Cleaving knife

Abstract

The application pertains to a knife comprising one first blade with a first cutting edge being linear having and a second blade with a second cutting edge. Furthermore, the knife comprises one connection means reversibly connectable to a robot arm. The cutting edges meet in at least one crossing point which is located in a position where its distance from the central point of the first cutting edge is at least 10% the length of the linear cutting edge.

Description

[0001] CAN3302

[0002] Cleaving knife

[0003] Description:

[0004] This application pertains to a knife and a method for cutting or cleaving strawberries and other fruits and vegetables.

[0005] In many parts of Europe and other parts of the world, strawberries are one of the most popular seasonal kinds of fruit which are - apart from the sale of whole strawberries - ingredients to a large amount of processed foods such as jams, yoghurt, different kinds of sweets and drinks. As availability of strawberries of good quality at least in European climates is strongly season dependent, strawberries are conserved by deep freezing in large amounts. Frozen strawberries are also important ingredients for different cocktails such as strawberry margaritas. Industrial processing of strawberries provides several challenges to the development of the corresponding devices. First, compared to other fruits and vegetables strawberries have low mechanical stability and damages to the fruit can initiate degradation processes within a couple of hours. Second, strawberries can be very heterogeneous in size. Even in one single supply, there may occur strawberries which are as small as a grape besides others which are as large as a peach. However, industrial processing typically requires a supply of fruits, vegetables or pieces thereof which is as homogeneous in size and shape as possible to e.g. fulfill cooking time requirements. This renders processing of strawberries a rather complex process.

[0006] Typical processing and raw consumption of whole strawberries starts with a cleaning step and removal of the stem and the leaves which are typically found on top of every strawberry. A system for automatic removal of the stem has been presented in WO2022 / 223186. However, after destemming, cutting of the strawberries into pieces of about homogeneous size is still necessary. It is the object of the invention, to render the processing of strawberries more efficient.

[0007] The object of the present application is solved by a knife comprising one first blade with a cutting edge, the cutting edge of the first blade being linear having a length, one second blade with a cutting edge, one connection means reversibly connectable to a robot arm, wherein the cutting edges meet in at least one crossing point, characterized in that the crossing point is located in a position where its distance from the central point of the first cutting edge is at least 10% the length of the linear cutting edge.

[0008] Throughout this application, the term “knife” will be used for a cutting means comprising at least one blade as well as connection means such as a handle or a mount such as a bayonet mount, a screw mount or a friction fit which allows for connection to a handle, a machine or a robot arm.

[0009] Throughout this application, the term “blade” will be used for a piece of solid material such as metal comprising at least one sharpened edge. This sharpened edge will be called “cutting edge” throughout this application. The cutting edge may be sharpened in a sharpening process, e.g. by grinding or peening. In an embodiment, the part of the blade comprising the cutting edge is made from especially hard material with good sharpening properties such as surgical stainless steel or carbon steel. In an embodiment, the cutting edge is made of RVS 304. Also cutting edges of suitable ceramic materials or glass are suitable. An advantage of metals as material is that the cleaving knife may be detected using metal detectors in case it turns loose during processing and gets lost e.g. in a product stream.

[0010] An advantage of a material comprising a reasonable amount of chemical elements of the fourth period or higher is that the knife can be detected by X-rays in a product stream of food processing which mainly comprises light-weight elements such as carbon, nitrogen, oxygen and hydrogen.

[0011] The cutting edge of the first blade is linear according to the present application which means that it has the shape of a straight line. Said linear cutting edge has a central point which has the same distance to both end points of the linear cutting edge.

[0012] The shape of the second blade is not particularly limited. Thus, in an embodiment, the second blade may have the form of a straight line, it may have the shape of an arc or a bow. Furthermore, the second blade may also have a closed shape and be triangular, rectangular, quadratic, oval or circle-shaped.

[0013] In combination with the linear first blade, the first and the second blade may be combined in any possible manner. In an embodiment, the two blades form a cross. In an embodiment, the two blades form a structure where the cutting edge of the first blade ends at a circular second blade.

[0014] Throughout this application, the term “circular” means that a structure is closed. If not mention otherwise, the term “circular” is thus not restricted to structures which have the shape of a circle but it can also be a structure of oblong, oval, elliptical, polygonal or irregular shape as long as it is closed structure.

[0015] In an embodiment, the connection means is mounted on the at least one first blade. The connection means can be mounted both using mounting means such as screws or bolts or by techniques using a connection material such as gluing, soldering or welding. The connection means may also be an integral part of the blade which has already been added to it during the manufacturing of the at least one first blade, e.g. by forging.

[0016] In an embodiment, the connection means is located opposite to the cutting edge of the at least one first blade. “Opposite” in the sense of this application means that the connection means is located in a way, that an imaginary line from the connection means to the cutting edge which forms an angle of 90° with the cutting edge divides the cutting edge into two parts of approximately the same length. “Approximate” in the sense of this application means that the two parts differ in length by not more than 20%. This arrangement allows a force to apply from above and perpendicular to the cutting edge. “Perpendicular” in the sense of this application means that the smallest angle two items form with each other is between 70 and 110 degrees. In case other fruits or vegetables than strawberries are to be processed, the mounting means and as well the connection means may be rendered robust as cleaving e.g. a large potato into several pieces requires application of comparably strong forces and therefore, both the mounting means and the connection means are exposed to strong wear. It is important to notice that the wear-resistance of the connection means, the mounting means and the at least one first blade should be oriented on the largest, hardest and thickest fruits or vegetables to be expected for processing.

[0017] A crossing point according to the present application is a point where the two cutting edges meet in the manner of an intersection. It is important to point out that this does not necessarily mean that both cutting edges must exist on both sides of the crossing point. On the contrary, it is also possible that one cutting edge ends at the crossing point while the other cutting edge continues. In general, the crossing point may be a point where a cutting edge ends, or it may be a point which divides a cutting edge into two parts.

[0018] Thus, according to the present application, a crossing point is a point from which at least three cutting edges or parts of cutting edges originate. Thus, a crossing point may look like a cross or a three-armed star. However, it may also have different shapes depending on the shape of the cutting edges that meet in this point such as the shape of a circular roadsign with a line pole attached to it. The crossing point has a distance to the central point of the first cutting edge which is at least 10% the length of first the cutting edge. Apart from this restriction, the distance between the crossing point and the central point of the first cutting edge is not limited until 50% of the length of the first cutting edge which means that the crossing point may be identical to an end point of the first cutting edge. It is important to point out that the term “crossing point” according to the present application means that the two blades have to be physically connected at this point. On the contrary, it is possible that there is a gap between the two blades at the crossing point, however this gap should be that small that it is not an obstacle for the two blades to work together in such a manner that they cut an item into more than two pieces. Thus, the acceptable size or the gap depends on the hardness, the size and the brittleness of the items to be cut. In an embodiment, a gap of three millimeters, one millimeter or less is acceptable. Although, the present application explicitly mentions strawberries which means, according to general understanding, the fruit of the botanical species Fragaria x annanassa, it is understood that the use of the devices and processes discussed in this application can also be applied to other fruits or vegetables such as fruits of other species of the botanical genus Fragaria and thus strawberries in a broader sense, apples, pears, kiwis, bananas, tomatoes, cucumbers, onions, leek, celery, parsnips or potatoes which may both be tubers of botanical species Solanum tuberosum and of botanical species Ipomoea batatas, i.e. sweet potatoes.

[0019] In general, the devices and processes disclosed herein are applicable to all fruits and vegetables which require processing and have a mechanical stability which enables them to withstand automatic processing. Possible fruits and vegetables are all kinds of fruits of the genus Capsicum such as chillis, peppers and bell peppers but also aubergines, pineapples, different kinds of cabbage such as white, red and savoy cabbage, brussels sprouts, kalettes, cauliflower or broccoli, pineapples or melons.

[0020] For the sake of readability, in the following discussion, the term “strawberry” is used as synonym for all foods and vegetables to be processed with the knifes and processes according to the present application unless stated otherwise.

[0021] It is furthermore noted that the use of the knife and the process according to the present application is not restricted to the processing of the mentioned or similar plant products to produce human food but also to produce animal foods which is especially relevant for the processing of mangelwurzels. Furthermore, the knifes and processes according to the present application may be used in the processing of the mentioned plant parts to industrial products such as sugar, starch, alcohol or other products.

[0022] As strawberries have high water content, slices and pieces of strawberries tend to stick on blades while cutting due to adhesion forces caused by a water film between the plane metal surface of the blade and the strawberry piece. This effect is an obstacle for the processing procedure as effort must be taken to properly remove the strawberry piece from the blade. This problem is overcome by an embodiment wherein the blades of the knife according to the present comprise a grid structure. A grid structure interrupts the large plane metal surface of the blade and therefore prevents formation of an extended water film which causes sticking of strawberry pieces. The grid structure may be one or more open spaces in the blade obtained by punching or cutting. It may also comprise bars which are welded, glued or soldered into the open space. The effect of the grid structure against sticking of strawberry pieces can be intensified by shaping the grid in a way that it comprises at least one bar, which bar may be perpendicular to the cutting edge, and which may have a thickness, measured perpendicular to the direction of the cutting edge, which exceeds the thickness of the blade by at least 3 millimeters. In an embodiment, this bar does not have the same thickness all over its length but turns broader with extending distance from the cutting edge. This shape makes sure that the strawberry pieces are moved away from the blade during the cleaving process.

[0023] Another way of reducing the problem of sticking of strawberry pieces on the blades is use of surface coatings on the blades which might either be liquid or solid coatings. Examples of liquid coatings are e.g. thin layers of hydrophobic liquids such as fatty, mineral or silicone oils which prevent formation of a water film on the blades. Such liquid coatings will have to be renewed on a regular basis. Examples of solid coatings are e.g. hydrophobic lacquers or resin coatings made from materials such as solid silicone or polytetrafluoroethylene. Both liquid and solid coatings will additionally provide oxidation protection to the blade as they shield the metal from the oxidizing effects of water. In contrast to solid coatings, liquid coatings will have this effect also on the cutting edge as liquid coating agents also have the possibility to penetrate the microscopic structure of the cutting edge without changing its cutting properties. A disadvantage of liquid coatings is that they can more easily contaminate the processed goods which might be undesired e.g. in food processing. This problem may be avoided by using e.g. paraffine oil of medical quality or natural oils such as tea seed oil, palm oil or coconut oil which can also be used as food.

[0024] In an embodiment, the sticking of the strawberry pieces to the blades is avoided by the shape of the cutting edge which is similar to a wedge, thus that the two sides of the cutting edge form an acute angle of at least 10°, in an embodiment at least 12°, 15° or 17°. The angle is at most 30°, in an embodiment 25°, 20°, 17° or 15°. In such a shape, the knife does not only cut the potato or other fruit or vegetable apart but also pushes the separated pieces away from each other in such a manner that they get in a movement away from the blades and do not stick thereon. Cleaving with a knife as such requires a higher momentum of the knife during the cleaving process and is thus more a splitting process than a cutting process comparable to splitting of a piece of wood using an axe. In general, knifes like this may be used for strawberries but can also provide strawberries with severe mechanical damage, however knifes like this can be useful for cleaving fruits and vegetables which are harder than strawberries such as potatoes.

[0025] In some embodiments, the cleaving process with the knife according to the present application requires a high momentum of the knife and can thus be considered a punching process. This of course necessitates the use of a machine or robot to handle said knife that is strong and robust enough to provide such momentum also in view of stiffness and rigidity of mounts and other components. It is understood that splitting or punching is only possible with fruits and vegetables which have a certain hardness such as potatoes, squashes, carrots, celery, pumpkins, sugar beets, mangelwurzels and beetroots.

[0026] For cleaving or cutting of softer fruits and vegetables such as strawberries, chillis, peppers, bell peppers other knifes may be used which have thoroughly sharpened cutting edges which lead to smooth cuts without pushing the pieces apart. In such cases, very thin blades and cutting edges may be used which are comparable to razor blades or a Stanley knife. Coarser, thicker and mechanically more robust blades would be used for cleaving or cutting harder fruits or vegetables such as potatoes, pumpkins, cucumbers, apples or the like.

[0027] In general, the knife according to the present application allows to cut or cleave a fruit or vegetable such as a strawberry into three or more pieces and to thus render the process of cutting or cleaving more efficient as from one cutting or cleaving process, more pieces can be obtained which leads to less use and thus less wear of tools and lower consumption of time. Throughout this application, the terms “cutting” and “cleaving” can be considered expressions for different aspects of the same thing - the separation of an item into pieces using a blade. However, while “cutting” means a process that is more precise and controlled, “cleaving” is a process that is more coarse and uses more force. “Cutting” in this sense would be something that is done with a well- sharpened knife while “cleaving” is carried out using tools like an axe. However, as long as nothing different is mentioned, “cleaving” and “cutting” should be taken as synonyms in the present application.

[0028] Like other fruits and vegetables, strawberries show a large difference in size. The big variety in size of strawberries makes it necessary to cut larger strawberries into two or more pieces to get strawberry pieces of about equal size in case processing of the strawberries requires . As every strawberry has a stem that needs to be removed, destemming is necessary in any case. In an embodiment, destemming may be carried out with a process and device as disclosed in WO2022 / 223186. This document discloses destemming of strawberries using a tube-shaped knife through which, after the cutting step, the removed stem can be removed by suction through the knife. Furthermore it discloses a process wherein the strawberry is destemmed according to a process with the following steps:

[0029] - Taking pictures of strawberries on a conveyor belt,

[0030] - Evaluating the pictures using a computer,

[0031] - Moving a tube-shaped knife towards the strawberry to be detemmed,

[0032] - Optionally touching the strawberry with the knife and thereby adjusting the strawberry on the conveyor belt e.g. by tilting,

[0033] - Pushing the knife down towards the conveyor belt to separate the stem from the strawberry,

[0034] - Removing the separated stem through the tube-shaped knife by suction. An embodiment of the knife according to the present application may now be used to combine the destemming process of WO2022 / 223186 with a cutting process. According to this embodiment, the first blade of the knife is linear while the second blade is ring-shaped with one end of the first blade being connected to the ring- shaped second blade by any technique known to the person skilled in the art such as forging, welding, soldering, glueing or mechanical connections such as hooks or clamps. The cross section of a knife according to this embodiment may then look like a circular road sign with a pole attached to it. If the knife according to the present application is adjusted properly towards a strawberry it may, at the same time, destem the strawberry in a similar process as the one disclosed in WO2022 / 223186 but may also separate the strawberry into two halves.

[0035] A knife of this embodiment could be, depending on the on its orientation towards the fruit or vegetable, used to carry out several operations on fruit or vegetable such as a strawberry depending on the size:

[0036] - -Destem a strawberry (when oriented such that only the circular blade is in contact with the strawberry)

[0037] - Destem a strawberry and cut it into halves (when the linear blade and the circular blade are in touch with the strawberry),

[0038] - Cut an already destemmed strawberry or a part thereof into halves (when only the linear blade is in touch with the strawberry),

[0039] Thus, a knife according to this embodiment can be used in a rather universal manner. Knifes according to this embodiment may comprise a means to modify their orientation towards the fruit or vegetable such as a rotatable mount and optionally a means for steering such rotation. Said means may e.g. be a servo motor that is integrated into the mount of the knife.

[0040] In this embodiment, the knife has a cross section which does not comprise a rotational axis as perpendicular to the plane as a symmetry element of the cross section. Thus, the functionality of the knife differs depending on its orientation towards the fruit or vegetable to be processed.

[0041] A knife according to this embodiment allows for processing of strawberries in a very efficient manner as the cutting and destemming can be combined in one cutting step and one and the same knife can be used for a lot of different cutting operations.

[0042] In an embodiment a knife is provided wherein both the first blade and the second blade are linear and inclined to each other crossing in the crossing point that both blades are separated into two parts by the crossing point. It is understood that the cutting edges of the first and the second blade may cross each other in any possible angle. In an embodiment, the angle is in the range of 90° which means that it deviates from 90° by not more than 10°.

[0043] In an embodiment, the first and the second blade are of different length and their crossing therefore forms a cross or a star of irregular shape.

[0044] As a result, a cross-shaped knife is obtained wherein the knife has the form of e.g. a Latin cross or a cross of Lorraine. A Latin cross is a cross comprising two bars of different lengths wherein the crossing point is in the central point of the shorter bar but off the central point of the longer bar. The form of the Latin cross is widely known as the typical “church cross” of the roman catholic and protestant denominations. The cross of Lorraine is a double cross comprising a longer bar and two shorter bars wherein both shorter bars have an individual crossing point with the longer bar. Derived forms of the Latin cross or the cross of Lorraine can be obtained e.g. by extension of at least one shorter bar on one side of the crossing point to further decrease the symmetry of the cross.

[0045] The cross-shape allows for cutting or cleaving round-shaped fruits or vegetables such as apples, tomatoes, already destemmed strawberries or round potatoes into quarters or other fragments of about equal size. To make sure a clean cut, the cutting edges of the crossing blades may also be sharpened in the direct proximity of the crossing point and also at the crossing point itself in case the knife does not comprise any gap at the crossing point.

[0046] A knife according to this embodiment could be used to carry out several operations on a fruit or vegetables such as a destemmed strawberry or a potato depending on the size:

[0047] - Cut a fruit or vegetable into halves (when only a linear part of a blade is in touch with the fruit or vegetable),

[0048] - Cut a fruit or vegetable into quarters (when the crossing point and all blades are in touch with the fruit or vegetable.

[0049] Of course, a knife according to the present embodiment may even be used on the same fruit or vegetable twice when it first cuts e.g. a large potato into quarters and, afterwards, cuts one of the quarters into halves once again. This has the advantage that fruits or vegetables do no longer have to be sorted by their size and / or shape and can be cut into parts of about equal size in a very efficient manner.

[0050] In an embodiment, the knife according to the present application has a crosssection shape like the astronomical symbol for “Venus” or the symbol for “female” with a circle to which a cross is attached. Such a knife would allow for destemming a strawberry and, at the same time, cut the strawberry into quarters which is an excellent problem solution to cope with the big size variety shown by strawberries. However, this still necessitates the use of different knifes for different sizes of strawberries. Another embodiment solves this problem by combining two embodiments of the present application. A knife according to this embodiment has a cross section which looks like a circle to which both a line and a cross are attached e.g. in an angle of about 120° to each other. Such a knife can, depending on how it is oriented towards a strawberry, carry out a big variety of different cutting operations:

[0051] - Destem a strawberry (when oriented such that only the circular blade is in touch with the strawberry),

[0052] - Destem a strawberry and cut it into halves (when the linear blade and the circular blade are in touch with the strawberry),

[0053] - Destem a strawberry and cut it into quarters (when the linear blade and the cross-shaped blade are in touch with the strawberry,

[0054] - Cut an already destemmed strawberry or a part thereof into halves (when only the linear blade is in touch with the strawberry),

[0055] - Cut an already destemmed strawberry or a part thereof into quarters (when only the cross-shaped blade is in touch with the strawberry).

[0056] Thus, such a knife is very universal and may even be used several times on one and the same strawberry - first for destemming and cutting into halves and second for cutting one of the halves into halves once again. Knifes according to this embodiment may comprise a means to modify their orientation towards the fruit or vegetable such as a rotatable mount and optionally a means for steering such rotation. Said means may e.g. be a servo motor that is integrated into the mount of the knife.

[0057] In this embodiment, the knife has a cross section which does not comprise a rotational axis as perpendicular to the plane as a symmetry element of the cross section. Thus, the functionality of the knife differs depending on its orientation towards the fruit or vegetable to be processed.

[0058] A knife according to this embodiment allows for processing of strawberries in a very efficient manner as the cutting and destemming can be combined in one cutting step and one and the same knife can be used for a lot of different cutting operations.

[0059] In embodiments where the second blade of the knife is circular, it may be a part of a tube-shaped knife and thus be a part of a sharpened edge of a metal tube and form the inlet of a tube.

[0060] In an embodiment, said metal tube may be connected to a suction device through e.g. a metal tube or a flexible hose e.g. of polymeric material. Through such a tube or hose, suction may be applied to the outlet of the tube in such a manner that a piece of potato, fruit or vegetable that has been cut off by the tube-shaped knife can be sucked into the tube and / or the hose and be removed as it is e.g. rotten, damaged or in general inedible such as a rotten or damaged part of a potato or the stem of a strawberry.

[0061] In an embodiment, the connection means of the knife may comprise a motor or an actuator and is rotatable. Rotatability allows for an orientation of the knife towards the potato, fruit or vegetable.

[0062] In an embodiment, the motor may be a servo motor, a stepper motor, a piezo motor or a hypersonic motor. A servo motor is advantageous as the rotation angle of a servo motor can be adjusted very accurately. As depending on the potato, fruit or vegetable to be cleaved, the knife and the connection means may be exposed to strong mechanical stress, it is advantageous if the motor or actuator is able to withstand such mechanical stress for as long time as possible. On the other hand, to render processing using the knife according to the present application as fast as possible, the motor should be able to rotate as fast as possible. In an embodiment, it is possible to start and stop the motor 50 times in a minute.

[0063] Use of a knife of any shape such as the shape of a Latin cross or of a cross of Lorraine for cutting strawberries into pieces of equal size requires proper positioning of the knife with respect to the strawberry. For positioning the cleaving knife may be comprised in an apparatus for processing vegetables or fruits.

[0064] This problem is solved by an apparatus for cutting strawberries or other fruits or vegetables comprising a knife according to the previous application which apparatus furthermore comprises at least one computer, at least one device to take images such as a camera for visible or ultraviolet light, at least one device to provide strawberries, fruit or vegetables, such as a conveyor belt as well as at least one robot, such as a Delta robot to which the knife is mounted.

[0065] The fruits or vegetables to be processed with said apparatus may be strawberries but also potatoes, carrots, zucchini, apples, pears, leek, aubergines, squash or any other fruits or vegetables, namely the ones named earlier in the present application.

[0066] Apart from the knife, said apparatus may comprise a device for both positioning and moving the knife such as a robot with a robot arm, as well as a device for moving the fruits or vegetables through the workspace of the robot such as a conveyor belt as well as a device for detection of the size and the shape of the fruits or vegetables to be cleaved such as a camera which is connected to a computer which both evaluates the camera pictures and - according to the results of the picture evaluation - conducts the robot arm.

[0067] The robot arm which has the major purpose of positioning the knife with respect to the fruit or vegetable and to, if necessary, compensate for the movement of fruit or vegetable e.g. on a conveyor belt may furthermore comprise a means to rotate the knife to adapt the orientation of the knife to the orientation of the fruit or vegetable to be processed.

[0068] The robot arm used in said apparatus may be the arm of a delta robot. Delta robots are industrial robots wherein the base of the robot is located over the workspace of the robot comprising all actuators of the robot. From the base of the robot, three middle-jointed handles are extended with the ends of said handles being connected to a trigonal platform. In a delta robot, this platform carries the tools of the robot and therefore, this platform can be identified with the arm of the delta robot which is moved by the interplay of said three middle-jointed handles. The platform may carry connection means which are compatible with the connection means of the knife. If e.g. the knife comprises the female part of a bayonet mount, then the platform may comprise a male part of a bayonet mount or vice versa. If e.g. the knife comprises the female part of a screw mount, then the platform may comprise a male part of a screw mount or vice versa. If e.g. the knife comprises the female part of a friction fit, then the platform may comprise a male part of a friction fit or vice versa. Furthermore, the platform may also carry means to move the knife e.g. by rotation or vibration. For this purpose the platform may comprise a servo motor, a stepper motor or a piezoelectric motor as means for rotation or a vibrator or a piezo actuator as a means for inducing vibration. In this embodiment, the delta robot positions the knife at the right position overneath the fruit or vegetable to be cleaved and the motor of the rotatable mount then turns the knife into the right orientation. Rotation of the knife thus allows to adopt the knife to the orientation of the fruit and vegetable. Rotation of the knife thus allows for the fruits or vegetables to be provided in random orientation. Furthermore, the rotation allows for adjusting the knife in such a manner that it does not collide with a neighboring knife during the cleaving procedure if more than one knife is used. The combination of camera and computer will then identify the size and the shape of an object moving through the workspace of the robot and then automatically place the cleaving knife overneath the fruit or vegetable to be cleaved and exert the right amount of force to move the knife downwards to cleave the fruit or vegetable. In a continuous process, the fruits or vegetables are moving through the workspace of the robot and the robot arm will be able to compensate the continuous movement of the fruits or vegetables to make sure that the knife remains centered on the same point of the fruit or vegetable to be cleaved during the whole cleaving process. The application further pertains to a process for cleaving and optionally destemming strawberries or other fruits and vegetables. It is understood that also if only the term “strawberries” is used, all other fruits and vegetables named previously in the present application may be cleaved using a process according to the present application as well as further fruits and vegetables known to the person skilled in the art.

[0069] The process according to the present application has the purpose of producing pieces in a determined size range and comprises the steps of determining a size range of the pieces of the strawberry, fruit or vegetables that is to be processed, providing strawberries, fruits or vegetables, taking pictures of the strawberries, fruits or vegetables, determine the size and orientation of the strawberries, fruits or vegetables, positioning a knife according to the present application towards the strawberry, fruit or vegetable in such a manner that the cleaving knife cleaves the strawberry, fruit or vegetable into pieces within the determined size range, pushing the knife onto the strawberry, fruit or vegetable in such a manner that the strawberry, fruit or vegetable is cleaved into pieces in the determined size range whereby the positioning step and the pushing step may be carried out together characterized in that the positioning step involves a translatory and a rotatory movement of the knife.

[0070] It is understood that in the discussion of the method according to the present application, the terms “cleaving” and “cutting” include “destemming” where this is appropriate, namely in cases where fruits or vegetables are processed which need to be destemmed such as strawberries.

[0071] For the process according to the present application, the size range of the pieces of strawberries, fruits or vegetables to be produced may be determined according to different requirements. In some embodiments, boiling times may be important, e.g. in the production of strawberry jam. In some embodiments, it may be important to provide pieces which are conveniently edible for human without further chopping. In other cases, processability in further industrial processes such as milling, shredding, boiling, frying, steaming, fermentation or any combination thereof may be relevant. In an embodiment, the strawberries, fruits or vegetables may be provided for processing on a conveyor belt which conveyor belt may show enough mechanical robustness to stand the wear that is provided in the cleaving process. As the wear being provided to the conveyor belt depends on the hardness, brittleness and size of the fruits and vegetables to be processed, the choice of the material and the properties of the conveyor belt may be adapted to the fruit or vegetable to be processed.

[0072] Pictures of the strawberries, fruits or vegetables may be taken using at least one detection device for electromagnetic radiation such as a camera, analyzing the at least one picture using a computer in order to obtain data concerning the distribution of the strawberries, fruits or vegetables which are provided e.g. on a conveyor belt, the orientation of the strawberries or fruits or vegetables that are provided and the size of the strawberries or fruits or vegetables that are provided, positioning a knife according to the present application towards the strawberry, fruit or vegetable where the orientation of the knife is determined depending on the size, and the shape of the strawberry, fruit or vegetable as well as depending on its orientation on the conveyor belt, cleaving and optionally destemming the strawberry, fruit or vegetable by punching the knife towards the strawberry, fruit or vegetable.

[0073] The computer-based processes for the determination of the orientation of the knife may involve elements of artificial intelligence such as e.g. neural networks to make estimates about the size and dimensions of both the strawberry to be cleaved and the pieces to be obtained. As the size and dimensions of strawberries, fruits or vegetables may vary due to both the origin and the variety of strawberry, fruit or vegetable that is provided, artificial intelligence could be trained to processing different varieties of potatoes or fruit or vegetables.

[0074] The process according to the application allows for cleavage and optionally destemming of strawberries, fruits or vegetables of different sizes into pieces of more regular size than in the prior art. Thus, a step of sorting strawberries, fruits or vegetables by size can be avoided when the knife according to the application is a knife according to the present application. Furthermore, the process according to the present application leads to less movement of the strawberries, fruits or vegetables during processing as the number of contacts with the knife is reduced when e.g. destemming of a strawberry and cutting the destemmed strawberry into quarters are carried out in one step. This which reduces the risk of uncontrolled movements and change of orientation of the strawberries, fruit or vegetables e.g. on a conveyor belt. Uncontrolled movements can both provide damages to the strawberries, fruits or vegetables and severely change the orientation of other strawberries, fruits or vegetables due to collisions which would adversely affect the result of the cleaving process, especially when pieces of regular size are sought after. It is of course understood that according to the process, it is possible that strawberries, fruits or vegetables which by themselves already have a size that fit within the size range determine at the beginning of the process can pass through the process without being cleaved at all.

[0075] Description of the figures

[0076] Figure 1 shows one embodiment of the knife 1 according to this invention. The knife 1 comprises a first blade 2 and a second blade 3 both blades comprising cutting edges 4. On top of the blades, a connection means 5 is mounted. The blades comprise a grid structure 6 which contains bars 7. The first blade 2 and the second blade 3 cross in the crossing point 8.

[0077] Figure 2 shows another perspective of the knife already shown in Fig. 1 Figure 3 shows the shape of a Latin cross.

[0078] Figure 4 shows an example for a form derived from the Latin cross by extension of the shorter bar on one side of the crossing point.

[0079] Figure 5 shows the shape of a cross of Lorraine.

[0080] In general, the present application pertains to the following aspects:

[0081] 1. A knife comprising

[0082] - at least one first blade with at least one cutting edge, - at least one connection means, characterized in that

[0083] - the connection means is opposite to the at least one cutting edge and

[0084] - the connection means is reversibly connectable to a robot arm

[0085] 2. The knife of aspect 1 , wherein the connection means is mounted on the blade.

[0086] 3. The knife of aspect 2, wherein an imaginary line from the connection means to the cutting edge which imaginary line forms an angle of 90° with the cutting edge and which line divides the cutting edge into two parts of approximately the same length.

[0087] 4. The knife of any one of the previous aspects wherein the connection means is connectable by a bayonet mount, a screw mount or a friction fit.

[0088] 5. The knife of any one of the previous aspects, wherein the at least one first blade has a grid structure.

[0089] 6. The knife of aspect 5, wherein the grid structure comprises at least one bar which thickness, measured perpendicular to the direction of the cutting edge, exceeds the thickness of the blade by at least 3 millimeters.

[0090] 7. The knife of any one of the previous aspects comprising at least a second blade which second blade is crossed by the at least one first blade.

[0091] 8. The knife of aspect 7, wherein the at least one first blade and the second blade are of different lengths.

[0092] 9. The knife of aspect 8, wherein the at least one first blade is crossed by the second blade in the shape of a Latin cross or the cross of Lorraine.

[0093] 10. An apparatus for processing fruits or vegetables comprising a knife according to any one of the previous aspects.

[0094] 11 .The apparatus of aspect 10 comprising delta robot.

[0095] 12. A process for using an apparatus of aspect 10 or 11 , wherein the vegetable is a carrot.

[0096] 13. A process for using an apparatus of aspect 10 or 11 , wherein the vegetable is a potato.

[0097] 14. A process for cleaving potatoes comprising the steps of - determining a size range

[0098] - Providing potatoes on a conveyor belt

[0099] - Taking at least one picture of the potatoes using at least one detection device for electromagnetic radiation, - Analyzing the at least one picture using a computer in order to obtain data concerning the distribution of the potatoes on the conveyor belt, the orientation of the potatoes on the conveyor belt and the size of the potatoes on the conveyor belt,

[0100] - Positioning a cleaving knife according to the present application towards the potato in an orientation depending on the size, the orientation and the shape of the potato as well as depending on the determined size range,

[0101] - Cleaving the potato by punching the knife towards the potato.

Claims

Cleaving knifeClaims:

1. A knife comprising- one first blade with a first cutting edge, the cutting edge of the first blade being linear having a length- one second blade with a second cutting edge which second blade is circular,- one connection means reversibly connectable to a robot arm, wherein the cutting edges meet in at least one crossing point, characterized in that the crossing point is located in a position where its distance from the central point of the first cutting edge is at least 10% the length of the linear cutting edge and that the knife is rotatable against the robot arm2. The knife of claim 1 wherein the cross section of the knife does not comprise a rotational axis perpendicular to the plane of the cross section as symmetry element.

3. The knife of claim 1 or 2 wherein the circular cutting edge is part of a tubeshaped knife.

4. The knife of claim 3 wherein the tube-shaped knife is connected to a suction device.

5. The knife of claim 1 wherein the two cutting edges form the shape of a latin cross.

6. The knife of any one or more of claims 1 -4 wherein the knife comprises a third blade with a cutting edge whose cutting edge meets with the cutting edge of the first blade in a second crossing point.

7. The knife of claim 6 wherein the knife has the shape of a cross of Lorraine.

8. The knife of anyone or more of the previous claims wherein the connection means comprises a motor and is rotatable.

9. An apparatus for cleaving and / or cutting and optionally destemming strawberries, fruits or vegetables comprising a knife according to any one or more of the previous claims which apparatus furthermore comprises at least one computer, at least one device to take images, preferably a camera for visible or ultraviolet light, at least one device to provide strawberries, fruit or vegetables, preferably a conveyor belt as well as at least one robot, preferably a Delta robot to which the knife is mounted.

10. The apparatus according to claim 9 wherein the knife is a knife according to claim 4 and wherein the apparatus comprises a suction device connected to the knife.11 . A process for cleaving and / or cutting and optionally destemming a strawberry, fruit or vegetable comprising the steps of a. Determining a size range of the pieces of the strawberry, fruit or vegetables that is to be processed, b. Providing strawberries, fruits or vegetables, c. Taking at least one picture of the strawberries, fruits or vegetables, d. Determine the size and orientation of the strawberries, fruits or vegetables, e. Positioning a knife according to any one or more of claims 1 -8 towards the strawberry, fruit or vegetable in such a manner that the cleaving knife cleaves the potato, fruit or vegetable into pieces within the determined size range, f. Pushing the knife onto the strawberry, fruit or vegetable in such a manner that the strawberry, fruit or vegetable is cleaved into pieces in the determined size range whereby the positioning step and the pushing step may be carried out together characterized in that the positioning step involves a translatory and a rotatory movement of the knife.

12. The process of claim 11 wherein the positioning step and the pushing step are carried out by a robot, preferably a Delta robot.

13. The process of claims 11 or 12 wherein in the process, unwanted parts such as rotten parts, damaged parts or inedible parts such as the stem are removed from the strawberry, fruit or vegetable and wherein the wanted part of the of the potato fruit or vegetable is cleaved into at least two further parts in the same step.

14. The process according to claim 14 wherein the unwanted part is removed by suction, preferably through a tube-shaped knife.

Images