The present invention concerns an apparatus for automatic preparation of food products such as bread. cakes and the other products, starting from dry and or wet substance ingredients and of the kind comprising a mixing, kneading and heat treatment station.

Background of the Invention

Baking e.g. bread for househo'ld purposes is a relatively complicated, time consuming, work . intensive and messy business. By the fact that the quality of the bread in a certain extent depends on the fermentation time and a fermentation procedure performed under correct condition, which takes a relatively long time, there are few people that have the privilege of eating fresh home-made bread ^" or breakfast.

Through the US patent 3.194.185 there is previously known a method of manually mixing and kneading the ingredients to a pizza dough in a flat, flexible bag, e.g. a plastic bag. This is designed so that the dough, which is rolled out in the bag, has the circular shape of the bag. Further the bag is designed so that one of its sides can be torn away, so that the rolled-out dough easily can be placed on a baking-plate. This method states a solution of the problem with the messy procedure of mixing and kneading the dough, but it does not give any advice of how it would be possible to automatically produce e.g. bread.

Through the US patent 4 234 605 there is known a bread baking apparatus, in which one and the same vessel is used for mixing the ingredients and kneading the dough. Further the fermentation as well as the baking of the dough takes place in this vessel in one and the same dough preparation and baking sta ion. φ &E

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This baking apparatus in fact is only suited for relatively liquid doughs and since neither the vessel, the dough preparation utensils nor the lid of the vessel will be cleaned between the dough kneading procedure and the baking, dough adhered to these utensils will be burned and stuck during the baking procedure, which on one hand can influence the taste of the baked product and on the other hand makes the cleaning considerably more difficult. The baking apparatus also requires relatively complicated equipment with special driving means for raising and lowering the vessel to and from the kneading - and mixing potentions.

Summary and Advantages ^' of the Invention

The object of the invention is to provide a baking apparatus which can produce food products such as bread, without any real manual work involved, without soiling various vessels and utensils, and which apparatus can be programmed so that- a correctly performed fermentation process under the correct temperture is achieved so that a qualitatively excellent product is obtained.

Another object of the invention is to provide a baking apparatus the construction of which is simple and therefore relatively inexpensive to manufacture. It should also be compact, it should not require any more space than e.g. a coffee percolator, as it should be placed on a work bench or washing stand in the kitchen. A further desire is to bake food products of various kinds, i.e. different kinds of bread, cakes, pies and the like.

This is achieved by the fact that the mixing- and kneading station is provided with means for holding and/or moving at least one flexible vessel, e.g. a plastic bag, which contains or is intended to receive the ingredients and that the mixing and kneading means of the first station are arranged to mix the ingredients and work the mass located in the vessel by external mechanical agitation of the vessel.

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Brief Description of the Drawings

Figure 1 shows schematically a section ^" through a baking apparatus according to the invention with hydraulic or pneumatic dough preparation.

Figure 2 shows a section through a second embodiment of a holding means with double vessels.

Figure 3 shows a section through a second embodiment of the baking apparatus according to the invention with a separate dough preparation and heat treatment station.

Figures 4 shows on a larger scale a section through a roller which is part the apparatus according to Figure 3.

Figure 5 shows the roller according to Figure 4 in perspective. Fig. 6-8 show sections through a third embodiment of a modified baking apparatus.

Fig. 9 is a section through a baking apparatus according to a fourth embodiment where the dough preparation takes place ^" in cooperation with the baking oven. Figure 10 shows a section through a fifth embodiment of the baking apparatus modified with respect to fig. 9. Fig. 11 shows a section according to the line XI-XI in fig. 10.

Figure 12 shows a section through a sixth embodiment in which the baking oven is movable with respect to the fixed vessel. Fig. 13 shows a section through a seventh embodiment of a baking apparatus for making round loafs, pizzas or the like.

Description of Preferred Embodiments

Figures 1 and 2:

The apparatus according to the embodiment shown in Figure 1 consists of holding means 11. a flexible vessel 12 attachable thereto and a common dough preparation and heat treatment station 13,14. The whole arrangement is located inside a thermally insulated casing 15.

The flexible vessel 12, which e.g. can be a plastic bag of a

heat resistant material. can be used as a transportation package for the dry ingredients from the producer to the user and as a vessel during the preparation of the dough and possibly also during the baking. The plastic bag 12 must therefore withstand rough mechanical treatment and possibly also contains a second plastic bag or the like, in which is contained the liquid required for preparation of the dough. Alternatively, the liquid for the dough can also be added through a nozzle 16, especially if the liquid is only water. The plastic bag 12 is attached to least two holding means 11 which are so formed that the end pieces of the opening 18 of the plastic bag can be squeezed between gripping means 17. After attaching the plastic bag 12 to the holding means 11 the baking apparatus is programmed by, for example, a punched card which is sensed by the programmer which then takes care of the whole production process The punched card could possibly be supplied with the dry ingredients, attached to the package, or alternatively be part of a program library belonging to the baking apparatus.

The holding pieces 11 are rotatable about their own axles 19 so that the bag can either be held open, as shown in fig 1 with continuous lines, or also be closed as shown with dash-dotted lines.

In the case where the plastic bag contains an inner bag containing liquid for the dough, it could be sufficient that the dough preparation station has only one holding means 11 as the entire dough preparation procedure can take place in the unopened bag.

The dough preparation station 13 is placed directly under the holding means 11 and can be made in a number of different embodiments. In the embodiment shown in Fig 1 the dough preparation station consists of a hydraulically or pneumatically driven device, spaced from the plastic bag 12 and provided with a number of kneading means 20 around the bag. Each kneading means consists of a flexible wall 21, which by increasing the pressure of the working medium, can expa

and upon reducing the pressure return to the original contracted position. Through individual regulation of the different kneading means 20 a systematic and effective mixing together of the ingredients and the desired kneading of the dough is achieved.

If the liquid for the dough is in a plastic bag in an inner vessel or in a compartment provided by e.g. a weld joint, the kneading means 20 directly opposite the inner plastic bag can be activated before the other kneading means are started, so that the inner vessel is burst, possibly along a breaking line, and the baking liquid is added to the dry ingredients 22.

The programmer interrupts the dough preparation after an empirically pre-determined dough preparation time so that no overworking of the dough occurs which could lead to dry bread. Already during the preparation of the dough the heater 23 ^~ in the heat treatment station 14 can be started in order to obtain an appropriate fermentation time. The dough can be made to ferment several times possibly interrupted by new kneading operations according to the inserted program. When the fermentation of the dough is finished the baking takes place directly in the combined dough preparation - and baking station 13,14. It is possible to have spray nozzles (not shown) for spraying the dough or the finished baked product with water or another appropriate liqgid for creating a crust and/or a glossy surface on the bread.

Because the flexible vessel 12. preferrably a plastic bag. must be made of thick plastic which can withstand the kneading of its contents, it will be relatively expensive. According to an alternative embodiment shown in Figure 2, an outer flexible container 30 is attachble to the holding means 11, inside which container the flexible vessel 12 can be placed, which contains the ingredients which are needed for making the desired food product. The flexible vessel, that is the plastic bag, can in this embodiment consist of very thin plastic foil since the real mechanical work is done on the

outer flexible container 30.

Figures 3-5:

The dough preparation station of the baking apparatus can as was already mentioned, be designed in many ways, and a second variant is shown in Figs. 3-4. In this embodiment the ingredients in the plastic bag 12 and the dough 24 are worked along a path, which principally has the same function as a rolling board. The path or the rolling board 38 is curved and forms a part of a circular arc in the center of which a pivot axle 39 is arranged, which transfers its movement to two arms 40. The rolling board 38 is fixedly attached in a housing 41 comprising the dough preparation station 13 with the driving means 42 for the arms 40 and a heat treatment station 14 or baking oven with a driving means 43 for linear movement of the baking oven 14 from a pushed-in to a drawn-out position. The housing 41 is further provided with a lid 44 pivoted about a hinge 45. A holding means 11 for carrying the upper opening of the plastic bag 12 is also pivoted about said hinge.

The dough preparation station 13 consists of the above mentioned arms 40 placed on each side of the part-cylindrical rolling board 38. To the upper end of the arms 40 are attached kneading means 20 consisting of a roller 46 arranged at the free end of a pair of links 47 which are rotatably attached to a pressing roll 48 which is freely rotatably mounted at the free ends of the arms 40.

The upper end of the rolling board 38 is formed with a somewhat larger radius than the rest of the rolling board so that a harder pressure by the pressing roll 48 against the rolling board 38 is obtained in that area. The arms are preferably in the form of telescoping arms in which is arranged a tension spring exerting a predetermined pressure on the pressing roll 48 against the rolling board 38.

The roller 46 is appropriately made with fixation pieces 49 through which the lower end of the plastic bag 12 can be

affixed to the roller. In the embodiment of Figures 4 and 5 the roller 46 consists of an outer casing, for example of a somewhat elastic material, such as synthetic rubber, and an inner cylinder 51. which is rotably mounted at the free ends of the links 47. Both the outer casing 50 and the inner cylinder 51 are equipped with its own slit 52, 53 in which the lower end of the plastic bag can be inserted and fixed by moving the outer casing 50 relative to the cylinder 51. The lower end part of the plastic bag inserted in the slit may already be slitted and held closed by the fixation pieces 49, but it is also possible to equip the roller 46 with a cutting device 27 in the form of a slitted bushing 54 inside the inner cylinder. the slit being placed opposite the slits S3 and 52 so that the extreme end of the plastic bag can be inserted in the slit 55. The bushing 54 is longer than the inner cylinder

51 and actuating members 56 are attached to the portions outside the inner cylinder 51 which in a certain position of the roller 46 cooperates with fixed abutments (not shown) ^" so that the bushing is turned in relation to the cylinder whereby the end of the plastic bag inserted in the slit 55 is cut off.

The plastic bag 12 can either in a separate bag contain the baking liquid, which separate bag through the action of the dough preparation station is opened so that its content is emptied into the plastic bag, or also it is also possible to add the liquid manually as will be described below.

In accordance with what is shown in Figure 3, the upper end of the plastic bag is fixed in the holding means 11 of the baking apparatus, which holds the bag open so that an opening is formed. In that position the kneading means 20 of the dough preparation station are placed in their initial position in which the plastic bag can be drawn under the pressing roll 48 while the lower end of the plastic bag can simultaneously be fixed to the roller 46.

When the bag is in place the arms 40 are moved to their upper position in which the roller 48 exerts a pressure so great against the bag and rolling board 38 that an effective sealing

is achieved. Then the liquid for the dough can be poured into the funnelshaped upper part of the plastic bag 12 and the timer in the baking apparatus programmer is set to the desired initiation time.

At an appropriate time the arms 40 are activated and moved downwards so that the liquid can run down and after a number of up and down movements about the axle 39 the dry ingredients have been mixed with the baking liquid to form a doughy mass. Depending the baking recipe the kneading is repeated an appropriate number of times interrupted by fermentation periods. When the dough is completely worked and fermented the programmer starts the drive mechanism which moves the baking oven 14 to the position in which the baking tin 28 is positioned under the lower end of the plastic bag 12.

In order to open the plastic bag the arms 40 execute a much larger arcuate motion in comparison to the kneading motion, whereby tire lower part of the plastic bag is cut off and released from the roller 46 while the pressing roll 48 presses the dough mass out of the lower opening of the plastic bag and into the baking tin 28 during the rollers downward motion. The baking oven 14 is then drawn back to its original position where the actual baking takes place.

Figure 6-8

In the embodiment according to Figures 6-8 the curved path i.e. the baking board 38 consists of a cylinder with a circular cross section and rotatably mounted in the baking oven housing 41. In the same way as in the previous embodiments this is equipped with a kneading means 20 rotatable from the center of a drum 58, which kneading means is equipped with fixation means 49 at its free end for holding the lower end of the plastic bag 12. The upper end of the bag is connected to a holding means 11 in such a way that a funnel-shaped opening is formed, whereby the attachment can be performed by drawing the folded edges of the plastic bag around the opening over a frame 59 fastened to the holding

means 11.

A pressing roll 48 is also rotatably affixed at the center of the drum 58 and is spring biased and supported by two arms 40 whereby the springs draw the pressing roll 48 radially inwardly towards the envelope surface of the drum 58. The pressing roll 46 is further guided by guide means 60 which is curved along the curve of the drum and which is rotatable about a hinge 61 by a drive mechanism 62. The guide means 60 can also be formed by the front cover of the baking apparatus.

It is possible that a rod means 63 can come from the drive mechanism 62 which together with' ^" manouvering the cover 60 moves the baking tin 28 from a position outside the heat treatment station 14 to a position within.

In the initial position (fig. 6) the holding means 11 is placed on one side, the right side, of the highest point of the drum 58. In that position the plastic bag with the ^~ dry ingredients is attached to the holding means 11, at which the upper part of the plastic bag forms a funnel-like opening. Into this opening is poured the required amount of liquid to form the dough and then the baking apparatus timer is adjusted to the desired start time. In a programmer, not shown, a program card is inserted or a desired program is started. After the alloted time the drum 58 is turned slowly counter clockwise until the funnel-shaped opening is located at the highest point of the drum 58 and the liquid can flow over to that part of the plastic bag where the dry ingredients are located (fig. 2). Ouring rotation of the drum in counter clockwise direction the kneading means 20, which is fixed to the lower end of the bag, will move. When essentially all of the liquid has been emptied into the plastic bag the kneading means 20 is activated and carries out a to and fro motion about the central drive axle 39 of the drum by means of a drive mechanism 42 placed in the drum.

It is possible that the kneading can be augmented by the pressing roll 48 which independently of the kneading means 20 is rotatable about a pipe axle 64 about the rotation axle 39.

By means of the guide 60 the pressing roll 48 can be held at an appropriate distance from the baking board 38 of the drum 58 by means of a spring 65 so that an appropriate redistribution of the dough mass in the plastic bag 12 is achieved. Working the dough through the kneading piece 20 is shown in Figure 7.

The guide 60 acting as a cover can be adjusted for light pressure on the plastic bag during the fermentation periods whereby an effective distribution of the heat from the fermentation process is achieved. The cover is appropriately made of a heat conducting material, for example aluminum. During the fermentation itself the cover can only weakly contact the plastic bag and must give way when the dough expands. When the dough preparation is finished the drum 58 is rotated clockwise enough that the unnel-shaped opening with the holding means 11 is located above the baking tin 28, as shown in Figure 8. The kneading means 20 also partakes of this motion so that the plastic bag 12 is turned upside down. In this position the pressing roll 48 is activated, which has left the guide 60 and is biased by the spring 65 in the direction towards the rolling board 38 of the drum 58. The pressing roll 48 is moved over the whole length of the plastic bag up to the funnel-shaped holding means 11 pressing the dough out of the plastic bag opening and into the baking tin 28. Finally the drive the mechanism 62 moves the baking tin 28 into the heat treatment station 14 where it is possible for a final fermentation to take place and the baking is carried out. When the baking procedure is concluded it is possible that the baking tin 28 is again taken out of the baking oven so that the bread can cool outside the oven.

Depending on what kind of food product are to be produced in the baking apparatus the heat treatment station is adjusted also in accordance with those requirements. If the dough for example is to be boiled in water or fried in oil the baking tin is exchanged for appropriate cooking vessel.

Figure 9:

The embodiment shown in fig. 9 comprises a common dough preparation and heat treatment station 13,14 consisting of two housing halves 81,82 of which the first one 81 is stationary while the second one 82 is displaceable or rotatable with respect to the stationary half. In the embodiment shown the movable housing half 82 is rotatable about a vertical hinge 83 so that the dough preparation and heat treatment stations 13,14 and the holding means can be reached.

The mixing of the ingredients and the dough preparation is accomplished by attaching the uppe'r end portion of the plastic bag 12 to a holding means 11 at an upper rotatable roll 84, while the lower end of the plastic bag in a corresponding way is attached to another holding means 11 at a lower rotatable roll 85. The rolls 84 and 85 are driven by a reversible motor (not shown) about one revolution, after which the motor is reversed. In this way the plastic bag 12 is given ^" an oscillating up and downwards movement. The plastic bag must pass through an upper and a lower slit-shaped opening 86 between the housing halves 81 and 82, which only permits a substantially empty plastic bag to pass. This means that the content of the plastic bag - the dough - alternatively will be kneaded against the upper and lower part of the inner walls of the baking oven 14. where the slit 86 is located. In order to reduce the friction between the plastic bag and the edge between the slit and the inner wall, these parts can be provided with rounded sliding surfaces 87 or rolls 88.

Practical test have proved that a very effective mixing and kneading of the dough is achieved by this very simple device, even if the dough is relatively stiff. If rolls 88 are used as friction-reducing means, these can be driven so that they also can serve as transport and feeding rolls.

The plastic bags with the ingredients are preferably delivered hermetically sealed and if the baking recipe prescribes that the preparation of the dough and/or the baking should be made under atmospheric conditions it is appropriate to arrange a

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perforation and/or cutting device 89, which can perforate the plastic bag in a certain position, so that the interior of the bag will communicate with the atmosphere the device also can provide a cutting-off of the bag. which may be desired during the baking procedure, especially in cases where the interior space of the baking oven also should serve as a baking tin and where it is desired that the dough should spread over the entire baking tin and not be limited by an expanded bag 12.

Figures 10 and 11:

In the embodiment according to ^* "fig. 10 the holding means 11 consist of driven rolls 91 provided with teeth 90, which engage perforations 92 at the side edges of the plastic bag. by which the plastic bag 12 can be transported up and down in the same way as was described with reference to the embodiment of fig. 9. This new embodiment however has the advantage that the construction can be made even more compact, i.e. with a lower constructional height, and that the attachment of the plastic bag 12 to the attachment members of the combined holding- and transport device, i.e. the teeth 90, can be simplified further.

Figure 12:

Another alternative embodiment of the baking apparatus shown in Figures 9,10 and 11 is shown in fig. 12. where the plastic bag is stationary, i.e. it is at its upper and lower ends attached to appropriate holding means 11. while the combined dough preparation and heat treatment station 13,14 in its two-piece design is movable in the longitudinal direction of the plastic bag 12. This displaceability of the baking oven is provided by means of two spindles 95 arranged on opposite sides of the baking oven and rotatable by means of a motor 42, the spindles cooperating with nuts 96 fixedly attached to the outer casing of the baking oven. With the up-and downwards movement of the baking oven a bag 97 with the baking liquid will in the same way as in the embodiment according to Figures 9-11 and in cooperation with the slide or roll members 87

and/or 88 in the slits 86 burst the bag 97 so that its contents, i.e. the liquid can mix with the dry ingredients in the plastic bag 12. 8y giving the baking oven 14 an up- and downwards motion the dough in the plastic bag will be kneaded to and fro, by which an effective kneading is achieved.

Figure 13:

The baking of round bread loafs, pizzas and the like is also possible with the baking apparatus according to the invention.

In Fig. 13 is shown a section through a baking apparatus which is constructed so that the mixing'Of the ingredients and the kneading of the dough is made by the combined dough kneading - and heat treatment station 13,14 located in vertical position, while the bread loaf or pizza is rolled out with the apparatus in horizontal position. For this purpose the baking oven is pivoted about a pivot 98, which by way of a gear 99 and a motor (not shown) can be turned from vertical to horizon*tal position and vice versa. The working of the dough is made by means of a kneading means 20 movable in the longitudinal direction of the dough kneading station 13 and which during its up-and downwards motion in the kneading station works the dough mass. In the same way as was described above the liquid can be supplied to the ingredients at an appropriate time.

The invention is not limited to the embodiments described and shown but a plurality of modifications and combinations of details from the different embodiments are possible within the scope of the claims.

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