Method and device for spreading a bed of dough
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-02-03
- Publication Date
- 2026-08-13
Smart Images
Figure EP2026052770_13082026_PF_FP_ABST
Abstract
Description
Description Title of the invention: Method and device for spreading a bed of dough
[0001] The present invention relates to the field of preparation of dough for bread, pastries, cakes, or the like.
[0002] In this context of the preparation of bakery dough and similar products, and of the facilities for doing so, the invention relates more particularly to a method for spreading a bed of dough, as well as to a device for implementing this method of spreading a bed of dough.
[0003] In the field of industrial baking, the generation of dough pieces from a strip or roll of dough, also called a dough bed, can be carried out in several ways.
[0004] In all cases, the input for this operation consists of a "block of dough", weighing several tens of kilograms, from which we will want to extract dough pieces weighing a few tens of grams, to about one kilogram.
[0005] This block of dough always arrives sequentially, itself resulting from a rough division of the contents of a kneading bowl.
[0006] This block of dough must then be divided, which can be done in various ways.
[0007] Thus, it is possible to perform a so-called "volumetric" division of this block of dough.
[0008] In this type of division, it is common to fill a feeding chamber with bread dough or similar material, either by suction or mechanical pressure. Once the chamber is filled, the dough inside is pushed out and ejected onto a conveyor belt.
[0009] This method, which is very widespread, generally works with a single or multiple piston / cylinder assembly, allowing filling, under constraint, of a force-feeding chamber with paste.
[0010] It is also known from the European patent published under number EP1973410 a method and device for volumetric division of bakery dough or the like contained in a hopper having, in the lower part, an opening from which the dough is allowed to flow by gravity into a chamber suitable for dosing a quantity of dough to be divided.
[0011] After at least partial closure of said chamber, the quantity of dough contained in the chamber is divided volumetrically into dough pieces, then the divided dough pieces are extracted from the chamber, possibly with the aid of suitable gripping means, such as pairs of retractable needles, to be deposited on an evacuation support.
[0012] Volumetric division has the advantage of ensuring good volumetric accuracy, and, if the density of the dough to be divided is regular on the scale of the dough pieces to be divided, in other words in the absence of irregular bubbles on the scale of the dough pieces to be divided, good regularity of weight.
[0013] That being said, it is rare that the expected shape coming out of the machine is the final shape.
[0014] Therefore, a "balling" operation can be carried out downstream, in order to obtain a regular shape and to homogenize the tensions in the dough in all directions.
[0015] This rounding operation can be followed by a shaping stage, which consists, firstly, of flattening the ball to obtain a pancake, then rolling the pancake thus formed to obtain a cylindrical dough piece with a circular cross-section.
[0016] The resulting dough balls are likely to be of relatively constant volume and weight.
[0017] This volumetric division technology is particularly suitable for pastes considered to be relatively "easy" to work with, namely those with low fluidity and low stickiness.
[0018] These are pastas that are generally low in hydration, corresponding to a maximum volume of 60 L of water for 100 kg of flour, and lightly fermented before dividing, to obtain a generally higher density.
[0019] However, this type of volumetric division is not suitable for low density doughs resulting from long fermentations.
[0020] In another method, still involving volumetric division, the dough is introduced into a hopper, which is emptied sequentially by longitudinal blocks, which will overlap each other to create a continuous roll of dough.
[0021] Next, an optical reading of the profile of this roll of dough is carried out to control a tool designed to cut it into pieces of constant weight.
[0022] This technology allows for the processing of doughs that are much more demanding, stickier, more fluid, more hydrated, and more fermented than the first type of volumetric division mentioned earlier. This results in breads with characteristics closer to those of artisanal products, meaning a more pronounced fermented flavor, a more random crumb structure, and improved shelf life.
[0023] In addition, this method has the advantage of using the entire roll of dough, without trimmings, that is to say without cutting off a part of this roll of dough that does not have the desired geometric or mechanical properties.
[0024] However, one of the disadvantages of this method is that it allows the working of a paste bed of restricted width, which prevents high hourly tonnages from being achieved.
[0025] Other state-of-the-art documents relating to the preforming of a bed of bread dough for division into dough pieces describe processes for forming a bed of dough by flowing it from a hopper onto a conveyor belt, generally continuously, before a rolling stage to obtain a sheet of dough of the desired thickness, the bed thus formed then feeding a device comprising suitable longitudinal and / or transverse cutting means.
[0026] The bed of dough formed at the hopper outlet is, therefore, flattened, by stretching it laterally a little and longitudinally, a lot.
[0027] The resulting dough bed is wider than the dough roll generated by the volumetric dividing process, and has a specific height at which the dough pieces can be cut. Generally, this cutting is done first in the direction of feed and then perpendicular to the feed direction.
[0028] This produces polygonal dough pieces, generally rectangular, which can be used as is, or, in other cases, undergo further operations, such as folding, rolling, or even rounding.
[0029] One of the problems arising from this rolling process of forming a dough bed is that the width of the bed after rolling is uneven. Consequently, the dough bed must undergo significant lateral trimming, or clipping, as previously mentioned, to obtain a bed of consistent width and ultimately improve the uniformity of the products.
[0030] The dough pieces obtained by implementing the rolling method generally have a constant volume, provided that the bed of dough is homogeneous in height over the entire width of the cut.
[0031] Generally, the weight of the dough pieces is also constant, modulo however local variations in the dough or variations over time, which may result from a longer or shorter stay of the dough in the hopper, or even variations in the dough on the width of the bed.
[0032] Indeed, it is particularly complicated to manage local variations in dough density, as these depend, in particular, on the irregular constraints applied to it throughout the dough preparation and dough making process.
[0033] Finally, the dough pieces obtained by rolling may exhibit local density variations leading to mass dispersions.
[0034] In any case, the method of preparing dough pieces by rolling allows for working with very hydrated and highly fermented doughs, and also allows for the implementation of high production rates.
[0035] That being said, the primary bed of paste deposited on the conveyor belt, under the hopper, necessarily has a thickness considered to be relatively thick, that is to say, generally between 6 and 8 cm.
[0036] However, a final height of around 15 mm is often sought, which corresponds to a reduction rate of up to 5, before a possible steaming operation, which will increase the volume of this bed of paste.
[0037] The reduction ratio to be applied mechanically results in a stretching of the dough.
[0038] These reductions are currently achieved through successive lowering processes, using several devices in series, separated by resting phases for the dough. The devices used work the dough locally and, consequently, have a relatively limited action over time, resulting in high working kinetics, the effectiveness of which is limited on a viscoelastic dough.
[0039] With each pastry sheet, the bed of dough is subjected, on the one hand, to a geometric impact, namely that the dough lengthens and decreases in height, and on the other hand, to a physical impact, creating internal tensions due to the viscoelastic behavior of the dough.
[0040] It is worth recalling here that bread dough consists of an elastic and shape-memory (viscoelastic) material, properties which result in an accumulation of tension under the effect of the stresses applied to it, these tensions having a direct consequence on the quality of the final products obtained.
[0041] In other words, any stress applied to the dough during the dough preparation process influences the characteristics of the finished product.
[0042] In particular, significant and / or rapid dough working results in, among other things, degassing and a reduction in the dough's ability to resist the formation of air pockets during proofing and at the beginning of baking. The goal is to retain as much fermentation gas as possible within the dough, meaning large bubbles and a significant external volume. However, when the dough lacks sufficient resistance to elongation, and the bubbles grow larger due to fermentation, only small bubbles can remain.
[0043] The fact that the small bubbles burst before completing their expansion is likely to create two types of defects. On the one hand, a particularly large bubble can form between the crust and the crumb, and on the other hand, this bubble pierces the surface and escapes, leaving only small bubbles in the dough and, ultimately, a smaller product containing small bubbles.
[0044] The result is a crumb with finer alveoli than desired.
[0045] In addition to the geometric and physical impacts, the rolling out of the dough can, to some extent, have a chemical impact. Indeed, the heat generated by the rolling process can lead to accelerated fermentation.
[0046] Therefore, the rate of descent at each stage is intentionally limited to avoid subjecting the dough to excessive instantaneous stress. Furthermore, in some cases, it may be necessary to allow the dough to rest between operations to release tension, while simultaneously repeating these operations to achieve the desired dough bed height.
[0047] This inevitably results in a significant lengthening of the rolling lines, a lengthening which is also directly linked to the expected pulp throughput. The length of the lines, combined with the multiple abrupt pulp drops, leads to a noticeable change in the pulp and its characteristics, due in particular to the stresses it accumulates along the rolling line.
[0048] To overcome these drawbacks, make the dough easier to roll out and prevent it from working too much under the repeated blows of the rolling pins, the baker may have to add ingredients, which has the disadvantage, in particular, of leading to an increase in the production costs of the final products.
[0049] Furthermore, the resulting dough bed exhibits different lateral and longitudinal tensions, which is not favorable, particularly for the regularity of the dough pieces after they are cut.
[0050] Indeed, we understand from the above that, on a rolling line, once the bed of pulp has been placed on the conveyor belt, it will be lowered in width, and also in length.
[0051] In particular, working the dough bed widthwise is difficult due to its adhesion to the conveyor belt on which it rests. It therefore tends not to move laterally, even after adding flour to prevent excessive sticking.
[0052] The widening of the paste bed then occurs by displacement of the paste within the paste bed, in other words with an internal transfer of the paste, which flows irregularly, between the center of the paste bed and its lateral ends, in the thickness, generating significant tensions within the paste, this for a lateral elongation rate which generally remains very low.
[0053] A schematic representation of the lateral work of the dough bed, as it currently occurs, by pushing towards the lateral ends of the dough bed, with internal transfer of the dough within said bed, is visible in Figure 1 A of the attached drawings.
[0054] One existing technique involves vibrating or shocking the conveyor belt on which the bed of dough rests, to help the dough expand; however, this technique is not very reproducible and is relatively empirical, while also requiring the presence and constant intervention of an operator.
[0055] It is also known to install diverging rollers under the conveyor belt, which again has the effect of widening this bed of dough.
[0056] Another solution, mainly used to level the side of the dough bed or to moderately maintain / increase its width, is to use a large diameter roller, usually called a "cross roller", which moves perpendicularly to the direction of advance of the dough bed, in a back and forth motion.
[0057] As regards, now, the working of the bed of dough according to its longitudinal direction, this operation is traditionally done in successive stages, during which the said bed of dough is forced to pass from a belt of a first upstream conveyor, at a speed V, to a belt of a downstream conveyor, at a speed r*V, r being an acceleration rate which corresponds to the rate of descent of the dough at the stage considered.
[0058] To achieve this, the transition from one conveyor to another is ensured by a system that guides the bed of dough from the upstream conveyor to the downstream conveyor.
[0059] The various existing standard support mechanisms are as follows:
[0060] - Laminating / calendering between a motorized roller on top and the conveyor belt below, or between two motorized rollers. This operation allows for a significant reduction in thickness, but at the expense of a significant impact on the properties of the dough;
[0061] - The multi-roller, or "multiroller," can be single (only on the top surface of the dough bed) or double (on both the top and bottom of the dough bed, much less common). This system consists of a set of rollers, either free or driven, arranged on a rotating cylinder. This system acts like a series of successive rolling pin passes.
[0062] That being said, although the devices described above and currently implemented on rolling lines allow a significant lowering of the pulp bed, whether in the lateral direction of the pulp bed, or longitudinally, between two conveyors, each of these devices necessarily uses the application of pressure to widen or lengthen the pulp bed, putting significant stress on the pulp and negatively affecting the quality of the finished products.
[0063] The present invention is intended to remedy, at least in part, the drawbacks of existing methods and devices for spreading a bed of paste in the state of the art.
[0064] In an inventive process, a solution was devised to stretch the dough bed primarily from below by elongating the conveyor belt on which it rests, greatly limiting any crushing or flattening action, thereby drastically reducing the stresses applied to the dough bed during the rolling operation. This inventive approach allows for gradual and continuous elongation, without any sudden, abrupt action followed by rest periods.
[0065] To this end, the invention relates, initially, to a method for spreading a bed of dough for bread, pastries, cakes, or the like, consisting of:
[0066] - to deposit continuously or discontinuously a bed of paste on a conveyor belt winding around at least one upstream return roller and one downstream return roller by describing an upper strand of the belt and a lower strand of the belt extending between said rollers, on which upper strand, extending between an upstream end and a downstream end, is deposited said bed of paste, said conveyor belt being defined as elastically deformable at least in one direction transversely and / or longitudinally, in the direction of movement of said belt;
[0067] - to exert on the upper strip strand, between the upstream end and the downstream end, a progressively increasing transverse and / or longitudinal traction to progressively widen and / or lengthen said upper strip strand between said upstream end and the downstream end and to impart, to the bed of pulp deposited on said upper strip strand, a progressive transverse elongation and / or a progressive longitudinal elongation between said upstream end and said downstream end.
[0068] According to other features of the process of the present invention:
[0069] - a spreading action is exerted, in combination, on the top of the bed of dough, transversely and / or longitudinally;
[0070] - the spreading action applied to the bed of dough transversely is of progressively increasing amplitude between the upstream end and the downstream end of the upper strip strand;
[0071] - the spreading applied to the bed of paste longitudinally is of progressively increasing amplitude between the upstream end and the downstream end of the upper strip strand.
[0072] The invention also relates to a device for spreading a bed of dough for bakery, viennoiserie, pastry, or the like, comprising a conveyor including a transport belt winding around at least one upstream return roller and a downstream return roller by describing an upper belt strand and a lower belt strand extending between said rollers, said upper belt strand extending between an upstream end and a downstream end.
[0073] The spreading device for a bed of paste of the present invention is particular in that said conveyor belt is defined as elastically deformable at least in one direction, transversely and / or longitudinally, in the direction of movement of said belt, said device further comprising at least divergent lateral guiding means for progressively lengthening, transversely, said upper belt strand, between the upstream end and the downstream end, and / or traction means designed to apply a progressively increasing lengthening in the longitudinal direction, of the upper belt strand, between said upstream end and said downstream end of said upper belt strand.
[0074] Thus, longitudinally, the dough is deposited onto a conveyor belt whose upstream section is completely relaxed, and is then transported downstream. The belt itself gradually lengthens under the effect of a tension that is almost zero at the start and maximum near the traction roller. Under the effect of this progressive tension, the belt, itself elastic, gradually lengthens, allowing the dough bed, if it adheres sufficiently to the belt, to also gradually lengthen. Laterally, the belt, narrow upstream and wide downstream, imparts the same progressive widening to the dough. In viscoelastic fluids, internal stresses are a function of the applied deformation rate: it is clear that widening and lengthening the dough very slowly reduces the internal stresses generated within the dough. Various devices can allow the batch of dough to adhere to the belt during its widening or elongation.
[0075] According to specific modes of implementation:
[0076] - the diverging lateral guidance means are defined by profiles with a C-groove into which guide rods or guide rollers are inserted, laterally equipping the conveyor belt, said profiles being diverging so that the belt gradually widens between the upstream end and the downstream end of the profile, in association with the action of the downstream return roller, which pulls the conveyor belt;
[0077] - said guiding means are defined by chains with diverging pins or clips, said pins or clips cooperating with the lateral edges of said conveyor belt;
[0078] - The traction means, designed to apply a progressively increasing elongation, in the longitudinal direction, of the upper strand of the belt, between said upstream end and said downstream end, are defined, on the one hand, by the downstream return roller defining the drive means for said conveyor belt, and around which the latter is wound at the downstream end of the upper strand of the belt, and, on the other hand, by friction means exerting, over at least a portion of the length of said upper strand of the belt, preferably over more than half of the length of said upper strand of the belt, and even more preferably over the entire length of said upper strand of the belt, a restraining force opposing the movement of said upper strand of the belt, this restraining force being exerted continuously or discontinuously over more than half the length of the belt
[0079] - said friction means are defined by vacuum suction nozzles distributed at the level of a support table above which said upper strand of strip moves, resting on it;
[0080] - said traction means are defined by a plurality of transverse rods, attached to the conveyor belt, and whose ends are equipped with rollers which engage in the thread of rotating drum cams in the form of worm gears with increasing pitch, extending laterally on either side of the upper strand of the conveyor belt.
[0081] The present invention also relates to a dough-spreading unit for bakery, viennoiserie, pastry, or the like, said unit comprising, at least in series, a dough-spreading device having divergent lateral guide means for progressively lengthening, transversely, said upper strip strand, between the upstream end and the downstream end, and a dough-spreading device comprising traction means designed to apply a progressively increasing lengthening in the longitudinal direction, of the upper strip strand, between said upstream end and said downstream end.
[0082] Also, advantageously, through the process and device for spreading a bed of bread dough or the like, it is sought to apply, at each point of said bed of dough, an identical elongation, by the lower part of said bed, and a lowering proportional to this elongation, while avoiding that the lateral and / or longitudinal elongation of the bed of dough is carried out exclusively by the application of pressure which may lead to crushing of the dough, and / or by a stretching applied only to the ends of the bed of dough which may cause tearing of the dough.
[0083] Other objects and advantages of the present invention will become apparent during the following description relating to embodiments which are given only as indicative and non-limiting examples.
[0084] Understanding this description will be facilitated by referring to the attached drawings, in which:
[0085] [Fig.1 A] and [Fig.1 B] include two schematic front views of the working of a dough bed for the manufacture of bakery and similar products, namely [Fig.1 A] which shows a front view of the standard working of a dough bed, as it occurs on current spreading lines, with an illustration, by means of arrows, of the internal transfer of the dough, while [Fig.1 B] shows a front view of the working of the dough bed according to the present invention, without internal movement of the dough;
[0086] [Fig.2] represents a schematic and perspective view of an advantageous embodiment of a device for spreading, in a lateral direction relative to the direction of travel on a conveyor belt, a bed of dough of bakery or similar products, comprising lateral guiding means diverging from said conveyor belt on which said bed of dough is deposited, at the level of an upper strand of the belt, while an oscillating roller, with a truncated conical geometry, also shown, can accompany the lateral elongation of the bed of dough in order to ensure its adhesion to the upper surface of the conveyor belt, by being positioned above the latter;
[0087] [Fig.3] represents a schematic and top view of an embodiment of a device for spreading a bed of dough for bakery or similar products, this time in a longitudinal direction relative to the direction of advance, comprising traction means designed to allow a progressively increasing elongation, also illustrated, in the longitudinal direction, of the upper strand of the conveyor belt, these means being presented here in the form of transverse rods made integral with said elastic conveyor belt, arranged at equidistant intervals when said conveyor belt is relaxed, while a variable pitch cam system imposes a progressive increase in the inter-rod pitch from the upstream end to the downstream end of said upper strand of the belt;
[0088] [Fig.4] represents a schematic and side view of another embodiment of a device for spreading, longitudinally, a bed of dough for bakery or similar products, again comprising traction means designed to allow a progressively increasing elongation, also illustrated, in the longitudinal direction, of the upper strand of the conveyor belt, these means being presented here in the form of vacuum suction nozzles distributed at the level of a support table above which the said upper strand of the belt moves, resting on it.
[0089] With reference to the figures in the attached drawings, the present invention relates to a method of spreading a bed of dough 1 for bakery, viennoiserie, pastry, or the like, consisting, in the first instance, of depositing continuously or discontinuously a bed of dough 1 on a transport belt 2 of a conveyor 3.
[0090] In a known manner, said conveyor belt 2 winds around at least one upstream return roller and one downstream return roller, whose axes of rotation, respectively 4 and 5, are visible in figure 4 of the attached drawings, describing, on the one hand, an upper belt strand 6 and, on the other hand, a lower belt strand 7 extending between said rollers 4, 5.
[0091] Preferably, the downstream return roller is a drive roller. However, the downstream return roller can also, alternatively, be combined with a second, drive roller.
[0092] Advantageously, at least the upper strand of the band 6 extends horizontally between said rollers 4, 5.
[0093] Thus, on this upper strip strand 6, extending between an upstream end 61 and a downstream end 62, the said bed of paste 1 is deposited.
[0094] Particularly to the method of spreading a bed of paste according to the present invention, said conveyor belt 2 is defined as elastically deformable at least in one direction, namely transversely and / or longitudinally, taking into account, as a reference, the direction of movement 8 of said belt 2, this direction of movement 8 being represented, in the attached figures 2 to 4, by an arrow.
[0095] In a second part of the process of spreading a bed of paste 1, a progressively increasing transverse and / or longitudinal traction is exerted on the upper strip strand 6, between its upstream end 61 and its downstream end 62, to progressively widen and / or lengthen said upper strip strand 6 between said upstream end 61 and said downstream end 62.
[0096] It is thus imprinted, on the bed of paste 1 deposited on said upper strip strand 6, a progressive transverse elongation and / or a progressive longitudinal elongation, as the case may be, between said upstream end 61 and said downstream end 62.
[0097] According to a highly preferred feature of the method of spreading a bed of dough 1 which is the subject of the present invention, in combination with the application of a progressive transverse and / or longitudinal traction of the upper strip strand 6, which will therefore apply a progressive elongation to the bed of dough 1 at the level of its lower face, a spreading action can be exerted on the top of the bed of dough 1, transversely and / or longitudinally.
[0098] Further details will be given later in the text of this application, in connection with the spreading device for a bed of paste 1, which is also the subject of this application, and which will be described below, with regard to the means of carrying out such a spreading action, transversely and / or longitudinally.
[0099] According to a particular feature of the spreading method of a bed of paste 1 of the present invention, the spreading action applied to the bed of paste 1, in the transverse direction considering, as a reference, the direction of movement 8 of the conveyor belt 2, is of progressively increasing amplitude, constant or not, between the upstream end 61 and the downstream end 62 of the upper strand of the belt 6 of said conveyor belt 2.
[0100] Similarly, and most preferably, the spreading applied to the bed of paste 1 longitudinally with respect to the direction of movement 8 of the conveyor belt 2, is of progressively increasing amplitude, constant or not, between the upstream end 61 and the downstream end 62 of the upper strand of the belt 6 of said conveyor belt 2.
[0101] The present invention also relates to a spreading device 10, 100, 101 of a bed of dough 1 for bakery, viennoiserie, pastry, or similar products, intended to be integrated into a production installation for bakery, viennoiserie, pastry, or similar products.
[0102] It is therefore understood that such a spreading device 10, 100, 101 according to the present invention is positioned, in a bakery or similar product production installation, downstream of a hopper through which a bed of dough 1 called "primary" is formed which must be lowered.
[0103] The spreading device 10, 100, 101 of a bed of paste 1 according to the present invention comprises, in a known manner, a conveyor 3 comprising a conveyor belt 2 winding around at least one upstream return roller and one downstream return roller, the axes of which, referenced respectively 4 and 5, are represented in the attached figure 4, describing an upper strand of belt 6, preferably horizontal, and a lower strand of belt 7 extending between said return rollers 4, 5, said upper strand 6 extending between an upstream end 61 and a downstream end 62.
[0104] The spreading device 10, 100, 101 of a bed of paste 1 of the invention is particular in that said conveyor belt 2 of the conveyor 3, on which said bed 1 is deposited at the hopper outlet, is defined as elastically deformable, and this at least in one direction, namely transversely and / or longitudinally, taking into account the direction of movement 8 of said conveyor belt 2.
[0105] Essentially to the present invention, said spreading device 10, 100, 101 of a bed of paste 1 further comprises, at least, diverging lateral guiding means 91, 92 for progressively lengthening, transversely, said upper strip strand 6, between the upstream end 61 and the downstream end 62, and / or traction means 13 designed to apply a progressively increasing lengthening in the longitudinal direction, of the upper strip strand 6, between said upstream end 61 and said downstream end 62.
[0106] In the attached drawings, figure 3 illustrates, more particularly, a spreading device 10 of a bed of paste 1 comprising divergent lateral guiding means 91, 92 to progressively lengthen, transversely, said upper strip strand 6, between its upstream end 61 and its downstream end 62.
[0107] In an advantageous embodiment of the spreading device 10 of a bed of paste 1, which should not however be considered limiting to the present invention, said diverging lateral guide means 91, 92 are defined by profiles with a C-groove extending laterally and on either side of the upper strand of the belt at least over a part of the length of the latter and in which guide rods, or guide rollers, fitted to the lateral edges of the conveyor belt 2 of the conveyor 3, are engaged.
[0108] Preferably, said divergent lateral guiding means 91, 92 are defined by profiles with a C-groove extending laterally and on either side of the upper strip strand over the entire length of the latter.
[0109] The said profiles 91, 92 are divergent, so that the upper strand 6 described by the said conveyor belt 2 on which the bed of paste 1 rests comes to widen, progressively, over at least part, or even over the whole, of the length of the strand 6 between the upstream end 61 and the downstream end 62 of the profiles 91, 92, in association, moreover, with the action of the downstream return roller 5, which comes to exert traction on the conveyor belt 2 of the conveyor 3.
[0110] In such a configuration of a transport belt 2 which is essentially elastic transversely, this belt 2 may advantageously have an internal structure which is significantly more rigid in its longitudinal direction, compared to its lateral elasticity.
[0111] The conveyor belt 2 of the conveyor 3 can therefore preferably consist of a belt made of an elastic synthetic material, reinforced by a rigid longitudinal weave.
[0112] In another equally advantageous embodiment of the spreading device 10 of a bed of paste 1, said divergent lateral guiding means 91, 92 are defined by divergent stud chains.
[0113] In this example, the said pins cooperate, over at least part of the length of the upper band 6 of the transport band 2, or even over the entire length of this length, with eyelets equipping each of the lateral edges of the latter.
[0114] It could also be conceivable clamp systems, allowing the laterally fixing of the transport belt 2 on two diverging lateral chains constituting the diverging lateral guidance means 91, 92.
[0115] Regardless of the embodiment chosen, said diverging side chains can be driven by sprockets having different center distances at the entry and exit of the conveyor belt 2, the center distance of said sprockets being adjustable, so as to allow an adjustment of the widening of said conveyor belt 2.
[0116] Note that possible C-profiles defining the said divergent lateral guidance means 91, 92 can also be provided with adjustable spacing for this same purpose.
[0117] On top of the paste bed 1 resting on the conveyor belt 2, it can be particularly advantageous to guide the lateral movement of the paste. This is preferable to ensure that the paste follows the belt thanks to its adhesion; otherwise, it might slip to avoid spreading. Therefore, the device according to the invention may include, for this purpose, means for spreading said paste bed 1 from its top.
[0118] Such spreading means, allowing work on the bed of dough on the upper part thereof, may consist, in a very preferential embodiment illustrated in figure 2 of the attached drawings, in the form of an oscillating roller 12, having a truncated conical geometry, the largest diameter of the cone being located on the side of the downstream end 62 of said upper strand of the belt 6 of the conveyor belt 2 of the conveyor 3.
[0119] Such a truncated conical geometry of the oscillating roller 12 makes it possible to cover the entire surface of the bed of dough 1, even though it goes from an initial width to a final width greater than said initial width, while the height of the bed of dough 1 has decreased in the same proportion.
[0120] Various implementations are possible: downstream, a vertical pivot joint between roller 12 and the conveyor frame 3, positioned at the point where the belt converges, can be used to impart the circular translational movement to roller 12 at its downstream end. The pressure exerted can be purely gravitational or imposed by force (via a vertical spring, for example) or by stroke (by setting the height of the lateral guide of the downstream mounting). The rotation of roller 12 can be natural, through friction, or forced by a motor.
[0121] However, such an embodiment should not be considered as limiting the present invention, and the work of the dough bed 1 at its upper part can also be carried out by a diverging counter belt, similar to the conveyor belt 2 of the conveyor 3, or even by a large diameter roller moving in a direction perpendicular to the direction of advance 8 of the dough bed 1, also commonly called a "cross roller".
[0122] In such a device 10 for spreading the bed of dough 1 in a transverse direction, it is permitted an elongation, in the lower part, of said bed of dough 1, in other words at the level of the lower face of said bed 1 which is in contact with the transport belt 2 of the conveyor 3.
[0123] Since said conveyor belt 2 of the device 10 for spreading a bed of dough is itself divergent, there is no lateral slippage of the bakery dough for the bed of dough 1 to widen, between the upstream end 61 and the downstream end 62 of the upper strand of the belt 6 of said conveyor belt 2.
[0124] Also, the "path traveled" by the paste inside the paste bed 1 is very significantly less than the path it travels in the rolling lines traditionally implemented in known state-of-the-art installations.
[0125] The result is, in the end, a substantial reduction in the internal tensions imparted to the bread dough, compared to those it undergoes during the implementation of the usual spreading techniques.
[0126] It should also be noted that such a spreading device 10 of a bed of paste 1 makes it possible to obtain an enlargement of said bed of paste 1 in substantially greater proportions than the enlargement made possible by the implementation of current techniques.
[0127] With reference now to figures 3 and 4 of the attached drawings, examples of the realization of a device 100, 101 allowing the longitudinal lowering of the bed of paste 1, considering the direction of movement 8 of the conveyor belt 2, will be described below.
[0128] For the record, such a spreading device 100, 101 of a bed of paste 1 longitudinally includes traction means 13 designed to apply a progressively increasing elongation, in the longitudinal direction, of the upper strand of strip 6 over at least part of its length, between its upstream end 61 and its downstream end 62.
[0129] Such traction means 13 are defined, on the one hand, by the downstream return roller 5 defining drive means for said conveyor belt 2, and around which the latter is wound at the downstream end 62 of the upper belt strand 6, and, on the other hand, by friction means exerting, on at least a portion, or even on more than half of the length of said upper belt strand 6, or even on the entire length, a restraining force opposing the movement of said upper belt strand 6, this restraining force being exerted continuously or discontinuously over more than half of the length of the conveyor belt 2 of the conveyor 3.
[0130] In such a configuration, this conveyor belt 2 can advantageously present a rigid but longitudinally elastic lateral structure.
[0131] In such a spreading device 101 visible in figure 4, friction is exerted over a large part of the length of the upper strand 6 of the conveyor belt 2. Thus, the tension of the belt 2 increases progressively over the length of this upper strand 6 of the belt on which this friction is exerted between the upstream end 61 and the downstream end 62 so that the conveyor belt 2 gradually lengthens due to its elastic character.
[0132] Indeed, along this upper strand 2 of the belt the friction forces add up, so that the local tension of the transport belt 2, at a given distance from the upstream end 61 of the upper strand 6 of the belt 2 must balance the friction force generated from said upstream end 61.
[0133] The tension then increases in an affine manner, the tension at the upstream end 61 of the transport band 2 being macroscopically the pre-tension of said band 2 and, at the downstream end 62 of the transport band 2, the pre-tension added to the total friction force.
[0134] Preferably, a support device for the bed of dough 1 is positioned above this conveyor 3, to promote the lengthening of said bed of dough 1, and therefore its lowering, in a very gradual manner.
[0135] The upper strand 6 of the belt may be made to move at least over part of its length above a friction plane arranged between the upstream return roller and the downstream return roller, this friction plane being designed in a non-slip material over which the conveyor belt 2 slides with difficulty.
[0136] Preferably, with particular reference to the attached figure 4, in order to increase the friction effort, the friction means of the spreading device 101 can be defined by suction nozzles 141 distributed at the level of a support table 141 above which the upper strand of the belt 6 of the transport belt 2 moves, resting on it at least for part of its length, so as to press the belt against this support table 141.
[0137] The vacuum thus created under the upper strand of the transport belt 2 is likely to cause a differential elongation of said upper strand of the belt 6 along its entire length. Depending on this elongation, which can, for example, be measured in real time by any suitable means, particularly a laser, it is possible to implement a control system for the vacuum, based on the desired elongation, along the length of said upper strand of the belt 6.
[0138] Another methodology to ensure this affine elongation between the beginning and the end of the transport belt 2, described now with reference to the attached figure 3, consists of using a mechanical drive performing this function.
[0139] One possible implementation consists of arranging a plurality of transverse rods 15 embedded in the mass of the transport band 2, or made integral to it, said rods 15 being preferentially but not necessarily equidistant from each other, when said transport band 2 of the spreading device 100 is relaxed.
[0140] At their ends, these rods 15 are equipped with rollers or pins 152 which engage in the thread of rotating drum cams 151 a, 151 b in the form of worm gears with increasing pitch, extending laterally on either side of the upper strand 6 of the conveyor belt 2.
[0141] Thus, under the effect of the rotation of these rotating drum cams 151a, 151b, and the increasing pitch of the thread between their upstream and downstream ends, a progressively increasing tension is exerted between two successive rods 15. The consequence is the progressive elongation of the upper strand 6 of the conveyor belt along these rotating drum cams 151a, 151b.
[0142] It is also conceivable, within a single device for spreading a bed of paste 1, to combine the lateral spreading effect with the longitudinal spreading effect of said bed of paste 1, so that this can drastically shorten the length of the rolling table, resulting, consequently, in a smaller footprint of the rolling line, as well as a reduction in the maintenance operations required.
[0143] Such a combination also entails an advantage that can be described as "technological"; indeed, in such a device, the spreading process of the bed of dough 1 being shorter, the dough has less time to work.
[0144] Therefore, this helps to limit the tensions in the dough, with the negative consequences that this induces on the behavior of the dough.
[0145] Thus, by means of the invention, and moreover in the case of a combination of lateral and longitudinal elongation, the bread dough is not subjected to violent and successive assaults, but, on the contrary, to a very progressive work, which allows the obtaining of a considerable elongation, without risk of tearing.
[0146] Furthermore, such a combination promotes an "isotropy" of tensions, which will still be likely to appear, such an isotropy thus facilitating the subsequent working of the paste.
[0147] In order to obtain such a combination of lateral and longitudinal spreading of the paste bed within a single device, the lateral divergence rate of the conveyor belt 2 and / or the tension in the longitudinal direction of said belt 2 may be adjusted, as appropriate, by a variation of the depression in the vacuum plenum or by a change of the cam.
[0148] The present invention also relates to a unit for spreading a bed of dough 1 for bakery, viennoiserie, pastry, or similar purposes, comprising, at least, in series:
[0149] - on the one hand a spreading device 10 of a bed of paste 1 comprising divergent lateral guiding means 91, 92 to progressively lengthen, transversely, said upper strip strand 6, between the upstream end 61 and the downstream end 62 thereof;
[0150] - on the other hand, a spreading device 100, 101 of a bed of paste 1, comprising traction means 13 designed to apply a progressively increasing elongation, in the longitudinal direction, of the upper strand of strip 6, between said upstream end 61 and said downstream end 62.
[0151] Note that, within said spreading unit, the device 10 allowing the lateral extension of the dough bed 1 and the device 100, or 101, allowing the longitudinal extension of the dough bed 1, always considering the direction of advancement 8 of the dough bed, can be positioned indifferently with respect to each other.
[0152] It is therefore conceivable to have, in such a unit for spreading a bed of dough 1 for bakery, viennoiserie, pastry, or similar, a certain modularity with a succession of spreading devices allowing, alternately, a lateral elongation and a longitudinal elongation of said bed of dough 1.
[0153] In summary, the present invention has the advantage of preventing the ends of the bed of dough 1 to be spread from undergoing excessive displacement, compared to the solutions implemented in the prior art to obtain a lateral or longitudinal spreading of said bed of dough 1.
[0154] In the method and device for spreading a bed of dough of the invention, the traction on said bed of dough 1 is exerted in a homogeneous or almost homogeneous manner, by the lower part of the bed of dough 1, in contact with the transport belt 2 of the conveyor 3, and over the entire width and / or length of the bed of dough 1.
[0155] In addition, each portion of bread dough resting on the conveyor belt 2 will, through the invention, undergo a traction proportional to the elongation that is ultimately sought, and the elongation is exerted proportionally and homogeneously over the entire length and / or width of the dough bed.
[0156] Therefore, the process and device of the present invention make it possible to obtain a progressive enlargement and / or elongation of the paste bed 2, making it possible to drastically reduce internal tensions in the paste, tension differentials across the width, local heating of the paste, the addition of improvers to make the paste more extensible, and to decrease the length of production lines.
[0157] The dough is worked uniformly across the entire surface of the dough bed 1, progressively and slowly, and not abruptly and at specific points. In other words, the elongation per unit length or width is constant. The work produced by the invention is schematically illustrated in the accompanying Figure 1B.
[0158] By means of the present invention, the work is carried out, moreover, without pushing the dough back with an asymmetry on the thickness which creates tensions in the dough, contrary to what happens by means of current techniques, and which is illustrated in figure 1 A of the attached drawings.
[0159] Moreover, contrary to expectations, the solution provided by the present invention to allow lowering of the dough bed both laterally and longitudinally, and which is considerably less abrupt than existing solutions, simultaneously allows for a reduction in the footprint of the rolling lines, the present solution being more compact than traditional means.
Claims
Demands
1. A method for spreading a bed of dough (1) for bakery, pastry, viennoiserie, or the like, consisting of: - to deposit continuously or discontinuously a bed of paste (1) on a conveyor belt (2) of a conveyor (3) winding around at least one upstream return roller (4) and one downstream return roller (5) by describing an upper strand of belt (6) and a lower strand of belt (7) extending between said rollers, on which upper strand (6), extending between an upstream end (61) and a downstream end (62), is deposited said bed of paste (1), said conveyor belt (2) being defined as elastically deformable at least in one direction transversely and / or longitudinally, in the direction of movement (8) of said belt (2); - to exert on the upper strip strand (6), between the upstream end (61) and the downstream end (62), a progressively increasing transverse and / or longitudinal traction to progressively widen and / or lengthen said upper strip strand (6) between said upstream end (61) and said downstream end (62) and to impart to the bed of pulp (2) deposited on said upper strip strand (6) a progressive transverse elongation and / or a progressive longitudinal elongation between said upstream end (61) and said downstream end (62).
2. A method for spreading a bed of dough (1) according to claim 1 characterized in that a spreading action is exerted, in combination, on the top of the bed of dough (1), transversely and / or longitudinally.
3. A method for spreading a bed of paste (1) according to claim 2 characterized in that the spreading action applied to the bed of paste (1) transversely is of progressively increasing amplitude between the upstream end (61) and the downstream end (62) of the upper strip strand (6).
4. A method for spreading a bed of dough (1) according to claim 2 or claim 3, characterized in that the spreading applied longitudinally to the bed of dough (1) is of progressively increasing amplitude between the upstream end (61) and the downstream end (62) of the upper belt strand (6).
5. A device for spreading (10, 100, 101) a bed of dough (1) for bakery, viennoiserie, pastry, or the like, comprising a conveyor (3) including a conveyor belt (2) winding around at least one upstream return roller (4) and one downstream return roller (5) by describing an upper belt strand (6) and a lower belt strand (7) extending between said rollers (4, 5), said upper strand (6) extending between an upstream end (61) and a downstream end (62), characterized in that said conveyor belt (2) is defined as elastically deformable in at least one direction, transversely and / or longitudinally,in the sense of displacement (8) of said strip (2), characterized in that said device (10, 100) further comprises at least diverging lateral guiding means (91, 92) for progressively lengthening, transversely, said upper strip strand (6), between the upstream end (61) and the downstream end (62), and / or traction means (13) designed to apply a progressively increasing lengthening, in the longitudinal direction, of the upper strip strand (6), between said upstream end (61) and said downstream end (62).
6. Spreading device (10) of a bed of paste (1) according to the preceding claim characterized in that the diverging lateral guide means (91, 92) are defined by profiles with a C-groove into which guide rods or guide rollers are introduced laterally equipping the conveyor belt (2), said profiles being diverging so that the belt (2) gradually widens between the upstream end (61) and the downstream end of the profile (62), in association with the action of the downstream return roller (5), which pulls the conveyor belt (2).
7. Spreading device (10) of a bed of paste (1) according to claim 5 characterized in that said guiding means (91, 92) are defined by chains with diverging pins or clips, said pins or clips cooperating with the lateral edges of said conveyor belt (2).
8. Spreading device (101) for a bed of paste (1) according to claim 5 characterized in that the traction means (13), designed to apply a progressively increasing elongation, in the longitudinal direction, of the upper strand of the belt (6), between said upstream end (61) and said downstream end (62), are defined, on the one hand, by the downstream return roller (5) defining drive means for said conveyor belt (2), and around which the latter is wound at the downstream end (62) of the upper strand of the belt (6), and, on the other hand, by friction means exerting, over at least a portion of the length of said upper strand (6) of the belt, preferably over more than half of the length of said upper strand (6) of the belt, and even more preferably over the entire length of this length, a restraining force opposing the movement of said upper strand (6) of the belt,this restraining force being exerted continuously or discontinuously over more than half the length of the strip (2).
9. Spreading device (101) of a bed of paste (1) according to the preceding claim characterized in that said friction means are defined by vacuum suction nozzles (141) distributed at the level of a support table (14) above which said upper strand of strip (6) moves, resting on it.
10. Spreading device (100) of a bed of paste (1) according to claim 5 characterized in that said traction means (13) are defined by a plurality of transverse rods (15), integral with the conveyor belt (2), and whose ends are equipped with rollers (152) engaging in the thread of rotating drum cams (151 a, 151 b) in the form of increasing pitch worm gears, extending laterally on either side of the upper strand (6) of the conveyor belt (2).
11. A dough bed spreading unit (1) for bakery, viennoiserie, pastry, or the like, characterized in that it comprises, at least in series, a dough bed spreading device (10) according to any one of claims 5 to 7, which comprises diverging lateral guiding means (91, 92) for progressively lengthening, transversely, said upper strip strand (6), between the upstream end (61) and the downstream end (62), and a dough bed spreading device (100, 101) according to claim 5 or any one of claims 8 to 10, which comprises traction means (13) designed to apply a progressively increasing lengthening in the longitudinal direction, of the upper strip strand (6), between said upstream end (61) and said downstream end (62).