Abstract:
A mobile supermarket trolley washing apparatus including an enclosure through which the trolleys pass. Spray nozzles deliver a liquid stream to the trolleys within the enclosure to clean the trolleys.

Description:
FIELD OF THE INVENTION 
     Supermarket trolleys, if cleaned at all, are cleaned manually with detergent and water. In some larger supermarkets, the expense associated with the washing of trolleys can be excessive due to the time involved in the manual operation and the wages which must be paid to the washing personnel. 
     OBJECT OF THE INVENTION 
     It is the object of the present invention to provide a convenient means by which supermarket trolleys can be washed en mass. 
     DISCLOSURE OF THE INVENTION 
     There is disclosed herein a mobile supermarket trolley washing apparatus for simultaneously washing a plurality of trolleys, said apparatus comprising: a chassis; an enclosure to contain the plurality of trolleys, said enclosure having first and second ends and being mounted on the chassis and into which said trolleys are delivered from either the first or second end to be cleaned, an opening at each of said ends through which said trolleys enter or leave said enclosure; a conveyor mounted on said chassis and extending through said enclosure, the conveyor being adapted to receive said trolleys to move the trolleys in either direction between said first and second ends; a plurality of liquid spray nozzles mounted to direct liquid spray at the interior of said enclosure to clean said trolleys being conveyed; an assembly to deliver an air curtain across each said opening such that said trolleys are dried; and means for recycling said sprayed liquid from said enclosure back to said nozzles. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings wherein: 
     FIG. 1 is a schematic side elevation of a mobile supermarket trolley wash unit; and 
     FIG. 2 is a schematic modification of the mobile supermarket trolley wash unit of FIG.  1 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In FIG. 1 of the accompanying drawings there is schematically depicted a mobile supermarket trolley washing unit  10 . Unit  10  is in the form of a trailer including a chassis  11  having a towing hitch  12  at its forward extremity. Unit  10  may be drawn behind a motor vehicle, a truck or a tractor for example. The chassis  11  supports an enclosed washing space defined by a pair of side walls  13 , a front wall  14 , a roof  15  and a rear wall  16  which is shown in a down-folded configuration providing an on/off ramp in the drawing. A tank  170  is attached to the chassis  11  and is adapted to store a mixture of water and a biodegradable detergent. The detergent might be of the type known as TURCO PLAUDIT F as provided by Elf Atochem. It is a multi-purpose, non perfumed liquid cleaner which can be diluted to forty parts of water. However, it should be appreciated that many other different types of detergent can be used. Associated with the storage tank  170  is a pump  180  which might be an electric pump driven by a battery. Pump  180  delivers liquid via tube  190  to two arrays of liquid nozzles  20 . Each array of nozzles  20  would be situated at one lateral side of the enclosed space defined by the walls of the cleaning unit. 
     Typically, each array of nozzles  20  is situated so as to direct a stream of diluted detergent at shopping trolleys  21 , laterally from one side thereof. That is, each array generally faces the other so as to spray the trolleys  21  therebetween. Alternatively, the nozzles  20  might be situated above and to the side of the trolleys and directed downwardly at an angle thereat. 
     The floor of the washing unit can include a tarp or other waterproof catchment means by which the over sprayed water and detergent is caught and returned via line  220  to the storage tank  170 . 
     Typically, each sidewall  13  is about 5.5 meters in length so as to accommodate the number of interengaged or stacked trolleys. Also, the floor of the unit is to be sufficiently wide to receive two trolleys side-by-side. The walls of the washing unit might typically be fabricated from aluminium sheet or other solid material. In an alternative arrangement, where the washing unit were constructed from a non-purpose built trailer, the walls thereof could have a waterproof membrane affixed thereto, which membrane might also extend across the floor of the trailer. Such a membrane would be adapted to prevent over sprayed washing liquid from permeating into the car park space and thus contaminating parked motor vehicles. 
     The unit might also include a grate at the upper edge of ramp  16  to prevent water from flowing down the ramp. Furthermore, plastic flaps could depend from the upper edge of the roof  15  down to the floor to prevent over spray. Similarly, plastic flaps might depend from the forward edge of the roof  15  and down to the floor of the unit. A grate might be provided at the floor at the vicinity of such plastic flaps for the purpose of water recirculation. 
     A walk platform might surround the enclosed space which receives the shopping trolleys which would serve the purpose of enabling access by an operator to inspect the operation of the unit. This might be particularly beneficial if the washing unit included no roof. 
     It should be appreciated that modifications and alterations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention. For example the water sprays  20  could be situated at the floor of the enclosed space and could be directed upwardly at the trolleys. 
     In an embodiment including no roof, if it were desirable to clean particularly stubborn dirt or grime from a trolley, an operator walking upon the exterior walking platform could direct a manual pressure washer over the walls of the unit at the trolley in question. 
     In the embodiment of FIG. 2 the unit  10  has the sidewalls  13  and roof  11  defining a tunnel  16  along which the trolleys are conveyed by means of a drivers conveyor  17 . 
     Also mounted on the chassis  11  is a “blower” assembly  18  which via ducting  19  delivers to the front  20  and rear  21  of the tunnel  16  air at raised pressure in order to recreate an air curtain. The air curtain aids to maintain water within the tunnel  11 . 
     Also mounted on the chassis  11  is a generator/pump, with the pump aspect thereof delivering water under pressure to the nozzles  20 . The generator/pump  22  is driven by means of a motor  23  having an exhaust  24 . The generator provides electric energy for the purposes of driving the blower  18  and motors which drive the conveyor  17 . 
     In operation of the unit  10 , trolleys are driven to through the tunnel  16  so that they are subjected to water exiting from the nozzles  20 . In this respect it should be appreciated that the conveyor  17  may be driven in either direction. 
     To aid in delivering and removing trolleys from the conveyor  17  there is provided ramps  25 .