The present invention is generally directed to surface cleaners having a liquid dispensing system and, more particularly, to a method and apparatus for purging air from a fluid flow path of the liquid dispensing system.
Surface cleaners are widely used to clean floors of industrial and commercial buildings. They range in size from a small model that is controlled by an operator walking behind the machine, which may clean a path ranging from 15 inches to 36 inches wide, to a large model that is controlled by an operator riding on the machine, which may clean a path as wide as 5 feet. These surface cleaners include motorized drive wheels, rotatable scrubber brushes, a cleaning liquid dispensing system and a recovery tank to hold soiled cleaning solution that is recovered from the surface being scrubbed.
The liquid dispensing system generally operates to dispense a cleaning liquid to the surface and/or the scrubber brushes. The liquid dispensing system can utilize a tank of cleaning liquid or solution. Alternatively, the liquid dispensing system can be configured to mix separate cleaning agent and water supplies to form the cleaning liquid prior to dispensing the cleaning liquid.
The liquid dispensing system also includes a pump that is configured to drive the liquid through at least one flow restriction member. In general, the flow restriction member produces a pressure drop in the flow of liquid driven by the pump. Thus, the flow of liquid at an inlet of the flow restriction member has a higher pressure than at an outlet of the flow restriction member. Exemplary flow restriction members include metering devices that control a flow rate of the liquid being pumped, a check valve that restricts the direction the liquid travels, and a nozzle through which the liquid is dispensed to the surface and/or the scrubber brushes.
In order for the pump of the liquid dispensing system to effectively drive the flow of liquid through the dispensing system, it must be filled with the liquid. When pumping liquid through a flow restriction member, air can get into the fluid flow path of the liquid and into the pump. When the pump is filled with air, or a low volume of liquid, it pumps very poorly.
The act of removing air from the fluid flow path and the pump is known as “priming” the pump. Methods of priming pumps of liquid dispensing systems are known. These generally include a rerouting of the fluid flow path of the liquid such that it bypasses the flow restriction member and “releases” the flow of liquid and the air such that the air can be moved in the fluid flow path downstream of the pump. Unfortunately, such methods of priming the pump of liquid dispensing systems of surface cleaners require the manual opening and closing of valves to modify the fluid flow path such that it bypasses the flow restriction member, which is time consuming. Additionally, such pump priming practices can produce large amounts of liquid waste.
There is a continuous demand for improvements to surface cleaners including improvements to the process by which the pump of the liquid dispensing system is primed and other improvements.
The present invention is generally directed to purging air from a liquid dispensing system of a surface cleaner. One embodiment of the invention is directed to a surface cleaner having a liquid dispensing system that includes a fluid flow path configured to receive a flow of liquid, a pump, an air purging component, and a valve actuator. The pump is in line with the fluid flow path and is configured to drive the flow of liquid through the fluid flow path. The air purging component includes an inlet in line with the fluid flow path, an outlet, an airflow path connecting the inlet and the outlet, and a valve in line with the airflow path. The valve includes an open position in which the airflow path is open between the inlet and the outlet and a closed position in which the airflow path is closed between the inlet and the outlet. The valve actuator is connected to the valve and is configured to bias the valve in the open position when air is detected in the fluid flow path.
Another aspect of the present invention includes a method of purging air from a liquid dispensing system of a surface cleaner. In the method, a pump, configured to drive a flow of liquid through a fluid flow path of the liquid dispensing system, is driven. The presence of air or liquid in the fluid flow path is detected. When air is detected in the fluid flow path, an airflow path connected the fluid flow path is opened to discharge the air from the fluid flow path. When liquid is detected in the fluid flow path, the airflow path is closed.
Other features and benefits that characterize embodiments of the present invention will be apparent upon reading the following detailed description and review of the associated drawings.
One embodiment of the present invention is directed to a liquid or cleaning liquid dispensing system, generally designated as 100, of a surface cleaner, such as hard floor surface cleaner or a carpet cleaner. To simplify the discussion of the invention, embodiments will be discussed with reference to a hard floor surface cleaner 110, shown in
Surface cleaner 110 is illustrated as a walk-behind cleaner used to clean hard floor surfaces 111, such as concrete, tile, vinyl, terrazzo, etc., over which cleaner 110 travels. Alternatively, cleaner 110 can be a ride-on or towed-behind cleaner performing a scrubbing operation as described herein. Cleaner 110 may include electrical motors powered through an on-board power source, such as batteries, or through an electrical cord. Alternatively, an internal combustion engine system could be used either alone, or in combination with, the electric motors.
Cleaner 110 generally includes a recovery tank 112, a lid 114, a tank 118, and a scrub head 120. Lid 114 is attached along one side of the recovery tank 112 by hinges (not shown) so that lid 114 can be pivoted up to provide access to the interior of tank 112. In accordance with one embodiment of the invention, tank 118 contains a cleaning liquid or solution that is dispensed to the surface 111 and/or brushes of the scrub head 120 by the dispensing system 100. In accordance with another embodiment of the invention, the tank 118 includes a primary cleaning liquid component, preferably water, that is combined with a cleaning agent by the dispensing system 100 to form a cleaning liquid that can be applied to the hard floor surface 111 or the brushes of the scrub head 120.
Scrub head 120 includes a scrubbing member 122, shrouds 124, and a scrubbing member drive 126. Scrubbing member 122 may be one or more brushes, such as bristle brushes, pad scrubbers, or other hard floor surface scrubbing elements. Drive 126 includes one or more electric motors to rotate the scrubbing member 122. Drive 126 may also oscillate scrubbing member 122. Scrub head 120 is attached to cleaner 110 such that scrub head 120 can be moved between a lowered cleaning position and a raised traveling position. Other embodiments of cleaner 110 will be discussed below that utilize alternative scrub heads 120 and that eliminate the scrub head 120 completely.
A machine frame or mobile body 127 supports recovery tank 112 on wheels 128 and castors 129. Details of the frame are shown and described in U.S. Pat. No. 5,611,105, the disclosure of which is incorporated herein by reference. Wheels 128 are preferably driven by a motor and transaxle assembly shown schematically at 130.
One embodiment of the cleaner 110 includes a linkage 131 mounted to a rear of the frame 127 and a fluid recovery device 132 attached to the linkage 131. In the embodiment of
Cleaner 110 can include a battery compartment 150 in which batteries 152 reside. Batteries 152 provide power to drive motors 126, vacuum fan 154 of vacuum 135, and other electrical components of cleaner 110. Vacuum fan 154 is mounted under lid 114. A control unit 156 mounted on the rear of the body of cleaner 110 includes steering control handles 158 and operating controls and gages for cleaner 110. Additional aspects of automatic surface cleaners are disclosed in U.S. Pat. Nos. 5,483,718, 5,515,568, and 5,566,422, 6,585,827, 6,662,600, 6,671,925, 6,705,332 and 6,735,811 each of which are incorporated herein by reference in their entirety.
One embodiment of the cleaning liquid dispensing system 100 dispenses a wet foamed cleaning liquid for use by the surface cleaner 110 during surface cleaning operations. In general, dispensing system 100 dispenses the cleaning liquid (formed either directly from tank 118 or through the combination of a cleaning agent with water), which is then aerated to produce a foamed cleaning liquid for use by cleaner 110 to clean a hard floor surface. As will be discussed below, the foamed cleaning liquid is generally a very wet foam that allows for the complete wetting of the surface. Additionally, the foamed cleaning liquid utilizes very little cleaning agent thereby reducing the amount of residue remaining on the hard floor surface, reducing chemical waste, and extending the life of the cleaning agent supply.
Cleaning agent container 200 is configured to contain supply of cleaning agent 201. The cleaning agent 201 may include one or more surfactants, builders, solvents, or other components. In accordance with one embodiment of the invention, cleaning agent 201 includes an anionic surfactant, a non-anionic surfactant, a cationic surfactant, or a combination thereof. A particularly preferred surfactant is DeTeric CP-Na-38 manufactured by DeForest Enterprises, Inc. of Boca Raton, Fla. Cleaning agent is preferably in a concentrated form (e.g., more than 30% solids). In accordance with one embodiment of the invention, the cleaning agent container 200 is a collapsible container that collapses as the cleaning agent contained therein is removed. The collapsible container is preferably sealed except at the output port of the container through which the cleaning agent is dispensed. This avoids a need to ventilate the container, which could give rise to leaks and cause the cleaning agent to dry out. In accordance with one embodiment of the invention, container 200 is a collapsible bag that can be contained in a cleaning agent cartridge 208 (
Cleaning agent supply line 202 is coupled to the cleaning agent container 200. Cleaning agent supply line 202 generally corresponds to the fluid flow path formed by tubing 210 (
First input 212 of flow control device 204 is configured to receive a flow of cleaning agent 214 from supply 200 through supply line 202 and other components of system 100. Flow control device 204 is also configured to receive a flow of primary cleaning liquid component 216 at a second input 218. Flow control device 204 is further configured to combine the flows of cleaning agent 214 and primary cleaning liquid component 216 and produce an output flow of cleaning liquid 220 at an output 222.
The primary cleaning liquid component 216 is preferably water and is contained in tank 118 of cleaner 110 or provided from another source. The flow of primary cleaning liquid component 216 is preferably driven through a fluid flow path defined by conduit 226 by a pump 228 at a flow rate that is desired for the cleaning operation. In accordance with one embodiment of the invention, the flow of primary cleaning liquid component 216 is driven at a substantially constant flow rate of approximately 0.5 gallons per minute or less. However, the flow rate can be modified depending on the application for system 100.
Pump 228 is generally positioned in line with fluid flow path or conduit 226 and includes an outlet 230 that is maintained at a desired high pressure. In accordance with one embodiment of the invention, the pressure at outlet 230 is held substantially constant at approximately 60 pounds per square inch (psi).
Flow control device 204 preferably combines the flow of cleaning agent 214 with the flow of primary cleaning liquid component 216 at a ratio of 1 part cleaning agent to 1000 parts primary cleaning liquid component. Accordingly, the resultant cleaning liquid 220 is formed of 0.1% cleaning agent, which is substantially less than conventional hard floor surface cleaning liquids. As a result, the present invention leaves very little cleaning agent residue following application to a hard surface, produces very little chemical waste, and increases the life of the supply of cleaning agent contained in container 200.
Flow control device 204 injects the flow of cleaning agent 214 into the flow of primary cleaning liquid component 216 using an injector 236 at a rate that is generally less than approximately 10.0 cubic centimeters per minute. In accordance with a preferred embodiment of the invention, the flow of cleaning agent 214 is preferably limited to less than approximately 2.0 cubic centimeters per minute to provide the desired 0.1% concentration level of cleaning agent in the cleaning liquid 220 relative to the flow of primary cleaning liquid 216. For example, a flow rate of approximately 1.2 cubic centimeters per minute is desired when the flow rate of the primary cleaning liquid component is approximately 0.33 gallons per minute, and a flow rate of approximately 0.5 cubic centimeters per minute is desired when the flow rate of the primary cleaning liquid component is approximately 0.13 gallons per minute. Injector 236 preferably operates to siphon the cleaning agent flow 214 from the supply 201 using a venturi member 238. In operation, the flow of primary cleaning liquid 216 through venturi member 238 creates a vacuum of approximately 370 inches of water (134.6 psi), that draws the flow of cleaning agent 214 into the flow of primary cleaning liquid component 216 at the desired rate. One such suitable flow control device 204 is the 50580 siphon produced by Spraying Systems Company of Wheaton, Ill.
The vacuum produced by flow control device 204 allows the cleaning agent supply 201 contained in collapsible bag 200 of cleaning agent cartridge 208 to be completely drained regardless of its position. That is, cleaning agent cartridge 208 can be positioned below flow control device 204 without affecting the draw of the cleaning agent 201 through supply line 202. However, it is preferred that the diameter and length of conduit 210 forming supply line 202 be selected to prevent substantial resistance to the flow of cleaning agent 214 there through.
In accordance with one embodiment of the invention, the rate of the flow of cleaning agent 214 through injector 236 is adjustable using a valve 242, such as a needle seat valve, for example. Valve 242 is preferably configured to provide accurate adjustment to the slow output flow of cleaning agent 214. Valve 242 preferably includes a sharp flow-regulating needle having for example, a two degree needle tip for improved sensitivity.
Although the valve 242 can be used to adjust the flow rate of the of cleaning agent flow 214, problems can arise as a result of the viscosity of the cleaning agent 201, the size of the orifice of the needle seat valve 242, and the vacuum generated by injector 236. In particular, it has been discovered that the most consistent cleaning agent flow rates are achieved when injector 236 generates a large vacuum, such as 370 inches of water, in response to the flow of primary cleaning liquid component 216. At such a high vacuum, the valve 242 that is in line with injector 236 must close the flow path through which the cleaning agent flow 214 travels to such a degree that clogging of the flow path can occur, which prevents accurate cleaning agent flow rate control. Unfortunately, when valve 242 is adjusted to a large enough opening to avoid clogging of the flow path for the cleaning agent, the opening is generally too large to restrict the flow of cleaning agent 214 to the desired rate. As a result, the cleaning agent flow rate would be higher than the preferred flow rate without additional controls.
One embodiment of the dispensing system 100 includes the pressure regulator 206, which provides the desired additional control over the flow rate of the cleaning agent flow 214. Pressure regulator 206 is positioned in line with the cleaning agent supply line 202 between the first input 212 of the flow control device 204 and the cleaning agent container 200. Pressure Regulator 206 generally operates to maintain the pressure at first input 212 of flow control device 204 at a preferred pressure to provide the desired flow rate for the flow of cleaning agent through the flow control device 204. As the pressure in supply line 202 is decreased by pressure regulator 206, the volumetric flow rate of the cleaning agent flow 214 decreases. As a result, the pressure regulator 206 can be used to control the flow rate of the cleaning agent flow 214 to the desired low flow rate for the given flow control device 204 being used including a flow control device 204 that includes a valve 242 having a large enough opening to avoid clogging by the cleaning agent.
In accordance with one embodiment of the invention, pressure regulator 206 includes an air inlet port 244 and an airflow path 246, as shown in
During normal operation, the flow of primary cleaning liquid component 216 through venturi member 238 generates a vacuum of approximately 370 inches of water at the first input 212 of flow control device 204 when valve 252 or 254 of pressure regulator 206 is closed or pressure regulator 206 is not present. At this high pressure, the flow of cleaning agent 208 is injected into the flow of primary cleaning liquid at a rate of much greater than 2.0 cubic centimeters per minute. However, when valve 252 and/or 254 are open, the vacuum generated by flow control device 204 causes air 256 to be drawn in through air inlet port 244 and airflow path 246 of pressure regulator 206 and into the flow of cleaning agent 214. This reduces the pressure at the first inlet 212 of the flow control device 204 to a desired level and controls the flow rate of the cleaning agent flow 214 injected into the flow of primary cleaning liquid 216.
The particular settings for pressure regulator 206 can be selected empirically based upon the vacuum generated by flow control device 204 and the desired flow rate for the flow of cleaning agent 214. For example, when pressure regulator 206 is a 6 psi relief-check valve, the vacuum at the first input of flow control device can be reduced from 370 inches of water to approximately 150 inches of water, thereby causing the resultant flow rate of the flow of cleaning agent that is injected into the flow of primary cleaning liquid component to drop to approximately 1.2 cubic centimeters per minute when valve 242 is property set or when a suitable metering device 260 (
The valve 252 and/or 254 of pressure regulator 206 controls the introduction of air 256 into supply line 202 and, therefore, the amount of vacuum relief and the resultant flow rate of the flow of cleaning agent 214. In accordance with one embodiment of the invention, valve 252 is controllable by an operator of system 100, such as an operator of a surface cleaner 110 in which system 100 is installed. In general, valve 254 can be formed as a component of a remote airflow control 262 (
Additional control of the flow rate of the flow of cleaning agent 214 can be provided by a metering device 260, shown in
In accordance with one embodiment of the invention, metering device 260 includes a metering orifice or orifice plate 274, as shown in
In accordance with another embodiment of the invention, metering device 2604 includes a labyrinthine fluid flow path to provide the desired flow restriction. The labyrinthine path is preferably formed by one or more drip irrigators 278, as shown in
In accordance with one embodiment of the invention, system 100 includes one or more additional supplies of cleaning agent 201, as shown in
In accordance with one embodiment of the invention, a second flow control device 292, which is substantially identical to flow control device 204, is provided to control the injection of a flow 294 of the second cleaning agent from supply 290. Additionally, a valve 293, a pressure regulator 295 and/or a metering device 296 can also be included to provide additional control over the flow 294 of the second cleaning agent. Valves, such as valves 242 and 293, can be selectively opened and closed to control whether one or both of the first and second cleaning agent supplies 200 and 290 is added to the flow of the primary cleaning liquid component 216 to form the desired cleaning liquid 220. Alternatively, the second cleaning agent supply 290 can be fed to valve 298 of the dispensing system 100 through conduit 299, which can be a multi-way valve capable of selecting the first cleaning agent supply 200 of the second cleaning agent 290 to be passed to flow control device 204 thereby eliminating the need for the second flow control device 292 and the related components.
In accordance with one embodiment of the invention, the supplies of cleaning agent, such as first and second supplies 200 and 290 (
One embodiment of the container 200 is in the form of a collapsible bag that is completely sealed except where connected to the conduit 302. Thus, the container 200 collapses in on itself or shrinks as the cleaning agent 201 stored therein is depleted. In accordance with this embodiment of the invention, the container 200 can be formed of vinyl or other suitable material. Alternatively, the container 200 can take the form of a rigid container, such as a box, that includes a vent for replacing dispensed cleaning agent 201 with air. Container 200 can be transparent or translucent to allow the cleaning agent 201 to be viewed. Additionally, container 200 can be formed of a material that prevents the exposure of the cleaning agent contained therein from light.
The first end 304 of the conduit 302 is preferably attached to the container 200 such that it is flush with the inside of an outlet 308. A seal 310 is formed between the first end 304 and the container 200 at the outlet 308 to prevent the cleaning agent 201 from escaping at that junction. In accordance with one embodiment, the seal 310 includes an annular neck 312 surrounding the first end 304 and adjoining the container 200. A weld can be formed between the annular neck 312, the first end 304 and the container 200 to further seal the junction. Other methods for sealing the junction of the first end 304 and the container 200 can also be used.
The conduit 302 can also include a flow control member 314, shown in
In accordance with one embodiment of the invention, the cleaning agent cartridge 208 includes a housing 318, shown in
The housing 318 also includes openings 322 and 324 on at least one side wall 326 that are preferably defined by removable portions 328 and 330, respectively. The portions 328 and 330 have perforated edges 332 and 334, which facilitate their easy removal to expose openings 322 and 324. The housing 318 can also include apertures 336 and 338 to provide finger access to further simplify the removal of the portions 328 and 330. The opening 322 generally provides visual access to the container 200 and allows a user to asses the volume of the cleaning agent 201 contained therein. The opening 324 also provides access to the conduit 302, the connector 316 and the flow control member 352 for connection to the flow control device 204. In accordance with one embodiment of the invention, the opening 324 and the removable portion 330 can also be formed on the bottom 340 through which the conduit 302 can extend for efficient dispensing of the cleaning agent 201 in the container 200, as shown in
The cleaning agent cartridge 208 is preferably removably receivable in a cartridge receiver 342 of the cleaner 110, shown in
In operation, the cleaning agent cartridge 208 is provided and a cleaning agent container 200 is stored in the interior cavity 300 of the container 200. Next, the second end 306 of the conduit 302 is coupled to the flow control device 204 and the cartridge 208 is installed in the cartridge receiver 342. The flow control device 204 can then receive the cleaning agent 208 through the conduit 302, which connects to the conduit 210 to form the supply line 202, and provide a controlled output flow 208 of cleaning agent, as discussed above. When the container 200 is a collapsible bag 308, the container 200 collapses in response to the output flow of cleaning agent 208.
In accordance with another embodiment of the invention, the cleaning liquid dispensing system 100 includes an aerator 400. Aerator 400 is configured to receive the output flow of cleaning liquid 220 and aerate the cleaning liquid to produce an output flow of foamed cleaning liquid 402. A foamed cleaning liquid distributor 404 can receive the output flow of foamed cleaning liquid 402 and discharge the output flow 402 for wetting of a surface 406, as illustrated in
The aerator 400 preferably includes at least one aerating nozzle 420, as shown in
A check valve, such as check valve 450 shown in
The foamed cleaning liquid 402 from aerator 400 when used for hard floor surfaces is preferably a very wet foam relative to that used for carpet cleaning operations. Such a wet foam is necessary to provide the desired wetting of the hard floor surface. A foam's “wetness” or “dryness” may be defined in relation to this volumetric expansion ratio. A “dry” foam has a higher expansion ratio as compared to a “wet” foam. High-expansion foams are “dry” due to the high ratio of air to water and are useful in carpet cleaning to facilitate quick drying of the cleaned carpet. A “wet” foam is not used in carpet cleaning devices since they can cause excessive wetting of the carpet, which leads to long drying times and may result in mold development. In a particular embodiment of the invention, the ratio of volumes between the cleaning liquid (non-aerated) 220 and the foamed cleaning liquid 402 is approximately 1:8. For example, 0.15 gallons of cleaning liquid is aerated to occupy 1.25 gallons. Other volume ratios may yield acceptable wetting results as well.
Cleaning liquid dispensing system 100 can also include a foamed cleaning liquid distributor 404, shown schematically in
In accordance with another embodiment of the invention, foamed cleaning liquid distributor 404 receives the output flow of foamed cleaning liquid 402 from outlet 434 of nozzle 420 and discharges the output flow of foamed cleaning liquid 402 for wetting of the desired surface 406, such as surface 111, as shown in
Branches 456 can also be configured to discharge the foamed cleaning liquid flow 402 onto scrubbing member 122 of scrub head 120, as shown in
Another embodiment of distributing conduit 452 is illustrated in the front plan view of
In accordance with another embodiment of the invention, foamed cleaning liquid distributor 404 includes a wand member 490, shown in
As discussed above, surface cleaner 110 can be configured to include a motorized scrub head 120 that includes a scrubbing member 122 that is configured for rotating engagement with hard or carpeted floor surfaces 111, over which the mobile body 127 of cleaner 110 travels.
In order to facilitate complete wetting of hard floor surface 111, cleaner 110 can include a non-motorized wetting component 540, shown in
Inline with the fluid flow path 226 are one or more flow restriction members 560 (
One embodiment of the liquid dispensing system 100 includes an air purging component 360 for purging air from the fluid flow path 226, that is in line with the pump 228 in order to prime the pump 228. A discussion of this aspect of the invention will be provided with reference to
As discussed above, the liquid dispensing system 100 includes a pump 228 that is configured to drive a flow of liquid (either a cleaning liquid contained in tank 118 or water 216) through the fluid flow path 226 in a downstream direction. The downstream direction is indicated by arrow 361 in
One embodiment of the air purging component includes an inlet 362 in line with the fluid flow path 226, an outlet 364, an airflow path 366 connecting the inlet 362 and the outlet 364, and a valve 368 in line with the airflow path 366. The valve 368 includes an open position, shown in
Actuation of the valve 368 is preferably performed automatically in response to the detection of air or liquid in the fluid flow path 226. In accordance with one embodiment of the invention, the liquid dispensing system includes a valve actuator 374 that biases the valve 368 in the open position (
The detection of the presence or absence of air or liquid in the fluid flow path 226 can be performed in many different ways including, for example, through the detection of the presence or absence of air or liquid in the airflow path 366, which is in line with the fluid flow path 226. The valve 368 of the air purging component 360 is preferably automatically moved to the open position when air is detected in the fluid flow path 226 and closed when liquid is detected in the fluid flow path 226.
In accordance with one embodiment of the invention, the liquid dispensing system includes a sensor 376 that is configured to detect the presence or absence of liquid or air in the fluid flow path 226. The sensor 376 can be an electronic device that communicates the presence or absence of air or liquid to a controller of the valve actuator 374, which controls the valve actuator 374 to open or close the valve 368 in response to the communication from the sensor 376.
In accordance with another embodiment of the invention, the sensor 376 is a passive device. For example, the sensor 376 can includes a float type sensor having a float member that is raised to a threshold level when liquid is sufficiently present (air absent) in the fluid flow path 226, and falls below the threshold level when air is present (liquid absent) in the fluid flow path 226. The detection of the absence or presence of air or liquid can then be communicated mechanically and/or electronically to the valve actuator 374, which responds by adjusting the valve 368 accordingly.
In accordance with one embodiment of the invention, such a passive sensor 376 can be a component of the valve actuator 374 and used to control the actuation of the valve 368 through the connection of the rising and falling float member to the valve 368 through a suitable mechanical linkage. One exemplary air purging component 360 that includes such a passive control of the valve 368 is the Amtrol Model 700-30, in which a float member, contained in the airflow passage 366, controls the opening and closing of the valve 368 in response to the absence and presence of liquid in the airflow passage 366. Air in the airflow passage 366 is discharged through the outlet 364 until the airflow passage 366 fills with liquid to a threshold level.
One embodiment of the air purging component 360 includes a non-return stage 378, which prevents air from returning to the fluid flow path 226 through the outlet 364 when the valve 368 is open. Such a non-return stage is included in the exemplary air purging component 360 mentioned above.
In accordance with one embodiment of the invention, the fluid flow path 226 includes a section of conduit 380 that is elevated relative to the outlet 230 or the inlet of the pump 228. The inlet 362 of the air purging component 360 is preferably coupled to the elevated conduit section 380 of the fluid flow path 226. The fluid flow path 226 is preferably configured such that air is routed to the elevated section of conduit 380 where it can be removed by the air purging component 380.
In accordance with one embodiment of the invention, the inlet 362 of the air purging component 360 is coupled to the fluid flow path 226, such as to the elevated conduit section 380, downstream of the pump 228 relative to the downstream direction 361 in which the pump is configured to drive the flow of liquid, as shown in
In accordance with another embodiment of the invention, the inlet 362 of the air purging component 360 is coupled to the fluid flow path 226, such as to the elevated conduit section 380, upstream of the pump 228 relative to the downstream direction 361 in which the pump is configured to drive the flow of liquid.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. It should be understood that fittings, couplings and other conventional components have not been illustrated to simplify the figures.
The present application is based on and claims the benefit of U.S. Provisional Patent Application Ser. No. 60/569,761, filed May 10, 2004; the present application is a Continuation-in-Part of U.S. application Ser. No. 10/653,347, filed Sep. 2, 2003 and entitled “FOAMED CLEANING LIQUID DISPENSING SYSTEM,” which is a Continuation-in-Part of U.S. application Ser. No. 10/143,582, filed May 9, 2002, issued as U.S. Pat. No. 6,735,811 on May 18, 2004, and entitled “CLEANING LIQUID DISPENSING SYSTEM FOR A HARD FLOOR SURFACE CLEANER,” which is a Continuation-in-Part of U.S. application Ser. No. 10/026,411, filed Dec. 21, 2001, issued as U.S. Pat. No. 6,585,827 on Jul. 1, 2003, and entitled “APPARATUS AND METHOD OF USE FOR CLEANING A HARD FLOOR SURFACE UTILIZING AN AERATED CLEANING LIQUID,” which claims the benefit of U.S. Provisional Application Ser. No. 60/308,773, filed Jul. 30, 2001 and entitled “APPARATUS AND METHOD OF USE FOR CLEANING A HARD FLOOR SURFACE UTILIZING AN AERATED CLEANING LIQUID”; and the present application is a Continuation-in-Part of U.S. application Ser. No. 10/749,129, filed Dec. 30, 2003, and entitled “CLEANING LIQUID DISPENSING SYSTEM”. All of the above-reference applications are incorporated herein by reference in their entirety.
Number | Date | Country | |
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60569761 | May 2004 | US | |
60308773 | Jul 2001 | US |
Number | Date | Country | |
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Parent | 10653347 | Sep 2003 | US |
Child | 11125764 | May 2005 | US |
Parent | 10143582 | May 2002 | US |
Child | 10653347 | Sep 2003 | US |
Parent | 10026411 | Dec 2001 | US |
Child | 10143582 | May 2002 | US |
Parent | 10749129 | Dec 2003 | US |
Child | 11125764 | May 2005 | US |