SE2350015A1 - Rotating mixer and method for operating the same - Google Patents

Abstract

Rotating mixer (100), comprisinga motor (120); anda rotating cutting knife (110) arranged to rotate forward.The invention is characterised in thatthe rotating mixer (100) can detect a rotational problem of the cutting knife (110), and in response automatically control the motor (120) to perform a first control program, comprising controlling the motor (120) to perform a first backward rotation and controlling the motor (120) to thereafter perform a first forward rotation.The invention also relates to a method.

Description

Rotating mixer and method for operating the same The present invention relates to a rotating mixer for foodstuffs. For instance, the rotating mixer may be a vertical cutter mixer (meaning that has a vertical cutting axis and an integrated bowl for foodstuff to be cut), a vegetable preparation machine (meaning that it has no integrated bowl), a blender or mixer, or a hand blender. lt is noted that at least some of these types of rotating mixers are various types of food processors. That the mixer is a "rotating" mixer means that the mixer comprises at least one knife blade that is driven by a rotating axis in a rotating movement so as to cut foodstuffs coming into contact with the knife blade in question. The present invention also relates to a method for operating such a vertical cutter mixer.

Such a rotating knife typically operates in a horizontal plane to cut or disintegrate food- stuff charged into an integrated or separate bowl or vessel, in which the knife rotates. The knife may be mounted on a vertical rotating axis in turn driving the knife to rotate.

A problem with such rotating mixers is that the knife runs the risk of getting stuck against foodstuff. For instance, when cutting raw vegetables such as carrots, a considerable impulse is required for the knife to completely cut apart larger pieces of such foodstuffs.

When the knife gets stuck, this leads to various problems.

For instance, in the case of a vertical cutter mixer and other types of mixers having an integrated bowl, the operator may need to manually open up the bowl for inspection and to remove or rearrange the problematic foodstuff before being able to continue the processing. lf sufficiently challenged, the motor protection of the motor driving the rotating knife may also be tripped, leading to substantial downtime.

Corresponding problems may arise when using a hand blender or similar, when the knife gets stuck in relation to foodstuffs in a separate bowl not being rigidly connected to the mixer in question. Namely, when the knife gets stuck manual intervention may be re- quired in the form of manually rearranging the cut foodstuffs in the separate bowl.

Hence, one problem is that the need for manual handling increases food production times and reliability. Another problem of manual handling is that it may lead to safety problems for the operator.

I\/|ixers of said types may operate at speeds of several thousand RPM, why heat develop- ment may be an issue affecting the processed foodstuffs.

At the same time, such mixers are often associated with strict requirements in terms both of throughput, reliability and safety. This is in particular true for professional food pro- cessing appliances comprising or constituting rotating mixers. They also need to be easily cleaned and provide a long useful life. The latter implies a sturdy and simple construction.

The present invention solves at least some ofthe above described problems.

Hence, the invention relates to a rotating mixer associated with a polar coordinate system having an axial dimension, a radial dimension and an angular dimension, the rotating mixer comprising a motor; a rotating cutting knife, arranged to be driven by the motor to rotate in a first angular direction about an axis of rotation; and a control mechanism, arranged to control the motor, the rotating mixer being characterised in that the control mechanism is arranged to detect an inability of the cutting knife to rotate in the first angular direction and/or a minimum load placed on the motor to cause the cutting knife to rotate in the first angular direction, and in response to such detection automatically control the motor to perform a first control program, the first control program comprising the control mechanism controlling the motor to perform a first backward rotation in which the motor rotates in a second angular direction, the second angular direction being opposite to the first angular direction, and the first control program further comprising the control mechanism controlling the motor to thereafter perform a first forward rota- tion in which the motor rotates in the first angular direction. ln some embodiments, the rotating mixer further comprises a cutting bowl, wherein the cutting knife is arranged to rotate in said cutting bowl. ln some embodiments, said first backward rotation is between 30° and 360°, preferably between 90° and 180°. ln some embodiments, the control mechanism is arranged to detect an inability of the cutting knife to rotate further in said second angular direction and/or a minimum load placed on the motor to cause the cutting knife to rotate further in the second angular direction during said first backward rotation. ln some embodiments, the control mechanism is arranged to, upon the detection of such inability and/or such minimum load, control the motor to stop the first backward rotation and to start the first forward rotation. ln some embodiments, said first control program comprises the control mechanism detecting an inability of the cutting knife to rotate in the first angular direction and/or a minimum load placed on the motor to cause the cutting knife to rotate in the first angular direction after the performance of said first backward rotation. ln some embodiments, the control mechanism, as a result of such detection after the first backward rotation, automatically controls the motor to perform a second backward rotation in which the motor rotates in the second angular direction, and thereafter the control mechanism controlling the motor to perform a second forward rotation in the first angular direction. ln some embodiments, the control mechanism is arranged to detect an inability of the cutting knife to rotate further in said second angular direction and/or a minimum load placed on the motor to cause the cutting knife to rotate further in the second angular direction during said second backward rotation. ln some embodiments, the control mechanism is arranged to, upon the detection during the second backward rotation of such inability and/or such minimum load, control the motor to stop the second backward rotation and to start the second forward rotation. ln some embodiments, said second backward rotation is angularly longer than the first backward rotation. ln some embodiments, the control mechanism is arranged to control an axial location of the cutting knife. ln some embodiments, the control mechanism is arranged to, between the first backward rotation and the second backward rotation, automatically move the cutting knife axially. ln some embodiments, the rotating mixer comprises an angular drive, the angular drive comprising an internal angular play causing a hysteresis, preferably of at least 30°, be- tween a drive shaft of the motor and the cutting knife. ln some embodiments, said hysteresis is smaller than the first backward rotation. ln some embodiments, said hysteresis is larger than the first backward rotation. ln some embodiments, the rotating mixer further comprises a manual backwards rotation override, arranged to, when activated by an operator, rotate the cutting knife in the second angular direction in relation to the cutting bowl. ln some embodiments, said manual backwards rotation override comprises a rotating lever angularly connected to the cutting knife and/or angularly connected to an axial drive shaft of the motor. ln some embodiments, the rotating mixer further comprises a cutting bowl. ln some embodiments, the cutting knife is arranged to rotate in said cutting bowl. ln some embodiments, said manual backwards rotation override comprises a mechanism arranged to allow the bowl to rotate in the angular direction in relation to the cutting knife. ln some embodiments, the manual backwards rotation override is arranged with a maxi- mum angular rotation interval, limiting the relative rotation of the cutting knife as a result of activation by the operator. ln some embodiments, said maximum angular rotation interval is at the most 180°. ln some embodiments, the manual backwards rotation override is arranged so that it, when activated, automatically cuts the power to the motor. ln some embodiments, the rotating mixer further comprises a knife axial displacing means, arranged to axially displace the cutting knife in relation to the cutting bowl. ln some embodiments, the knife axial displacing means comprises a manual knife axial displacing means, arranged to, when activated by an operator, axially displace the cutting knife in relation to the cutting bowl. ln some embodiments, the manual knife axial displacing means comprises a setting screw arranged along an axis of rotation of the cutting knife and arranged to translate a rotation of the setting screw into a corresponding axial displacement ofthe cutting knife in relation to the cutting bowl. ln some embodiments, the knife axial displacing means comprises an automatic knife axial displacing means, arranged to, as a result of and during the first backwards rotation, axially displace the cutting knife in relation to the cutting bowl. ln some embodiments, the rotating mixer further comprises a user interface. ln some embodiments, the control mechanism is arranged to control the motor in reac- tion to input received via said user interface. ln some embodiments, the user interface comprises an adjustment control arranged to, when activated by an operator, cause the control mechanism to perform the first control pfOgfam. ln some embodiments, said adjustment control comprises a motor speed adjustment control, arranged to allow the operator to set a desired motor speed by manipulating said speed adjustment control to a corresponding state. ln some embodiments, the speed adjustment control is arranged to manipulated in a first manipulation direction so as to increase a motor speed and to be manipulated in a sec- ond, different, manipulation direction so as to manually perform said first control pro- gram. ln some embodiments, the cutting knife is arranged with sharp edges on both angularly facing sides. ln some embodiments, the rotating mixer is a vertical cutter mixer.

I\/loreover, the invention relates to a method for operating a rotating mixer of said type, the method comprising the steps a) the control mechanism of the rotating mixer detecting an inability of the cutting knife of the rotating mixer to rotate in the first angular direction and/or a minimum angular load placed on the motor to cause the cutting knife to rotate in the first angular direction; b) in response to such detection, the control mechanism automatically controlling the motor of the rotating mixer to perform a first backward rotation in which the motor rotates in a second angular direction, the second angular direction being opposite to the first angular direction; and c) the control mechanism thereafter automatically controlling the motor to thereafter perform a first forward rotation in which the motor rotates in the first angular direction. ln some embodiments, the method further comprises d) the control mechanism detecting an inability of the cutting knife to rotate in the first angular direction and/or a minimum load placed on the motor to cause the cutting knife to rotate in the first angular direction after the performance of said first backward rotation; e) the control mechanism, as a result of such detection, automatically controlling the motor to perform a second back- ward rotation in which the motor rotates in the second angular direction; and f) the control mechanism thereafter automatically controlling the motor to perform a second forward rotation in the first angular direction. ln the following, the invention will be described in detail, with reference to exemplifying embodiments of the invention and to the enclosed drawings, wherein: Figure 1 is a perspective view of a rotating mixer; Figure 2 shows the rotating mixer of Figure 1 but with a lid removed; Figure 3 shows the rotating mixer of Figure 2 but with a bowl removed; Figure 4 shows the rotating mixer of Figure 1 but with a first horizontal cross-section removed; Figure 5 shows the rotating mixer of Figure 1 but with a second horizontal cross-section removed; Figure 6 shows the rotating mixer of Figure 1 but with a third horizontal cross-section removed; Figure 7 shows the rotating mixer of Figure 1 but with a first vertical cross-section re- moved; Figure 8 shows the rotating mixer of Figure 1 but with a second vertical cross-section removed; and Figure 9 is a flow chart showing a method.

All Figures share the same reference numerals for the same parts.

Figure 1 shows a rotating mixer 100 in the form of a vertical cutter mixer. The rotating mixer 100 is associated with a polar coordinate system, in turn having an axia| dimension A, a radial dimension R and an angular dimension V. The axia| dimension A may be parallel to a rotation axis 111 of a cutting knife 10 of the cutting mixer 100. The angular dimension V may describe an angular rotation of said cutting knife 10. As is understood, the coordi- nate dimensions A, R, V are orthogonal.

The rotating mixer 100 is an example of an embodiment of the present invention. The same principles described in relation to the rotating mixer 100 are equally applicable to a vegetable preparation machine, a blender or mixer or a hand blender. Various food processor types can embody the present invention. lt is also pointed out that the rotating mixer 100 shown in the Figures is designed to illustrate several of the principles described herein. ln practise, a rotating mixer 100 according to the present invention can incorpo- rate all or only a subset ofthese principles, as the case may be.

The rotating mixer 100 comprises a motor 120 as well as the rotating cutting knife 110, in turn arranged to be driven by the motor 120 to rotate in a first angular V direction about the axis of rotation 111.

The motor 120 can be arranged to drive the cutting knife 110 with at least 1000 RPM, such as at least 2000 RPM.

The Figures show a rotating mixer 100 with two cutting knives 110, set 180° from each other and at different axia| A heights. However, it is realised that only one cutting knife 110; or two or more cutting knives 110 set at different relative angular V and/or axia| A orientations, can be used.

The rotating mixer 100 can comprise a cutting bowl 150, that in turn can have a lid 151. Then, the cutting knife 110 can be arranged to rotate inside the cutting bowl 150, such as at a bottom of the cutting bowl 150.

To achieve this, a motor 120 axis can penetrate through a bottom ofthe cutting bowl 150, upwards and into engagement with the cutting knife 110. The penetration through hole can be equipped with a bearing or the like, and a liquid seal such as a rubber gasket. ln alternative embodiments, the motor 120 can instead be arranged above the bottom of the cutting bowl 150, and then no penetration of the bottom of the cutting bowl 150 would be necessary.

The rotating mixer 100 furthermore comprises a control mechanism 140, arranged to control the motor 120, including an angular A driving direction of the motor 120.

The control mechanism 140 can be arranged to detect a problem with the cutting knife 110. Such a problem can be an inability of the cutting knife 110 to rotate in the first angular V direction. This inability may, for instance, be because of the cutting knife 110 being stuck on a piece of foodstuff that cannot be penetrated by the cutting knife 110, causing the cutting knife 110 to be still despite a moment being applied to the cutting knife 110 by the motor 120. This inability can be detected by the control mechanism 140 monitoring an instantaneous load delivered to the motor 120, where a load above a certain threshold value indicates that the cutting knife 110 is stuck. The inability can, alternatively or in addition, be detected by the control mechanism 140 monitoring an instantaneous rotary movement the motor 120, where a rotary movement of zero or below a certain threshold value indicates that the cutting knife 110 is stuck. Such monitor- ing can take place in per se conventional ways, and information signals can be delivered as needed from the motor 120 to the control mechanism 140 using electric cables.

Alternatively or in addition to the detection of the cutting knife being 110 stuck, the control mechanism 140 can be arranged to detect a minimum required threshold load of the motor 120 to cause the cutting knife 110 to rotate (such as to maintain a rotation) in lO the first angular A direction. ln other words, the control mechanism 140 can be arranged to measure an instantaneous load of the motor 120 and to detect that the cutting knife 110 is stuck when the detected load surpasses the minimum threshold. lt is noted that this is similar to the load detection discussed above, but does not necessarily require the cutting knife 110 to be completely still. For instance, the cutting knife 110 may still move through tough foodstuff, but at a suboptimal rotary speed. ln response to the detection of the cutting knife 110 being stuck and/or said load of the motor 120, the control mechanism 140 is arranged to perform a first control program.

This first control program comprises the control mechanism 140 controlling the motor 120 to perform a first backward rotation, in which the motor 120 rotates in a second angular direction being opposite to the first angular direction. ln other words, the motor 120 rotates in an angular V backwards direction as compared to the angular V direction in which the motor 120 was driven when said detection was made.

Then, the first control program further comprises the control mechanism 140 controlling the motor 120 to thereafter perform a first forward rotation in which the motor 120 rotates in the first angular V direction. ln other words, after the backwards rotation of the motor 120, the motor 120 again drives in the forward angular V direction.

The backwards-forwards direction driving can be performed with or without a short pause in connection to each or any individual change of direction of rotation.

Since the motor 120, under control of the control mechanism 140, is automatically ar- ranged to rotate backwards and then again forwards upon the automatic detection of cutting knife 110 rotation problems, whenever the cutting knife 110 is unable to cut through foodstuff in the desired manner the rotating mixer 100 will automatically attempt to resolve the issue. Many times, the backwards-forwards rotation will cause the cutting knife 110 to be able to rotate freely again, and foodstuff disintegration (in the forwards ll angular V direction of movement of the cutting knife 110) can continue without the operator having to take any manual action. ln some embodiments, the first backward rotation is at least 30°, such as at least 60°, such as at least 90°. I\/|oreover, in some embodiments, the first backward rotation is at the most 360°, such as at the most 180°.

The first forward rotation, performed after the first backward rotation, can be the motor 120 continuing its normal operation, for instance according to a operator-set mode of operation, to drive the cutting knife 110 in the same manner and angular direction as before the detection of the cutting knife 110 problem.

A corresponding monitoring of the ability of the cutting knife 110 to rotate and to cut through foodstuff in the cutting bowl 150 can also take place during the first backward rotation. Hence, the control mechanism 140 can be arranged to detect an inability of the cutting knife 110 to rotate further in the second angular direction and/or a minimum load placed on the motor 120 to cause the cutting knife 110 to rotate further in the second angular direction during the first backward rotation. Then, the control mechanism 140 can be arranged to, upon the detection of such inability and/or such minimum load, control the motor 120 to stop the first backward rotation and to instead start the first forward rotation. This stopping of the first backward rotation can hence be a premature stopping as compared to a default control program that the control mechanism 140 attempts to follow as a result ofthe detection of the cutting knife 110 problem.

I\/|oreover, the control mechanism 140 can be arranged to perform the control of the motor 120 to perform multiple backwards-forwards rotations before reassuming its normal cutting knife 110 rotary driving operation.

Hence, in some embodiments the first control program comprises the control mechanism 140 detecting, after the performance of the first backward rotation, a cutting knife 110 problem of the type described above, in other words an inability of the cutting knife 110 12 to rotate in the first angular direction and/or a minimum load placed on the motor 120 to cause the cutting knife 110 to rotate in the first angular direction. ln other words, after the motor 120 has performed the first backward rotation and is about to (or has started) the forward rotation, the control mechanism 140 detects still existing cutting knife 110 prob- lems, such as problems left unresolved by the backwards rotation or additional problems that have arisen since or in connection to the backwards rotation. Such additional cutting knife 110 problems may arise due to foodstuff falling down in front of the cutting knife 110, by foodstuff still being jammed even after the backwards-forwards motion of the cutting knife 110, or in other ways. ln reaction to such detection, the control mechanism 140 can then be arranged to auto- matically control the motor 120 to perform a second control program, comprising a second backward rotation, in which the motor 120 again rotates in the second angular V direction, followed by a second forward rotation, again in the first angular V direction.

The second backward rotation and/or the second forward rotation may be as generally described above in relation to the first backward rotation and the first forward rotation. For instance, the control mechanism 140 can be arranged to detect a cutting knife 110 problem during the second backward rotation, and as a result immediately start the second forward rotation.

This pattern can then be repeated more than twice. Hence, in reaction to the detection of additional and/or remaining cutting knife 110 problems, the control mechanism 140 can be arranged to cause the motor 120 to perform a third, fourth and/or further backward rotations and corresponding forward rotations.

The alternation between backward rotation and forward rotation can go on for a certain predetermined number of times, such as at the most between 3 and 5 times; during a certain predetermined amount of time; or indefinitely. 13 ln addition thereto, any backward and/or forward rotation can be stopped as soon as a problem with the cutting knife 110 rotation is detected during such rotation, and the direction of rotary movement ofthe cutting knife 110 can then be reversed. ln some embodiments, the control mechanism 140 can be arranged to measure (directly or indirectly; and for instance using electric feedback signals from the motor 120) an amount of rotary deceleration of the cutting knife 110 when being stopped due to rota- tional problems of the type described herein. Then, the control mechanism 140 can be arranged to dynamically adapt the control program in dependence of such measured rotary deceleration, for instance by adjusting the corresponding backward rotation to be longer and/or more forceful in terms of an instantaneously applied rotary moment, for larger measured cutting knife 110 decelerations. ln case cutting knife 110 problems are still detected to be present after a certain prede- termined number of attempts (such as at the most 5, or even 3, attempts) and/or after a certain predetermined time period, the control mechanism 140 can be arranged to stop the motor 120 and to allow the operator to manually fix the problem, for instance by removing the lid 151 and manually remove or loosen anyjammed foodstuff in the cutting bowl 150, before resuming normal operation. ln some embodiments, the second backward rotation is angularly V longer than the first backward rotation, for instance between 10% and 100% longer. ln some embodiments, a rotary moment applied by the motor 120 is controlled, by the control mechanism 140, to be larger during the second backward rotation as compared to during the first backward rotation, such as at least 10% larger. Such an increasing angular V rotation length and/or increasing rotary moment can be further increased during any third or subsequent back- ward rotation. ln some embodiments, a rotary moment applied by the motor 120, under control of the control mechanism 140, during the first/second/further backward rotation is larger as compared to a rotary moment applied by the motor 120 during the first/second/further 14 forward rotation, and/or as compared to a rotary moment applied by the motor 120 during the normal operation of the motor 120 as set by the user.

As mentioned above, the control mechanism 140 can receive information about the operation of the motor 120 in any suitable, per se conventional manner. For instance, a current angle, rotary velocity or acceleration of the cutting knife 110 can be measured directly (such as using a per se conventional angle of rotation or RPM sensor) or indirectly (such as by measuring a time and/or an instantaneously applied current to the motor 120 and using known properties of the motor 120). Such sensors may be comprised in the motor 120 itself, for an uncomplicated design.

An alternative to measuring and controlling the rotational angle of the cutting knife 110 in the above-described embodiments during the first, second and any subsequent control programs, can be to instead measure a rotation time of the cutting knife 110, such as from the onset of the first/second/further backwards/forwards rotation of the cutting knife 110. Then, relevant threshold values can be set in terms of such rotation time rather than in terms of rotary angles. ln some embodiments, that will be described in closer detail below, an axial A, 111 loca- tion of the cutting knife 110 can be controlled, by displacing the cutting knife 110 axially A along the axis 111. ln some ofthese embodiments, the control mechanism 140 is arranged to control this axial A location of the cutting knife 110. Then, the control mechanism 140 can be arranged to, between the first backward rotation and the second backward rota- tion, automatically move the cutting knife 110 axially A. The displacement of the cutting knife 110 can be in any direction, as long as it ends up in a different axial A location after the displacement than before the displacement.

Correspondingly, the cutting knife 110 can be axially A displaced between the second or further backwards rotation and a corresponding second or further forwards rotation. ln some embodiments, the cutting knife 110 can also, or alternatively, be axially displaced A during the first, second and/or further backwards rotation and/or during the first, second and/or further forwards rotation, in any combination, so that the cutting knife 110 is pushed upwards or downwards along the axis 111 as the cutting knife 110 rotates backward or forward. For instance, the cutting knife 110 can be axially A displaced during the first and/or second and/or further backwards rotation as an alternative to, or in addition to, the cutting knife 110 being axially A displaced (in the same or opposite axial A, 111 direction) between the backwards rotation in question and a corresponding forwards rotation.

As is i||ustrated in the Figures, the rotating mixer 100 can comprise an angular V drive 130, generally being arranged to transfer a rotary moment from a drive shaft 121 the motor 120 to the cutting knife 110. The angular drive 130 can be arranged to transfer a rotary moment from the motor 120 about a drive shaft 121 axis that is the same or parallel to a rotary axis 111 of the cutting knife 110 (as is i||ustrated in the example embodiments shown in the Figures), or the angular drive 130 can be arranged to transfer the rotary moment from the motor 120 to a non-parallel and/or offset rotary axis of the cutting knife 110, the transfer then taking place using a per se conventional, suitable gear mechanism.

As is perhaps best i||ustrated in the example shown in Figure 5, the angular drive 130 can comprise an internal angular V play 131. Such a play can, for instance, be provided be- tween the drive shaft 121 from the motor 120 and the cutting knife 110 or a driving axis driving the cutting knife 110. The play causes a hysteresis, preferably of at least 30°, or even at least 45°, between the drive shaft 121 of the motor 120 and the cutting knife 110. ln the example of Fig. 5, the play 131 is embodied by the motor 120 drive shaft 121 and the angular drive 130 engaging via mutually cooperating rotary stoppers, making it possi- ble for the motor 120 drive shaft 121 and the angular drive 130 to rotate one in relation to the other across the hysteresis interval before the rotary engagement becomes driving in either direction. As can be seen in Fig. 5, in the shown example the angular drive 130 is arranged concentrically outside of the drive shaft 121. 16 ln some embodiments, the hysteresis is smaller, as measured in the angular V direction, than the first backward rotation. This means that the backward rotation achieved by the motor 120 will first rotate the drive shaft 121 an angular interval corresponding to the hysteresis, without the cutting knife 110 moving. As the angular interval limit is reached, the drive shaft 121 will force the cutting knife 110 to rotate the remainder of the back- ward rotation interval, if possible. As the forward movement commences, the motor shaft 121 will then again first travel across the hysteresis interval, with the cutting knife 110 being still, before, at the end of the hysteresis interval, again bring with it the cutting knife 110 in the forward direction. This achieves a slight hammering effect both in the back- wards and forwards rotation phases, but with the cutting knife 110 still rotating slightly backwa rds and forwards. ln other embodiments, the hysteresis is larger than the first backward rotation. This means that the cutting knife 110 will remain stationary during the whole backwards rotation, after which the motor shaft 121 in its subsequent forward rotation will strike onto the cutting knife 110 with a rotary hammering action, effectively pushing the cutting knife through anyjammed foodstuff in the cutting bowl 150.

The corresponding may equally well apply to the second and/or any subsequent backward rotation. ln some embodiments, the rotating mixer 100 further comprises a manual backwards rotation override 160, which is activatable by an operator. Such a manual backwards rotation override 160 can be arranged to, upon such activation, force the cutting knife 110 to rotate in the second angular V direction in relation to the cutting bowl 150. The forced relative rotation can be mechanically forced by the operator applying a corresponding mechanical activation force, for instance a rotary activation force, that is transferred by the override 160 into said forced relative rotation ofthe cutting knife 110.

As will be clear from the following, the relative rotation of the cutting knife 110 in relation to the cutting bowl 150 can take place by the cutting knife 110 rotating and the cutting 17 bowl 150 being stationary, or by the cutting knife 110 being stationary while the cutting bowl 150 rotates. lt is realised that combinations may also be possible, such that the cutting knife 110 is forced to rotate in the second angular V direction while the cutting bowl 150 is forced to rotate in the first angular V direction.

The Figures show a number of examples of such manual backwards rotation overrides 160, that can be applied and used individually or in parallel. ln a first example, the manual backwards rotation override 160 comprises a rotating lever 161, 162, angularly V connected to the cutting knife 110 and/or angularly V connected to the axial drive shaft 121 of the motor 120.

The Figures show an upper such rotating lever 161, mechanically connected to the angular drive 130 and as a result the cutting knife 110. As is illustrated in Fig. 6, a reverse gear 161' (similar to how the pedals are mounted in relation to the wheel on a bike) is used to transfer the rotary activation force (in the backwards direction) to the angular drive 130, so that the lever 161 does not rotate with the cutting knife 110 as the motor 120 drives the angular drive 130 in the forward direction.

The Figures also show a lower such rotating lever 162, mechanically connected to the motor 120 axial drive shaft 121. A similar reverse gear may be used also in this case. lt is noted that two such levers 161, 162 are normally not required, in other words one would be sufficient in most cases.

The Figures also show a third option for a manual backwards rotation override 160, namely using the cutting bowl 150 itself. Again, this manual backwards rotation override 160 can be used in isolation or in combination with other types, such as one or both of levers 161, 162. 18 ln this third option, the cutting knife 110 is arranged to rotate in the cutting bowl 150, and the manual backwards rotation override 160 comprises a mechanism allowing the bowl 150 to rotate in the angular direction V in relation to the cutting knife 110. Hence, the bowl 150 is arranged to rotate in relation to both the angular drive 130 and the motor 120 drive shaft 121. This rotation of the cutting bowl 150 can be in relation to a chassis 101 of the rotating mixer 100. For instance, such rotation can be made possible by the cutting bowl150 resting in angular V guides or tracks ofthe chassis 101.

This way, the operator can simply turn the cutting bowl 150 in the angular direction V, hence forcing a relative rotary movement of an inside surface of the cutting bowl 150 in relation to the cutting knife 110. ln some embodiments, the manual backwards rotation override 160 is arranged with a maximum angular V rotation interval, limiting the relative rotation of the cutting knife 110 as a result of activation by the operator. Such maximum angular V rotation interval can be, in some embodiments, 180° or less. ln the Figures it is illustrated how the levers 161, 162 are mechanically constrained in their rotational freedom of movement to an allowed angular V interval of rotation; and how the cutting bowl150 has a stopper 152 running in a corresponding track 102 ofthe chassis, limiting the relative rotary freedom of movement of the cutting bowl 150 in relation to the chassis 100. The stopper 152 and the track 102 can together constitute a bayonet mount of the cutting bowl 150 to the chassis 101. lt is realised that these are provided as examples, and that other solutions are possible to achieve said limited freedom of rotary movement. ln some embodiments, the manual backwards rotation override 160 is arranged so that it, when activated, automatically cuts the power to the motor 120. This can be achieved by a suitable breaker being provided in connection to the lever 161, 162 and/or the track 102, the breaker being electrically connected to the motor 120 and being arranged to cut the power to the motor 120 when the lever 161, 162 and/or cutting bowl 150 is or are actuat- ed to achieve said relative rotary movement of the cutting knife 110 in relation to the cutting bowl 150. Such breaking of the power to the motor 120 will prevent a motor 19 protection of the motor 120 from being activated as a result of the motor 120 trying to apply rotary moment to the angular drive 130 without being able to move the |atter. Preferably, the power to the motor 120 is again automatically connected, by said breaker, when the manual backwards rotation override 160 is again inactivated. Such inactivation takes place by the lever 161, 161 or the cutting bowl 150 again being brought to its respective original position. This can be achieved manually by the operator.

As mentioned above, the rotating mixer 100 can also comprise a knife axial A displacing means 170, arranged to axially A displace the cutting knife 110 in relation to the cutting bowl 150. This knife axial displacing means 170 can then comprise an automatic knife axial displacing means 173, arranged to, as a result of and during the first backwards rotation (or between the first backwards rotation and the first forwards rotation, as described above), axially A displace the cutting knife 110 in relation to the cutting bowl 150. For instance, such a manual cutting knife 110 axial A displacement means 170 can be provided as a part of, or in connection to, the motor 120, such as a mechanism adjusting an axial A location of the drive shaft 121; an axial A location of a point of engagement between the drive shaft 121 and the angular drive 130; or an axial A location of the angular drive 130. Examples include a an additional electric linear or rotary motor arranged to axially A displace said details via a suitable engagement. ln alternative or supplementary embodiments, the knife axial displacing means 170 can comprise a manual knife axial displacing means 171, arranged to, when activated by the operator, axially A displace the cutting knife 110 in relation to the cutting bowl (150). For instance, and as is illustrated in the Figures, the manual knife axial displacing means 171 can comprise a setting screw 172, arranged along the axis 111 of rotation of the cutting knife 110, such as on an external side of the lid 15, and arranged to translate a rotation of the setting screw 172 into a corresponding axial A displacement of the cutting knife 110 in relation to the cutting bowl 150. As the operator turns the setting screw 172, a threaded engagement between the setting screw 172 and the angular drive 130 forces the angular drive 130 upwards or downwards, depending on the screwing direction, in turn forcing the cutting knife 110 upwards or downwards in relation to the cutting bowl 150.

As further illustrated in the Figures, the rotating mixer 100 can also comprise a user interface 180. The user interface 180 can be connected to, be comprised in, or comprise, the control mechanism 140. The control mechanism 140 can then be arranged to control the motor 120 in reaction to input received via said user interface 180. ln some embodi- ments, a user setting via the user interface 180 can be overridden, such as by the auto- matic detection of cutting knife problems as described herein, resulting in backwards rotation, and/or by the manual backwards rotation override 160 also described above. ln some embodiments, the user interface 180 is arranged to allow the operator to start, maintain and stop one or more control programs arranged to drive the cutting knife 110 in the first angular A direction so as to disintegrate foodstuff in the cutting bowl. Hence, the user interface 180 can comprise an adjustment control 181, such as a turning knob or button controls, arranged to, when so activated by the operator, cause the control mech- anism 140 to perform a normal control program for foodstuff disintegration. Alternatively or in addition thereto, the adjustment control 181 can be arranged to, when so activated by the operator, cause the control mechanism 140 to perform the first control program, at least until overridden in any of the ways described herein. ln some embodiments, the adjustment control 181 comprises a motor speed adjustment control, arranged to allow the operator to set, directly or indirectly (for instance by translating an operator-selected number 0-3 to a corresponding applied power to the motor 120), a desired motor 120 speed by manipulating said speed adjustment control to a corresponding state. ln these and other embodiments, one and the same speed adjustment control can be arranged to be manipulated in a first manipulation direction so as to increase a motor 120 speed and to be manipulated in a second, different, manipulation direction so as to manually perform said first control program. Such first and second manipulation direc- tions can be rotary or translational directions. 21 As is illustrated in the Figures, the cutting knife 110, or at least one of a set of cutting knives 110, can be arranged with sharp edges 112, 113 on both respective angularly V facing sides. This way, foodstuff is more easily penetrated by the cutting knife 110 during the backwards rotation thereof.

Figure 9 illustrates a method for operating the rotating mixer 100 described herein. ln a first step, the method starts. ln a subsequent step, the control mechanism 140 detects a cutting knife problem 110 of the general type described above, in other words an inability of the cutting knife 110 to rotate in the first angular direction and/or a minimum angular load placed on the motor 120 to cause the cutting knife 110 to rotate in the first angular direction. ln a subsequent step, performed by the control mechanism in response to such detection, the motor 120 is automatically controlled to perform the first backward rotation as described above. ln a subsequent step, the control mechanism 140 automatically controls the motor 120 to perform the first forward rotation as described above. ln a subsequent step, after the performance of said first backward rotation, the control mechanism 140 can again detect a cutting knife 110 problem of said type, in other words an inability of the cutting knife 110 to rotate in the first angular direction and/or a mini- mum load placed on the motor 120 to cause the cutting knife 110 to rotate in the first angular direction. ln a subsequent step, the control mechanism 140, as a result of such detection, can automatically control the motor 120 to perform a second backward rotation as described above. 22 ln a subsequent step, the control mechanism 140 can thereafter automatically control the motor 120 to perform a second forward rotation as described above.

The method can also comprise performing further backward and forward rotations, as described above; the operator controlling the control mechanism 140 via the user inter- face 180 or any manual backwards rotation override 160; the cutting knife 110 being manually and/or automatically axially A displaced; and so forth as described hereinabove.

As indicated by the progress arrows in Fig. 9, the method can be performed in different ways, including iterations. This is in line with what has been described above. ln a subsequent step, the method ends.

Above, preferred embodiments have been described. However, it is apparent to the skilled person that many modifications can be made to the disclosed embodiments without departing from the basic idea of the invention.

As described above, the rotating mixer 100 illustrated in the drawings is one example a mixer in which the present invention can be embodied, the rotating mixer 100 embodying several different aspects that may be used together or separate.

Various details, such as the design of the cutting knives, the design of the chassis 101 and the general purpose (in term of what foodstuff the rotating mixer is designed to process) can va ry. ln general, everything that has been said in relation to the rotating mixer 100 is equally applicable to the method described herein, and vice versa.

Hence, the invention is not limited to the described embodiments, but can be varied within the scope of the enclosed claims.

Claims (26)

1. Rotating mixer (100) associated with a polar coordinate system having an axial dimension (A), a radial dimension (R) and an angular dimension (V), the rotating mixer (100) comprising a motor (120); a rotating cutting knife (110), arranged to be driven by the motor (120) to rotate in a first angular direction about an axis of rotation (111); and a control mechanism (140), arranged to control the motor (120), characterised in that the control mechanism (140) is arranged to detect an inability of the cutting knife (110) to rotate in the first angular direction and/or a minimum load placed on the motor (120) to cause the cutting knife (110) to rotate in the first angular direction, and in re- sponse to such detection automatically control the motor (120) to perform a first control program, the first control program comprising the control mechanism (140) controlling the motor (120) to perform a first backward rotation in which the motor (120) rotates in a second angular direction, the second angular direction being opposite to the first angular direction, and the first control program further comprising the control mechanism (140) controlling the motor (120) to thereafter perform a first forward rotation in which the motor (120) rotates in the first angular direction.

2. Rotating mixer (100) according to claim 1, further comprising a cutting bowl (150), wherein the cutting knife (110) is arranged to rotate in said cutting bowl (150).

3. Rotating mixer (100) according to claim 1 or 2, wherein said first backward rotation is between 30° and 360°, preferably between 90° and 180°.

4. Rotating mixer (100) according to any preceding claim, whereinthe control mechanism (140) is arranged to detect an inability of the cutting knife (110) to rotate further in said second angular direction and/or a minimum load placed on the motor (120) to cause the cutting knife (110) to rotate further in the second angular direction during said first backward rotation, and wherein the control mechanism (140) is arranged to, upon the detection of such inability and/or such minimum load, control the motor (120) to stop the first backward rotation and to start the first forward rotation.

5. Rotating mixer (100) according to any preceding claim, wherein said first control program comprises the control mechanism (140) detecting an ina- bility of the cutting knife (110) to rotate in the first angular direction and/or a minimum load placed on the motor (120) to cause the cutting knife (110) to rotate in the first angular direction after the performance of said first backward rotation, and wherein the control mechanism (140), as a result of such detection, automatically controls the motor (120) to perform a second backward rotation in which the motor (120) rotates in the second angular direction, and thereafter the control mechanism (140) controlling the motor (120) to perform a second forward rotation in the first angular direction.

6. Rotating mixer (100) according to claim 5, wherein the control mechanism (140) is arranged to detect an inability of the cutting knife (110) to rotate further in said second angular direction and/or a minimum load placed on the motor (120) to cause the cutting knife (110) to rotate further in the second angular direction during said second backward rotation, and wherein the control mechanism (140) is arranged to, upon the detection of such inability and/or such minimum load, control the motor (120) to stop the second backward rotation and to start the second forward rotation.

7. Rotating mixer (100) according to claim 5 or 6, wherein said second backward rotation is angularly (V) longer than the first backward rota- tion.

8. Rotating mixer (100) according to any one of claims 5-7, wherein the control mechanism (140) is arranged to control an axial (A) location of the cut- ting knife (110), and wherein the control mechanism (140) is arranged to, between the first backward rotation and the second backward rotation, automatically move the cutting knife (110) axially (A).

9. Rotating mixer (100) according to any preceding claim, wherein the rotating mixer (100) comprises an angular drive (130), the angular drive (130) comprising an internal angular (V) play (131) causing a hysteresis, preferably of at least 30°, between a drive shaft (121) of the motor (120) and the cutting knife (110).

10. Rotating mixer (100) according to claim 9, wherein said hysteresis is smaller than the first backward rotation, or wherein said hysteresis is larger than the first backward rotation.

11. Rotating mixer (100) according to any preceding claim, further comprising a manual backwards rotation override (160), arranged to, when activated by an op- erator, rotate the cutting knife (110) in the second angular direction in relation to the cutting bowl (150).

12. Rotating mixer (100) according to claim 10, wherein said manual backwards rotation override (160) comprises a rotating lever (161,162) angularly (V) connected to the cutting knife (110) and/or angularly (V) connected to an axial drive shaft (121) of the motor (120).

13. Rotating mixer (100) according to any one of claims 11 or 12, further comprising a cutting bowl (150), wherein the cutting knife (110) is arranged to rotate in said cutting bowl (150), and wherein said manual backwards rotation override (160) comprises a mechanism allowing the bowl (150) to rotate in the angular direction (V) in relation to the cutting knife (110).

14. Rotating mixer (100) according to any one of c|aims 11-13, wherein the manual backwards rotation override (160) is arranged with a maximum angular (V) rotation interval, limiting the relative rotation of the cutting knife (110) as a result of activation by the operator.

15. Rotating mixer (100) according to c|aim 14, wherein said maximum angular (V) rotation interval is at the most 180°.

16. Rotating mixer (100) according to any one of c|aims 11-15, wherein the manual backwards rotation override (160) is arra nged so that it, when activated, automatically cuts the power to the motor (120).

17. Rotating mixer (100) according to any preceding c|aim, further comprising a knife axial displacing means (170), arranged to axially (A) displace the cutting knife (110) in relation to the cutting bowl (150).

18. Rotating mixer (100) according to c|aim 17, wherein the knife axial displacing means (170) comprises a manual knife axial displacing means (171), arranged to, when activated by an operator, axially (A) displace the cutting knife (110) in relation to the cutting bowl (150).

19. Rotating mixer (100) according to c|aim 18, wherein the manual knife axial displacing means (171) comprises a setting screw (172) ar- ranged along an axis (111) of rotation of the cutting knife (110) and arranged to translate a rotation of the setting screw (172) into a corresponding axial (A) displacement of the cutting knife (110) in relation to the cutting bowl (150).

20. Rotating mixer (100) according to any one of c|aims 17-19, wherein the knife axial displacing means (170) comprises an automatic knife axial displacing means (173), arranged to, as a result of and during the first backwards rotation, axially (A) displace the cutting knife (110) in relation to the cutting bowl (150).

21. Rotating mixer (100) according to any preceding claim, further comprising a user interface (180), wherein the control mechanism (140) is arranged to control the motor (120) in reaction to input received via said user interface (180).

22. Rotating mixer (100) according to c|aim 21, wherein the user interface (180) comprises an adjustment control (181) arranged to, when activated by an operator, cause the control mechanism (140) to perform the first control pfOgfam.

23. Rotating mixer (100) according to c|aim 22, wherein said adjustment control (181) comprises a motor speed adjustment control, ar- ranged to allow the operator to set a desired motor (120) speed by manipulating said speed adjustment control to a corresponding state, and wherein the speed adjustment control is arranged to manipulated in a first manipulation di- rection so as to increase a motor (120) speed and to be manipulated in a second, differ- ent, manipulation direction so as to manually perform said first control program.

24. Rotating mixer (100) according to any preceding claim, wherein the cutting knife (110) is arranged with sharp edges (112,113) on both angularly (V) facing sides.

25. Rotating mixer (100) according to any preceding claim, wherein the rotating mixer (100) is a vertical cutter mixer.

26. Method for operating a rotating mixer (100) according to any preceding claim, the method comprising the steps a) the control mechanism (140) of the rotating mixer (100) detecting an inability of the cutting knife (110) of the rotating mixer (100) to rotate in the first angular direction ingand/or a minimum angular load placed on the motor (120) to cause the cutting knife (110) to rotate in the first angular direction; in response to such detection, the control mechanism (140) automatically control- ling the motor (120) of the rotating mixer (100) to perform a first backward rotation in which the motor (120) rotates in a second angular direction, the second angular direction being opposite to the first angular direction; and the control mechanism (140) thereafter automatically controlling the motor (120) to thereafter perform a first forward rotation in which the motor (120) rotates in the first angular direction. I\/|ethod for operating a rotating mixer (100) according to claim 26, further compris- the control mechanism (140) detecting an inability of the cutting knife (110) to rotate in the first angular direction and/or a minimum load placed on the motor (120) to cause the cutting knife (110) to rotate in the first angular direction after the performance of said first backward rotation; the control mechanism (140), as a result of such detection, automatically controlling the motor (120) to perform a second backward rotation in which the motor (120) ro- tates in the second angular direction; and the control mechanism (140) thereafter automatically controlling the motor (120) to perform a second forward rotation in the first angular direction.