Abstract:
A microprocessor is used to control various components of a carpet cleaning machine to improve its functionality. In various aspects of the invention, the microprocessor is software controlled, and can provide sequential operating instructions to the operator, enforce start-up and shut down sequences, store an electronic record of operating parameters for future use, provide auto- and remote diagnostics, and provide remote control. In another aspect of the invention the microprocessor can affect the operation of the entire system by dynamically controlling the speed of the motor. In another aspect of the invention, a more effective muffler can be attached to the exhaust of the motor, thereby greatly reducing the noise level. In still other aspects of the invention, the microprocessor can operate an ignition kill switch to the motor, solenoid and/or clutch controls for the fluid and air pumps, an energy cutoff switch for the heater, and software updates via modem.

Description:
This application is a continuation of parent application Ser. No. 08/853,920 filed May 9, 1997, now abandoned, which is a divisional of parent application Ser. No. 08/774,088 dated Dec. 24, 1996, now U.S. Pat. No. 5,987,696. 
    
    
     FIELD OF THE INVENTION 
     The inventive subject matter herein relates generally to machine cleaning which can be adapted to carpets, drapery, blinds, upholstery and the like. 
     BACKGROUND OF THE INVENTION 
     Carpets, draperies, blinds, upholstery and the like are often cleaned using steam/hot water systems. Since these units usually operate on similar principles, but at different pressures and with different solvents, they are all generically and interchangeably referred to herein as carpet cleaners, carpet cleaning machines, systems, equipment, units and so on. In general, steam/hot water systems include the same basic components, namely a wand for dispensing and recovering a cleaning fluid, an optional reservoir for holding reserve fluid, a fluid pump for providing pressurized cleaning fluid at the wand, an air pump (sometimes referred to as a vacuum pump) for sucking up spent fluid, and a spent fluid holding tank. Carpet cleaning equipment contemplated herein ranges from relatively small residential units to large, truck mounted units with long hoses reaching from the truck to the surface to be cleaned. 
     The efficacy of steam/hot water type carpet cleaning equipment is dependent upon many factors, including operator skill and experience, the quality and condition of the machine, the solvents used, the temperature and pressure at which the cleaning fluid is dispensed, and the vacuum with which the cleaning fluid is recovered. Due to the many factors involved, it is not unusual to experience some or all of the following problems. First, an operator may keep his equipment in a poor state of maintenance. For example, the holding tanks may not be emptied regularly, or the equipment may not be serviced regularly. Second, operators tend to push their equipment to the limit, for example by setting the thermostat on the heater at an unsafe level. Third, operators do not necessarily know how to operate the equipment properly. This problem can be addressed to some extent with operator manuals, but such manuals are of little use where the manuals are not available at an operating site, or an operator is unwilling to wade through a manual to find the relevant section. Fourth, operators do not necessarily keep accurate records of operating conditions, so that when an equipment failure occurs it is often almost impossible to pinpoint the cause as being something which is or is not covered by warranty. Fifth, when equipment failures do occur, the equipment may be at a great distance from a suitable repair facility, and individual operators may not have the skills to effectively diagnose the failure. 
     Even where carpet cleaning equipment is maintained in top shape and is operated properly, a particular machine may not have the capacity required for a particular job. Commonly the heater is inadequate to provide sufficiently hot solvent, or the vacuum pump does not draw a sufficient volume of air to adequately remove spent solvent. Of course, it is not difficult to design ever larger carpet cleaning machines having larger heater and air pumps, but this generally makes the equipment even larger and noisier. Many truck mounted units are already so loud that their use in residential and even commercial districts is unacceptable. 
     Thus, there exits a need to improve the operation of carpet cleaning equipment in a manner which can resolve the above mentioned problems, and there is nothing in the art which teaches or suggests how that can be accomplished. UK patent application GB 2,243,992 (the &#39;992 application), for example, discloses a carpet cleaning machine which incorporates a microprocessor, but that microprocessor is not used to improve the operation of the equipment. Instead, the &#39;992 application only uses the microprocessor as a safety switching mechanism, to distance the operator from the high voltage switches connected to the various pumps. Other patents such as U.S. Pat. No. 5,075,921 are directed to a particular component of a carpet cleaning system, but do not address the problems set forth above. 
     SUMMARY OF THE INVENTION 
     Methods and apparatus are provided in which a microprocessor controls various components of a carpet cleaning machine to improve its functionality. 
     In various aspects of the invention, the microprocessor is software controlled, and can provide sequential operating instructions to the operator, enforce start-up and shut down sequences, store an electronic record of operating parameters for future use, provide auto- and remote diagnostics, and provide remote control. In another aspect of the invention the microprocessor can affect the operation of the entire system by dynamically controlling the speed of the motor. In another aspect of the invention, a more effective muffler can be attached to the exhaust of the motor, thereby greatly reducing the noise level. In still other aspects of the invention, the microprocessor can operate an ignition kill switch to the motor, solenoid and/or clutch controls for the fluid and air pumps, an energy cutoff switch for the heater, and software updates via modem. 
     Various objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic of a preferred carpet cleaning machine according to the disclosure herein. 
     FIG. 2 is a schematic showing details of the driving subsystem of FIG.  1 . 
     FIG. 3 is a schematic showing details of the fluid subsystem of FIG.  1 . 
     FIG. 4 is a schematic showing details of the applicator subsystem of FIG.  1 . 
     FIG. 5 is a schematic of a preferred pressure regulator arrangement. 
     FIG. 6 is a perspective view of the controller subsystem of FIG.  1 . 
     FIGS.  7   a - 7   n  is a flow chart of the logic embedded in a preferred software embodiment. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 generally depicts a carpet cleaning machine  1  comprising a power subsystem  100 , an air subsystem  200 , a fluid subsystem  300 , an applicator subsystem  400  and a controller subsystem  500 . 
     Turning to each subsystem in greater detail, FIG. 2 depicts additional details of the driving subsystem  100 , which comprises a motor  110 , a drive train  120  a battery  130 , a charging circuit  140 , a motor muffler  150 , a throttle  160  and an ignition  170 . 
     The motor  110  is preferably an overhead cam Kohler™ gasoline engine, although engines from other manufacturers may function as well, and other types of engines such as propane, diesel or electric would also work. It is contemplated that the motor  110  would range from about 16 hp to about 50 hp, with a preferred rating of about 25 hp. The motor speed is also not critical, as long as the motor  110  can be geared to provide a rotational speed to the air pump of at least about 900 rpm. A preferred speed of the motor is 3600 rpm. 
     The preferred driving subsystem  100  has four sensors, a speed sensor  111 , a throttle position sensor  112 , an oil pressure sensor  113  and a subsystem voltage sensor  114 . The sensors are all standard units and their connections and operation are well within the ordinary skill in the art. 
     The driving subsystem  100  also has two effectors, a throttle controller  162  and an ignition kill switch  172 . The throttle controller  162  is preferably a Dayton 12 volt DC gear motor model 2L004, although many other throttle controllers would also be satisfactory. The ignition kill switch  172  is once again any standard unit, and is connected and operated in an ordinary manner. 
     FIG. 3 generally depicts additional details of the air subsystem  200 , including an air pump  210 , a spent fluid storage tank  220 , a vacuum line  230  connecting the air pump  210  and the spent fluid storage tank  220 , and an incoming line  240  from the applicator subsystem  400 . 
     The preferred air pump  210  is a Roots™ Universal RAI model 47 positive displacement rotary lobed blower designed to operate at 3600 RPM. This matches the nominal operating speed of the motor  110  so that a conversion box can be eliminated. It is not necessary for the air pump to provide a near perfect vacuum, and the preferred pump can achieve approximately 15″ Hg. Of course, other types and makes of pumps may also be suitable. 
     FIG. 3 also includes a main muffler  250  which is connected to air pump  210  via line  260 . The preferred design comprises a large stainless steel metal box  252  measuring about 5″ by about 20″, with offset baffles  254  covered with foam  256 , and having passageways between the baffles of approximately 3″ by 18″. The preferred foam is Technifoam TFX-1.5″ flat Melomyn, although other foams could also be used, including foams with pyramidal or other projections. Fiberglass is to be avoided as a foam replacement because it tends to become wetted, which then greatly diminishes its sound deadening qualities. Line  260  pneumatically coupling the air pump  210  and the muffler  250  is preferably about 3″ in inside diameter. There is also a pipe  151  from the exhaust of the motor muffler  150 , which is about 1″ in inside diameter. The main muffler  250  of this design can handle about 500 ft 3 /min. 
     The air subsystem  200  has a vacuum sensor  232  coupled to the vacuum line  230 , and a fluid level sensor  222  coupled to the spent fluid storage tank  220 . These sensors are all standard units, the operation of which is well within the ordinary skill of the art. 
     The air subsystem  200  also includes a vacuum relief  234 , which can comprise an ordinary spring actuated valve, but which advantageously comprises a solenoid operated valve controlled by the control subsystem  500 . There are numerous advantages to this feature. In particular, spring operated relief valves are inherently inefficient because they open well below their rated relief threshold. For example, in a vacuum line of a typical carpet cleaning machine, it is usually desirable to keep the vacuum at no more than 14″ Hg to prevent damage to the motor, air pump and spent fluid storage tank. A spring operated vacuum relief valve nominally rated at 14″ Hg will be almost 50% open at 7.5″ Hg, thereby wasting a significant amount of energy, and requiring a relatively large motor and air pump. In a preferred embodiment, however, the control subsystem  500  receives signals from the vacuum sensor  232 , and controls the solenoid (not shown) of vacuum relief  234 , which operates a gate valve (not shown) to maintain the vacuum at about 14″ Hg. This allows the motor and air pump to be much smaller than would otherwise be required, and/or permits additional wands to be used simultaneously with a given size motor and air pump. 
     FIG. 4 generally depicts additional details of the fluid subsystem  300 , which comprises a fluid pump  310 , a clean fluid reservoir  320 , a line  330  connecting the fluid pump  310  and clean fluid reservoir  320 , a heater  340  with energy source  350  connected via line  352 , a line  360  connecting the fluid pump  310  and the heater  340 , and an outgoing line  370  to the applicator subsystem  400 . 
     The preferred fluid pump  310  is a positive displacement Hypro™ model 2345B, which is rated at 4.8 gallons per minute and up to 1500 psi. Of course, other fluid pumps may also be satisfactory provided they can provide pressures within the 500 to 3000 psi, including the Cat™ or Giant™ pumps commonly used in the industry. 
     The fluid subsystem  300  has a low side fluid pressure sensor  332 , a high side fluid pressure sensor  372 , and a heater temperature sensor  342 . The fluid subsystem  300  also has a high side pressure controller  380  (see FIG.  5 ), an electronic clutch  312 , and a heater shut off solenoid  342 . Except for the high side pressure controller  380 , these are all standard units. 
     FIG. 5 shows a preferred high side pressure controller  380  in which a solenoid  362  controlled valve  364  selects between two different pressures. In this arrangement, both first and second pressure relief valves  366 ,  368  couple the high side pressure line  360  with the low side pressure line  330  via shunt  363 . Assuming that the set point of pressure relief valve  364  is higher than the set point of pressure relief valve  366 , then the pressure fed to the applicator subsystem  400  will match the set point of relief valve  366  when valve  364  is closed, and will match the set point of relief valve  368  when valve  364  is open. The preferred pressure regulator is a Suttner™ model ST230. The dual set point high side pressure controller  380  is advantageous because it allows convenient electronic switching between two different pressures suited for different applications. A preferred pressure for cleaning upholstery, for example, may be about 20 to about 200 psi, while preferred pressures for cleaning carpet range from about 50 to about 700 psi. 
     The applicator subsystem  400  (not shown in detail) can be one of many different designs. Typically the applicator subsystem includes a wand with hand trigger control(s) at one end and an adapter at the other end. The adapter typically includes spray jets, suction ports, and a hood. Optional features include articulations or pivots, wheels and the like. It is contemplated that the applicator subsystem  400  may include a plurality of application specific wands, with different wands being especially suited to different carpets, draperies, blinds, upholstery, or other applications. 
     FIG. 6 generally depicts additional details of the controller subsystem  500 , which comprises a base  510  connecting a CPU module  520  with a plurality of slots containing plug-in modules  530 A,  530 B etc. Connectors  540  on the various models  530  are wired to the various sensors and effectors described above through wires (not shown in FIG. 6) and through appropriate analog/digital and counter interfaces (not shown). Of course, the specific type of base  510  and modules  520 ,  530 , the specific location of the modules  520 ,  530  within the base  510 , and the specific wiring of the connectors can occur in many different permutations, all of which are well within the skill in the art when taken in conjunction with the teachings herein. 
     A preferred subsystem was built using a 6 slot base W/12/24/VDC by Koyo™ as the base and power supply. The preferred system contains a CPU module  520  which has a microprocessor (not shown), 2 serial ports  522 , a CPU battery (not shown), RAM and ROM memory (not shown) into which is loaded the software (not shown) for operating the subsystem. The preferred system plug-in modules  530  are a 12-24 VDC input module, a 5-30 VDC isolated relay out, a 4-20 mA analog input module, a 5 K Hz counter input module, and a filler module, all of which are also available from Koyo™. 
     FIG. 6 also depicts a user interface  550  which includes an LCD display  552  and a plurality of data entry keys  554 . The preferred display  552  is a 2×40 4 line display by Optimizer™. The user interface  550  is coupled to at least one of the serial ports  522  via cable  524 . 
     FIGS.  7   a - 7   n  depicts the logic of the preferred software. As with the hardware, the actual implementation of the software can take innumerable different forms within the inventive concepts taught herein. The software flow sheet of FIG. 7 is self explanatory. 
     A description of FIGS.  7   a - 7   n  follows: 
     FIG.  7   a : The system software provides a visual display of all the status lights, after which the “WANG LABS” or “TSUNAMI” is displayed. The software checks the time out levels to see if the service timer has reached 100 hours. If the service timer has not reached 100, then the machine will start. “Do you need information?” will then be displayed to ask the customer if he/she wants to see the information library. 
     FIG.  7   b : The software checks the waste tank levels. Then the water pressure level is checked. Then the system checks the engine R.P.M., then the oil pressure and pump pressure is checked, and if these levels are acceptable, the system displays a message to light the pilot light and set the heater. 
     FIG.  7   c : The system checks the heater temperature and if there is a problem, the system displays a warning and shuts down the system. If the temperature level is acceptable, then the system enables the temperature, waste tank, power and pressure logic. 
     FIG.  7   d : This figure represents “shut down” logic. The machine idles down and turns off everything, and displays a reminder to empty the tank and turn off the propane supply. 
     FIG.  7   e : This figure represents the shut down logic if service is not provided. The system displays “service machine” type messages. 
     FIG.  7   f : This figure represents the shut down logic if the oil pressure is not acceptable. An appropriate message is displayed. 
     FIG.  7   g : This figure represents the shut down logic if the waste tank is full. An appropriate message is displayed. 
     FIG.  7   h : This figure represents the shut down logic if there is no water pressure. An appropriate message is displayed. 
     FIG.  7   i : This figure represents the shut down logic if the pump is over the set pressure. An appropriate message is displayed. 
     FIG.  7   j : This figure represents the shut down logic if the heater is too hot. An appropriate message is displayed. 
     FIG.  7   k : The systems checks the heater and if it is too hot, a message is displayed to turn off the burner. 
     FIG.  7   l : This figure represents the S.O.V.C. logic i.e. vacuum/airlift control. 
     FIG.  7   m : This figure represents the power level settings and the logic to control the engine R.P.M. 
     FIG.  7   n : This figure represents the setting of the pressure levels and controls the pump clutch. 
     FIGS.  7   a - 7   n , Abbreviations: 
     TON=Turn On 
     TOFF=Turn Off 
     T.D.=Time Delay 
     T.O.=Time Out 
     HR=Hour 
     MT=Empty 
     SW=Switch 
     PRES=Pressure 
     SOV=Solenoid Operated Valve 
     OVERPRES=Over Pressure 
     TK=Tank 
     S.P.=Set Point 
     HG=Inches of Mercury 
     VAC=Vacuum 
     Thus, various aspects of improved carpet cleaning machines have been disclosed. While specific embodiments and applications have been shown and described, it would be apparent to those skilled in the art that many more modifications are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the appended claims.