dolly.

[0045] FIG. 4 shows a vehicle serving as mobile base for the apparatus where mixing of the component solutions occurs at the mobile base, according to an embodiment of the invention.

[0046] FIG. 5 shows a vehicle serving as mobile base for the apparatus where mixing of the component solutions occurs at the applicator, according to an embodiment of the invention.

[0047] The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.

[0048] The present invention defines a method and apparatus for providing a prepared, pressurized solution for cleaning a surface, the prepared solution being dynamically mixed as needed by the apparatus. A pressurization means applies a constant pressure to each container via a common compression line connected to a gas disconnect on each container. Constant equal pressure is maintained throughout all hardware components of the system by use of valves in the form of quick disconnects at all connection points of the system. A blow-by valve for bleeding excess pressure is used with the pressurization means to prevent pressure from exceeding a given value and thus causing damage to the system.

[0049] Because of the pressurization of the system is maintained by pressurized containers or tanks holding the component solutions, the system can be used for limited lengths of time in areas where power for the pressurization means is unavailable. This capability is also useful when the power requirements of the equipment being used in the cleaning process, e.g. vacuums, heaters, rotary brush attachments, compressors, etc., exceed that which is available at the work site. Such a situation is sometimes encountered in residential settings where heaters for large amounts of hot water and the motors of individual tools place too much of a load on residential power capacity. The compressor may be turned on for short periods of time and the invention operated from its residual pressurization when simultaneous use of the invention and other power equipment is required.

[0050] Each container is of a standard design normally found in the beverage industry, having a gas disconnect for pressurization and a liquid disconnect for the output of solution under pressure. Containers are rapidly changed within the base unit by disconnecting the compression line and the liquid line, lifting the container free of the base unit, and then replacing with another container containing the desired solution. The compression and liquid lines are then reconnected and the system is repressurized. The small amount of solution that remains in the feed lines is expelled and work is ready to resume. One-directional check valves are provided on each feed line between the tank and the mixing means to prevent inadvertent backflow of the contents one tank into the other tank.

[0051] When heating of component solutions is required, an optional inline heater is used to heat the pressurized solution as it exits the container and before it reaches the mixing means. Such a mechanism eliminates the need for recirculation hoses and specialty heating containers. The containers can be configured for individual operation by inserting a tee connector with a quick disconnect in each feed line between the container and the mixing means, so that additional applicators can be attached to the individual feed line of each container before their contents are mixed. Such a mode of operation might be useful, for example, when a hot cleaner is to be used, followed by application of cold water to rinse the cleaned surface. The invention would be configured with one container filled with water and the other container filled with cleaner. An inline heater would be configured in the feed line for the container filled with cleaner. A first applicator would be connected to the tee and quick disconnect in the cleaner feed line, a second applicator would be connect to the tee and quick disconnect in the cold water line, and the output from the mixing means would be left vacant. The invention would allow both applicators to be used simultaneously by different operators, or they could be used sequentially by the same operator without attachment and reattachment of applicators. Furthermore, backflow between the two tanks would be prevented by the presence of the check valves. Other similar examples of such flexible use are readily apparent from an examination of the invention.

[0052] FIG. 1 presents a schematic view of the logical layout of an embodiment of the cleaner application system for preparing and mixing a two component cleaner for use in cleaning carpet and upholstery, while FIGS. 2 and 3 give a front and rear view, respectively, of an embodiment of the apparatus without several optional components. With reference to FIG. 1, an embodiment of the cleaning solution application system 10 is shown for mixing a two component cleaning solution. The embodiment 10 is shown as configured for two component solutions contained in tanks 20a, 20b. Each tank 20a, 20b is shown as having a liquid outlet valve 35a, 35b in its top surface, gas inlet valve 45a, 45b, and a pressurized lid 38a, 38b (FIG. 2) for filling the tank.

[0053] The tanks 20a, 20b are of a standard design well known to the industry for maintaining pressurization therein. The preferred embodiment for commercial cleaning operations is a five gallon stainless steel tank as is commonly found in the beverage industry for holding carbonated beverages. Although five gallon tanks are preferred, other capacities may be used without departing from the scope of the invention, such as smaller, three gallon tanks for tasks requiring a more compact configuration. Gas pressures required to mix and expel component liquids may expected to be in the range of from 70 to 200 pounds. Pressurization may be achieved by placing a single charge on each tank or by connecting both tanks to a common tank of pressurized gas, typically air or carbon dioxide; however, pressurization may be preferably provided by an air compressor powered by electricity or gasoline engine, connected to both tanks. One aspect of using standard pressurized containers as used in the beverage industry is that multiple tanks containing the same liquid component may be connected in series to provide more volume for larger jobs while using standard sized tanks; this aspect may have utility if a mobile base supporting the apparatus has sufficient carrying capacity for more than one tank at each of the feed lines.

[0054] Referring again to FIG. 1, compressor 70 provides pressurized air through main line 72 connected to one of the ports on tee 74 for distribution to tanks 20a, 20b. The choice of port is irrelevant for purposes of compressed air distribution; air tee 74 could be replaced by a Y fitting without changing the functionality of the junction. Air feed lines 76a, 76b connect air tee 74 to gas disconnects 40a, 40b, which in turn are removably connected to input valves 45a, 45b on respective tanks 20a, 20b. Gas disconnects 40a, 40b are of standard design with a flare inlet and are commonly used with tanks 20a, 20b in the beverage industry. They are designed to cut off flow of gas, in this case compressed air, when they are disconnected from a valve, so as to maintain pressure within a system. Each component solution contained in tanks 20a, 20b is forced by compressed air entering tanks 20a, 20b to exit its respective tank through liquid outlet valve 35a, 35b. Compressor 70 may be of common design for providing up to 200 pounds of pressure to tanks 20a, 20b, although 70 psi is preferred. Compressor 70 may be provided with a means for regulating pressure (not shown) to prevent damage to the system. Various forms of pressure regulators and blow-by valves can be used for this purpose, but the preferred mechanism is a blow-by valve because of its simplicity and low expense. The compressor 70 may be mounted on a platform 103 (FIG. 2) which may rigidly supported by frame 100. Compressor 70 may be powered by electricity, gasoline, or other suitable means, but it is preferably electrically powered.

[0055] The feed means which conveys component solutions from the tanks to the mixing means may be coupled to liquid output valves 35a, 35b by liquid disconnects 30a, 30b which may be of standard design with a flare inlet and designed to maintain pressure in the system whenever they are not connected. Liquid disconnects 30a, 30b of a type known in the beverage industry as Becker plastic disconnects for general beverage use may be preferably used, although other types of disconnects having similar function may be used without departing from the scope of the invention. Main feed line 52a, 52b leads to a series of feed line components, some of which may be optional depending upon the desired capabilities for the completed application system. The feed line sections connecting the feed line components may be preferably composed of plastic, copper, braided steel, or other suitable tubing material which can withstand pressures in the range of approximately 70 pounds per square inch (PSI) to 200 PSI and temperatures of up to approximately 180 Fahrenheit. Feed line sections may be connected to various components by use of hose barbs or compression fittings, both of which are standard and well known in the art; such hose barbs and compression fittings have been omitted for clarity in FIG. 1.

[0056] Main feed lines 52a, 52b may be connected to filters 54a, 54b which may have a removable screen to allow any foreign debris present in the solutions in tanks 20a, 20b to be removed from the line before encountering later feed line components where the debris might lodge and block liquid passage. There is no other special requirement for filters 54a, 54b other than they be compatible with the other feed line components.

[0057] Inline heaters 56a, 56b of standard design may be inserted into the feed line to heat component solutions before mixing. Such inline heaters may have reservoirs of up to a quart of liquid and may be thermostat controlled to allow selective control of liquid temperature. A thermostat may also prevent the liquid from overheating when the system user ceases use of the system for a period of time. For application systems for use in residential environments, it has been found that the electrical requirements for the application system should not exceed approximately 2000 watts; higher electrical demands will increase the occurrence of tripping circuit breakers and blowing fuses. This requirement places a practical limit of the size of the inline heaters not to exceed 1000 watts each for residential environments, although in industrial or commercial environments the inline heaters may not have such a limitation. For most tasks, the component fluids are heated to temperatures as much as 180, but it has been found in practice that such heated solutions are not always necessary. Such inline heaters are of standard design known to the industry and are commonly provided by such companies as Watlow Electric Manufacturing Company, St. Louis, Mo.

[0058] Tees 57a, 57b may be optionally inserted into the feed line to permit use of tank 20a or tank 20b by a second operator, by attaching the applicator hose to quick disconnects 58a, 58b of standard industry design. Such quick disconnects allow rapid attachment and detachment of the hose and contain a one-way valve to maintain line pressure when no hose is connected.

[0059] Check valves 59a, 59b are located in the feed line immediately before entry into the mixing means and are necessary for the proper operation of the application system. They are standard design one-way valves known to the industry and require approximately one pound of pressure differential to operate the valve. They are generally configured with male-male or male-female threaded ends and with or without a centrally positioned nut to facilitate insertion into other components such as compression tees, although other one-way valve types may be used without departing from the spirit of the invention. The preferred embodiment uses a check valve with male-male threaded ends and with a centrally positioned nut.

[0060] A mixing means 60 may used to mix the cleaning solution components from tanks 20a and 20b, where the mixing means 60 accepts the solution from tank 20a through port 61 and the solution from tank 20b through port 62, and provides a mixture of the two solutions at output port 63. Although any of a number of systems may be used as the mixing means to mix the two component solutions evenly and consistently without departing from the nature of the invention, a single compression tee 60 may be preferred as being the simplest in construction, easily obtainable, and features opposed ports which ensures thorough mixing of the input solutions. A compression tee 64 having quick disconnects 66 and 65 attached to two of its ports is optionally connected to port 63 when it is desired to provide the capability for two operators to use the prepared cleaning solution produced by the application system. A quick disconnect may be used in place of compression tee 64 when a two operator capability is not important. Other devices having a single input with a multiple output, such as a Y connector, may be used in place of compression tee 64 without departing from the scope of the invention, as long as each of the multiple output ports features a quick disconnect or some other type of valve to maintain internal pressure of the system. In practice, the mixing means may be attached to the rear of frame 100 (FIG. 3) for convenience so that it does not obstruct easy and rapid removal of tanks 20a, 20b.

[0061] Use of a mixing means 60 assumes that the application system supports only two tanks. When three or more tanks are required, a special fitting (not shown) could be used, in which each input port may be equally spaced radially about the inner end of the output port. Such a fitting is not readily available and would have to be custom manufactured. Several compression tees and Y fittings could also be sequentially assembled in a serial fashion to provide the necessary input ports. Other fittings such as a cross fitting might also be used. Such an assembly would not provide as optimal a mixing process as the equidistant radial design, but it would be sufficient when precision combination of the component solutions is not critical.

[0062] Use of a compression tee as mixing means 60 ensures that the component solutions are provided in a 1:1 ratio. However, some situations may require the component solutions to be mixed in a different ratio. To accomplish this, a standard mixing valve may be used as mixing means 60. The mixing valve allows two component solution streams to be mixed in any ratio. Such an arrangement would be desirable when, for example, the component solutions consist of an acidic solution and an alkaline solution, both of known pH; by using a mixing valve to control the ratio by which the two solutions are mixed, then the pH of the prepared solution may be selectively determined. The mixing valve would be calibrated for various settings based upon standard component solutions, thus providing a range of prepared solutions from the same component solutions.

[0063] It should also be noted that an inline heater of the type described herein may be interposed at the outlet port 63 or at any point thereafter to heat the prepared solution after mixing its components, instead in the feed lines as described previously, without departing from the scope of the invention. Such a heating arrangement may be incorporated as a portion of the applicator as well. Finally, inline heaters may be simultaneously used both in the feed lines of each component solution and again at any point after the component solutions have been mixed within the mixing means 60 to produce the prepared solution without departing from the scope of the invention.

[0064] During operation by a single operator, an applicator may be connected to a quick disconnect configured to port 63 of mixing means 60, with or without an inline heater. Any standard spray wand, extraction tool, or similar device may be used as an applicator, and such applicators may be found at any of a number of suppliers, e.g. Jon-Don, Inc, Roselle, Ill.; Powr-Flite, Ft. Worth, Tex.; Bridgepoint Cleaning Network, Salt Lake City, Utah; Kleenrite, Inc., Albuquerque, N. Mex.; Tennent Company, Tennent, N.J.; etc. If the apparatus is to be operated with a single premixed cleaning solution, then both tanks 20a, 20b may be filled with the same solution. If the apparatus is to be operated to dispense a cleaning solution having two separate component solutions, then tank 20a may be filled with one component solution and tank 20b may be filled with the other component solution. Compressor 70 may be used to pressurize the system to approximately 70 psi, but no flow of solutions is produced since all pressure within the system is equal. Then the operator triggers the applicator, pressure at port 63 of mixing means 60 is suddenly reduced to ambient pressure, which causes a pressure differential of 70 psi at check valves 59a, 59b. Both valves immediately open, resulting in flow of component solutions under equal pressures into mixing means 60 where the force of flow thoroughly mixes the solutions to produce the prepared solution at port 63. When the operator releases the trigger on the applicator, the pressure at port 63 rapidly builds up to 70 psi and check valves 59a, 59b close so that the component solutions do not mix further.

[0065] As operation proceeds, liquids from both tanks may be mixed in equal proportions at the mixing means until all liquid from one of the tanks is expended. When this event occurs, all flow of component solutions as well as the prepared solution ceases, although the remaining tank may still contain an amount of a component solution. This result can be explained by the fact that when the applicator is triggered to demand prepared solution and one tank, say tank 20a, is empty and tank 20b still contains an amount of component solution, then all compressed air produced by compressor 70 flows unobstructed through tank 20a, check valve 59a, mixing means 60, and port 63, and the applicator, resulting in reduced pressure in lines 76a and 76b. This reduces the pressure within the system to approximately that of ambient air which is insufficient to force the component solution in tank 20b through the system. The result is that all liquid flow ceases when the applicator connected to port 63 demands more prepared solution. Mixing ceases because air pressure is diverted from the remaining tank when the application tool demands prepared solution. When a tank runs dry, it may simply and rapidly be replaced without powering down compressor 70 or depressurizing the system. Operation may then continued until the other tank runs dry.

[0066] The unobvious advantage to this arrangement is that the contents of tanks 20a and 20b do not have to contain equal amounts of liquid to ensure equal mixing of component solutions in the mixing means. System operation ensures that when one component solution is unavailable, then flow of the remaining solution cannot occur. The operator spends less time preparing measured amounts of solution and in changing empty containers. Furthermore, either tank may be removed from the system without reducing system internal pressure, since each tank is connected to the feed means by liquid disconnects 30a, 30b connected to valves 35a,35b, respectively, and to the compressed air source by gas disconnects 40a, 40b connected to valves 45a, 45b, respectively.

[0067] Another nonobvious advantage of the closed, pressurized system employed by the invention is seen in the use of carbonating cleaners, where the two component solutions, when combined, produce carbon dioxide which effervesces when it is applied to a surface to be cleaned. Some prior art requires that the component solutions be heated to increase the reactivity of the component solutions. The pressurized system of the invention has been observed to retain the carbon dioxide in solution until the pressure is released, regardless of the temperature of the component solutions. Thus, although the invention provides for the addition of inline heaters to heat the component solutions when producing a self-carbonating cleaning preparation, the invention may be used without heating and still retain the self-carbonating quality of the preparation.

[0068] For convenience, the invention may incorporate a mobile base for mounting the components of the invention in an organized and convenient manner. One embodiment of a mobile base is illustrated in FIGS. 2 and 3. Tanks 20a, 20b are shown secured to a dolly comprising a frame 100, a set of wheels 120, and a handle 110. Tanks 20a, 20b are secured thereto by means of straps 105 or other suitable means. Straps 105 are configured according to standard methods commonly known in the industry, so that tanks 20a, 20b may be easily removed from frame 100 for refilling or replacement.

[0069] Other embodiments of a mobile base are illustrated in FIGS. 4 and 5. Here, tanks 20a, 20b are shown mounted in the rear portion of a vehicle 200 serving as the mobile base. Referring first to the embodiment shown in FIG. 4, applicator 210 is connected by hose 211 to compression tee 60, illustrating the case where mixing of component solutions is performed within the mobile base. Compressor 70 provides pressurization for tanks 20a, 20b. Referring next to the embodiment shown in FIG. 5, applicator 210 contains an integral compression tee 60 as a part of and within the applicator 210. The compression tee 60 accepts hose 212 and 213, each containing a component solution provided by tank 20a and 20b, respectively.

[0070] While two different embodiments of the mobile base are illustrated, obvious combinations of these other embodiments may be made without departing from the scope of the invention. For example (not illustrated), one of the component solutions might be mounted in a vehicle 200 while the other component solution might be transported in a dolly around the area to be cleaned; the interconnection of hoses, tees, heaters, valves, and other components would be made in an obvious manner according to the earlier detailed description of the invention. Such an arrangement might be desirable to reduce the weight carried by the dolly by keeping one component solution in the vehicle, while the component solution more frequently changed or less caustic might be transported in the dolly.

[0071] While only a preferred embodiment has been illustrated and described, obvious modifications may be made within the scope of this invention and the following claims without substantially changing its functions. Accordingly, the scope of the invention should be determined not by the embodiments illustrated but by the appended claims and their legal equivalents.