Automated Cleansing Chamber With Air Knife

CROSS REFERENCE PATENTS The following U.S. patents are incorporated herein by reference: 5,265,628 (1993) to Sage et al., 4,817,651 (1989) to Crisp et al . , and 4,925,495 (1990) to Crisp et al .

FIELD OF INVENTION The present invention relates to revolving cylindrical cleansing chambers having an air knife blower suited for washing and drying hands.

BACKGROUND OF THE INVENTION

Touchless automated handwashing devices are designed to provide the proper amount of antimicrobial solution in a set time. The present art uses recommended handwashing methodology. Additionally these systems diminish the deterrent effects of friction and irritation associated with frequent manual handwashing.

Medical experts have concluded that automated handwashing increases handwashing compliance and reduces the risk of infection.

Other industries including food service, food processing, and clean room manufacturing use automated handwashers to help eliminate the spread of infection.

The '628, '651, and '495 patents teach a touchless handwashing system having a pair of rotating cylinders. These cylinders contain slits which function as rotating nozzles. The rotating cylinder is housed in a basin for the wash, rinse, and cleaning liquids. The rotating nozzles provide a helical array of spray to the hands starting

at the forearm and finishing at the finger tips. A control center allows the user to select and program the desired cleaning cycle. A soap, disinfectant and rinse cycle is shown. The invention pioneers the use of rotating nozzles to simulate pulsating or varying pressure cleaning fluid jets which produce a trampoline effect to remove dirt.

Considerably less effort and energy is required to rotate cylinders than to vary pressure.

The '628 patent teaches an automatic sensing means, multi function control means, programmable purge, wash, dwell, rinse and clean cycles, a ten second complete wash and rinse cycle with precise chemical formula and precise volumetric control of wash and rinse water to eliminate residue on the hands.

The above noted prior art patents are used primarily in clean room and food processing applications. Workmen must wash their hands many times a day and return to work. These prior art devices do not teach the removal of water droplets from the newly washed hands. Thus, the workmen tend to drip water onto the floor adjacent the hand washer. This water causes a hazard. In a clean room application this water also becomes a source of pollution. The present invention blows off excess water and provides drip- free hands in about 6-8 seconds. It can provide dry hands in about 45 seconds without using heated air. Optional air heaters can reduce this time.

SUMMARY OF THE INVENTION

The primary object of the present invention is to provide an air knife blower on a rotating nozzle hand cleaning system.

Another object of the present invention is to provide a hand

sensing air "OFF" circuit which turns the t-Q ,ftaΛdB.fc OTT retracted.

Other objects of this invention will appear from the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. l (prior art) is a front perspective view of a free standing cleansing unit having no air knives.

FIG. 2 is a left side plan view of a cleansing unit having an air knife system.

FIG. 3 is a front perspective view of the unit shown in FIG. 2.

FIG. 4 is a top plan view of the unit shown in FIGS. 2, 3 with the air knife cover partially cut-away.

FIG. 5 is a left side view of a hand sensing system.

FIG. 6 is a block diagram of the controller and sensors.

FIG. 7 is a block diagram of the controller logic.

Before explaining the disclosed embodiment of the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the particular arrangement shown, since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1 cleansing unit 1 is a free standing hand and forearm washing unit. Cabinet 22 includes a pair of parallel

cylindrical hand openings 3, 4. .E.D. panel 5 shows the user how to interface with the cleansing unit 1. An electronic controller is housed behind L.E.D. panel 5. The soap container storage area is shown at 6. A photoeye 7 senses the presence of a hand in hand opening 4 and starts the washing cycle.

Usual washing cycles range around ten seconds. The user merely inserts his hands (gloved or ungloved) into cylindrical hand opening 3, 4 and receives a purge, soap, dwell and rinse cycle within around ten seconds. The purge cycle allows the water to reach the proper temperature. The soap cycle washes. The dwell cycle allows the soap and/or disinfectant to kill germs, and the rinse cycle removes the soap. Referring next to FIG. 2 cleansing unit 10 is a free standing hand and forearm washing unit having an air knife assembly. The air knife cover 11 is mounted on the top surface 12 of cabinet 13. Cabinet 13 has a front cover 16. A compressed air inlet 14 powers the air knife assembly (shown in FIG. 4) via air line 15. The solenoid valve 17 is a two position valve normally closed. Nominal input to air inlet 14 is fifteen standard cubic feet per minute at a minimum of 50 PSI.

Referring next to FIG. 3 the cleansing unit 10 is shown to have a control panel 200 containing a diffuse photoeye 7. Hand port 201 has air knives 203, 204, 205. Hand port 202 has air knives 206, 207, 208.

Referring next to FIG. 4 the air knife assembly is shown under the cut-away of cover 11. The solenoid valve 17 feeds air to the distribution block 210 which feeds air via air lines 215 to the various air knives 203-208. Standard air fittings 213, 214 are mounted to surface 12 by clamps 211, 212. Air knives 203-208 are known in the art. They are mounted about one inch above the washing cylinder(s) shown as 8 in FIG. 5. The air knives 203-208 are mounted with about a 15_ slope

pointing down into the hand ports 201, 202. This ensures that the water blown off the hands is directed down into the handports where it will drain. The air knives produce a thin high velocity layer of air in a fan shaped pattern. The air removes water from the hands by knocking it off (because the air is not heated - water removal by evaporation is minimal) . The operator must rotate and translate the hands in this thin high velocity air layer for effective water removal.

Referring next to FIG. 5 control panel 200 houses the diffuse photoeye 7. The diffuse photoeye is DC powered and sends infrared signal 72 toward the hand 71 which bounces signal 73 back to the sensing means in diffuse photoeye 7. The current sink line 74 is active when photoeye 7 senses reflected light of its own frequency 73. Upon receiving a sinking circuit from line 74 the gate array logic 75 initiates a wash cycle. The gate array logic could also be written to accept a current source from the photoeye 7 in lieu of a current sink. Other means for no touch control include retroreflective photoeye sensing, convergent/divergent photoeye sensing, thru scan photoeye sensing, ultrasonic sensing, and proximity sensing.

Referring next to FIG. 6 the flow chart illustrates the electronic module 1803 as powered by converted AC power 1801 to 24 V/DC power

1802. Once on, the no touch activation 1804 gives a continuous signal thru the current sink line 1804a to the electronic module 1803. As the thermal sensor 1805 sends a signal to the electronic module 1803, anti- scalding is in effect . Thus shut down occurs for too high a temperature.

If the no touch activator 1804 is triggered, the electric module 1803 will communicate with different components of the invention. The L.E.D. indicator for user information, on panel 5 is to warn or inform

the user during operation. The motor 1808 which powers the cylinders 8 (FIG. 5) has a motor torque control 1807 with a current limit chip to prevent finger injury. The mix valve 1809 for soap and water, the rinse valve 1810 for water only, or the soap valves 1811 for soap or self clean in accordance with the pressure sensor 1812 can be operated by the electronic module 1803. The pressure sensor 1812 is a transducer which senses from 0 psia to 14.7 psia. It can communicate to the electronic module 1803 if a problem occurs in the pressure. A basin water level sensor 1813 has a float switch that will send a signal to the electronic module 1803.

The solenoid valve 17 is controlled by the unit's electronics module shown as 1803. The valve 17 remains closed during the wash cycle and opens when the water flow stops. The valve 17 will remain open for as long as the user's hands block the photoeye 7 up to a limit of 30 seconds. If the user momentarily unblocks the photoeye (minimum of 10 milliseconds, maximum of 2 seconds) and then reblocks the photoeye 7, then the timer will reset to 0 and begin a new 30 second cycle. This allows the user an unlimited amount of time for drying. But, it ensures that all accidental blockage of the photoeye (soap scum, paper towel, photoeye failure, etc.) will not allow air flow for any longer than 30 seconds .

FIG. 7 will allow us to move thru a cycle of the invention at any state. The hot water supply enters the machine through a one-way check value 1814. Cold water enters the machine first through a ball valve 1815 and then through a one-way check valve 1816. The two check valves 1814 and 1816 prevent the hot and cold water from mixing outside of the hand washing device. The hot and cold water then join together and enter a filter 1817 which removes particulates. (Note: the temperature

of the water is controlled by the position of the cold water ball valve 1815 which can range from fully open (low temp) to fully closed (high temp) ) .

Water exiting the filter 1817 enters a pressure regulator 1818 and water pressure gauge 1819a by which the operating pressure of the machine is set. Water then enters and flows through a backflow preventer 1819b which protects the potable water supply from contamination with cleaning chemicals. After the backflow preventer 1819b, the water flows around a thermistor probe 1805 which is mounted in the flow stream. The thermistor 1805 works in conjunction with the electronic module 1803 to allow the machine to operate only when the water temperature at the thermistor 1805 probe is at or below a preset limit - usually 120_ F. If the water temperature exceeds this limit the water valves 1810 and 1809a are closed by the electronics module 1803 to prevent scalding the user.

Non-scalding water will pass the thermistor 1805 and enter a tee. The rinse circuit of the tee passes through the rinse solenoid valve 1810, to prevent soap from being mixed. The rinse cycle is controlled by the electronic module 1803. The soap mixing leg of the plumbing circuit allows the water to pass through a wash solenoid valve 1809a which is controlled by the electronic module 1803 before it gets to the aspirator 1809b. The aspirator 1809b is a device which creates a suction at the expense of the water pressure.

The vacuum signal is used to draw soap from their containers and mix it with the water stream. Soap is drawn from either solution container 1811a or solution container 1811b by solenoid lθllaa or lθllbb respectively. The electronic module 1803 chooses either solution container if the other is empty. When either solution's solenoid valve

1811aa or 1811bb is open it will remain open for a preprogrammed amount of time (nominal = 2.5 sec) at the beginning of the wash cycle. Soap is allowed to enter the water stream as long as either solution solenoid valve lβllaa or lθllbb stays open. To prevent soap from mixing with the self-clean mixtures a shuttle valve 1821 is used after solution solenoid lθllaa and solution solenoid lθllbb. On a preprogrammed basis, the electronic module 1803 will open the self-clean solenoid valve lθllcc and allow self-cleaning fluid (preferably ammonium chloride) to flow from its solution container 1811c through the self-clean solenoid valve lθllcc and the shuttle valve 1821 into the aspirator 1809b Self- cleaning fluid will ]oιn the water stream into the rotating cylinder 8 and then to the system drain 50 (see U.S. Pat. No. 4,925,495)

The shuttle valve 1821 allows the use of three different fluids 1811a or 1811b and 1811c with only a single aspirator 1809b Soap or self-cleaner in the plumbing between the shuttle valve 1821 and the aspirator is pressure monitored by a pressure transducer 1812 installed in the line. This pressure transducer 1812 creates a variable voltage signal inversely proportional to the absolute pressure of the fluid. The electronic module 1803 will sense this voltage signal and thereby determine the amount of soap flowing. It will alert the user at panel 200 if any anomalies are found (e.g. empty soap bottle) . All water mixture exiting the aspirator 1809b and all water flowing through the rinse circuit of the plumbing flows directly to the rotating cylinders 8 and out the series of nozzles located on the inner surface of the cylinders 8. At this point the gauge pressure of the water stream drops to zero. Drain water exits the cylinder through the drain slot(s) and is collected in the drain basin 50 and allowed to drain to the facility sewer. The water level in the dram basin 50 is monitored from the

basin water level sender 1813 by a float switch which signals the electronic module 1803 of a high water level. The electronic module 1803 will then stop the flow of pressurized water in the plumbing circuit to prevent a drain basin 50 overflow. Power is obtained to a handwashing device when connected to AC power at the wall outlet 1801. Its 24 v DC power supply 1802 is present after moving through a ground fault interrupt 1802a, power cord 1802b, power switch 1802c and a fuse 1802d before reaching the electronic module 1803.

After this wash cycle the air knife cycle described in FIG. 6 begins.

Although the present invention has been described with reference to preferred embodiments, numerous modifications and variations can be made and still the result will come within the scope of the invention. No limitation with respect to the specific embodiments disclosed herein is intended or should be inferred.