MULTIFUNCTION TUNNEL MACHINE FOR SANITIZING TABLEWARE, AND RELATED METHOD

Abstract

 A multifunction tunnel machine (1) comprising sanitizing treatment zones (4, 5, 6) following each other along a conveying direction (T) of tableware (V, P, S), from an input end (2) of the tunnel machine (1) to an output end (3) of the tunnel machine (1), comprising a first and a second conveyor devices (7, 8), each of which conveys tableware (V, P, S) of a respective class along the treatment zones (4, 5, 6), characterized in that said at least one first and second conveyor devices (7, 8) are arranged at two levels. A corresponding method for sanitizing tableware.

Description

[0001] The present invention relates to a multifunction tunnel machine for sanitizing tableware, as well as to a related method. Multifunction tunnel machines are used in the professional field, and in particular in the context of catering for collective use, for example in the context of canteens.

[0002] In the present description and in the attached claims:

• under term "tunnel machine", a machine is meant which is configured to sanitize tableware, as well as any supports therefor, wherein tableware and any support are displaced inside the machine, so as to pass through a plurality of working zones in succession,
• in contrast thereto, under term "cycle machine" a machine is meant, which is configured to sanitize tableware, as well as any supports therefor, wherein tableware and any support remain stationary inside the machine, and undergo a plurality of working steps following each other over time,
• under term "cycle", a step of the sanitizing process is meant, irrespectively of whether it occurs in a zone of tunnel machine or in a time span in a cycle machine;
• under term "sanitize" and derived forms, the sequence of washing and rinsing steps, with optionally a pre-washing step and/or a pre-rinsing step and/or a dripping step and/or a drying step is meant;
• under term "canteen", an environment where meals are taken collectively is meant;
• under term "crockery", the assembly of plates, glasses, cups, bowls, jugs, teapots and the like, used to serve food and beverages at the table, is meant;
• under term "cutlery", the assembly of spoons, forks, knives and the like, used to serve food at the table, cut them and bring the food to the mouth, is meant;
• under term "tray", a container with a flat bottom with a raised edge and intended to contain crockery, cutlery, food, beverages and other items to be brought to the table is meant;
• under term "tableware", the assembly of crockery, cutlery and trays is meant;
• under term "tableware class" or briefly "class", any one of crockery, cutlery and trays is meant;
• under term "food", cooked or raw food, prepared to be eaten, is meant;
• under term "beverage", any liquid suitable to be drunk is meant;
• under term "multifunction tunnel machine", a tunnel machine providing for two or more tracks for different tableware classes is meant;
• expressions "upstream" and "downstream" refer to the oriented displacement direction of tableware with respect to the tunnel machine; expressions like "enter", "arrive", "exit" and derived forms are also to be meant with reference to such oriented displacement direction.

[0003] For sanitizing tableware, in the professional field and in particular in canteens, several solutions are known.

[0004] While it is possible to sanitize crockery, cutlery and trays in a non-sorted manner, in a single machine and, for what of most interest herein, in a single tunnel machine, this is not desirable because the three tableware classes have different sanitizing requirements in terms of times, temperatures, liquid solutions to be used, etc.; furthermore, the arrangement of all tableware on a same conveyor device does not turn out to be efficient and/or poses problems of shadowing of crockery and cutlery by the trays.

[0005] Therefore, the trays having dirty crockery and cutlery besides remains of food and beverages after catering, hereinafter called "dirty, full trays", are treated in advance (by dedicated staff or by the canteen customers) sorting the tableware to be sanitized into the three classes: crockery, cutlery and trays (and possibly other classes or subclasses), typically simultaneously with removal of remains of food and beverages, waste, and any other object such as non-disposable napkins or placemats.

[0006] Sometimes, each tableware class is separately fed to a respective tunnel machine or even, especially in the case of cutlery, cycle machine.

[0007] Tunnel machines specific for sanitizing trays are in general known, wherein trays are made to pass through at least a washing station and a rinsing station (and possible prewash, post-wash or pre-rinse, dripping and/or drying stations), remaining with the bottom resting on the conveyor device and moving in a horizontal or almost horizontal plane.

[0008] In other cases, two or more tableware classes are fed to respective tracks of a multifunction tunnel machine. A multifunction tunnel machine is in general cheaper to manufacture than two or more distinct tunnel machines, and allows space and operating resources to be spared, including staff in charge.

[0009] In WO2012/078424A2 a multifunction tunnel machine is disclosed, having at least one wash zone and at least one final rinse zone, and a conveyor apparatus for conveying washware through said zones. The conveyor apparatus has a first conveyor belt for trays or tray-like washware, and a second conveyor belt for other washware, which runs parallel to the first conveyor belt. The first conveyor belt has a width which is reduced in comparison to the second conveyor belt in such a way that a tray or tray-like item can be held by the first conveyor belt only when it is in a state in which it is placed on edge and is oriented parallel to the conveying direction. The machine may further have at least one further conveyor belt which runs parallel to the first and second conveyor belts, in particular for cutlery, which runs directly next to the first conveyor belt and between the first and second conveyor belts.

[0010] In other known multifunction tunnel machines, the trays are arranged on a conveyor device resting on an edge, but with an orientation of their plane essentially orthogonal to the conveying direction.

[0011] The known solutions are however very cumbersome.

[0012] Also cutlery magnetic capturing devices are in general known, arranged upstream of or at the sanitizing tunnel input.

[0013] The technical problem at the basis of the invention is to provide a multifunction tunnel machine with a reduced occupied space on the floor (or footprint).

[0014] The invention relates to a multifunction tunnel machine according to claim 1 and to a method for sanitizing tableware according to claim 11.

[0015] The provision of arranging a first and a second conveyor devices at two (or more) levels allows the footprint of the machine to be decreased.

[0016] Advantageous features of the machine and of the method are disclosed in the dependent claims.

[0017] Further features and advantages of the present invention will become clearer from the following detailed description of some preferred embodiments thereof, made with reference to the attached drawings, wherein:

• FIG. 1 is a schematic side view of a multifunction tunnel machine,
• FIG. 2 is a cross-section taken through section plane II-II of FIG. 1, internal to the tunnel machine,
• FIG. 3 is a cross-section taken through section plane III-III of FIG. 1, at the clean end of the tunnel machine,
• FIG. 4 is a cross-section corresponding to that of FIG. 2, but taken through another tunnel machine, and
• la FIG. 5 s a cross-section corresponding to that of FIG. 2, but taken through still another tunnel machine.

[0018] The drawings are totally schematic representations, and only the main components of a multifunction tunnel machine are shown therein.

[0019] With reference to FIGs. 1-3, a multifunction tunnel machine 1 comprises tableware sanitizing treatment zones, following each other along a conveying direction T of tableware, from an input end 2 or upstream end or dirty end of the tunnel machine 1 to an output end 3 or downstream end or clean end of the tunnel machine 1.

[0020] The treatment zones comprise, in the illustrated example machine 1 and as better described hereinafter, a washing zone 4, a rinsing zone 5, and a drying zone 6 following each other in the indicated order. However, there may be additional treatment zones, such as one or more of a pre-washing zone, a pre-rinsing zone, and a dripping zone.

[0021] The multifunction tunnel machine 1 shown in FIG. 1 is a tray washing- and cutlery washing machine and comprises two conveyor devices: a tray conveyor device 7 and a cutlery conveyor device 8, each of which conveys tableware of the respective class, namely trays V and cutlery P (shown totally schematically) through the treatment zones 4, 5, 6 along the conveying direction T.

[0022] The two conveyor devices 7, 8 are arranged at two levels, namely at different heights from the floor F, vertically spaced from one another. In the illustrated case, advantageously the cutlery conveyor device 8 is at an upper level, and the tray conveyor device 7 is at a lower level; this configuration is advantageous for the reasons that will become clear hereinafter, but also the opposite configuration is possible.

[0023] The tray conveyor device 7 is shown as comprising several sequential closed loop conveyors, but it could also be a single closed loop conveyor. The provision of two or more sequential conveyors is preferable to lessen the water transfer from the washing and rinsing zones 4, 5 to the drying zone 6.

[0024] The tray conveyor device 7 is configured to convey the trays V with the bottom of the trays resting thereon. The tray conveyor device 7 may thus, advantageously, be comprised even only of one or more conveying ropes, and in any case it may be without fingers or other holders, thus proving to be light, easily washable, and inexpensive both to manufacture and in terms of energy necessary for moving it.

[0025] The tray conveyor device 7 preferably extends, as shown, with at least one uphill section, a central section thereof in FIG. 1, preferably with a maximum climb angle comprised between 2° and 15°, preferably comprised between 3° and 6°. This favours the escape from the trays V of any remains of food and beverages, as well as liquid washing and rinsing solutions, by gravity.

[0026] The cutlery conveyor device 8 is preferably a single closed loop conveyor, but it also could comprise several closed loop conveyors following each other.

[0027] The cutlery conveyor device 8 is preferably formed of a plurality of members 9 having a holed bottom and retaining shoulders, articulated to each other along axes orthogonal to the closed loop path.

[0028] The cutlery conveyor device 8 preferably extends essentially flat. This limits the height extent of the tunnel machine 1.

[0029] The specific embodiment of the conveyor devices 7, 8 could be of any known type, both for flight-type machines, and for rack-conveyor machines.

[0030] In the case of the tunnel machine 1 shown in FIGs. 1-3, the two conveyor devices 7, 8 have longitudinal median axes extended in a same vertical plane, and have comparable widths, so as to totally overlap in the direction transverse to the conveying direction T (cf. FIG. 2). However, this is not strictly necessary and the two conveyor devices 7, 8 may have different widths and/or be misaligned, so as to overlap only partially in the direction transverse to the conveying direction T. The greater the overlapping, the smaller the total size of the tunnel machine 1 in the direction transverse to the conveying direction T, or width of the tunnel machine 1.

[0031] In the case of the tunnel machine 1 shown in FIGs. 1-3, the cutlery conveyor device 8 has a greater length than that of the tray conveyor device 7, and protrudes beyond the latter at both ends 2, 3 of the machine, protruding comparatively much at the input end 2 and comparatively little at the output end 3. In other words, the forward travel along the conveying direction T of the cutlery conveyor device 8 starts earlier and ends later with respect to that of the tray conveyor device 7. The cutlery conveyor device 8 thus totally overlaps the tray conveyor device 7 in that direction and their median transverse planes do not coincide. However, this is not strictly necessary, it being enough that the two devices overlap at least partially in the conveying direction T; it is possible to select whether and which one of the two starts earlier independently of the choice whether and which one of the two ends first (with reference to the forward travel).

[0032] However, the greater the overlap, the smaller the total size of the tunnel machine 1 in conveying direction T, or length of the tunnel machine 1. However, the fact that the conveyor devices 7, 8 do not start their respective forward travel at the same position and/or do not end it at the same position favours the arrangement of bearing structures and drive members thereof, as well as the arrangement of loading and/or unloading apparatuses of the tunnel machine 1 and/or of the maneuvering station for operators in charge of loading and/or unloading the tunnel machine 1.

[0033] The provision of arranging a first and a second conveyor devices 7, 8 at two levels allows the footprint of the machine to be reduced.

[0034] At the input end of the tunnel machine 1 there may be a loading apparatus 50 of the tunnel machine 1, which may be an integral part of the tunnel machine 1, or it may be distinct from and operatively coupled to the tunnel machine 1.

[0035] The loading apparatus 50 of FIG. 1 comprises a cutlery magnetic capturing device 51 or magnetic cutlery handler.

[0036] The cutlery magnetic capturing device 51 may comprise a conveyor belt 52 magnetized by a suitable electromagnetic device not shown, and for example, closed in a loop in a triangular path, having a horizontal section 53, an uphill ramp section 54 departing from an end of the horizontal section 53, and a return section 55.

[0037] At the upper end of the uphill ramp section 54, in the loading apparatus 50 there are, preferably, a deviator 56 and a chute 57. The lower end 58 of the chute 57 is operatively coupled to the cutlery conveyor device 8.

[0038] The horizontal section 53 of the cutlery magnetic capturing device 51 is arranged parallel to and above a zone of the loading apparatus 50 wherein dirty trays V with dirty cutlery P thereon pass through, on a dirty trays conveyor device 70 which may be part of the loading apparatus 50 or distinct therefrom, in any case external to the sanitizing tunnel of machine 1.

[0039] The conveyor device 70 for dirty trays V may, advantageously, be loaded directly by the canteen users or by the staff in an upstream position of the cutlery magnetic capturing device 51. Preferably, as shown, the horizontal section 53 of the cutlery magnetic capturing device 51 is arranged above the conveyor device 70 for dirty trays V downstream of a station whereat users or a person in charge of loading the tunnel machine 1 remove from the dirty trays V possible crockery S, waste, as much as possible remains of food and beverages, as well as items other than cutlery P and the trays V themselves - or wherein an apparatus automatically carries out those operations. Cutlery P arranged on the trays V is attracted by the horizontal section 53 of the cutlery magnetic capturing device 50, and is conveyed along the uphill ramp section 54 up to deviator 56, which detaches them from the conveyor belt 52 of the magnetic capturing device 51, making it fall into chute 56. At the lower end of chute 56, cutlery falls on the cutlery conveyor device 8 to be conveyed in the conveying direction T along the tunnel machine 1.

[0040] Those skilled in the art will understand that other configurations of the cutlery magnetic capturing device 51 are possible, provided that it is operatively coupled between the arrival zone of trays V and dirty cutlery P, and the cutlery conveyor device 8. Merely by way of an example, roll magnetic capturing devices are mentioned.

[0041] Advantageously, the dirty trays conveyor device 70 proceeds, by then with just the trays V arranged thereon, up to the tray conveyor device 7, with which the trays V are conveyed in conveying direction T along the tunnel machine 1. Advantageously, the dirty trays V need not be moved from their flat position.

[0042] Alternatively, the dirty trays conveyor device 70 may coincide with the tray conveyor device 7 itself.

[0043] At the dirty end 2 of the tunnel machine, the service staff therefore only needs to take care of crockery S and other tableware, but not of trays and cutlery, with manifest advantages in terms of time, efficiency, cost, occupied space, hygiene.

[0044] At the output end of the tunnel machine 1, as also manifest form FIG. 3, the cutlery conveyor device 8 preferably ends its forward travel above the mouth 11 of a chute 10, from which lower output 12 clean cutlery P exits, to fall for example in a collection container (not shown) transportable by hand or mobile for example on wheels. Preferably, the chute 10 extends transversely or obliquely to the conveying direction T, so that the cutlery collection container can be arranged out of the line followed by the trays V.

[0045] At the output end of the tunnel machine 1, the tray conveyor device 7 lets the trays fall for example onto a tray accumulator 60, which may be an integral part of the tunnel machine 1 or more advantageously may be distinct therefrom, operatively coupled thereto, and preferably mobile for example on rails or wheels. The tray accumulator 80, per se well known, may for example comprise a bottom movable along vertical guides against the force of elastic members (springs), which lowers under the weight of the clean V trays that gradually accumulate thereon. Alternatively, at the output end of the tunnel machine 1, at the tray conveyor device 7 there may be a conveyor device for clean trays V, or any other provision well known per se.

[0046] At the clean end 3 of the tunnel machine 1, no staff in charge is needed. The staff in charge therefore needs only to take care of unloading crockery S from a special sanitizing machine, similarly with manifest advantages in terms of time, efficiency, cost, size, hygiene.

[0047] A merely example arrangement of the sanitizing zones 4, 5, 6 is schematically shown in FIG. 1.

[0048] The tunnel machine 1 comprises a tunnel 13 wherein the trays and cutlery conveyor devices 7, 8 extend, and a service zone 14 below the tunnel 13. The bottom of the tunnel 13 is preferably slightly tilted, the clean end being higher than the dirty end, so that the liquid washing and rinsing solutions and the remains of food and beverages slide toward the dirty end.

[0049] The washing zone 4 comprises a tray washing subzone 15 and a cutlery washing subzone 16. The tray washing subzone 15 comprises a plurality of nozzles 17 arranged above and below the forward travel of the tray conveyor device 7, however nozzles arranged only above the forward travel of the tray conveyor device 7 may be provided for. Alternatively or additionally, there may be washing nozzles arranged laterally of the forward travel of the tray conveyor device 7. The cutlery washing subzone 16 comprises a plurality of nozzles 18 arranged above and below the forward travel of the cutlery conveyor device 8, however nozzles arranged only above or only below the forward travel of the cutlery conveyor device 8 may be provided for. Alternatively or additionally, there may be washing nozzles arranged laterally of the forward travel of the cutlery conveyor device 8.

[0050] A liquid washing solution is pumped from a recycle tank 19 to the washing nozzles 17, 18 by respective washing pumps 20, 21, and then sprayed from the washing nozzles 17, 18 on the trays V, respectively on the cutlery P conveyed within the tunnel machine 1.

[0051] The conduits extended between the washing pumps 20, 21 and the washing nozzles 17, 18, as well as other conduits extended between the components described further below, are shown schematically by a dotted line and are not numbered for the sake of clarity.

[0052] The recycle tank 19 and the washing pumps 20, 21 are housed in the service zone 14. The recycle tank 19 opens on the bottom of the tunnel 13 to receive, among other things, the liquid washing solution which falls from the trays V and the cutlery P, so that the liquid washing solution is circulated in the washing zone 4. The liquid washing solution typically comprises water added with a detergent.

[0053] There is typically a filter (not shown) on the bottom of the recycle tank 19, upstream of the washing pumps 20, 21, in order to hold remains of food and any other object. In a well-known manner, a part of dirty liquid washing solution may be discharged from the recycle tank 19 in a manner not shown, so that the liquid washing solution is partially renewed.

[0054] Alternatively, there could be only one washing pump to supply the washing nozzles 17 and 18.

[0055] The rinsing zone 5 comprises a tray rinsing subzone 22 and a cutlery rinsing subzone 23. The tray rinsing subzone 22 comprises a plurality of nozzles 24 arranged above and below the forward travel of the tray conveyor device 7, however nozzles arranged only above the forward travel of the tray conveyor device 7 may be provided for. Alternatively or additionally, there may be rinsing nozzles arranged laterally of the forward travel of the tray conveyor device 7. The cutlery rinsing subzone 23 comprises a plurality of nozzles 25 arranged above and below the forward travel of the cutlery conveyor device 8, however nozzles arranged only above or only below the forward travel of the cutlery conveyor device 8 may be provided for. Alternatively or additionally, there may be rinsing nozzles arranged laterally of the forward travel of the cutlery conveyor device 8.

[0056] A liquid rinsing solution, comprising clean water possibly added with rinse aid, is heated by a respective boiler 26, 27 and supplied to the rinsing nozzles 24, 25 and sprayed from the rinsing nozzles 24, 25 onto the trays V, respectively onto the cutlery P, conveyed within tunnel machine 1. The boilers 26, 27 are housed in the service zone 14. The boilers 26, 27 receive clean water directly form the water supply, there being typically a respective non-return device (not shown) upstream of each boiler 26, 27, or from the water supply through a tank (not shown). There may also be, upstream or downstream of each boiler 26, 27, pumps (rinsing pumps, not shown) in order to impart a proper pressure to the liquid solution at the rinsing nozzles 24, 25, especially in the case where the intermediate tank is provided for. The boilers 26, 27 might be replaced by a single boiler, and possibly by two distinct mixers with cold water in order to obtain different rinsing temperatures for trays and cutlery.

[0057] The liquid rinsing solution falling from the trays V and the cutlery P is collected on the bottom of the tunnel 13 and conveyed to the recycle tank 19, where it mixes with the liquid washing solution and partly renews it. The liquid washing solution typically comprises water added with a detergent.

[0058] The rinsing zone 6 comprises a tray drying subzone 28 and a cutlery drying subzone 29. The tray drying subzone 28 comprises a plurality of nozzles 30 arranged above and below the forward travel of the tray conveyor device 7, however nozzles arranged only above the forward travel of the tray conveyor device 7 may be provided for. Alternatively or additionally, there may be drying nozzles arranged laterally of the forward travel of the tray conveyor device 7. The tray drying nozzles 30 are preferably of the flat type so that each emits an air blade.

[0059] A high temperature, low humidity degree air flow (hot dry air) is forced by one or more blowers 31 (two being shown in FIG. 1) and supplied to the drying nozzles 30 and blown from the drying nozzles 30 onto the trays V conveyed within the tunnel machine 1, favouring the removal of water from the trays and/or its evaporation in situ. The blowers 31 are housed in the service zone 14.

[0060] The cutlery drying subzone 29 comprises a fan 32 and a heater 33, for example an electric resistance, arranged at the input of a conduit 34 having a mouth 35 above the cutlery conveyor device 8. A high temperature, low humidity air flow (hot dry air) is in this way forced onto the cutlery P conveyed within the tunnel machine 1, favouring the removal of water from the cutlery and/or its evaporation in situ. However, drying nozzles might be provided for also for cutlery.

[0061] Alternatively, in the drying zone 6 or in one of its subzones 28, 29, drying could take place in different manners, as well known per se, for example only through heating.

[0062] Last, in the tunnel machine 1 of FIG. 1 there are shown a motor 36 for moving the tray conveyor 7, and a motor 37 for moving the cutlery conveyor 8, advantageously also housed in the service zone 14. The provision of two distinct motors 36, 37 aids the independent setting of the speed of the two conveyor devices 7, 8 and their stop and start. Alternatively, however, there may be a single motor, in that case two motion transmission devices being preferably provided for from the motor shaft to the conveyors 7, 8, having a different gear ratio.

[0063] In general, the first and the second conveyor devices are preferably driven at a different speed.

[0064] The treatment subzones of each tableware class (trays V and cutlery P in the case of the tunnel machine of FIG. 1) are preferably staggered in the conveying direction T, as shown at least for the washing subzones 15, 16 and, most of all, for the rinsing subzones 22, 23. The treatment subzone of the tableware class conveyed by the conveyor device at the upper level, cutlery P in the case shown, is more upstream, in conveying direction T, with respect to the treatment subzone of the tableware class conveyed by the conveyor device at the lower level, trays V in the case shown. In that manner, the liquid rinsing solution falling from cutlery P falls onto the trays V, if it does, before the latter are rinsed, and preferably also the liquid washing solution falling from cutlery P falls onto the trays V, if it does, before the latter are washed.

[0065] However, at least in some of the treatment zones 4-6 there may be fluid deviating means extended between the two conveyor devices 7, 8 in order to deviate the liquid solution falling from the upper conveyor device 8 away from the lower conveyor device 7 and/or to deviate the forced air flow, by that time cooled down and more humid after the passage through the upper conveyor device 8, away from the lower conveyor device 7. In the section of FIG. 2 there are shown, for example, two deviators 38.

[0066] In the tunnel machine 1 of FIG. 1 there are, in the order from its input end 2 towards its output end 3: a first compartment 39 wherein there are the tray and cutlery washing zone 4 and the cutlery rinsing subzone 23, as well as the recycle tank 19 and the pumps 20, 21; a second compartment 40 wherein there are the tray rinsing subzone 22 and the respective boiler 26; a third compartment 41 wherein there is the tray and cutlery drying zone 6 with the blowers 31 for the forced air flow onto the trays and the fan 32 and the heater 33 for the forced air flow onto the cutlery; and a fourth compartment 42 housing the boiler 27 for heating the cutlery liquid rinsing solution and the motor 37 of the cutlery conveyor device 8.

[0067] The compartments 39-42 are partially divided by (unnumbered) partition walls which restrain the liquid washing and rinsing solutions, and the forced air flows, besides maintaining the various zones at different temperatures.

[0068] In the tunnel machine 1 of FIG. 1 there are also two compartments without the service zone 14: a fifth compartment 43 arranged at the input end 2 and containing the beginning of the cutlery conveyor device 8 and coupled to the lower output 58 of the chute 57 of the cutlery magnetic capturing device 51; and a sixth compartment 44 arranged at the output end 3 and containing the end of the tray conveyor device 7 and the end of the cutlery conveyor device 8 with the respective chute 10.

[0069] Those skilled in the art will understand that the various components of the tunnel machine 1 of FIG. 1 and the respective arrangement are merely examples and may undergo several changes, omissions, and/or integrations. In particular, besides the already mentioned variants, it is mentioned that in the drying zone, heat recovery means and/or moisture recovery means may be provided for. For example, heat recovery devices, both passive and active (e.g. heat pumps), may be provided for, typically housed above the washing zone 4 and/or above the rinsing zone 5 and/or connected with the drying zone 6, which recovery part of the heat that would be dispersed in the environment to heat and/or pre-heat the water used, both for rinsing and for washing.

[0070] Furthermore, as mentioned, also other treatment zones may be provided for, for example one or more among pre-washing, pre-rinsing, dripping zones, possibly provided with respective recycle tanks. The additional recycle tanks may be in fluid communication with each other and/or with the recycle tank 19 through overflow devices, so that a part of the less dirty liquid solution is "counter-current" conveyed within the tunnel machine, from downstream towards upstream with respect to the tableware conveying direction T.

[0071] Furthermore, as mentioned, each of the sanitizing zones 4, 5, 6 may be a multistage one.

[0072] A pre-rinsing zone and/or the rinsing zone 5 might additionally comprise nozzles for supplying an air flow under pressure in order to exert a "mechanical" cleaning action onto the tableware and/or in order to "mechanically" remove the liquid washing solution from the tableware.

[0073] FIG. 4 schematically shows a multifunction tunnel machine 80, for sanitizing three classes of tableware. Indeed, additionally to a conveyor device 81 for trays V and a conveyor device 82 for cutlery P, there is also a conveyor device 83 for crockery V, which conveys crockery V through the treatment zones 4-6, where associated treatment subzones may be provided for, analogously to what has been described above with reference to the tunnel machine 1.

[0074] In the multifunction tunnel machine 80 shown in FIG. 4, the third conveyor device 83 is substantially at the level of the upper, cutlery conveyor device 82, side by side and parallel thereto. In the case shown, they are specifically side by side tracks of one and the same conveyor device, wherein in the track forming the conveyor device 83 for crockery V, fingers 84 for retaining the crockery are provided for, suitable to retain for example the plates in an orientation substantially transverse to the conveying direction. Such an arrangement allows a single motor to be used for the two conveyors 82, 83, but the latter could alternatively be independent from each other so as to allow their speed, start and stop to be independently set. The conveyor device 81 for crockery V may be loaded by hand by the staff in charge of the tunnel machine 80, or by automatic loading apparatuses per se well known.

[0075] Alternatively to specific treatment subzones, the same subzones 16, 23, 29 provided for cutlery may be used, suitably extended in the width direction of the machine 80.

[0076] FIG. 5 schematically shows a multifunction tunnel machine 90, also for sanitizing three tableware classes. Indeed, additionally to a conveyor device 91 for trays V and a conveyor device 92 for cutlery P, also in this case there is also a conveyor device 93 for crockery V, which conveys crockery V through the treatment zones 4-6, where associated treatment subzones may be provided for, analogously to what has been described above with reference to the tunnel machine 1. Also on the conveyor device 93 for crockery V, fingers 94 for retaining the crockery are provided for, suitable to retain for example the plates in an orientation substantially transverse to the conveying direction. The conveyor device 93 for crockery V may be loaded by hand by the staff in charge of the tunnel machine 90, or by automatic loading apparatuses per se well known.

[0077] In the multifunction tunnel machine 90 shown in FIG. 5, the third conveyor device 93 is substantially at the level of the lower, tray conveyor device 91, side by side and parallel thereto. However, the tray conveyor device 91 differs from the tray conveyor device 7 of the tunnel machine 1 of FIGs. 1-3 in that it is configured to convey trays V with an edge of the trays V resting thereonto, and with the plane of the trays V extending parallel to the conveying direction T and forming an angle less than or equal to 45° with the vertical.

[0078] The trays conveyor device 91 does not need to be or have an uphill section, differently from what is shown in the tunnel machine 1 of FIGs. 1-3.

[0079] The tilting of the dirty trays V from the flat orientation to said orientation at the input end 2 of the multifunction tunnel machine 90, and the tilting of the clean trays V from said orientation to the flat orientation at the output end 3 of the multifunction tunnel machine 90, may take place manually by the staff in charge or by suitable automatic or semi-automatic loading and unloading devices or apparatuses per se well known in the art and, as such, not described herein in detail.

[0080] Alternatively to the magnetic capturer 51 for cutlery P, because the trays V are conveyed vertically or almost vertically, it may be provided for cutlery P to slide by gravity, during the tilting of the tray V, onto a conveyor device aligned thereto along the conveying direction T and rising up to the cutlery conveyor device 92.

[0081] Alternatively to specific treatment subzones, the same subzones 15, 22, 28 provided for the trays may be used, suitably extended in the width direction of the machine 80.

[0082] For the sake of brevity, a detailed description of the multifunction tunnel machines 80, 90 is omitted, the same being within the skills of those skilled in the art in the light of the present description.

[0083] However, it is noted that with such multifunction tunnel machines 80, 90, service staff has at most to take care of the crockery S both at the dirty end and at the clean end of the tunnel machine, with manifest advantages in terms of time, efficiency, cost, occupied space, hygiene.

[0084] In a multifunction tunnel machine (not shown) wherein the trays V are conveyed vertically or almost vertically on the respective conveyor device as shown for example in FIG. 5, but the tray conveyor device is at a level above that of the cutlery conveyor device, it may be provided for cutlery P to slide by gravity, during tilting of the tray V, directly onto the cutlery conveyor device.

[0085] A multifunction tunnel machine as disclosed herein may also have three or more conveyor devices which convey tableware of a respective class through the treatment zones, the conveyor devices being arranged at three or more levels, and preferably overlapped at least partially. For example, crockery might be conveyed at an intermediate level between the upper level wherein cutlery is conveyed and the lower level wherein trays are conveyed.

[0086] When there are more than three conveyor devices which convey tableware of a respective class through the treatment zones, the conveyor devices may be arranged at two or more levels, and preferably overlapped at least partially.

[0087] A controller (not shown) controls and coordinates the operation of the components of the multifunction tunnel machine 1 during the sanitizing cycle.

[0088] Those skilled in the art will understand that hereinabove a method for sanitizing tableware has also been described in detail, comprising the steps of sorting said tableware into at least two classes, which preferably comprise trays and cutlery; arranging the tableware of at least two classes onto at least a first and a second conveyor devices arranged at two different levels, and conveying the tableware through sanitizing zones by said at least a first and a second conveyor devices.

[0089] Sanitizing may comprise the steps of:

a) washing tableware through supply of a washing solution from washing nozzles;

b) rinsing the tableware through supply of a rinsing solution from rinsing nozzles;

c) drying the tableware,

wherein each of steps a), b), c) is carried out through substeps which are respectively dedicated to a respective class of tableware.

[0090] Preferably the sorting step comprises magnetically capturing the tableware belonging to the cutlery class from tableware belonging to the tray class.

[0091] Preferably moreover the method comprises conveying the tableware belonging to the tray class by keeping them with the bottom resting onto one of said first and second conveyor devices.

[0092] Alternatively, the method comprises tilting the tableware belonging to the tray class by arranging the tray plane parallel to the conveying direction, and forming an angle less than or equal to 45° with the vertical, before conveying them by one of said first and second conveyor devices.

[0093] Preferred features of the method correspond to preferred features of the above-described controller.

[0094] The various embodiments, variants and/or possibilities of each component or group of components that have been described are to be meant as combinable with each other in any manner, unless they are mutually incompatible.

[0095] The above is a description of various embodiments, variants and/or possibilities of inventive aspects, and further changes can be made without departing from the scope of the present invention. The shape and/or size and/or location and/or orientation of the various components and/or the succession of the various steps can be changed. The functions of an element or module can be carried out by two or more components or modules, and vice-versa. Components shown directly connected to or contacting each other can have intermediate structures arranged in between them. Steps shown directly following each other can have intermediate steps carried out between them. The details shown in a figure and/or described with reference to a figure or to an embodiment can apply in other figures or embodiments. Not all of the details shown in a figure or described in a same context must necessarily be present in a same embodiment. Features or aspects that turn out to be innovative with respect to the prior art, alone or in combination with other features, should be deemed to be described per se, irrespective of what is explicitly described as innovative.

Claims

1. Multifunction tunnel machine (1; 80; 90) comprising sanitizing treatment zones (4, 5, 6) following each other along a conveying direction (T) of tableware (V, P, S), from an input end (2) of the tunnel machine (1) to an output end (3) of the tunnel machine (1), comprising a first and a second conveyor devices (7, 8; 81, 82; 91, 92), each of which conveys tableware (V, P, S) of a respective class along the treatment zones (4, 5, 6), characterized in that said at least one first and second conveyor devices (7, 8; 81, 82; 91, 92) are arranged at two levels.

2. Multifunction tunnel machine (1; 80; 90) according to claim 1, wherein said at least one first and second conveyor devices (7, 8; 81, 82; 91, 92) overlap at least partially.

3. Multifunction tunnel machine (1; 80; 90) according to any of claims 1-2, wherein the first and second classes of tableware (V, P, S) comprise trays (V) and cutlery (P), respectively.

4. Multifunction tunnel machine (1; 80; 90) according to any of claims 1-3, wherein said first, tray conveyor device (7; 81; 91) is at a lower level and said second, cutlery conveyor device (8; 82; 92) is at an upper level.

5. Multifunction tunnel machine (1; 80) according to any of claims 1-4, wherein said first, tray conveyor device (7; 81) is configured to convey the trays (V) with the bottom of the trays (V) resting on the first tray conveyor device (7; 81), and preferably extends with at least one uphill section, preferably with a maximum climb angle comprised between 2° and 15°, preferably comprised between 3° and 6°.

6. Multifunction tunnel machine (1; 80; 90) according to any of claims 1-5, wherein the treatment zones (4, 5, 6) comprise treatment subzones (15, 16, 22, 23, 28, 29) of each class of tableware (V, P, S), wherein in at least some treatment zones (4, 5) and in particular at least in a rinsing zone (5), the treatment subzones (15, 16, 22, 23) are staggered in the conveying direction (T), the treatment subzone (16, 23) of the class of tableware (P) conveyed by the conveyor device (8; 82; 92) at the upper level being more upstream, in the conveying direction (T), than the treatment sub zone (15, 22) of the class of tableware (V) conveyed by the conveyor device (7; 81; 91) at the lower level.

7. Multifunction tunnel machine (1; 80; 90) according to any of claims 1-6, wherein in at least some of the treatment zones (4, 5, 6) there are fluid deviating means (38) extended between the first and the second conveyor devices (7, 8; 81, 82; 91, 92).

8. Multifunction tunnel machine (80; 90) according to any of claims 1-7, further comprising at least one third conveyor device (83; 93) which conveys tableware (S) of a third class through the treatment zones (4, 5, 6), wherein preferably the third class of tableware comprises crockery (S).

9. Multifunction tunnel machine (80; 90) according to claim 8, wherein said at least one third conveyor device (83; 93) is essentially at the level of one of the first and second conveyor devices (81, 82; 91, 92), side by side and parallel thereto.

10. Multifunction tunnel machine (1; 80; 90) according to any of claims 1-9, comprising a cutlery magnetic capturing device (magnetic cutlery handler) (51) upstream of said second conveyor device (8; 82; 92) intended for cutlery (P), the cutlery magnetic capturing device (51) preferably extending above a conveyor device (70) along which dirty, full trays (V) are suitably emptied of crockery (S), are emptied of cutlery (P) by the cutlery magnetic capturing device (51), and are finally fed to the multifunction tunnel machine (1; 80; 90).

11. Method for sanitizing tableware, comprising the steps of sorting said tableware into at least two classes, which preferably comprise trays and cutlery; arranging the tableware of at least two classes onto at least a first and a second conveyor devices arranged at two different levels, and conveying the tableware through sanitizing zones by said at least a first and a second conveyor devices.

12. Method according to claim 11, wherein sanitizing comprises the steps of:

a) washing tableware through supply of a washing solution from washing nozzles;

b) rinsing the tableware through supply of a rinsing solution from rinsing nozzles;

c) drying the tableware,

wherein each of steps a), b), c) is carried out through substeps which are respectively dedicated to a respective class of tableware.

13. Method according to any of claims 11-12, wherein the sorting step comprises magnetically capturing the tableware belonging to the cutlery class from tableware belonging to the tray class.

14. Method according to any of claims 11-13, comprising conveying the tableware belonging to the tray class by keeping them with the bottom resting onto one of said first and second conveyor devices, or comprising tilting the tableware belonging to the tray class by arranging the tray plane parallel to the conveying direction, and forming an angle less than or equal to 45° with the vertical, before conveying them by one of said first and second conveyor devices.

Drawing