Patent Application
20140083266
The present invention relates to an apparatus for cutting products, such as for example food products or ingredients for pharmaceuticals or the like, comprising an impeller which can rotate concentrically within a cutting head to impart centrifugal force to the products to be cut.
The present invention further relates to a method for cutting a product in which the product is fed to a cutting head in which an impeller rotates concentrically to impart centrifugal force to the product.
An apparatus for cutting food products of the type comprising an impeller rotating inside a cutting head is known for example from U.S. Pat. No. 6,968,765. The cutting head is a stationary drum which is fitted with multiple cutting stations. Products cut with this technology include potato chips, cheese shreds, vegetable slicing, nut slicing and countless others. Centrifugal force is required to apply pressure to the product for stability when it passes the blades in the cutting stations. The centrifugal force is specific to the product, but it is known that too high centrifugal force can produce excess friction and compression on the product and that too low centrifugal force can cause poor knife engagement resulting in damage of the product. The desired cutting velocity is also specific for a given product.
In this type of apparatus, the cutting velocity is directly related to centrifugal force as both depend directly on the rotational speed of the impeller. However, the optimal impeller rotational speed from a viewpoint of centrifugal force is often different from the optimal impeller rotational speed from a viewpoint of cutting velocity. In those cases, upon selecting the impeller rotational speed a trade-off has to be made between more optimal centrifugal force and more optimal cutting velocity.
U.S. Pat. No. 4,604,925 discloses an apparatus of this type in which the cutting head is cutting head is not stationary as in U.S. Pat. No. 6,968,765 but can be rotated in the same direction as the impeller at a slower speed.
It is an aim of the present invention to provide an apparatus for cutting products of the type comprising an impeller rotating inside a cutting head, with which the cutting operation can be improved for at least some products.
This aim is achieved according to the invention with an apparatus showing the technical characteristics of the first independent claim.
It is another aim of the present invention to provide a method for cutting products by means of a cutting head in which an impeller rotates, with which the cutting operation can be improved for at least some products.
This aim is achieved according to the invention with a method comprising the steps of the second independent claim.
As used herein, “rotational speed” is intended to mean the speed at which an object rotates around a given axis, i.e. how many rotations the object completes per time unit. A synonym of rotational speed is speed of revolution. Rotational speed is commonly expressed in RPM (revolutions per minute).
As used herein, “cutting velocity” is intended to mean the speed at which a cutting element cuts through a product or alternatively states the speed at which a product passes a cutting element. Cutting velocity is commonly expressed in m/sec.
As used herein, a “cutting element” is intended to mean any element which is configured for cutting a particle or a piece from an object or otherwise reducing the size of the object, such as for example a knife, a blade, a grating surface, a cutting edge, a milling element, a comminuting element, a cutting element having multiple blades, etc., the foregoing being non-limiting examples.
According to the invention, the impeller is rotated by means of an impeller drive mechanism at an impeller rotational speed, which sets the centrifugal force imparted to the product. The cutting head is not stationary as in the prior art document U.S. Pat. No. 6,968,765 but can be rotated by means of a cutting head drive mechanism at a cutting head rotational speed. The cutting head rotational speed is determined such with respect to the impeller rotational speed that the product is cut by the at least one cutting element at a predetermined cutting velocity. By determining the cutting head rotational speed in relation to the impeller rotational speed, the cutting velocity is set.
According to the invention, the centrifugal force and the cutting velocity can be made independent from each other. The centrifugal force is proportional to the impeller rotational speed. The cutting velocity is dependent on the impeller rotational speed as well as the cutting head rotational speed. As a result, by establishing these rotational speeds, both the centrifugal force and the cutting velocity can be optimized for the product which is to be cut and the need for making a trade-off like in the prior art can be avoided.
According to the invention, the apparatus is configured for rotating the cutting head and the impeller in the same rotational direction, which is the rotational direction towards which the cutting element(s) of the cutting head are oriented to impart cutting action, with the cutting head rotating at a greater rotational speed than the impeller. The cutting velocity is thus proportional to the cutting head rotational speed minus the impeller rotational speed. It has been found that for at least some products, the cutting operation can be improved by rotating the cutting head and the impeller in the same rotational direction with the cutting head rotating at a greater rotational speed than the impeller, resulting in e.g. less scrap, smoother cuts, less damage to the product, reduced starch loss (for potatoes), improved shred quality and/or more consistent shreds (e.g. for cheese) etc. It has further been found that, surprisingly, wear on the cutting elements may affect the quality of the cut to a lesser extent, i.e. relatively dull cutting elements may still yield a cutting operation of sufficient quality, so that with the solution according to the invention, the life of the cutting elements can be extended.
Another advantage of the invention is that the cutting velocity and the centrifugal force can be set to any desired value. The impeller rotational speed determines the centrifugal force at which the product is cut. The impeller rotational speed can be set to any desired value. The cutting velocity is proportional to the cutting head rotational speed minus the impeller rotational speed. As a result, the only requirement to achieve cutting operation is that the cutting head is rotated at a greater speed than the impeller; there is no upper limit for the cutting head rotational speed. This means that the cutting velocity can be set anywhere from 0 to infinity, which is important since lower cutting velocities may be desirable for products which require a more gentle cutting operation and higher cutting velocities may be desirable if a high throughput is required. In this aspect, it further is important to note that, since the cutting head is rotated in the direction of the cutting action of the cutting elements, the air resistance that the cut product experiences when exiting the cutting head at one of the cutting elements presses the cut product onto the outside of the cutting head, rather than pulling the product away from the outside. This means that the cut product exits the cutting head in substantially straight pieces and tearing or “feathering” of the cut product as a result of tensile stress can be avoided.
In preferred embodiments, the impeller drive mechanism and the cutting head drive mechanism are provided with controls for adjusting the the impeller rotational speed and the cutting head rotational speed within respectively a first range and a second range. In this way, the cutting velocity and the centrifugal force can be established for a wide range of products. The controls can comprise a user interface, by means of which the user can set the impeller rotational speed and the cutting head rotational speed. The controls can also be adjusted by means of another device, such as for example a PLC which takes a feedback input from sensors which sense for example temperature, product density, or other parameters, and on the basis thereof adjusts the rotational speeds. Another example is the use of the apparatus for cutting potato chips in combination with a fryer for frying the potato chips. In this case the controls can be adjusted on the basis of fryer requirements. One such requirement is for example a supply of potato chips to the fryer which is as uniform as possible, which means that the cutting apparatus has to be speeded up or slowed down to a given extent at times. Up to now, this speeding up or slowing down could lead to a significant amount of miscuts and product damage. With the apparatus of the invention, this can be minimised, as the centrifugal force and the cutting velocity can be optimised.
In preferred embodiments, the impeller drive mechanism comprises an impeller drive shaft by which the impeller is driven and the cutting head drive mechanism comprises a cutting head drive shaft by which the cutting head is driven, the cutting head drive shaft being hollow and the impeller drive shaft being rotatably mounted within the cutting head drive shaft. This has the advantage that the impeller and the cutting head are driven from the same side, e.g. the bottom side, leaving the top side unobstructed for feeding the product into the cutting head.
In preferred embodiments, the drive mechanisms of the impeller and the cutting head can have separate motors, so that the rotation of the impeller is entirely independent from the rotation of the cutting head. This has the advantage that the cutting velocity is totally independent of the centrifugal force.
In preferred embodiments wherein the apparatus has separate motors, the impeller is directly driven by the impeller motor of the impeller drive mechanism and the cutting head is directly driven by the cutting head motor of the cutting head drive mechanism. This has the advantages that any intermediate drive components can be avoided and the construction can be simplified. Preferably, in such embodiments, the base comprises a post with an impeller arm carrying the impeller motor with the impeller and a cutting head arm carrying the cutting head motor with the cutting head, the cutting head arm being movably mounted to the post in such a way that the cutting head can be removed from around the impeller. Preferably, in such embodiments, the rotation of the impeller inside the cutting head is stabilised by means of a spring-loaded pin on the impeller which fits into a tapered hole in the centre of the cutting head, or vice versa.
In other embodiments, the wherein the impeller drive mechanism and the cutting head drive mechanism can have a shared motor, which drives the rotation of both the impeller and the cutting head, and a gearbox, by means of which the difference between the impeller rotational speed and the cutting head rotational speed can be set. The gearbox can have multiple gears, so that different ratios between the rotational speeds can be set.
In preferred embodiments, the cutting head and the impeller can be oriented to rotate around a vertical axis or a horizontal axis. However, other angles with respect to horizontal are also possible.
In preferred embodiments, the cutting head and the impeller are mounted on a tiltable part of the base, by means of which the rotation axis of the cutting head and the impeller can be tilted to different angles. In this way, the orientation of the rotation axis can be adapted.
In preferred embodiments, at least one of the impeller drive mechanism and the cutting head drive mechanism is further adapted for driving the impeller, resp. the cutting head, to make it rotate in a second rotational direction opposite said first rotational direction.
The invention will be further elucidated by means of the following description and the appended figures.
The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not necessarily correspond to actual reductions to practice of the invention.
Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. The terms are interchangeable under appropriate circumstances and the embodiments of the invention can operate in other sequences than described or illustrated herein.
Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. The terms so used are interchangeable under appropriate circumstances and the embodiments of the invention described herein can operate in other orientations than described or illustrated herein.
Furthermore, the various embodiments, although referred to as “preferred” are to be construed as exemplary manners in which the invention may be implemented rather than as limiting the scope of the invention.
The term “comprising”, used in the claims, should not be interpreted as being restricted to the elements or steps listed thereafter; it does not exclude other elements or steps. It needs to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising A and B” should not be limited to devices consisting only of components A and B, rather with respect to the present invention, the only enumerated components of the device are A and B, and further the claim should be interpreted as including equivalents of those components.
The cutting apparatus shown in
The base 100 comprises an arm 101, which is rotatably mounted on a post 102, so that the cutting head 200 and impeller 300 can be rotated away from the cutting position for cleaning, maintenance, replacement etc.
The cutting head 200 is fitted with cutting elements 208, for example blades which make straight cuts in the product, for example to make potato chips. As an alternative, corrugated cutting elements could be fitted in order to make for example crinkle cut potato chips or shreds.
In further alternatives, cutting stations can be used with cutting edges for milling or comminuting products (e.g. salt, spices) or viscous liquids (e.g. butters, spreads). With these cutting stations, the apparatus can also be used for manufacturing pharmaceutical products like for example ointments.
In further alternatives, cutting stations can be used with grating surfaces for making grated cheese, or with any other cutting elements known to the person skilled in the art. The cutting apparatus of
The cutting apparatus shown in
The cutting apparatus shown in
The cutting head 600 is in this embodiment an assembly of a top ring 606, cutting stations 607 and a spider support 609 at the bottom. The cutting stations 607 are held between the top ring 606 and the spider support 609 like in the above described embodiment. The spider support 609 is used instead of a full bottom plate in order to save weight. The spider support can be connected to the shaft of the motor 603 by means of notches which are engaged by pins on the shaft. This can be a quick release engagement which can be fixed/loosened by for example turning the spider support 609 over +5°/−5° with respect to the motor shaft. Of course, the spider support 609 could also be bolted to the motor shaft, or releasably fixed by any other means known to the person skilled in the art.
In this embodiment, the base 110 comprises a vertical post 111 with a fixed top arm 112 on which the impeller motor 503 is mounted with the shaft pointing downwards. The cutting head motor 603 is mounted on the post 111 with the shaft pointing upwards by means of a vertically movable and horizontally rotatable arm 113. In this way, the cutting head 600 can be removed from the impeller 500 for maintenance, replacement, etc. by subsequently moving the arm 113 downwards (
The cutting apparatus shown in
The cutting apparatus shown in
The cutting apparatus shown in
Below, the operation of the cutting apparatus of the invention will be discussed in general by reference to
In the situation of
In the situation of
In the situation of
By way of example, some preferred settings for cutting potatoes are given. Table 1 below shows the relationship between the impeller rotational speed for a 178 mm radius and the centrifugal force experienced by potatoes of different weights. At 260 RPM, the centrifugal acceleration (g-force) is 131.95 m/s2 (≅13 g) which corresponds to the centrifugal forces in the second column for the weights given in the first column; at 230 RPM, the centrifugal acceleration (g-force) is 103.26 m/s2 (≅10 g) which corresponds to the centrifugal forces in the third column for the weights given in the first column.
It has been found that the impeller rotational speed is preferably controlled such that the g-force experienced by product being cut is in the range of 1 to 50 g's (1 g=9.8 m/s2), although even higher g-forces may be used, for example in comminuting.
For cutting potatoes, a range of 3 to 30 g's appears to yield the best results.
For cutting potatoes, the cutting velocity is preferably in the range of 0.3 to 4.8 m/s, more preferably in the lower half of this range.
For cutting or shredding cheese products, also a range of 3 to 30 g's appears to yield the best results.
For cutting or shredding cheese products, the cutting velocity is preferably in the range of 0.3 to 5.5 m/s.
Importantly, with the apparatus and method of the invention, the centrifugal force can be reduced with respect to the prior art with a stationary cutting head. In such prior art apparatuses, when cutting cheese products the impeller is rotated at a relatively high speed (e.g. 400 RPM) in order to obtain the desired cutting velocity, but at such speeds the cheese products may be undesirably compressed against the interior of the cutting head. So in order to obtain a good quality of cutting, the cheese product needed to be cooled to a temperature of −4° C. to harden the product and avoid compression. With the apparatus of the invention, the centrifugal force can be reduced and the cutting velocity set independently therefrom, so that the cutting operation can occur at higher temperatures, i.e. temperatures of −3° C. or above, e.g. at 10° C., reducing the extent of cooling needed prior to cutting.
Examples of other products which can be cut in a more advantageous way with the apparatus and method of the invention are nut products, e.g. almonds, peanuts (e.g. to manufacture peanut butter) or other nuts; root products, e.g. ginger, garlic, or other; and also other products such as e.g. orange peel.
In further embodiments (not shown), the impeller drive shaft could also be made hollow, for example for accommodating a large bolt with which the impeller is fixed to the impeller drive shaft, or for connecting a liquid supply and supplying a liquid (e.g. water) to the cutting head from the bottom side through the impeller drive shaft, or both, in which case the bolt would also be hollow.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011/0295 | May 2011 | BE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2012/056404 | 4/10/2012 | WO | 00 | 11/12/2013 |
| Number | Date | Country | |
|---|---|---|---|
| 61473826 | Apr 2011 | US |
