Processes for the production of work equipment for food and work equipment for the processing of food

Abstract

The present invention relates to a method for producing working tools for processing food, wherein the working tool has a hub and one or more processing bodies extending from the hub, the method comprising the following steps: providing a hub, wherein the hub has recesses on the outer surface, inserting one or more processing bodies into the recesses, deforming the hub so that the one or more processing bodies are fixed in the hub, wherein the deformation of the hub (112) takes place starting from a surface of the hub (112) which is different from a surface through which the processing bodies (114) exit.

Description

Technical FieldThe present invention relates to a method for producing working fluids which can be used for processing foods, and working fluids which are produced by such a method.BACKGROUND OF THE INVENTIONIn many fields of food processing, working agents such as quirls, snowbeeses and hand blenders are used for mixing and optionally crushing foods. Common to these structures is that a shaft, typically made of metal, has wire loops or other components attached to it that extend outward.These components are introduced into a food to be processed and moved within the food, for example rotated, in order to process and mix the food. The working means are often operated electrically, but it is also possible to operate them manually. An example of such a working medium is described in U.S. Pat. No. 9,060,651 B2, which describes kneading hooks of a hand blender which are used in the production of doughs. Other fields of application are, for example, the production of beating cream or ice cream and generally all applications in which foods are to be mixed or foamed or beaten.Various methods are known in the art for securing the wire loops to the shaft. Thus, one method is to weld the loops to the central shaft and then cast them around with a cylindrical plastic hub, resulting in a clean appearance and concealing the welds. An alternative is to bend the ends of the wire loops by 90° for example and then insert them into a hub assembly. In this case, the bent ends lead to an axial fastening in the hub. An example of such a process is described in U.S. Pat. No. 4,730,939. However, the two methods are complex to implement and thus result in increased costs.In view of this, a manufacturing method has been implemented, which will be explained with reference to FIG. 1. A working means 10 for processing food has a hub 12 which is mounted on a shaft 16 and fastened to the latter. The hub 12, which is made of metal, has recesses provided on the radially outer side of the cylindrical hub 12. Into these recesses, wire loops 14 are inserted as examples of processing bodies. The radial outer side of the hub 12 is acted upon by a force K, which leads to deformations 18 of the hub 12. At the same time, this deformation also leads to deformations 20 of the processing bodies 14. This caulking force K is applied in a radial direction or at an angle of up to 45° to the radial direction of the hub 12 and results in the processing bodies 14 being fixed in the hub 12.However, it has been noticed by the inventors that, when manufacturing the working medium 10 in this way, the point S of the processing bodies 14 with the highest deformation is directly on the outside of the hub 12 and thus lies at the point S at which the processing bodies 14 exit from the hub 12. However, this location is the point which is exposed to the highest stresses during use of the working medium 10.Thus, just at the location subjected to the strongest stresses during operation, the material of the processing bodies 14 is deformed and weakened, resulting in defects and material failures as a result of the reduced cross-section and possible notching effect. For this reason, the working means 10 often fail at these locations, resulting in the processing bodies 14 breaking off.SUMMARY OF THE INVENTIONThe invention aims to eliminate or at least alleviate the disadvantages mentioned.The invention is defined by the independent claims. Preferred embodiments are defined in the dependent claims.According to the invention, a method for producing working agents for processing foods is claimed. Such working means are any kind of working means intended for processing food, the working means comprising a hub and one or more processing bodies extending from the hub. The processing bodies act on the foods when used and serve to process them, in particular mix them.The method comprises, as a first step, providing the hub, wherein the hub has recesses on its outer surface, which preferably run radially and whose number corresponds to the number of processing bodies to be introduced. Subsequently, one or more processing bodies are introduced into these recesses (one processing body being introduced per recess). The recesses serve to later hold the processing bodies and are designed such that the processing bodies are inserted into them with little play.The hub is then deformed, so that the one or more processing bodies are fixed in the hub by a form fit. As a result, the processing bodies are fastened in the hub and can therefore no longer slide out of the recesses.According to the invention, the deformation of the hub takes place such that the hub is deformed on a surface which differs from the surface through which the processing bodies emerge. This ensures a certain distance between the processing bodies and the point of action of the force, which ensures that the deformation of the processing bodies is comparatively small (or ideally zero) at the point at which the processing bodies emerge from the hub. This prevents the material of the processing bodies from being weakened at the point at which they emerge from the hub.In the case of a hub in which there are no transitions between the boundary surfaces defined by edges (for example spheres or ellipsoids), the deformation starting from a surface which differs from the surface through which the processing bodies emerge is understood to mean that the point at which the hub is acted upon during the deformation is offset by an angle of at least 20° with respect to the center point of the hub from the point at which the associated processing body emerges from the hub.In a preferred embodiment, the hub has a cylindrical shape, wherein the processing bodies extend from the lateral surface or one of the flat sides of the cylinder. Such a configuration is relevant in kitchen appliances, in particular quirls, snowbeeses and mixers. Alternatively, other hub shapes are also conceivable which deviate from the cylindrical shape, such as, for example, barrel-shaped or truncated cone-shaped hubs or hubs whose circumferential surface represents a polygonal shape.It is furthermore preferred that a shaft is provided which extends from the hub along the cylinder axis of the hub and is fixed to the hub in a rotationally fixed manner. By means of such a shaft, the hub with the processing bodies can be rotated. The shaft is preferably fastened to the hub by means of an interference fit and / or deformation, particularly preferably caulking. Thus, since further fastening means are avoided which could collect dirt in use, such working means are comparatively easy to clean. Other types of rotationally fixed fastening are also possible (for example welding, soldering, adhesive bonding, screwing, etc.).It is preferred that the deformation of the hub takes place by acting of a deformation tool on a radial outer surface of the hub, wherein the processing bodies particularly preferably extend axially out of the hub. Such a manufacturing method can be easily implemented.It is preferred alternatively that the deformation of the hub takes place by acting on an axial end face of the hub by a deformation punch. Such a manufacturing method is easy to implement. Since the processing bodies extend from the lateral surface of the cylinder, a distance of the deformation from the lateral surface of the hub can also be more easily ensured in this case.The deforming die is preferably designed such that it acts on the hub along an annular surface, wherein the annular surface is particularly preferably spaced apart from the radial outer side of the hub during the pressing-on of the deforming die. By such an annular surface, the deformation can be kept substantially constant, thereby preventing the deformation from differing along the hub. This increases the quality of the working fluids thus produced. In addition, the use of an annular surface facilitates the production process, since the deformation punch and the hub only have to be aligned coaxially, but no alignment of the angular positions about the axis of rotation is necessary.The axial end surface is preferably an end surface different from the end surface from which the shaft extends.Alternatively, instead of an annular deformation geometry, the deformation punch can also have individual, non-contiguous, for example hemispherical elevations which cause the deformation. Here, however, these elevations must then be aligned in the rotational direction with respect to the position of the processing bodies during production. The hub is thus acted upon at points, i.e. at individual, separate points, in order to deform the hub. As a result, higher pressures for deforming the hub can be generated more easily.Preferably, the direction of action of the force during the deformation of the hub deviates by at least 45° from the direction with which the processing bodies emerge from the hub. This makes it possible to increase more easily the distance of the point at which the maximum deformation of the processing bodies occurs from the point at which they emerge from the hub.It is particularly preferred that the processing bodies are deformed during the deformation of the hub and are thus fastened in the hub. Such a method is easily implementable, since no specially shaped processing bodies are required. In such a method, in the case of at least one, preferably all, processing bodies, that region which is most deformed is located within the hub and not on the outer side of the hub, so that the deformation continuously decreases from a point which lies within the hub outwards and at least up to the point at which the processing body exits from the hub. Preferably, the point of maximum deformation of the processing bodies is at least 10% of the radial diameter of the hub away from the exit surface.In this context, the degree of deformation of the processing bodies is understood to mean a measure which describes how strongly the deformed shape of the processing bodies deviates from their original shape. One way of defining this is, for example, the minimum radial diameter of the processing bodies (in which connection the radial direction is defined with respect to the axis of the processing bodies). The deformation can also be defined differently and can be detected on the finished working medium, for example by examining the microstructure. Alternatively, the deformation may be detected by the deviation of the circumference at the deformed location compared to the initial state or the deviation of the cross-sectional area at the deformed location compared to the initial state. If the processing body is a body having an original circular cross section, the deformation can also be determined by determining the deviation of the maximum radius compared to the original cross section. If the deformation is so strong that the processing body is squeezed flat on one side (typically into a D-shape), the deformation can also be determined over the length of the location which is flat.According to the invention, it is avoided that the point at which the processing body / bodies have the strongest deformation coincides with the point which is subjected to the highest stresses when using the working medium. This makes it less likely or delays the time for the processing bodies to have a material failure at this point and thus break or increase the maximum tolerable load, increases the maximum tolerable number of load cycles or reduces the necessary diameter of the processing bodies.Particularly preferably, there is no deformation or only an insignificant deformation at the point at which the processing body / bodies emerge from the hub. Further preferably, the deformation, viewed in the direction of the processing bodies, lies as far as possible in the interior of the hub, preferably by at least 10% of the diameter of the hub. An insubstantial deformation is understood to mean a deformation which is not detectable without a study of the microstructure of the processing bodies. This leads to a particularly improved quality of working means and in particular to a particularly good durability even under loads, since the material of the processing bodies is substantially in its original state at the point subjected to the highest loads and is thus not weakened by deformations.Alternatively, it is preferred that the processing bodies have form-fitting features, preferably depressions in the form of, for example, grooves or generally sections with a reduced diameter, before the introduction into the hub, with which the material of the hub engages during the deformation of the hub in order to fasten the processing bodies in the hub. These features are fully internal to the hub and thus do not abut the outer surfaces of the hub, thereby avoiding the material weakened thereby being located at the locations subjected to high stress in use. In principle, projections on the processing bodies are also conceivable as form-fitting features. The preferred features reduce the force required when deforming the hub, since only the material of the hub has to be deformed, but not the material of the processing bodies. However, a disadvantage of this embodiment is that an additional manufacturing step in front of it is necessary, in which the processing bodies are deformed.The hub is preferably made of metal, particularly preferably steel, in particular stainless steel. Such hubs are particularly well suited for use in food.Likewise, the processing bodies are preferably also produced from metal, particularly preferably steel, in particular stainless steel. This also leads to the above-mentioned advantages.Preferably, the thickness of the deformed material of the hub over processing bodies is in the range of 0.2 mm - 2 mm. This can ensure that the material of the hub is sufficiently thick to reliably hold the processing bodies. In this context, the thickness of the material over the deformed regions is understood to mean the minimum distance between the outer side of the deformed regions of the processing bodies and the outer side of the deformed regions of the hub.Preferably, the working medium is a quirl, kneading hooks or snowbeese and the processing bodies are loops.Alternatively, the working medium can be a knife star for a stand blender, wherein the processing bodies of this knife star are blades or that the working medium is generally intended for use in electrically operated kitchen appliances.Furthermore, according to the invention, a working medium for processing food is produced by a method according to one of the previously defined claims. Such a working medium combines the above-mentioned advantages.Brief Description of the FiguresFIG. 1 shows a manufacturing method according to a comparative example. FIG. 2 shows a production method according to the invention. FIG. 3 shows a quirl according to the invention according to a variant.Detailed Description of the FiguresFIG. 2 shows a method for producing a quirl 110 according to the invention. In a hub 112, which is connected to a shaft 116 in a rotationally fixed manner, processing bodies 114 in the form of loops are inserted into radially extending recesses. Subsequently, a force K is applied to the axial end face of the hub 112 facing the shaft 116 via a deformation punch 122, which force is applied by an annular protrusion 126 of the deformation punch 122. This produces annular deformations 118 on the outside of the hub 112, which correspond to deformations 120 in the processing bodies 114. The deformations 120 extend completely within the hub 112, so that no weakening or deformation of the material of the processing bodies 114 occurs at the point S at which they emerge from the hub 112 and where the strongest loads occur when the quirl 110 is used. These deformations 118, 120 hold the processing bodies 114 in the hub 112 so that they are fastened to the hub 112.FIG. 3 shows a quirl 210 according to the invention according to a variant of the invention. Also in such a quirl 210 there is a hub 212 which is connected to a shaft 216 in a rotationally fixed manner. At the end of the hub 212 opposite the shaft 216, processing bodies 214 (in the present case: wire loops) are provided, which are inserted into an axial end face of the hub 212.Deformations 218 are formed on the lateral surface of the cylinder of the hub 212 which have led to corresponding deformations 220 of the processing bodies 214. As can be seen from FIG. 3, these deformations 220 of the processing bodies 214 are provided completely inside the hub 212 so that there are no deformations at the point S with the highest loads, which is located at the transition of the processing bodies 214 from the inside of the hub 212 to the outside. The deformations 218, 220 hold the processing bodies 214 in the hub 212 so that they are fastened to the hub 212. In contrast to the embodiment according to FIG. 2, the deformations 218 are provided on the lateral surface of the hub 212. The deformations 218 can be produced in the present case by acting on the hub 212 at points. However, it is also possible to produce the deformations 218 of the hub 212 as a continuous, circumferential deformation by a rolling or rolling tool.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedU.S. Pat. No. 9,060,651 B2

[0003] U.S. Pat. No. 4,730,939

[0004]

Claims

Method for producing working means (110) for processing food, wherein the working means (110) has a hub (112) and one or more processing bodies (114) extending from the hub, the method having the following steps: - providing a hub (112), wherein the hub (112) has recesses on its outer surface, - inserting one or more processing bodies (114) into the recesses, - deforming the hub (112) such that the one or more processing bodies (114) are fixed in the hub (112), wherein the deformation of the hub (112) takes place starting from a surface of the hub (112) which differs from a surface through which the processing bodies (114) exit.The method of claim 1, wherein the hub (112) has a cylindrical shape and the processing bodies (114) extend from the shell surface or one of the flat sides of the cylinder.The method of claim 2, further comprising providing a shaft (116) extending from the hub (112) along the cylinder axis of the hub (112) and rotationally fixed to the hub (112), wherein the shaft (116) is preferably fixed to the hub (112) by an interference fit and / or a deformation, particularly preferably caulking.The method according to any one of claims 2 to 3, wherein the deformation of the hub (212) is effected by acting on a radial outer surface of the hub (212) by means of a deformation tool, wherein the processing bodies (214) preferably extend axially out of the hub (216).The method of any of claims 2 to 3, wherein the deformation of the hub (112) is performed by applying a deformation punch (122) to an axial end surface of the hub (112).The method of claim 5, wherein the deforming punch (122) acts on the hub (112) along an annular surface.Method according to claim 5, wherein the deformation punch (122) acts on the hub (112) at points.Method according to one of the preceding claims, wherein the direction of action of the force during the deformation of the hub (112) deviates by more than 45° from the direction with which the processing bodies (114) emerge from the hub (112).Method according to any one of the preceding claims, wherein the processing bodies (114) are deformed and thus fixed in the hub (112).Method according to any one of the preceding claims, wherein the deformation is effected such that the processing bodies (114) have no deformation or only an insignificant deformation at the point at which they emerge from the hub (112).Method according to one of claims 1 to 8, wherein the processing bodies (114), before being inserted into the hub (112), have form-fitting features, preferably depressions, in which the material of the hub (112) engages during the deformation of the hub (112) in order to fasten the processing bodies (114) in the hub (112).Method according to any of the preceding claims, wherein the hub (112) is made of metal, preferably steel.Method according to any one of the preceding claims, wherein the processing bodies (114) are made of metal, preferably steel.The method of any preceding claim, wherein the thickness of the deformed material of the hub (112) over the processing bodies (114) is in the range of 0.2 to 2 mm.A method according to any preceding claim, wherein the working means (110) is a quirl, snowbeese or kneader hook and wherein the processing bodies (114) are loops which, in use, serve to mix the food to be processed.Method according to one of the preceding claims, wherein the working means (110) is provided for use in an electrical domestic appliance, preferably a stick blender or hand-held mixer.Method according to any one of the preceding claims, wherein the working means is a knife star for a stand blender or a stick blender and wherein the processing bodies are blades of the knife star.Working medium (110) for processing food, preferably quirl, knife star wheels for a stand blender or stick blender, kneader hook or snowbea, comprising: - a hub (112), wherein the hub (112) has recesses on its outer surface, - one or more processing bodies (114) which are inserted into the recesses, wherein the hub (112) is deformed and thus the processing bodies (114) are fixed in the hub (112), and wherein the deformation of the hub (112) originates from a surface of the hub (112) which is different from a surface through which the processing bodies (114) emerge, wherein the working medium has preferably been produced by a method according to one of the preceding claims.

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