Abstract:
An oven contains a continuous chain of baking tongs that can be opened and closed, and locked in the closed state. The chain circulates in the oven and moves through the baking chamber in two transport planes, one above the other. A device for opening the baking tongs, a delivery station, a loading station, a device for closing the baking tongs, and a device for locking the tongs are successively arranged in the running direction of the baking tongs, in the front part of the oven, along the upper transport plane. A product removal device contains a flatly arranged rotating support and is arranged in the delivery station. The rotating support carries removal elements embodied as suction elements along the outer periphery thereof, which it uses to remove the baked products from the open baking tongs.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to baking ovens having an endless baking tong chain circulating in the baking oven, which contains baking tongs comprising baking moulds consisting of baking mould upper parts and baking mould lower parts, which can be locked in their openable and closable state and in the closed state, in which crispy-brittle baked products produced by a baking process are formed. 
     The baking ovens each have a front oven part, a rear oven part, an oven frame provided with an external thermal insulation, a baking chamber disposed inside the thermal insulation and an endless baking tong chain circulating continuously in the baking oven and moving through the baking chamber. The baking tong chain is disposed in the baking oven along an orbit which is closed in itself, which extends in two superposed transport levels through both oven parts. The baking tong chain contains baking tongs which can be opened and closed, and which can be locked in the closed state, in which baking moulds consisting of baking mould upper parts and baking mould lower parts are disposed, which are opened by opening the baking tongs and closed by closing the baking tongs. Located in the front oven part of the baking oven is a device for unlocking the baking tongs on the orbit of the baking tong chain and along the upper transport level, a device for opening the baking tongs, a dispensing station, a loading station and a device for closing the baking tongs and a device for locking the baking tongs are disposed consecutively in the running direction of the baking tongs. Located in the dispensing station is a product removal device which removes the baked products from the opened baking tongs, which is followed by an upper transport device for the removed baked products. 
     In these baking ovens, flowable baking preparations are processed and converted by a baking process into baked products which are crispy and brittle at room temperature. 
     The baking preparations are produced in a mixer. In the mixer the liquid ingredients of the baking preparation and the solid or powdery ingredients of the baking preparation are blended with one another. A shapeless mass is thereby produced. The shapeless mass is flowable. It has a liquid, i.e., thin-liquid to thick-liquid, and sometimes also a pasty consistency. The liquid ingredients are principally water comprising a fraction of 42.0 to 60.0 wt. % of the baking preparation. The powdery ingredients are principally a starch-containing main component comprising a fraction of 36.0 to 56.5 wt. % of the baking preparation. Usually wheat flour is used as the starch-containing main component. The starch-containing main component can also be a starch flour or a mixture of wheat flour and starch flour or a mixture of various grain or starch flours. 
     The baked products produced from these baking preparations can be edible baked products such as, for example, wafers, crispy-brittle wafer sheets for producing wafer slices filled with cream, etc. 
     The baked products produced from these baking preparations can however also be products not provided for consumption per se. These products include, for example, packaging articles such as, for example, packaging cups produced from a starch-containing baking preparation or parts of disposable crockery produced from a starch-containing baking preparation such as, for example, plates and cups and also knives, forks and spoons. 
     The baking preparations are supplied as shapeless, liquid to pasty masses to the baking ovens, the baking tong chain of which contains openable and closable baking tongs provided with a locking device. 
     In the baking oven, the shapeless mass is conveyed by means of a dough pump through dough lines to the loading station. In the loading station the shapeless mass is divided into dough portions and the dough portions are introduced into the opened baking moulds located in the opened baking tongs which pass the loading station in the upper transport level of the baking oven. After introducing the dough portions, the baking tongs are closed. When closing the baking tongs, the baking moulds are closed and the dough portions enclosed in the baking moulds. After closing the baking tongs, the closed baking tongs are locked. The circulating baking tong chain conveys the closed and locked baking tongs through the baking chamber into the rear oven part. Whilst the baking tongs pass through the baking chamber, the baking tongs together with the baking moulds are heated and thereby heated up to baking temperatures between 150° C. (degrees Celsius) and 250° C. (degrees Celsius). As a result, the dough portions enclosed in the closed baking moulds are subjected to a baking process and baked under pressure in the closed and locked baking tongs. The circulating baking tong chain conveys the closed and locked baking tongs into the front oven part. There the closed baking tongs are unlocked. The circulating baking tong chain conveys the closed and unlocked baking tongs into the upper transport level. During passage through the upper transport level, the baking tongs are opened and conveyed in the opened state through the dispensing station to the input station. In the dispensing station the baked crispy-brittle products are removed in the hot state from the opened baking moulds located in the opened baking tongs. The baked products are dispensed in the hot state from the baking oven. The circulating baking tong chain conveys the opened baking tongs with the opened empty baking moulds to the loading station. In the loading station, the dough portions formed recently from the shapeless mass are introduced into the opened baking moulds. 
     Baking ovens in which baking moulds consisting of baking mould upper parts and baking mould lower parts in which the openable and closable baking tongs provided with a locking device of an endless baking tong chain circulating in the baking oven and moving through the baking chamber are arranged are known, for example from the documents AT 378 470 B1 and U.S. Pat. No. 4,438,685 A. 
     BRIEF SUMMARY OF THE INVENTION 
     It is the object of the invention to improve a baking oven of the type mentioned initially. 
     According to the invention a new baking oven is proposed. The new baking oven has a front oven part, a rear oven part, an oven frame provided with an external thermal insulation, a baking chamber disposed inside the thermal insulation and an endless baking tong chain which circulates continuously in the baking oven and moves through the baking chamber. The baking tong chain is disposed along an orbit closed in itself, which extends through two superposed transport levels through the two oven parts. The baking tong chain contains baking tongs which can be opened and closed and which can be locked in the closed state, in which baking moulds consisting of baking mould upper parts and baking mould lower parts are disposed, which are opened by opening the baking tongs and closed by closing the baking tongs. In the front oven part a device for unlocking the baking tongs is disposed on the orbit of the baking tong chain. Along the upper transport level, a device for opening the baking tongs, a dispensing station, a loading station and a device for closing the baking tongs and a device for locking the baking tongs are disposed consecutively in the running direction of the baking tongs. In the dispensing station there is provided a product removing device which removes the baked products from the opened baking tongs, which is followed by an upper transport device for the removed baked products. 
     The new baking oven is characterised according to the invention in that the product removal device has a horizontally disposed rotary unit which is rotatable about a horizontal axis of rotation, which projects into the opened baking tongs, that the rotary unit carries removal elements disposed along its outer circumference, which are disposed consecutively on the outer circumference of the rotary unit in at least one longitudinal row extending along the circumference of the rotary unit and that the removal elements are configured as suction elements connected to a vacuum source. 
     In this baking oven it can further be provided according to the invention that the horizontally disposed rotary unit is disposed in a height-adjustable manner in the front oven part. Furthermore, the horizontally disposed rotary unit can have outwardly projecting drive lugs on its outer circumference, which in the baking tong chain engage in the intermediate spaces of the baking tong chain disposed between the baking tongs. 
     In the baking oven according to the invention, the baked products formed in the closed baking tongs are removed from the circulating opened baking tongs at the dispensing station of the baking oven. In the opened baking tongs the baked products lie on the baking mould lower parts of the opened baking moulds located in the tong lower parts of the baking tongs. 
     Removal is accomplished by the product removal device or by the horizontally disposed rotating rotary unit of the product removal device. The horizontally disposed rotary unit rotates about its horizontally disposed central axis and removes the baked products from the opened baking tongs without deforming the baked products. 
     The rotating rotary unit grips the product pieces lying on the baking mould lower parts with its removal elements. The removal elements of the rotary unit are configured as suction elements which are connected to a vacuum source. The vacuum produced by a vacuum source acts via the removal elements of the rotary unit configured as suction elements directly on the product pieces lying on the baking mould lower parts. The product pieces are gripped individually. Each product piece is gripped by at least one suction element and held firmly on the rotary unit. The product piece is removed from the opened baking tong by the rotating movement of the rotary unit and conveyed to the upper transport device by the rotating movement of the rotary unit. The product piece is gripped by means of the vacuum applied to the suction element. When transferring the product piece to the upper transport device, the vacuum acting on the product piece via the suction element is interrupted. 
     According to the invention, the horizontally disposed rotary unit can be arranged in a height-adjustable manner in the front oven part. This configuration allows the position of the horizontal axis of rotation of the rotary unit to be varied inside the oven frame. As a result, on the underside of the rotary unit the distance between the removal elements disposed on the circumference of the rotating rotary unit and the horizontally disposed tong lower parts of the opened baking tongs can be adjusted or varied. 
     The height-adjustable arrangement of the rotary unit allows the height position of the rotary unit to be adjusted on the upper side of the baked products which, in the opened baking tongs, lie on the baking mould lower parts disposed in the tong lower parts of the baking tongs. 
     According to the invention, the horizontally disposed rotary unit can have outwardly projecting drive lugs on its outer circumference which, in the circulating baking tong chain, engage in the intermediate spaces of the baking tong chain located between the baking tongs. This configuration provides a direct drive of the horizontally disposed rotary unit through the baking tong chain circulating in the baking oven which is driven and set in motion by the main drive of the baking oven. 
     According to a further feature of the invention, it can be provided that the rotary unit has at least two product carrying arms, which are disposed at a distance from one another along the circumference of the rotary unit and that each product carrying arm carries at least one removal element configured as a suction element. 
     The rotary unit with its product carrying arms is assigned to the baked product pieces located in the tong lower parts of the opened baking tongs which pass successively through the dispensing station of the baking oven. Each product carrying arm is assigned to a product piece. The product carrying arm grips the product piece with its removal element configured as a suction element. The product piece is removed from the opened baking tong by the rotating movement of the rotary unit and conveyed to the upper transport device. 
     The rotary unit can have product carrying arms arranged consecutively in the direction of rotation, which are assigned to the product pieces arranged consecutively in the tong lower part of an opened baking tong. 
     According to a further feature of the invention, it can be provided that the product carrying arm has at least one rod which carries at least two removal elements configured as suction elements, which are disposed along the rod at a distance from one another. In this configuration, each product piece is gripped by two or more removal elements of a product carrying arm configured as a suction element and held firmly by vacuum on the rotary unit. The product piece abuts against the product carrying arm and is removed from the opened baking tong by the rotating movement of the rotary unit. 
     According to a further feature of the invention, it can be provided that the product carrying arm has at least one longitudinal rod disposed parallel to the axis of rotation of the rotary unit, which carries at least one removal element configured as a suction element. In this configuration, the product carrying arms disposed along the circumference of the rotary unit at a distance from one another are aligned parallel to the axis of rotation of the rotary unit. 
     According to a further feature of the invention, the longitudinal rod of the product carrying arm parallel to the axis of rotation of the rotary unit can carry at least two removal elements configured as suction elements, which are disposed along the longitudinal rod at a distance from one another. 
     This configuration of the rotary unit allows a single broad product piece or two adjacently disposed product pieces to be removed with a single product carrying arm from a tong lower part of an opened baking tong. 
     According to a further feature of the invention, it can be provided that the product carrying arm has at least two longitudinal rods disposed parallel to the axis of rotation of the rotary unit, which are disposed in a reference plane parallel to the axis of rotation of the rotary unit, and that the longitudinal rods carry removal elements configured as suction elements, which are disposed perpendicular to the reference plane. 
     This configuration of the rotary unit is advantageous for the manipulation of plate-shaped product pieces which are gripped by the two longitudinal rods of the product carrying arm in each case close to the front or rear edge of the product piece. The product carrying arm can also have three or more longitudinal rods each carrying a plurality of removal elements configured as suction elements, which are arranged along the respective longitudinal rod at a distance from one another and are each arranged perpendicular to the reference plane formed by the longitudinal rods. 
     According to a further feature of the invention, it can be provided that the product carrying arm has a longitudinal rod arranged parallel to the axis of rotation of the rotary unit, which carries at least one transverse rod disposed transversely to the longitudinal rod, which is disposed in a reference plane parallel to the axis of rotation of the rotary unit, and that the transverse rod carries two or more removal elements configured as suction elements, which are disposed along the transverse rod at a distance from one another and are each arranged perpendicular to the reference plane. 
     This configuration is advantageous when manipulating broad product pieces. These are each gripped at two or more places by the product carrying arm and the removal elements configured as suction elements hold them firmly on the transverse rod of the product carrying arm. 
     According to a further feature of the invention, in a product carrying arm of the rotary unit, it can be provided that the longitudinal rod carries two or more transverse rods disposed at a distance from one another, which are disposed in a reference plane parallel to the axis of rotation of the rotary unit, and that each transverse rod carries at least two removal elements configured as suction elements, which are disposed at a distance from one another along the transverse rod and are each disposed perpendicular to the reference plane. 
     This configuration is advantageous for the manipulation of large plate-shaped product pieces. The product carrying arm grips each product piece at several places simultaneously. The removal elements exposed to vacuum, which are configured as suction elements, hold the product piece firmly on the transverse rods of the product carrying arm. The product piece held firmly on the product carrying arm is removed from the opened baking tongs by the rotating movement of the rotary unit. 
     According to a further feature of the invention, it can be provided that in a product carrying arm of the rotary unit, the product carrying arm has at least two longitudinal rods disposed parallel to the axis of rotation of the rotary unit, which are disposed in a reference plane parallel to the axis of rotation of the rotary unit and that the product carrying arm has at least two transverse rods disposed transversely to the longitudinal rods which each carry at least two removal elements configured as suction elements, which are disposed at a distance from one another along the transverse rod and are each disposed perpendicular to the reference plane. 
     This configuration is advantageous for the manipulation of large-area plate-shaped product pieces. For the manipulation of very large, plate-shaped product pieces, three, four, five or even more transverse rods arranged at a distance from one another can be attached to the longitudinal rods of the product carrying arm, which are each arranged parallel to the reference plane. Each transverse rod can carry three, four, five or even more removal elements configured as suction elements arranged at a distance from one another, which are each aligned perpendicular to the reference plane parallel to the transverse rods. The product piece gripped by this product carrying arm abuts against the transverse rods of the product carrying arm. The vacuum acting on the product piece via the removal elements attached to the transverse rods, which are configured as suction elements hold the product piece firmly on the product carrying arm. The product piece is removed from the opened baking tongs by the rotating movement of the rotary unit. 
     According to a further feature of the invention, it can be provided that the product-carrying arms are each configured as hollow profiles and form a part of the suction lines which lead from the removal elements configured as suction elements, attached to the product carrying arms, to a vacuum source. In this configuration of the rotary unit, the suction lines leading from the removal elements configured as suction elements to the vacuum source run inside the hollow rods of the product carrying arms. 
     According to a further feature of the invention, it can be provided that the removal elements disposed on the circumference of the rotary unit are configured as suction cups preferably each provided with an elastic bellows, which are attached to the product carrying arms and are connected via suction lines to a vacuum source. 
     According to a further feature of the invention, it can be provided that the removal elements disposed on the circumference of the rotary unit are configured as suction sleeves which can be pushed together elastically into themselves, which are attached to the product carrying arms and are connected via suction lines to a vacuum source. 
     According to a further feature of the invention, it can be provided that the horizontally disposed rotary unit has at least one vertically disposed rotary star which carries removal elements configured as suction elements, disposed on the circumference of the rotary unit, and that the horizontally disposed rotary unit possesses possibly two or more rotary stars disposed adjacent to one another at a distance, which carry removal elements configured as suction elements, disposed on the circumference of the rotary unit. 
     In this configuration of the rotary unit, the product pieces are removed from the opened baking tongs by the vertically disposed rotary star of the rotating rotary unit. The removal elements configured as suction elements, attached to the rotary star are each exposed to vacuum. The product pieces are gripped by the removal elements by means of vacuum and held firmly by means of vacuum on the rotary star. The product pieces are removed from the opened baking tongs by the rotating movement of the rotary star and conveyed to the upper transport device located downstream of the rotary unit. 
     According to the invention, the horizontally disposed rotary unit can have two or more rotary stars arranged adjacent to one another which carry removal elements configured as suction elements, disposed on the circumference of the rotary unit. 
     In this configuration, the removal elements of the rotary unit configured as suction elements are disposed on the outer side of the rotary stars. The removal elements are disposed consecutively on the outer side of the rotary stars in longitudinal rows extending along the circumference of the rotary unit. At the same time, the removal elements are disposed in transverse rows parallel to the axis of rotation of the rotary unit. Individual large-area product pieces or adjacently disposed smaller product pieces can be removed from the opened baking tongs with the adjacently disposed rotary stars. 
     According to a further feature of the invention, it can be provided that the vertically disposed rotary star has an outer circumference configured as a polygon, in which the removal elements configured as suction elements are disposed on the straight segments. 
     According to a further feature of the invention, it can be provided that in each case at least two removal elements configured as suction elements are disposed at a distance from one another on the straight segments of the outer circumference. 
     According to a further feature of the invention, it can be provided that the rotary star is configured as a hollow body and forms a part of the suction line which leads from the removal elements configured as suction elements to a vacuum source. 
     According to a further feature of the invention, it can be provided that the removal elements of the rotary unit configured as suction elements are configured as suction cups preferably each provided with an elastic bellows, which are attached to the outer circumference of a rotary star and connected via suction lines to a vacuum source. 
     According to a further feature of the invention, it can be provided that the removal elements of the rotary unit configured as suction elements are configured as suction sleeves which can be pushed elastically into themselves, which are attached to the outer circumference of a rotary star and connected via suction lines to a vacuum source. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       The invention is explained in detail hereinafter with reference to exemplary embodiments by means of the drawings. In the drawings: 
         FIG. 1  shows schematically a first baking oven from the side, 
         FIG. 2  shows schematically a second baking oven from the side, 
         FIG. 3  shows schematically a third baking oven from the side, 
         FIG. 4 a  to 4 c    show a first rotary unit 
         FIG. 5 a  to 5 c    show a second rotary unit 
         FIG. 6 a  to 6 g    show a third rotary unit 
         FIGS. 7 a  to 4 d    show a product carrying arm 
         FIGS. 8 a  to 8 d    show another rotary unit 
         FIGS. 9 a  to 9 d    show a first removal element and 
         FIGS. 10 a  to 10 d    show a second removal element. 
         FIG. 11  shows a plan view of a section of the baking tong chain and 
         FIG. 12  shows a view of a baking tong viewed in the direction of travel of the baking tongs. 
         FIG. 13  shows the side view according to arrow XIII in  FIG. 11  and  FIG. 14  shows a detail. 
     
    
    
     DESCRIPTION OF THE INVENTION 
       FIG. 1  shows schematically a first baking oven  1  from the side. The baking oven  1  has a front oven part  1   a , a rear oven part  1   b , an oven frame  1   d  provided with an external thermal insulation  1   c , furthermore a baking chamber  2  located inside the thermal insulation and an endless baking tong chain  3  circulating continuously in the baking oven  1  and moving through the baking chamber  2 . The endless baking tong chain  3  is located in the baking oven  1  along an orbit which is closed in itself, which extends in two superposed transport levels  4  and  5  through both oven parts  1   a  and  1   b . The baking tong chain  3  is driven by a drive wheel  6  located close to the front end of the baking oven  1  and is deflected by the drive wheel  6  from the lower transport level  5  upwards into the upper transport level  4 . The circulating baking tong chain  3  moves in the upper transport level  4  away from the drive wheel  6  in the baking oven towards the back. Close to the rear end of the baking oven  1  the baking tong chain  3  passes a rear baking tong chain deflecting device  7 . At the deflecting device  7  the baking tong chain  3  is deflected from the upper transport level  4  downwards into the lower transport level  5 . 
     The baking tong chain  3  contains openable and closable baking tongs  8 . The baking tongs  8  are arranged one after the other in the baking tong chain  3 . Located in the baking tongs  8  are baking moulds consisting of baking mould upper parts and baking mould lower parts, which are opened by opening the baking tongs  8  and closed by closing the baking tongs  8 . The baking tongs  8  each consist of a tong lower part  8   a  and a tong upper part  8   b  connected pivotably to this. A control roller  8   c  is attached to the tong upper part  8   b  by means of which the baking tong  8  is opened and closed. Flat baking plates are disposed in the tong lower parts  8   a , which contain the baking mould lower parts of the baking moulds. Flat baking plates are disposed in the tong upper parts  8   b  which contain the baking mould upper parts of the baking moulds. 
     On their front sides, the baking tongs  8  are provided with locking devices, not shown in the drawing, which are actuated when the baking tongs are closed in order to keep the baking moulds disposed in the closed baking tongs closed during the entire baking process 
     The baking oven  1  is provided with an electrical induction heater. This includes an alternating current generator  9  located next to the front oven part  1   a  and elongated inductors  10 ,  11  located in the baking chamber  2 . The alternating current generator  9  is connected to the inductors  10 ,  11  via power leads  12 ,  13  and supplies these with current. The elongated inductors  10 ,  11  are located in the baking chamber  2  above and below the orbit of the baking tong chain  3 . The flat baking plates contained in the baking tongs  8  are configured as susceptor plates which are heated inductively in a contact-free manner by the magnetic fields generated by the inductors  10 ,  11 . 
     A lower actuating device  18  for unlocking the locking devices of the baking tongs  8  is located in the front oven part  1   a  on the lower transport level  5 . 
     In the front oven part  1   a , a linkage  14  for engagement with the control rollers  8   c  of the baking tongs  8  is provided along the upper transport level  4 . The linkage  14  provides three consecutive sections in the running direction of the baking tongs  8 . The linkage  14  provides a gradually ascending linkage section  14   a  which forms a device for opening the baking tongs  8 . The linkage section  14   a  is adjoined by an upper horizontal linkage section  14   b . This holds the opened baking tongs  8  in the opened state whilst they pass the dispensing station  15  of the baking oven  1  and the adjoining loading station  16 . The linkage section  14   b  is adjoined by a gradually descending linkage section  14   c  which forms a device for closing the baking tongs  8 . Located at the end of the linkage  14  is an upper actuating device  19  for locking the locking devices of the baking tongs  8 . 
     The product removal device  17  which projects into the opened baking tongs  8 , shown only schematically in  FIG. 1 , is provided in the dispensing station  15 . The product removal device  17  removes the baked products from the tong lower parts  8   a  of the opened baking tongs  8  and transfers them to an upper transport device, not shown in  FIG. 1 , by which the baked products are conveyed out of the baking oven  1 . 
     During operation of the baking oven  1  a baking preparation is introduced in individual dough portions into the circulating opened baking tongs  8  in the loading station  16 . After leaving the loading station  16 , the baking tongs  8  with the control rollers  8   c  move along the gradually descending linkage section  14   c . At the same time the tong upper parts  8   b  are folded downwards to the tong lower parts  8   a  and the baking tongs  8  are closed. During closure of the baking tongs  8  the baking moulds contained in the baking tongs  8  are closed and the dough portions enclosed in the closed baking moulds. After closure of the baking tongs  8  the locking devices of the baking tongs  8  are actuated by lower actuating device  19  and the closed baking tongs  8  are locked. The closed and locked baking tongs  8  are conveyed by the circulating baking tong chain  3  through the baking chamber  2 . In the baking chamber  2  the baking moulds are heated inductively in a contact-free manner and the dough portions enclosed in the baking moulds are baked. The closed and locked baking tongs  8  are conveyed with the baked dough portions contained therein by the circulation baking tong chain  3  in the lower transport level  5  in the baking oven  1  forwards to the drive wheel  6 . When passing the lower actuating device  18 , the locking devices of the baking tongs  8  are actuated by the lower actuating device  18  and the closed baking tongs  8  are unlocked. The closed and unlocked baking tongs  8  are conveyed along the drive wheel  6  into the upper transport level  4 . In the upper transport level  4  the baking tongs  8  with their control rollers  8   c  move along the gradually ascending linkage section  14   a . At the same time, the baking tongs  8  are opened and the tong upper part  8   b  folded upwards. The baked dough portions or the baked products remain in the tong lower part  8   a  of the opened baking tongs  8 . In the dispensing station  15  the baked products are removed by the product removal device  17  from the tong lower parts  8   a  of the opened baking tongs  8 . 
       FIG. 2  shows schematically a second baking oven  20  from the side. The baking oven  20  has a front oven part  20   a , a rear oven part  20   b , an oven frame provided with external thermal insulation  20   c , a baking chamber  21  disposed inside the thermal insulation  20   c  and an endless baking tong chain  22  circulating continuously in the baking oven  20  and moving through the baking chamber  21 . The baking tong chain  22  is disposed in the baking oven  20  along an orbit which is closed in itself which extends in two superposed transport levels  23  and  24  through both oven parts  20   a  and  20   b . The baking tong chain  22  is driven by a drive wheel, not shown in  FIG. 2 , located near the front end  25  of the baking oven  20  and is deflected by the drive wheel from the lower transport level  24  upwards into the upper transport level  23 . The circulating baking tong chain  22  moves in the upper transport level  23  from the front end  25  of the baking oven  20  towards the rear to the rear end  26  of the baking oven  20 . The baking tong chain  22  is deflected near the rear end  26  of the baking oven  20  by a rear baking tong chain deflecting device  27  from the upper transport level  23  downwards into the lower transport level  24 . 
     The baking tong chain  22  contains openable and closable baking tongs  38  in which baking moulds consisting of baking mould upper parts and baking mould lower parts are disposed, which are opened by opening the baking tongs  28  and closed by closing the baking tongs  28 . The baking tongs  28  each have a tong lower part  28   a  and a tong upper part  28   b  connected pivotably thereto. Attached to the tong upper part  28   b  is a control roller, not shown in  FIG. 2 , by which means the baking tongs  28  are opened and closed. Flat baking plates are disposed in the tong lower parts  28   a  which contain the baking mould lower parts of the baking moulds. Flat baking plates are disposed in the tong upper parts  28   b  which contain the baking mould upper parts of the baking moulds. 
     The baking chamber  21  is disposed in the rear oven part  20   b . The baking chamber  21  is provided with an electrical induction heater which includes elongated inductors  29 ,  30  each disposed above and below the orbit of the baking tongs  28  in the two transport levels  23  and  24 . 
     In the front oven part  20   a  of the baking oven  20 , a device  31  for opening the baking tongs  28 , a dispensing station  32 , a loading station  33  and a device  34  for closing the baking tongs  28  are disposed consecutively in the running direction of the baking tongs  28  along the upper transport level  23 . Located in the dispensing station  32  is a product removal device  35  with a horizontally disposed rotary unit  36 . The rotary unit  36  rotates about its horizontally disposed central axis and removes the baked products from the opened baking tongs  28   a  and conveys them to an upper transport device  37  which conveys the baked products out from the baking oven  20 . 
       FIG. 3  shows schematically a third baking oven  40  from the side. The baking oven  40  has a front oven part  40   a , a rear oven part  40   b , an oven frame provided with external thermal insulation  40   c , a baking chamber  41  disposed inside the thermal insulation  40   c  in the rear oven part  40   b  and an endless baking tong chain  42  circulating continuously in the baking oven  40  and moving through the baking chamber  41 . The baking oven  40  corresponds in its design structure to the baking oven  20  of  FIG. 2  and only differs from this by the baking chamber heating which is configured as gas heating  43  in the baking oven  40 . The gas heating  43  includes elongated gas burners  44  and  45  which are disposed in the baking chamber  41  below the orbit of the baking tong chain  42 . 
       FIGS. 4 a  to 4 c    show a first embodiment of the horizontally disposed rotary unit of the product removal device.  FIG. 4 a    shows the rotary unit  50  in an oblique view from the rear side.  FIG. 4 b    shows the rotary unit  50  in its working position.  FIG. 4 c    shows the rear side of the rotary unit  50 . 
     The rotary unit  50  is mounted rotatably on its rear side in a retaining device  51  fastened to the oven frame. The retaining device  51  is fastened to the oven frame in a height-adjustable manner. The rotary unit  50  has a horizontally disposed hollow shaft  52 . The rear drive star  53  of the rotary unit  50  sits on the hollow shaft  52 , which has arms  54  arranged in a star shape, which carry drive rollers  55  mounted rotatably at their end sections, which engage in the intermediate spaces between the successive baking tongs of the circulating baking tong chain. 
     A vertically disposed rotary star  56  is fastened to the front end of the hollow shaft  52 . The rotary star  56  is configured as a hollow body. The interior of the hollow star  56  is connected to the cavity of the hollow shaft  52 . The outer circumference of the rotary star  56  is configured as a polygon. Respectively two adjacently disposed longitudinal rods  58  parallel to the hollow shaft  52  are fastened to the straight segments  57  of the polygon. The longitudinal rods  58  are configured as hollow profiles and each carry three removal elements  59  disposed at a distance from one another. Each removal element  59  is configured as a suction element and is connected via a suction line to a vacuum source. The suction line runs inside the rotary unit  50  from the removal element  59  through the hollow longitudinal rod  58  and the hollow rotary star  56  to the hollow shaft  52  and through the hollow shaft  52  out from the rotary unit  50 . The removal elements  59  fastened to the longitudinal rods  58  are configured as suction cups provided with an elastic bellows. 
     The two longitudinal rods  58  fastened to the straight segment  57  of the outer circumference in the rotary star  56  are disposed in a reference plane parallel to the axis of rotation of the rotary unit  50 . The suction cups attached to the two longitudinal rods  58 , which are provided with an elastic bellows are disposed perpendicular to the reference plane. The two longitudinal rods  58  together form a product carrying arm of the rotary unit  50 . The rotary unit  50  has nine such product carrying arms which are disposed at a distance from one another along the circumference of the rotary unit  50 . 
       FIGS. 5 a  to 5 c    show a second embodiment of the horizontally disposed rotary unit of the product removal device.  FIG. 5 a    shows the rotary unit  60  in an oblique view from the rear side.  FIG. 5 b    shows the rotary unit  60  in its working position.  FIG. 5 c    shows the rear side of the rotary unit  60 . 
     The rotary unit  60  is rotatably mounted at its rear side in a retaining device  61  fastened to the oven frame. The retaining device  61  is fastened in a height-adjustable manner on the oven frame. The rotary unit  60  has a horizontally disposed hollow shaft  62 . The rear drive star  63  of the rotary unit  60  sits on the hollow shaft  62 , which has arms  64  arranged in a star shape, which carry drive rollers  65  mounted rotatably at their end sections, which engage in the intermediate spaces between the successive baking tongs of the circulating baking tong chain. 
     The rotary unit  60  has two vertically disposed rotary stars  66  configured as hollow bodies, the interior of each is connected to the cavity of the hollow shaft  62 . The outer circumference of the rotary stars  66  is configured as a polygon. Respectively two removal elements  68  disposed at a distance from one another are attached to each straight segment  67  of the polygon, which are configured as suction cups provided with an elastic bellows and which are connected via the hollow rotary stars  66  to a vacuum source. 
       FIGS. 6 a  to 6 g    show a third embodiment of the horizontally disposed rotary unit of the product removal device.  FIG. 6 a    shows the rotary unit  70  projecting into the opened baking tongs of a baking oven in an oblique view from the rear side.  FIG. 6 b    shows the rotary unit  70  in its working position without baking tongs.  FIG. 6 c    shows the rear side of the rotary unit  70 .  FIG. 6 d    shows the rotary unit  70  projecting into the opened baking tongs of a baking oven in a vertical section perpendicular to the axis of rotation of the rotary unit  70 .  FIG. 6 e    shows the rotary unit  70  projecting into the opened baking tongs of a baking oven in a vertical section through the axis of rotation of the rotary framework  70 .  FIG. 6 f    shows, in a vertical section, a product carrying arm of the rotary unit  70  in an opened baking tong above the tong lower part of the baking tong.  FIG. 6 g    shows a side view of  FIG. 6   f.    
     The rotary unit  70  shown in  FIG. 6 a    projects into three successive opened baking tongs  71  of a baking oven.  FIG. 6 a    only shows the opened baking tongs  71  schematically. The rotary unit  70  is disposed in the opened baking tongs  71  above the tong lower parts  71   a  and extends with its front side close to the folded-upwards tong upper parts  71   b . The rotary unit  70  is rotatably mounted on its rear side in a retaining device  72  fastened to the oven frame. The retaining device  72  is fastened to the oven frame in a height-adjustable manner. The rotary unit  70  has a short horizontal hollow shaft  73 . A drive star  74  disposed on the rear side of the rotary unit  70  sits on the hollow shaft  73 , which has arms  75  arranged in a star shape which carry rotatably mounted drive rollers  76  at its end sections, which engage in the intermediate spaces between the consecutive baking tongs  71  of the circulating baking tong chain. 
     The rotary unit  70  includes product carrying arms  77  adjacent to its outer circumference which are disposed at a distance from one another in the circumferential direction of the rotary unit  70  and which carry removal elements  78  of the rotary unit  70  each configured as a suction element, disposed on the outer circumference of the rotary unit  70 . 
     Each product carrying arm  77  has a longitudinal rod  79  parallel to the axis of rotation of the rotary unit  70 . Located on the radially outward-pointing side of the longitudinal rod  79  in the rotary unit  70  are five transverse rods  80  which are connected to the longitudinal rod  79  by a radially disposed connecting rod  81 . Each transverse rod  80  carries three removal elements  78  disposed at a distance from one another on its radially outwardly pointing side in the rotary unit  70 . Each removal element  78  is configured as a suction cup provided with an elastic bellows, which is fastened to the transverse rod  80 . The longitudinal rod  79 , the five transverse rods  80  and the five connecting rods  81  are configured as hollow profiles. The longitudinal rod  79  is connected by a radial connecting tube  83  disposed close to the drive star  74  to a vacuum distributor  83  located at the end of the hollow shaft  73 . The product carrying arm  77  carries fifteen removal elements  78  configured as suction cups which are disposed in a plane parallel to the axis of rotation of the rotary unit  70 . The fifteen suction cups are connected the in the product carrying arm  77 . The suction lines run through the hollow transverse rods  80  and the hollow connecting rods  81  to the hollow longitudinal rod  79  and through the radial connecting tube  82  to the vacuum distributor  83 . 
     The rotary unit  70  has nine product carrying arms  77  disposed at a distance from one another in the circumferential direction of the rotary unit  70 . The rotary unit  70  rotates about its horizontal axis of rotation. In the region of the lower apex of the rotary unit  70 , one product carrying arm  77  after the other is placed with its suction cups each provided with an elastic bellows through the rotary movement of the rotary unit  70  onto the baked product pieces which lie on the tong lower parts  71   a  of the opened baking tongs  71  which pass through the lower apex of the rotary unit  70 . 
       FIGS. 7 a  to 7 d    each show a product carrying arm  77  of the rotary unit  70 .  FIG. 7 a    shows the product carrying arm  77  from the side,  FIG. 7 b    shows said product carrying arm in front view,  FIG. 7 c    shows it from above and  FIG. 7 d    shows it in oblique view. 
       FIGS. 8 a  to 8 d    show another embodiment of the rotary unit of the product removal device in engagement with a circulating baking tong chain of the baking oven.  FIG. 8 a    shows three consecutive opened baking tongs of a baking tong chain with the rotary unit projecting into the opened baking tongs from the rear side.  FIG. 8 b    shows an oblique view of  FIG. 8 a   .  FIG. 8 c    shows the engagement of the rotary unit in the baking tong chain.  FIG. 8 d    shows an oblique view of  FIG. 8   c.    
     The rotary unit  85  shown in  FIGS. 8 a  and 8 b    projects into three consecutive opened baking tongs  86  of an endless baking tong chain of a baking oven. In  FIGS. 8 a  and 8 b    the opened baking tongs  86  are only shown schematically. The rotary unit  85  is disposed in the opened baking tongs  86  above the tong lower parts  86   a  and extends with its front side close to the folded-upwards tong upper parts  86   b . The rotary unit  85  is rotatably mounted on its rear side in a retaining device  87  fastened to the oven frame. The retaining device  87  is fastened in a height-adjustable manner on the oven frame. The rotary unit  85  has a drive star  88  disposed on the rear side of the rotary frame  85  which has arms  89  arranged in a star shape, which carry rotatably mounted drive rollers  90  on its end sections which engage in the intermediate spaces located in the baking tong chain between the tong lower parts  86   a  of the baking tongs  86 . In the baking tongs  86  the tong lower parts  86   a  are provided at the front and rear edges with strips  91 ,  92  projecting over the tong lower parts  86   a  against which the drive rollers  90  of the rotary unit  85  abut. 
       FIGS. 9 a  to 9 d    show a removal element of the rotary unit which is configured as a suction sleeve which can be pushed elastically into itself.  FIG. 9 a    shows the suction sleeve from the side,  FIG. 9 b    shows a vertical section through the suction sleeve,  FIG. 9 c    shows the suction sleeve in oblique view and  FIG. 9 d    shows a plan view of the suction sleeve. The suction sleeve  94  has two coaxial tube pieces  94   a  and  94   b  which can be inserted telescopically into one another and a compression spring  95  which pushes the two tube pieces  94   a  and  94   b  apart in the interior of the suction sleeve  94 . The inner tube piece  94   b  carries a suction plate  96  disposed on the free end of the suction sleeve  94 . 
       FIGS. 10 a  to 10 b    show a removal element of the rotary unit which is configured as a suction cup  97  provided with an elastic bellows  96 .  FIG. 10 a    shows the suction cup from the side,  FIG. 10 b    shows a vertical section through the suction cup,  FIG. 10 c    shows the suction cup in oblique view and  FIG. 10 d    shows a plan view of the suction cup. 
       FIGS. 11 to 14  show an advantageous design for the lateral guidance of the baking tong carriage. It was known from the prior art to guide the running wheels of the baking tong carriage by means of wheel flanges on the running rails. This resulted in more rapid wear of the running bearings of the running wheels and the wheel flanges. The design shown in  FIGS. 11 to 14  avoids the disadvantages described and extends the stability. 
       FIG. 11  shows the plan view of a section of an arrangement of two consecutively disposed baking tongs  8  along a baking tong chain  3 . For better and low-wear guidance of the baking tong carriage, laterally disposed running bearings  98  are provided which are mounted on vertical axles  99  and which laterally guide the baking tongs over guide lugs  100 . The axles  99  sit on receiving panels  101  and the exact positioning of the running bearing  98  on the angle carrier  102  can be adjusted by an adjusting screw or an adjusting plate. The guidance via the guide lugs  100  can be adjusted with an adjustable play as indicated in  FIG. 14 . 
     The guide lugs  100  can be configured to be short or longer in their longitudinal extension and specifically adapted to the travel speed of the wafer oven. The number of laterally disposed running bearings  98  can also be increased to ensure a more exact lateral guidance. For example, in the region before the deflection of the tong carriage, the number of lateral guides and therefore the number of running bearings  98  can be increased in order to ensure a problem-free deflection. 
     Other than in the previously known running rollers with wheel flange, the ball bearings of the running rollers  104  running on the rails  105  are only radially loaded, with the result that the lifetime increases. The running bearings can easily be exchanged in the case of a malfunction. 
     The other machine parts shown in  FIGS. 11 to 14  are self-explanatory in view of the above explanations. As can be seen from  FIG. 12 , each baking tong comprises an upper baking plate  8   b  and a lower baking plate  8   a . Both baking plates are pivotably connected via the joint  103 . The opening and reclosing of the baking tong  8  is accomplished via the running roller  8   c  of the upper baking plate, as is prior art. 
     It can also be seen in  FIG. 11  that the baking tongs  8  suspended on one another to form the baking tong chain are connected to one another by means of connecting lugs  104 . The length of the guide lugs  100  is shown completely in its short form. The dashed lines indicate that the guide lugs can also be configured to be sufficiently long that they almost touch the guide lugs of the neighbouring baking tongs.