Abstract:
An apparatus for disinfecting a user&#39;s hands has a spray chamber or an open spray zone with an opening for a user to insert his or her hands into the chamber. A supply of a disinfecting solution is provided, and preferably comprises a storage tank with a concentrated solution. This solution is mixed with an incoming freshwater supply, e.g. in a venturi valve, and supplied through spray nozzles into the chamber. A sensor detects the presence of a user&#39;s hands and automatically operates the spray nozzles for a predetermined time. The apparatus can also include a fan with its own timer, to provide a supply of drying air. Thus, a user can insert his or her hands, disinfect them with the disinfecting solution, remove the hands and dry them, without requiring any manual operation.

Description:
RELATED APPLICATIONS 
     The following is a Continuation-in-Part Application to U.S. patent application Ser. No. 08/867,028, filed on Jun. 2, 1997 now abandoned. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to a method and apparatus for disinfecting a user&#39;s hands, and more particularly is concerned with apparatus which enables disinfecting of hands, without requiring a user to manually operate or physically touch the equipment. 
     BACKGROUND OF THE INVENTION 
     There are many instances, in a variety of businesses and institutional situations, where it is desirable, or even essential, that a person have clean hands. For example, anyone handling food, in restaurants or other situations, should ensure their hands are well cleaned, before handling food. In a variety of medical and laboratory situations, it is necessary for personnel to clean their hands regularly, to ensure that an individual does not pick up a disease or infection and to prevent transmission of disease and infection. 
     In many cases, while facilities might be provided for cleaning or washing of hands, these are not completely effective. In many cases, this requires someone to seek out a washroom or the like, in order to wash or clean their hands. If washrooms and the like are not properly maintained, there can be problems with soap or cleaning solutions being available and/or towels to dry one&#39;s hands. 
     Devices have been proposed on the art. U.S. Pat. No. 5,265,628 (Sage et al) discloses an automated cleansing chamber. This discloses a relatively complex machine in which two separate cylinders are provided, for a user&#39;s two hands. The intention is that each hand would be inserted into a respective cylinder. The cylinders are rotated and provided an array of nozzles to wash the user&#39;s hands. A program is provided comprising purge, wash, dry, rinse and self-clean cycles. Mechanically, the system is complex, and includes numerous moving parts, which would be subject to wear and deterioration. 
     An alternative proposal is found in the Stevenson U.S. Pat. No. 2,814,081. This provides a circled rapid hand sanitizer. It provides a transparent, generally rectangular housing, which is intended for conspicuous display, so that patrons in the restaurants and the like can see that a server is sterilizing his or her hands, etc. It again provides two separate openings into the enclosure. To prevent spray and the like from being splashed, etc. out the enclosure, a flexible closure is retained by grommet mouldings for each opening. This means that the flexible closure rubs against the user&#39;s hands, possibly transferring bacteria and the like to or from the user&#39;s hands. A single spray nozzle is provided, directed at least partially towards the openings from the user&#39;s hands, which will aggravate the problem of spray accidentally passing out of the unit. Somewhat surprisingly, while a number of apertures are provided in the bottom of the casing, apparently to exhaust air from a blower, no provision is made for drainage of any excess liquid sprayed onto a user&#39;s hands. 
     Accordingly, it is desirable to provide a device that can be used for disinfecting or sanitizing a user&#39;s hands, which device should be simple, compact and readily installed at a variety of different locations. The present inventor has additionally realised that the present invention should ideally automatically provide a disinfecting solution, without requiring manual operation by the user. 
     For a disinfecting or sanitizing operation, the inventor has realized that it is not necessary to provide a large volume of liquid. Rather, it is only necessary to provide a small quantity of liquid. Additionally, much of the prior art fails to provide a design or device which will appeal to users or encourage them to use the device. Thus, many people are reluctant to insert their hands through any small opening into a closed chamber, since they are not sure exactly how the device will operate or how their hands will be treated. 
     The present inventor has also realized that, unlike much of the prior art, it is not necessary to have a user thoroughly wash his or her hands. Rather, what is required, is to have a user disinfect the hands. For this purpose, it is sufficient to have a user thoroughly coat his/her hands with a disinfecting solution and rub this solution into the hands. This then eliminates the need for any distinct rinsing or drying steps. 
     SUMMARY OF THE INVENTION 
     In accordance with a first aspect of the present invention, there is provided an apparatus for disinfecting a user&#39;s hands, the apparatus comprising: 
     a housing defining a spray zone, the spray zone being substantially open at the front thereof to enable a user to insert both hands and to manipulate both hands within the spray zone without contacting the housing, the housing including a collection portion for collecting excess spray from the spray zone; 
     a spray means comprising a plurality of spray nozzles mounted on the housing and directed rearwardly away from the front of the spray zone, for generating a spray of a liquid within the spray chamber and mounted on the drum; 
     a supply means for supplying a liquid to the spray means; 
     a valve means connected between the supply means and the spray means for controlling supply of the cleaning liquid; 
     a sensor means mounted on the spray chamber, for sensing the presence of a user&#39;s hands within the spray chamber; and 
     a control circuit including a first timer and connected to the sensor means and the valve means, the control circuit being adapted to open the valve means to supply the liquid to the spray means when the sensor means detects the presence of a user&#39;s hands and maintaining the valve means open for a period determined by the first timer. 
     Preferably, the supply means comprises a storage tank for a concentrated solution and a first inlet for a water supply, and the valve means is then connected to both the first inlet and the storage tank and has an outlet connected to the spray means, the valve means, when open, mixing the concentrated solution and the water in a desired ratio, to form a dilute solution to form said liquid which is supplied to the spray means. The spray chamber preferably then includes an outlet for waste disinfecting solution, adapted to be connected to an external drain. 
     Advantageously, the valve means comprises a venturi valve. 
     The apparatus can further include a fan means for providing a flow of drying air. The fan is conveniently connected to and controlled by the control circuit and the control circuit then preferably includes a second timer for timing operation of the fan. The fan is provided mainly to encourage a user to rub the hands together, to promote even distribution of the liquid. In a preferred aspect of the invention only a small quantity of liquid is spraying, so that a full drying steps or cycle is not required. 
     More preferably, the control circuit includes a relay and the valve means includes an actuating solenoid. The first timer is then connected to the relay for actuation thereof, and the relay includes a first contact means connected to the solenoid for actuation thereof, to open the valve means, and to the second timer, to commence actuation thereof. 
     In a more preferred aspect of the present invention, the opening is provided at the front of the spray chamber and the spray means comprises a pair of spray nozzles mounted to the spray chamber below the opening and directed upwardly and rearwardly, and optionally a further spray nozzle mounted above the opening and directed downwardly and rearwardly. 
     The storage tank can be mounted either above or below the spray chamber. In a preferred embodiment, the storage tank is mounted above the spray chamber, so as to provide a compact unit which can be mounted on a counter surface or the like. The supply means preferably includes a filling funnel mounted above the spray chamber and connecting to the storage tank. A vent, to vent air from the storage tank during filling, can either be connected to the exterior or to the spray chamber. 
     Another aspect of the present invention provides a disinfecting solution and the storage tank is preferably filled with this solution, the disinfecting solution comprising: 
     1.6-2% N-alkyl dimethyl benzyl ammonium chloride; 
     1.6-2% didecyl dimethyl ammonium chloride; 
     0.2-0.4% lauramine oxide; 
     0.2-0.6% tetrasodium salt of EDTA; 
     4% glycerin; and water, the amount of water forming the balance of the composition. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a better understanding of the invention, and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: 
     FIG. 1 is a perspective view of an apparatus in accordance with the present invention; 
     FIG. 2 is a sectional view looking in the direction of arrows  2 — 2  of FIG. 1; 
     FIG. 3 is a sectional view looking in the direction of arrows  3 — 3  of FIG. 2; 
     FIG. 4 is a detailed, enlarged view of a single spray nozzle; 
     FIG. 5 is a perspective view, similar to FIG. 1, showing an outer casing removed; 
     FIG. 6 is a schematic of an electrical control circuit; 
     FIGS. 7 and 8 show views similar to FIGS. 2 and 3 of a second embodiment of an apparatus in accordance with the present invention; 
     FIG. 9 a  is a sectional view in a horizontal plane of the second embodiment; and 
     FIG. 9 b  is a view similar to FIG. 9 a,  showing details of a panel with electrical components; and 
     FIG. 10 a  is a front, perspective view of a third embodiment of an apparatus in accordance with the present invention; 
     FIG. 10 b  is a rear perspective view of the third embodiment of the apparatus; and 
     FIG. 10 c  is a side view of the third embodiment of the apparatus. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A first embodiment of an apparatus in accordance with the present invention is indicated generally by the reference  10 . The apparatus  10  has an external casing  12 , which can be formed from sheet metal or the like in known manner. As shown in FIG. 1, this casing  12  includes an opening  14  for a user&#39;s hands, as detailed below, and an outlet vent  16  for a fan. 
     Referring to FIG. 5, with the casing  12  removed, the apparatus  10  shows a base  20 , with a support framework  22  extending upwardly from the base  20 . A rear wall  24  extends up from the base  20 , and forms part of the casing  12 . 
     Mounted on top of the support framework  22  is a drum  26  defining a cylindrical spray chamber  28 . The opening  14  is rectangular and is inclined downwardly into the cylindrical spray chamber  28  as shown. As most clearly shown in FIG. 3, the opening  14  is defined by a generally rectangular tubular member  18 , effectively extending through the outer casing  12  and into the spray chamber  28 . As shown in FIGS. 2 and 3, three spray nozzles  30  are mounted in the drum  26 . Details of the nozzles  30  are shown in FIG.  4 . Each nozzle  30  comprises an atomizing fog nozzle producing a divergent spray. The preferred spray nozzle is a Lennox humidifier nozzle #21060 with a #54G49 holder supplied by LENNOX. This provides a 90° wide hollow cone spray at a flow rate of 3.00 gallons per hour. The actual atomizing nozzle is indicated at  32  and is secured to a mounting bracket  34 , which clamped, secured by adhesive or otherwise attached to the drum  26 . An angled compression fitting  36  provides a connection to flexible P.V.C. tubing  38 , the tubing  38 , together with other standard fittings connecting the nozzles  30  together. 
     Below the drum  26 , there is a storage tank  40  for a concentrated disinfecting solution, details of which are given below. The storage tank  40  is provided with a screened, generally conical refilling funnel  42  connected by tubing  44  to the top of the tank  40 . A back pressure vent tube  46  (see FIG. 3) is provided. 
     A filtered suction pickup  48  extends from near the bottom of the tank  40  out through the top surface of the tank  40 , and as shown in FIG. 2, to a venturi valve  50 . This connection is made by further tubing  52  and a non-return valve  54 . A valve  56  is provided to enable the flow rate through the venturi valve  50  to be adjusted. The outlet of the venturi valve  50  is connected to a union  58 , providing a connection to the spray nozzles  30 . 
     The inlet of the venturi valve  50  is connected by a solenoid valve  60 , including an actuating solenoid, to an inlet  62  providing a connection to a conventional freshwater source, i.e. to a water supply within a building. 
     The venturi valve  50  is preferably a single stage injector, supplied by DEMA Engineering Company of St. Louis, Mo., U.S.A. It serves to dilute the concentrated disinfecting solution to a desired ratio with the water, to form a dilute solution. 
     For waste water disinfecting solution, an outlet  70  is provided in the bottom of the drum  26 . This outlet  70  is connected by tubing  72  to an outlet  74 , which can be connected to conventional drains within a building. At the front of the apparatus  10 , various electrical control elements are arranged on a panel  76 . The electrical interconnection of these various elements is shown in FIG. 6. A junction box  78  is provided with an input lead  79  (FIG.  6 ), for connection with a conventional electricity supply, for example, 120 volts AC in North America. The junction box  78  is connected to a transformer  80  which converts the input supply to a 24 volt AC supply for powering the other components, as indicated in FIG.  6 . The junction box  78  and transformer  80  are weather proof and designed to withstand water spillage. 
     Mounted on the right hand side of the transformer  80 , as shown in FIG. 2, is a housing  82  for various low level electronics, and beside this is a fan  84 . 2″×4″ louvered vents  83  are provided for the incoming air to the fan  84 . 
     Along the bottom of the panel  76 , there is a first, multifunctional timer  86  for the spray nozzles and a second timer  87  for the fan, as detailed below. Beside the timers  86 ,  87 , there is a relay  88 . Also forming part of the electronic circuitry is a photoelectric proximity sensor  90 , shown in FIG.  3 . Preferably, this is Model No. E65-SMSD200-HL supplied by, Cutler-Hammer Eaton of Cleveland, Ohio, U.S.A. 
     Turning to FIG. 6, as shown, the transformer  80 , effectively included in the enclosure  78  of the junction box is provided with the input  79  for connection to a conventional  120  VAC supply. This is transformed down to 24 volts AC and connected to a pair of supply lines  92 . 
     As shown, the proximity sensor  90  is connected between the lines  92  and has an output  91 , connected to the first timer  86 . A contact pair  86   a  is an internal contact pair of the timer and serves to initiate operation of the timer  86 . The timer  86  controls a pair of contacts  86   b,  which when closed actuate the relay  88 . The relay  88  in turn closes a pair of contacts  88   a,  so as to actuate the solenoid valve  60 . Simultaneously, the closure of the contacts  88   a  activates the second timer  87 . 
     The second timer  87  closes a pair of contacts  87   a,  to provide power to the fan  84 . As shown, for the fan  84 , a bridge rectifier  85  is provided between the supply lines  92 , to provide a DC supply for the fan  84 . 
     Additionally, to monitor the level of liquid in the storage tank  40 , a probe  94  is provided. The probe  94  is connected to a level sensor  95 , which is also connected to a lower level warning light  96  which is provided through the front of the casing  12 . 
     Accordingly, in use, the apparatus is installed and connected up to conventional electrical and freshwater supplies. The storage tank  40  is filled with a suitable concentrated disinfecting solution through the funnel  42 . In accordance with the present invention, a preferred disinfecting formulation comprises: 
     1.6-2% N-alkyl dimethyl benzyl ammonium chloride; 
     1.6-2% didecyl dimethyl ammonium chloride; 
     0.2-0.4% lauramine oxide; 
     0.2-0.6% tetrasodium salt of EDTA; 
     4% glycerin; and water, the amount of water forming the balance of the composition. 
     When a user wishes to disinfect his/her hands, he or she simply inserts the hands through the opening  14 . The presence of the hands is detected by the proximity sensor  90 . This activates the first timer  86 , which in turn actuates the relay  88 . The relay  88  opens the solenoid valve  60 , permitting fresh water to flow through to the venturi valve  50 . In the venturi valve  50 , the low pressure entrains disinfecting solution from the tank  40  into the freshwater flow, to provide a desired dilution of the cleaning solution in the range 80:1 to 200:1. The disinfecting solution is then sprayed from the nozzles  30  and, in known manner, the user can rub his or her hands together and ensure they are adequately covered with the solution. The spraying operation is timed for a period set by the timer  86 . The sloping of the opening  14  ensures that any drops of solution falling on it are directed back in the chamber  28 . 
     Unlike many other proposal in this field, which rely on spraying relatively large quantities of a liquid or cleaning solution to effect it through washing action, the present invention is intended primarily to provide a disinfecting or sanitizing function. As such, it is recognized that only a relatively small amount of liquid needs to be sprayed. To this end, it is preferred for the spray nozzles to provide a combined spraying rate in the range of 2.5 to 3.2 GPH. Then, the spray nozzles can be actuated for a time in the range of 0.2 to 1.2 sec. Put another way, the total amount of liquid sprayed is preferably in the range of 3 to 5 cc. The most preferred operative conditions are two spray nozzles each operating at 3.00 gallons per hour providing a relatively fine mist or fog, with the spray nozzles operated at 0.5 seconds. This gives a total volume sprayed of 3.0 cc. 
     Then, it has been found that approximately 70% of the liquid sprayed coats the skin of the user&#39;s hands, with only a small or minor portion of the liquid being lost to waste. When the user removes his hands from the device, the fan  84 , as detailed below is actuated. However, in view of the relatively small volume of liquid that is deposited on the hands, no true drying action is required. Rather, the fan is provided more to encourage users to rub their hands together, to ensure even coverage of the hands with the liquid. It can be further noted that since no true drying action is required, the whole cycle takes a matter of a few seconds, which encourages users to use the device. It is not time-consuming, and does not require any separate true drying step, as in an apparatus that provides a full washing action. 
     When the solenoid  60  is actuated, as shown in FIG. 6, the second timer  87  is also actuated. This timer  87  can then immediately, or after a set delay, actuate the fan  84 . In any event, the timer  87  sets the fan  84  to run for a second period of time after the timer  86  is turned off and the dispensing of the disinfecting solution ended. 
     The fan  84  produces a flow of air, discharging out from the outlet vent  16 . Thus, after a user has disinfected his or her hands, their hands can be placed in front of a vent and rubbed together. If desired, a heater can be provided in addition to the fan  84 . 
     The fan and flow of air do not here provide a true drying action. Rather, it is provided simply to encourage a user to rub the hands together to spread the solution uniformly over the hands. 
     At the end of the second time period, the timer  87  shuts off the fan  84 , and the apparatus can then remain dormant and ready for another user. 
     The casing  12  can be formed in any known manner. Here, the casing  12  has generally rectangular top and bottom surfaces and includes the rectangular rear wall  24 . At the front, the casing  12  has a front wall  32 , with lower and upper portions  34 ,  36  (FIG.  3 ). The lower portion  34  is generally vertical and the upper portion  36  is inclined backwards slightly, with the opening  14  perpendicular to the upper portion  36 . The sides of the casing  12  are then correspondingly shaped. 
     In FIGS. 7-9, a second embodiment is shown and denoted by the reference  100 . Elements common to the first embodiment are given the same reference numeral as in the first embodiment, but with the suffix a. For brevity, a detailed description of similar or common components is not repeated, and it is to be understood that the individual components function as in the first embodiment. 
     The second embodiment of the apparatus  100  provides a more compact unit intended for mounting on a counter, table, wall or the like. As such, in many institutional, business and other settings, it should be easy to find a suitable surface for mounting the unit, and it then occupies little space. 
     The principal difference in the second embodiment is that the drum is now located below the storage tank. This is because the unit is intended for mounting on an elevated surface. For this purpose, the drum  26   a  has an external diameter of 10 inches. The drum is centered at 6¼ inches above the base  20   a  of the device. Here, rubber bumper pads  21   a  are provided. Consequently, the opening  14   a  is much closer to the base  20   a  than in the first embodiment. 
     The arrangement of the spray nozzles is modified as compared to the first embodiment. A single pair of nozzles  30   a  are provided. In FIG. 7, these are inclined at an angle of 60° towards the centre of the chamber, as viewed from the front. Similarly, as shown in FIG. 8, the nozzles  30   a  are also inclined at 60° to the horizontal, so as to be directed rearwardly. 
     The opening  14   a  is now tapered, and is provided above the centre line of the drum  26   a,  as best shown in FIG.  8 . At the bottom of the drum  26   a,  there is a drain screen  31  provided above the outlet connected to the outlet tube  72   a.  The back pressure vent  46   a,  instead of being connected to atmosphere, is now connected to the spray chamber, as shown. 
     The arrangement of the fan has now been altered. The fan  84   a  has the actual fan or drive motor provided on one side, as shown in FIG.  7 . An elongate grill or outlet vent  16   a  is provided. Again, this is merely to encourage a rubbing or massaging action, and not to provide a true drying function. 
     Turning to the arrangement of the control circuitry, similar components are provided as for the first embodiment and these operate similarly. However, the physical layout of their components has been varied. 
     Thus, the panel  76   a  is now horizontal. The arrangement of the solenoid valve  60   a  and the venturi valve  50   a  are shown in FIG. 9 b.  The non-return valve  54  and the valve  56  setting the flow rate would be retained, and the outlet of the venturi valve  50   a  is connected to tubing  38   a  and then through to the nozzles  30   a.    
     The overall profile of the front panel  32   a  is varied. It has a planar lower portion  34   a  and a rounded upper portion  36   a.  At its upper edge, as indicated at  33   a,  there is a hinge or the like permitting the front cover to be detached. A cam lock  37   a  at the bottom enables the front cover to be released at the bottom and then pivoted upwards. The hinge arrangement  33   a  can comprise a tongue and groove arrangement formed between folded ends of the panel sheets, permitting the front panel  32   a  to be removed, for servicing, maintenance etc. On the right hand side as indicated at  98 , a NEMA  4  fuse holder can be provided and  99  indicates a grommet for an input power supply cable. 
     The tubing for the different connections can be sized for the intended use. In this preferred embodiment, the connection tube  44   a  for filing the storage tank and the drain tube  72   a  are both ½ inch vinyl tubing. The other tubing, the connection tubing  38   a  to the nozzles, the back pressure vent tubing  46   a,  the filtered suction pick-up tubing  48   a  and the water inlet connection tubing  62   a  are all ¼ inch P.V.C. tube. 
     Referring now FIGS. 10 a,    10   b  and  10   c,  a description of a third and preferred embodiment will now be given. Again, elements common to the first and second embodiments are given the same reference numeral, but here are denoted with a suffix b. Also, as for the second embodiment, a detailed description of components common to at least one of the first and second embodiments, is not repeated, and it is to be understood that many components would be common with those in the first and second embodiments and would function in the same manner. The principal difference in this third embodiment is the overall configuration of the exterior of the housing and the zone or chamber for spraying a solution onto a user&#39;s hands, and just these features are described in detail below. 
     This third embodiment is designated by the reference  102 . It is intended as a compact unit, for mounting either on a table or other suitable horizontal support surface or on a wall. 
     As such, the second embodiment  102  has a planar base  104  and a rear wall  24   b  consisting largely of a removable rear panel  106 . The panel  106  provides access to the interior working components in known manner, for servicing and repair. 
     The housing  12   b  includes planar side walls  108  and a planar top surface  110 . The peripheries of the side walls  108  are determined by the shape of the other surfaces or panels. 
     Unlike the previous embodiments where a distinct spray chamber was provided and was defined by a separate drum or the like, no distinct fully enclosed spray chamber is provided, rather, there is a spraying zone here designated at  28   b.  The spraying zone  28   b  is defined primarily by an inner, concavely-shaped wall having a radius of 4½ inches as viewed in the cross-section of FIG. 10 c,  this concavely-shaped wall portion being indicated at  112 . Above the wall portion  112 , there is an upper convexly-shaped wall  114 , also having a radius of 4½ (again as in FIG. 10 c ), extending from the top wall or panel  110  and continuing smoothly into the concavely-shaped wall  112 . The centers of a curvature of the two walls  112 ,  114  are spaced apart by 9.45 inches, i.e. by slightly more than the radius. A transition portion  116  between the two curved walls  112 ,  114  is generally planar. 
     At the bottom of the housing  12   b,  there is a front or lower convexly-shaped wall  118  having a radius of 2 inches (again, as in FIG. 10 c ) and centered 2 inches above the base  104 , so as to continue smoothly into the base. The wall  118  extends through approximately  220  degrees and continues smoothly into the concavely-shaped wall  112 . 
     Corresonding to the previous embodiments, a drain outlet  70   b  is provided at the lower-most portion of the wall  112 , and is connected by tubing  72   b  to a drain outlet  74   b.  To ensure that excess liquid is contained by the wall  112  and does not flow off either end, either vertically upwardly extending lips can be provided or the center of the lower-most portion of the wall  112 , i.e. around the drain outlet  70   b,  can be dished downwards. If lips are provided, these need be provided just to the lower-most portion of the wall  112 , somewhat as extensions of the side wall  108 . 
     The arrangement of spray nozzles again follows that of the earlier embodiments. Here, there are two lower spray nozzles  30   b  mounted to the forward convexly-shaped wall  118 , these spray nozzles  30   b  being directed at an angle of 45 degrees to the horizontal, as viewed in FIG. 10 c,  and also directed inwardly. An upper spray nozzle  30   b  is mounted to the transition portion  116 , and is directed primarily downwardly but slightly rearwardly. It can be noted that all the spray nozzles can be arranged so as to be directed primarily to the centered curvature of the concavely-shaped wall  112 . 
     The other elements necessary for operation of this third embodiment would follow the previous embodiments, and are shown merely schematically. First, a blower is indicated at  84   b,  and would be directed forwardly and downwardly. As before, the blower  84   b  is intended mainly to encourage users to rub their hands together and obtain uniform coverage of a disinfecting solution. The amount of solution sprayed will be so small that no true drying action should be required. 
     Electronic controls are indicated at  76   b.  The storage tank stores the concentrated solution and is indicated at  40   b,  and as shown could be a generally rectangular parallelepiped. 
     In use, this third embodiment has the advantage that it is much more open, so as to encourage users to insert their hands. At the same time, it provides sufficient enclosure to contain spray and to collect and drain off any excess spray as only a fine mist of spray is used, in a small quantity, the problem of excess spray being splashed externally of the device should not be too great. 
     A user can insert his or her hands either directly from the front or indeed partially from the side. The relatively large open area enables a user to freely manipulate both hands and to rub the hands together, if desired, to obtain uniform coverage of the disinfecting solution. All of this can be accomplished without necessarily contacting the device or apparatus itself, thereby eliminating the problem of cross-contamination from one user to another. 
     It will be understood that the lower-most portion of the concavely-shaped wall  112  and at least part of the lower convexly-shaped wall  118 , together with lips at either side, as provided, or a dish-shape, provide a trough-shaped collection portion for collecting excess spray. As noted, this excess spray is then drained off through the drain  70   b.    
     The shape provided by the convex-shaped wall  114  provides an upper portion above the spray zone  28 . Correspondingly, the shape provided by the lower portion of the concavely-shaped wall  112 , together with the convexly-shaped wall  118  provides a lower portion defining the bottom of the spray chamber  28   b.  This lower portion is also considered to define a trough-shaped collection portion for collecting excess spray. The collection portion extends transversely and has ends at the two sides  108  of this embodiment. 
     It will be appreciated that while preferred embodiments of the present invention has been described, numerous variations are possible within the scope and spirit of the present invention.