Abstract:
The invention relates to an operative insert ( 10 ) for a device for processing foods and to a device for processing foods comprising such an operative insert, said device having a receptacle for the operative insert that is driven rotationally about an axis of rotation (R), to which receptacle the operative insert ( 10 ) can be detachably fastened in a torque-locked manner by means of a drive interface ( 20 ), wherein the operative insert ( 10 ) bears at least one working means ( 31, 32 ), which can be driven rotationally in a working direction by the drive interface ( 20 ) and which can be decoupled from the drive interface in regard to the rotational motion by a freewheel ( 40 ) when the direction of rotation of the drive interface ( 20 ) is reversed.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to an operative insert having processing means for processing foodstuffs in a processing device and to a device for processing foodstuffs having such an operative insert. 
         [0003]    2. Discussion of Related Art 
         [0004]    The prior art discloses rotors for manually operated devices for processing foodstuffs which bear various processing means for example for cutting, peeling, blending or tossing fruit, vegetables and herbs. Some of these devices, provided with special processing means, can also be used for kneading dough, for mixing sauces or for whipping cream. These devices are usually driven by means of crank drives, cord pull drives, toggle lever drives or humming top drives. 
         [0005]    U.S. Pat. No. 5,156,084A discloses a manually operated food processor, which comprises a working container with a central support axle, a cover having a hand-crank drive and a number of various exchangeable rotors with processing means. In addition to a draining basket to drain salad, a cutting rotor having a plurality of radially fastened cutting knives and a mixing rotor having likewise radially arranged stirring blades are proposed. The various rotors are each pushed onto a central bearing journal in the working container and, when the cover is pushed onto the working container, are detachably connected to the crank drive in the cover by way of a positively locking tool interface. The rotational movement of the crank is transmitted via a step-up transmission to a central drive shaft, which is pushed through the base of the cover and is provided at the bottom end with a connecting pin having an external square. Depending on the desired foodstuffs processing, the rotors can be exchanged very quickly and easily. As a result of the proposed crank drive, the rotational movements are transmitted to the rotor with step-up, such that the rotational speed of the rotor is significantly higher than the rotational speed of the crank. The direct connection makes it possible for the rotor which is used in each case to be rotated optionally in various directions depending on the direction of rotation of the crank. Such changes in direction of rotation are particularly desirable when stirring or emulsifying sauces or when tossing salad or herbs. When the cutting rotor is used, the cutting knives have to be provided with a cutting edge on both sides in order to prevent blocking in the event of a change in direction of rotation. The bent knife position has additionally proved to be unfavourable, however, for operation in both directions of rotation. 
         [0006]    The simple design, the low production costs and the mains-independent operation make such manually operated food processors popular kitchen devices, not only in emerging countries, but also in industrial countries. 
         [0007]    In order to make it easier to cut fruit and vegetables, in particular at the start of the cutting operation, WO11157511A proposes an operative insert for devices which process foodstuffs. These devices comprise a bowl and a receptacle for the operative insert which is driven in rotation about an axis of rotation. This rotating operative insert is formed in such a manner that foodstuffs located in the bowl can be processed and/or handled, wherein the operative insert has a support body, which can be connected or is connected to the receptacle, and at least one tool, which is mounted on the support body and is movable as a result by the processing and/or handling, and which is displaceable counter to the force of a resetting means from a position of rest into a working position. 
         [0008]    The apparatus for cutting foodstuffs which is known from US 2009/0090254 A1 eliminates the disadvantage of previously known apparatuses that, in the case of said apparatuses, a relatively large initial torque has to be applied, particularly in the case of hard foodstuffs, for instance in the form of onions or potatoes, in order to break the large, hard pieces up into smaller pieces which are easier to process. In order to avoid this, pivotable knives are arranged on the central rotor shaft, and, depending on the torque generated as a reaction to the externally applied drive torque, can be moved from a position of rest into a working position in a manner pivotable by a limited pivot angle. In the case of the applicant&#39;s known apparatus, which is marketed extremely successfully under the trade name SWIZZZPROZZZ®, two or more knives are arranged one above another, can be pivoted relative to one another and are driven about the common axis of rotation. In the position of rest, the knives are congruent one above another in an angular position. At least one of the knives is, however, mounted pivotably on the drive shaft, such that, as a consequence of the initial torque, this knife can initially yield, until it has reached a stop at which it is then likewise driven in rotation. In this way, the torque applied at the start of the processing can be lowered, since not all of the knives immediately engage with the material to be cut with a cutting action. 
         [0009]    A disadvantage of the known apparatus, however, is that—as already noted in WO11157511A—the angle by which the knives are mounted in a freely pivotable manner is limited and relatively small. 
         [0010]    WO10150263 A2 discloses inserts for food processors which can be used for chopping, mixing, stirring, beating and juicing. A central shaft can be connected to a drive motor by means of a spindle arranged at a first end. The second, opposite end of the central shaft is mounted in a receiving container. Radially protruding blades are fastened to the shaft in a lower region and additional processing tools can be arranged detachably in an upper region. When processing the foodstuffs, the additional processing tools are coupled fixedly to the central shaft. In certain embodiments, the central shaft is provided with a helical groove, in which corresponding cams of the additional processing tools engage and are moved into a locking position upon rotation of the central shaft in a downwards movement. 
       SUMMARY OF THE INVENTION 
       [0011]    It is an object of the present invention to provide an operative insert and a device for processing foodstuffs having such an operative insert which avoid or reduce at least certain disadvantages of the prior art. It is in particular an object of the present invention to propose an operative insert which can be used with a multiplicity of devices for processing foodstuffs with an extremely wide variety of drive mechanisms, decisively reduces the risk of malfunctions and further increases the variability of the processing options. 
         [0012]    According to the present invention, these objects are achieved by the elements of the independent claims. Further advantageous embodiments are additionally evident from the dependent claims and the description together with the drawings. 
         [0013]    The aforementioned objects are achieved by an operative insert for a device for processing foodstuffs, which has a receptacle for the operative insert which is driven in rotation about an axis of rotation and to which the operative insert can be releasably fastened in a torque-locking manner with a drive interface, and by a device for processing foodstuffs having an operative insert according to the invention. 
         [0014]    The drive is preferably a manual drive, as is known from the prior art relating to devices of the generic type, for example with crank drives, cord pull drives, toggle lever drives or humming top drives. The operative inserts according to the invention can also be used in devices with an electric drive, however. The operative insert bears at least one working means, which can be driven rotatably in a working direction by the drive interface and can be uncoupled therefrom in relation to the rotational movement by a freewheel upon reversal of the direction of rotation of the drive interface. 
         [0015]    The freewheel of the operative insert is preferably a clamping roller freewheel, a clamping body freewheel, a wrap spring freewheel, a ratchet freewheel or a locking member freewheel. 
         [0016]    The latter has proved to be advantageous since it manages with a minimum number of movable parts and can be produced and mounted easily and at low cost. At the same time, however, it ensures that the forces to be transmitted from the drive to the operative insert and ultimately to the working means are transmitted reliably, and uncoupling is effected reliably given the reverse rotational movement, i.e. during the rotation counter to the working direction. 
         [0017]    In preferred embodiments, the locking member freewheel comprises a coupling part toothed on the end face and a driver part, wherein the coupling part is arranged between the drive interface and the driver part and is displaceable into a locking position along a support spindle. The coupling part, the drive interface and the driver part are set up in such a manner that torque is transmitted between the drive interface and the driver part in the locking position, wherein coupling means are set up in order to displace the coupling part into the locking position upon rotation of the drive interface in the working direction and in order to enable the displacement of the coupling part from the locking position upon rotation of the drive interface counter to the working direction. 
         [0018]    According to further preferred embodiments, the operative insert is provided with a freewheel, in the case of which a corresponding locking toothing is fitted at the end face in each case of the driver part and of the coupling part, these locking toothings having a plurality of bevelled ramps which together have the effect that, in a direction of rotation of the drive interface counter to the working direction, a twisting movement between the coupling part and the driver part leads to axial displacement of the coupling part from the locking position into a release position. 
         [0019]    The coupling means comprise spring elements or corresponding positively locking, bevelled surfaces arranged on the drive interface and on the coupling part, which have the effect that, upon rotation of the drive interface in the working direction, a twisting movement between the drive interface and the coupling part leads to axial displacement of the coupling part into a locking position. If a spring element is used, for example a helical spring, the coupling part is pressed against the driver part under the action of spring force, or into the corresponding locking toothing. The transmission of torque between the drive interface and the coupling part can be effected by mounting the coupling part in an axially displaceable and torque-locking manner on or in the drive interface. The coupling part can be provided with an external polygon and be mounted in a corresponding positively locking receiving opening in the drive interface, or it has one or more radial cams which engage into corresponding vertical grooves in a receiving opening of the drive interface and bring about the axial, displaceable anti-twist mounting. In further embodiments, the drive interface is mounted in or on the coupling part and has the corresponding positive locking means. 
         [0020]    If a springless, circular coupling means is used according to a further preferred embodiment, at least one stop, preferably a plurality of stops, is or are fitted in each case to the drive interface and to the coupling part, which by rotation in working direction and against the working direction of the drive interface limits or limit a twisting movement between the drive interface and the coupling part and causes or cause torque to be transmitted between the drive interface and the coupling part. 
         [0021]    The working means of the operative inserts according to the invention preferably comprise in each case at least one cutting or chopping knife, a blending blade, a peeling arm, a stirring blade, an upward deflector blade or downward deflector blade or a kneading finger. According to preferred embodiments, two to six identical or different working means are arranged on an operative insert. Upward deflector blades and downward deflector blades can thus be arranged extremely advantageously, for example, underneath and above a plurality of cutting knives, for example two or three cutting knives. In another preferred configuration, the operative insert comprises a plurality of elastic peeling arms axially spaced apart from one another or two cutting knives and two blending blades. 
         [0022]    According to preferred embodiments, further working means are provided on the operative insert, coupled locked to the drive interface in a torque-locking manner. Whereas the other working means are uncoupled from the drive interface by the freewheel upon the rotational movement of the drive interface counter to the working direction, these further working means inevitably take part in the rotational movements of the drive interface in and counter to the working direction. An upper downward deflector or a lower upward deflector can thereby convey the material to be processed back into the region of the working means, for example the knife blades, locked with the drive interface upon the rotational movement in the working direction. In the case of reverse rotation counter to the working direction, they can be used to scrape adhering remains from the base and/or cover of the working container, whereas the knife blades do not take part in the reverse rotation in the freewheel mode. 
         [0023]    The operative inserts according to the invention can be formed in such a manner that the freewheel uncouples the at least one working means from the drive interface and the at least one further working means upon the rotational movement of said drive interface counter to the working direction. It is thereby possible to realize operative inserts in which, for example, a first lower stirring blade reaching deep into the foodstuff to be stirred is activated upon the reverse rotational movement counter to the working direction, whereas an upper stirring blade coupled directly to the drive interface takes part in the rotational movements thereof in and counter to the working direction. 
         [0024]    According to preferred embodiments, the operative insert according to the invention comprises a support spindle bearing at least one working means, wherein the support spindle can be driven rotatably in a working direction by the drive interface and can be uncoupled therefrom in relation to the rotational movement by a freewheel upon reversal of the direction of rotation of the drive interface. 
         [0025]    It is preferable for at least one working means arranged on a support spindle and acting in the circumferential direction of the support spindle to be pivotable relative to at least one further working means arranged on the support spindle within a limited pivot angle about the support spindle, wherein the working means are preferably oriented radially in relation to the support spindle. 
         [0026]    According to preferred embodiments, the freewheel is switchable in and counter to the working direction or completely lockable. 
         [0027]    The drive interface is preferably in the form of a drive journal, particularly preferably with a terminal external polygon for reception in the correspondingly shaped receptacle driven in rotation by the drive. 
         [0028]    The devices according to the invention for processing foodstuffs comprise a drive, having a receptacle which is driven in rotation about an axis of rotation and to which the operative insert can be releasably fastened in a torque-locking manner by means of a drive interface, and a container for receiving the foodstuffs to be processed, in which the operative insert is preferably mounted with an end lying opposite the drive interface. In further configurations, the receptacle is in the form of a spindle onto which the operative insert is pushed in a releasably fastenable manner with an appropriately adapted drive interface shaped like a hollow cylinder or hollow cone. 
         [0029]    The device according to the invention for processing foodstuffs is preferably driven by a manually operable crank drive, cord pull drive, toggle lever drive or humming top drive. The drive can comprise a step-up transmission in order to increase the rotational speed from the primary manual drive movement on the crank, cord pull, toggle lever or humming top pusher to the rotational speed of the receptacle. 
         [0030]    Since, in the case of the operative inserts according to the invention, the sensitive working means are already protected by the freewheel against damage in the case of incorrect manipulations, i.e. primarily against rotation counter to the intended working direction, it is possible to dispense with a freewheel in the drive in the case of the devices according to the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]    The invention is explained hereinbelow with reference to figures which show merely exemplary embodiments. 
           [0032]      FIG. 1  is a side view schematically showing an operative insert in the form of a cutting rotor having two cutting knives; 
           [0033]      FIG. 2  shows the cutting rotor shown in  FIG. 1  in a partially sectional illustration; 
           [0034]      FIG. 3  shows the cutting rotor in an exploded view, with a holding bushing which is arranged underneath an upper downward deflector in the assembled state being shown on the right on its own; 
           [0035]      FIG. 4  is a view of a driver from above; 
           [0036]      FIG. 5  shows the cutting rotor as shown in  FIG. 2  in longitudinal section in the region of a freewheel in the locked state; 
           [0037]      FIG. 6  shows the cutting rotor as shown in  FIG. 2  in longitudinal section in the region of the freewheel in the freewheel state, the coupling part being situated in a release position; 
           [0038]      FIG. 7  is a side view schematically showing an operative insert according to a further embodiment of the invention in the form of a cutting rotor having an upper downward deflector and a cutting knife; 
           [0039]      FIG. 8  is a side view schematically showing an operative insert according to a further embodiment of the invention in the form of a combined cutting and blending rotor having an upper downward deflector, two cutting knives and two blending blades; 
           [0040]      FIG. 9  is a side view of an operative insert according to a further embodiment of the invention in the form of a peeling rotor for peeling garlic; and 
           [0041]      FIG. 10  shows a coupling part in a view from above ( FIG. 10   a ), from the side ( FIG. 10   b ) and from below ( FIG. 10   c ); 
           [0042]      FIG. 11  shows interacting coupling means in the form of a drive interface shown in section and a corresponding coupling part in a view from above; and 
           [0043]      FIG. 12  shows a draining basket according to the prior art in longitudinal section. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0044]      FIG. 1  shows an operative insert  1  according to the invention in the form of a cutting rotor  10  having two cutting knives  31 ,  32  which are arranged axially offset in relation to one another approximately horizontally in the radial direction and each comprise a cylindrical knife holder  310 ,  320 , preferably made of plastic, and a knife blade  311 ,  321 . Whereas the two cutting knives  31 ,  32  are arranged at the lower end of the cutting rotor  10  on a support spindle  60 , an upper downward deflector  61  is locked on a drive interface  20 . The drive interface  20  comprises a journal  21  at the top with an external hexagon, which is designed for introducing the torque. By virtue of a freewheel  40 , which is received completely by a holding bushing  47  and the drive interface  20  in the embodiment shown in  FIG. 1 , the drive interface  20  and the upper downward deflector  61  are coupled to the two knives  31 ,  32  in a torque-locking manner upon rotation D in the working direction. In this operating state, all working means  31 ,  32 ,  61  rotate about the same axis of rotation R at the same speed in the same direction D. 
         [0045]    If the drive interface  20  is rotated counter to the working direction D, merely the upper downward deflector  61  is carried along with it. The freewheel  40  uncouples this rotational movement from the two knives  31 ,  32  on the support spindle  60 , such that these remain in a position of rest braked by applied material to be cut and do not take part in the rotational movement opposite to the working direction 
         [0046]    The side view shown partially in section in  FIG. 2  shows in detail the exact structure of the freewheel  40  in a cutting rotor  10  according to the embodiment shown in  FIG. 1 . The knife holder  320  of the lower knife  32  is formed integrally with the central support spindle  60 . The hollow-cylindrical knife holder  310  of the upper knife  31  is pushed onto said support spindle  60 . The upper knife  31  is mounted on the support spindle  60  so as to be pivotable to a limited extent by operative means, as are already known from US 2009/0090254 A1, as mentioned above, and can be moved from a position of rest into a working position in a manner pivotable by a limited pivot angle. 
         [0047]    According to further preferred embodiments, which are not shown in the figure, both knives are arranged fixed to the support spindle. 
         [0048]    In the case of both configurations relating to the mobility of the cutting knifes  31 ,  32 , the support spindle  60  is connected in the upper region to a driver part  43  in a torque-locking manner, passes through it and protrudes upward somewhat out of the driver part  43 . A coupling part  42  is pushed freely rotatably onto the support spindle  60  at the top. The support spindle  60  also passes through the coupling part  42  and protrudes by way of its free upper end into a circular-cylindrical receiving opening in the drive interface  20  on the underside. By virtue of the holding bushing  47 , the drive interface  20  and the support spindle  60  are held in a defined axial position and cannot be moved apart axially. To this end, an upper collar of the holding bushing  47  engages behind a lower peripheral flange on the drive interface  20  in such a manner that a low-friction rotation about the axis R is made possible, but displacement in the axial direction is made impossible. 
         [0049]    The structure of a freewheel according to a preferred embodiment of the present invention in the form of a locking member freewheel  41  is shown in the exploded view in  FIG. 3 . The locking member freewheel  41  comprises a coupling part  42  toothed on the end face and a driver part  43 , the coupling part  42  being arranged between the drive interface  20  and the driver part  43 . Whereas the driver part  43  is fastened fixedly to the support spindle  60  and can be moved neither radially nor axially in relation to the support spindle, the coupling part  42  is mounted such that it can be displaced along and rotated about the support spindle  60 . The coupling part  42 , the drive interface  20  and the driver part  43  are set up in such a manner that, in locking position, the toothing on the end face of the coupling part  42  and on the end face of the driver part  43  engage into one another in a torque-locking manner and torque is transmitted between the drive interface  20  and the driver part  43 . The engagement is ensured by a coupling means in the form of a helical spring  44 , which presses the axially movable coupling part  42  in the direction of the driver part  43 . 
         [0050]      FIG. 4  shows a view of the driver from above comprising the driver part  43  and a ramp  46 .  FIG. 5  shows, with reference to an enlarged detail in the region of the freewheel, that the coupling part  42  and the driver part  43  engage into one another by way of the toothings on the end face in the engaged or locking position and transmit the torque by way of axial locking surfaces. The drive interface  20  and the support spindle  60  which is coupled thereto via the coupling part  42  and the driver part  43  rotate in the working direction D in this position. Upon rotation of the drive interface  20  counter to the working direction D, the coupling part  42  and the driver part  43  are pressed apart in the axial direction by a plurality of interacting ramps  45 ,  46 . Since only the coupling part  42  is mounted axially movably on the support spindle  60 , it is pushed counter to the force of the spring  44  upward from the locking position into the release position shown in  FIG. 6 . Whereas the drive interface  20 , the upper downward deflector  61  and the coupling part  42  rotate in direction G counter to the working direction D, the support spindle  60  and the knives or other working means arranged thereon remain in their current position upon application of an external braking force, and do not co-rotate. 
         [0051]      FIG. 7  shows a further operative insert in the form of a cutting rotor  12  having a single knife on a support spindle and an upper downward deflector on the drive interface. 
         [0052]      FIG. 8  shows a further operative insert according to the present invention in the form of a cutting rotor  13  having two knives  33 ,  34  and two blending blades  35 ,  36  which are all arranged on a support spindle  60 . As has already been described in the description of  FIG. 2  as an advantageous embodiment, in the example shown the upper knife  34  and both blending blades  35 ,  36  are pivotable between a position of rest and a working position each by a limited pivot angle about the support spindle  60  and relative to the lower knife  33  arranged fixedly on the support spindle. It is thereby possible for the rotor  13  to be mounted in a space-saving manner. According to further preferred embodiments, knives and blending blades are fixedly arranged in each case alternately and spaced apart from one another by 90° on the support spindle. In both embodiments, the working means  33 - 36  and the working spindle  60  are operatively connected via the freewheel  40  to the drive interface  20 , which in turn bears the upper downward deflector  61 . 
         [0053]      FIG. 9  shows an operative insert according to a further preferred embodiment, which is in the form of a peeling rotor  14  preferably for peeling garlic. Three elastic peeling arms  37 ,  38 ,  39  are arranged on a support spindle  63  and, in turn, are connected via a freewheel  40  to the drive interface  20 . 
         [0054]      FIG. 10  shows a coupling part  420  according to a further embodiment in a view from above ( FIG. 10   a ), from the side ( FIG. 10   b ) and from below ( FIG. 10   c ). In the case of the coupling part  420  shown, a coupling means in the form of a spring is no longer required. The coupling part and the drive interface interact for coupling and uncoupling via the corresponding bevelled surfaces  48 ,  48 ′ which engage into one another as shown in  FIG. 11 . These have the effect that, upon rotation of the drive interface  20 ′ in the working direction D, a twisting movement between the drive interface  20 ′ and the coupling part  420  leads to axial displacement of the coupling part  420  into a locking position. If the springless, circular coupling means  44  integrally formed on the coupling part on the top side is used, four corresponding axial stops  49 ,  49 ′ are fitted in each case on the drive interface  20  and on the coupling part  420  and, in the case of rotation D in working direction and in direction G an opposite direction of the working direction of the drive interface  20 ′, limit a twisting movement between the drive interface and the coupling part  420  to about 90° and cause torque to be transmitted between the drive interface  20 ′ with an internal polygon and the coupling part  420 . 
         [0055]    Since the operative inserts according to the invention have an integrated freewheel, it is no longer necessary for the drive of the devices according to the invention for processing foodstuffs to be equipped with a freewheel. It is therefore possible for further working means which do not form part of the invention, such as for example the draining basket shown in  FIG. 12 , to advantageously be used with the devices. The possibility of reversing the direction of rotation improves the draining result quite considerably.