Abstract:
The apparatus comprises a horizontal, extensible shovel which is driven step by step through a predetermined path by motorized means; a distributor of dough loaves arranged for dropping loaves at a first stop in the shovel path; a pizza moulder arranged at a second stop in the shovel path, for pressing and spreading the loaf; several distributors of a dressing, placed at at least a third stop in the shovel path, for dropping metered portions of dressing on the pizza carried by the shovel; and an oven placed at a fourth stop in the shovel path, for receiving the pizza from the shovel.

Description:
BACKGROUND OF THE INVENTION 
     The invention is concerned with an apparatus for the mechanized and customized preparation of pizzas, particularly for use in self-service restaurants and pizzerias. 
     Today, pizzas are mostly prepared to order in pizzerias by a pizza-baker who generally, for each pizza, picks up a premixed and leavened portion of dough, spreads it out, and lays it on a baker&#39;s shovel. He then sprinkles the pizza with prepared dressings, such as hashed mozzarella, tomato, anchovies, minced ham and/or other dressings, and finally puts the pizza so prepared into the oven. It can be seen that the preparation of the pizza, though quick, is work-intensive, and compels the pizza-baker to a hard and continuous work over the full opening hours of the restaurant. 
     In order to reduce the requirements for specialized staff, U.S. Pat. No. 2,190,483 discloses a pizza-making machine where the pizzas are carried on a number of trays which are moved at fixed intervals along a circular path through loaf-flattening station, a seasoning station, a tunnel oven, and finally a pizza-unloading station. Beside being quite complex and costly to manufacture, the machine of U.S. Pat. No. 2,190,483 is also quite rigid in operation, because each of its trays proceeds through the operating cycle in equal steps. Moreover, the trays are led in queue through a tunnel oven while their associated pizzas are baked, adding to the operating rigidity of the machine, since the progression rate of the pizzas under preparation must conform to the dwelling time in the oven. Because of its large number of trays with underlying mechanisms, and because of the poorly accessible tunnel-shaped oven, the machine is also generally difficult to clean. In a similar approach, WO 98/04137 discloses a pizza-making machine having a carrousel structure, and which suffers from the same limitations of operating rigidity, mechanical complexity, high manufacturing cost, and difficult cleaning. The machine of WO 98/04137 includes, however, a distributor of dough loaves. 
     SUMMARY OF THE INVENTION 
     The main object of the invention is therefore to provide an apparatus for the mechanized preparation of pizzas, by which the pizzas can be prepared and baked on order, without appreciable human help, which is more flexible in operation with respect to known apparatuses, and which is of a simpler and less expensive construction. 
     Another important aim of the invention is to provide an apparatus for the mechanized preparation of pizzas, which can be cleaned more easily than known means, and which, in general, is more satisfactory from the sanitary viewpoint. 
     The invention achieves the above and other objects and advantages, such as will appear from the following disclosure, with an an apparatus for the mechanized and customized preparation of pizzas having the features recited in claim  1 . 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be further described with reference to a few preferred embodiments which are disclosed in the following disclosure and are shown, by way of nonlimiting example, in the attached drawings, wherein: 
     FIG. 1 is a perspective view of an apparatus for the preparation of pizzas according to the preferred embodiment of the invention; 
     FIG. 2 is a diagrammatical plan view of the apparatus of FIG. 1; 
     FIG. 3 is a enlarged view in axial cross-section of a detail of the apparatus of FIG. 1; 
     FIG. 4 is a perspective view, partly broken away, on an enlarged scale, of a loaf distributor belonging to the apparatus of FIG. 1; 
     FIG. 5 is a perspective view, partly broken away, on an enlarged scale, of a spreader device belonging to the apparatus of FIG. 1; 
     FIG. 6 is an exploded, perspective view of a dressing distributor belonging to the apparatus of FIG. 1; 
     FIG. 7 is a diagrammatical, plan view of a modification of the apparatus of FIG. 1; and 
     FIG. 8 is a view, similar to FIG. 1, showing a version of the apparatus according to the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With particular reference to FIGS. 1 and 2, a bedplate  10  supports a motor  12  with associated reduction gear  14 , having a vertical output shaft  16 . A bracket  18  is supported at the top of shaft  16  and carries a movable slide  20  having a horizontal shovel  22  at one end. A double-action air cylinder  24 , connected between slide  20  and a lug  26  integral with bracket  18 , is adapted to drive slide  20  in both directions. Cylinder  24  is driven through two air lines  28  and  30 , which are supplied through a rotating joint, shown in more detail on FIG.  3 . 
     With reference to FIG. 3, the rotating joint comprises a sleeve  32  surrounding shaft  16  and kept in position by a bracket  34 . Sleeve  32  has two connectors  36 ,  38 , which can be supplied alternatively with compressed air from a system not shown through an electrovalve  40 . The connectors open to respective internal peripheral grooves  42 ,  44 , provided with adjacent sealing gaskets  46 . Grooves  42 ,  44  communicate with respective ducts  48 ,  50 , which are machined within shaft  16  and terminate at respective fittings  52 ,  54 , with which air lines  28  and  30  are connected. 
     With further reference to FIG. 1 and 2, the apparatus according to the invention also comprises a loaf distributor  56 , a pizza moulder  58 , several dressing distributors  60  (only one being shown in FIG. 1 for simplicity), and finally a baking oven  62 , all of which are arranged around central shaft  16 , at substantially similar radial distances, as will be explained below in more detail. A circular raceway  64 , coaxial with shaft  16 , is placed beneath the delivery outlets of devices  56  to  60 , to act as a collector for any material that might drop from shovel  22 , as better disclosed below. 
     Turning now to FIG. 4, the loaf distributor  56  comprises a cylindrical casing  70 , which is supported on a pedestal  72  and which terminates below with a funnel  74  having a vertical delivery outlet  76  opening downwards at a small distance from the level of shovel  22 . Within casing  70 , a magazine of dough loaves comprises a frame having three annular shelves  78 , which are intended for storing a number of globular dough loaves such as  80  and are rotatably supported on three rubber-coated rollers  82 , one of which is driven by a motor  84  with reduction gear. At each shelf  78  a respective pusher paddle such as  86  is arranged, which can be driven by a respective hydraulic cylinder  88  for radially sweeping across the associated shelf and pushing a dough loaf  80  toward the shelf axis, and consequently dropping the loaf into inclined funnel  74  and toward outlet  76 . Near paddle  86 , a proximity sensor  90  is preferably arranged, which will detect the presence or absence of a loaf and will either enable the operation of the associated paddle, if a loaf is present, or step shelves  78  forward, if a loaf is absent, according to a program that is implemented in control circuits not shown, because they are obvious for a person skilled in the field and are outside the scope of the invention. 
     In operation, motor  12  steps shaft  16  around, together with shovel  22 . The shovel stops beneath outlet  76 , and, at the same time, one of actuator cylinders  88  to drop a loaf into funnel  74  and from there on the shovel. 
     Turning now to FIG. 5, pizza moulder  58  of FIG. 1 comprises a post  92  on which a vertical rod  94 , driven by an air cylinder  96 , is slidably supported. Rod  94  has a horizontal spreader disk  98  at its lower end, the disk having a flat lower surface, preferably provided with a peripheral groove  100 . Rod  94  is also bored axially, so that a duct  102  is formed from a fitting  104  to the center of spreader disk  98 , for connection of a source of compressed air to perform an ejector function, as further explained below. 
     Moreover, the upper end of rod  94  is integral with a transverse arm  106 , having one end guided in a slot  108  having an upper, vertical leg joining a lower, inclined leg, so that, as rod  94  is lowered, it is also rotated around its vertical axis. 
     Above spreader disk  98 , a restraining cup  110  is also arranged slidably on rod  94 . Cup  110  has a rim surrounding disk  98  and is biased toward the disk by a wound compression spring  114 . 
     When shovel  22 , carrying a globular loaf received from loaf distributor  56 , stops beneath spreader  58 , the air cylinder is operated to push disk  98  downwardly against the loaf, the latter being squeezed between the disk and the shovel. Cup  110  also follows the disk, and its rim  112  is stopped by abutment against shovel  22 , thus acting as a restraining enclosure for the dough of the loaf and giving each pizza a uniform size. Peripheral groove  100  in the spreader disk allows a thick peripheral bead to grow in the pizza. The rotation of the disk around its axis, caused by engagement of arm  106  in slot  108 , helps the dough to spread smoothly. 
     With reference to FIGS. 1 and 6, a dressing distributor will now be described by way of example. The dressing distributor comprises a vessel  116 , supported on a bracket  117 , and having a flat bottom with two symmetrically eccentric apertures  118 . An axial shaft  120  supports a stirring paddle  122  within the vessel and a thick metering disk  124  having two symmetrically eccentric apertures  126  which can be aligned with apertures  118 . Metering disk  124  is retained against the vessel bottom by a strap  128  made as a diametrically arranged plate, having a width equal or larger than the diameter of apertures  126 , and attached to the vessel with screws  128 . Metering disk  124  is engaged by an arm  130 , driven by an actuator  132 . 
     When at rest, metering disk  124  of dressing distributor  60  is maintained by arm  130  in a position where its apertures  126  are aligned with apertures  118  in the bottom of vessel  116 , and therefore closed by strap  128 . The dressing contained in the vessel (such as hashed mozzarella, tomato, or other minced o creamy food) flow down to fill apertures  124 , but are stopped by closure strap  128 . When shovel  22  has been stepped forward to a point beneath dressing distributor  60  and actuator  132  is operated, arm  130  turns metering disk  124  by an angle, such as 45°, apertures  126  are freed from strap  128  and discharge their contents on the underlying pizza, while the upper surface of the disk stops apertures  118  in the vessel bottom. A portion of dressing is therefore delivered that is equal to the overall volume of both apertures. Preferably, arm  130 , after it has moved back to its rest position, performs a similar rotation in the opposite direction, again discharging portions of dressing, so that the dressing is distributed with a reasonable degree of uniformity on the underlying pizza. At each rotation, stirring paddle  122  stirs the contents of the vessel. 
     The dressing distributor described above can be easily adapted to different kinds and quantities of minced dressings, by changing the gauge of apertures  126  and the thickness of disk  124 . Although only one dressing distributor  60  is shown on FIG. 1 for clarity and simplicity, the apparatus of the invention, as shown on FIG. 2, comprises a number of distributors, seven in the embodiment shown, all arranged at preferably equal distances from the central shaft. 
     With further reference to FIG. 1, oven  62  comprises a table  134  covered by a housing  136 , having passages  138 ,  140  on the front and the back, and internally provided with known heater means (not shown), e.g. electric resistance means. The inner room of the oven can house, for instance, two pizzas at a time, as shown in  142 . Within housing  136 , two curved paddles  144 ,  146  are also provided, which can be turned by actuator means such as  148 , to rotate the paddles around axes  150 ,  152 , respectively. 
     In operation, as explained above, shaft  16  rotates by steps, stopping shovel  22  first beneath loaf distributor  56 , then beneath moulder  58 , then, in sequence, under the dressing distributors  60 . At each stop, the associated device performs its appointed task, so that, finally, shovel  22  will carry a spread pizza, sprinkled with the desired dressings. 
     Preferably, rotation of shovel  22  and the operation of the several devices take place under control of an electronic control system not shown, as obvious for a person skilled in the art, preferably including a keypad for selection of various parameters such as kinds and quantities of dressing, possibly under direct command of the consumer. 
     When shovel  22 , after moving through the entire path, stops in front of oven  62 , air cylinder  24  is operated (also under program control) to move slide  20  forward at a first speed and insert shovel  22  into passage  140  leading into the oven, at one of both pizza positions shown. The cylinder is then operated in the opposite direction, at a second, high speed, so that shovel  22  will withdraw sharply from the oven, thus unloading the pizza by inertia. While shovel  22  starts a fresh operating cycle, the pizza left in the oven will be baked. At the end of a predetermined time, as set in the program, actuator  148  (or the other similar actuator not shown) is operated, in order to turn paddle  144  or  146  and to push the pizza out of the oven, where the waiting customer can pick it up. 
     FIG. 7 shows a modification of the preferred embodiment of the apparatus according to the invention, which is similar to the embodiment of FIGS. 1 and 2, and which differs from it essentially in that shovel  22  follows an oval, rather than a circular path, due to a translating mechanism  160  for support shaft  16 , driven by a motor  162 . In this embodiment, the apparatus can be provided with a larger number of dressing distributors  60 , for a wider range of the kinds of pizza. Moreover, the apparatus can be provided with two ovens  62 ′,  62 ″, for a higher production rate. 
     FIG. 8 shows a particular embodiment of the apparatus according to the invention, which is identical to the embodiment of FIG. 1 in its mechanical structure, but is provided with a tridimensional puppet  164 , representing a cook, integral with bracket  18 . The embodiment including a puppet contributes to make the apparatus mo 9 re agreeable to the public, also in consideration of the fact that the puppet turns around in step with the shovel, giving the illusion that the puppet&#39;s arm actually pushes and withdraws the shovel in and out of the oven. 
     It is evident that the preferred embodiments of the apparatus as described and shown in the Figures above are liable to numerous other variations, by means of alternative but equivalent mechanical solutions. Merely by way of example, the rotation of the shaft carrying shovel  22  might be obtained by a stepping motor instead of a motor with reduction gear; the distributor of dough loaves  56  might be a metering device operating on bulk dough; the spreading member  58  might be provided with one or more spreading rolls; and the dressing distributors  60  might be at least partially replaced with other kinds of known distributors or metering devices, depending on the kind of dressing. These and other modifications, which may be known or obvious for the person skilled in the art, are to be regarded as falling within the scope of the invention.