GB2295532A

GB2295532A - A knife peeling machine for vegetable products.

Info

Publication number: GB2295532A
Application number: GB9523622A
Authority: GB
Inventors: Bo Jonsson
Original assignee: Limas AB
Current assignee: Limas AB
Priority date: 1994-11-29
Filing date: 1995-11-17
Publication date: 1996-06-05
Anticipated expiration: 2015-11-17
Also published as: SE9404147D0; SE507397C2; GB9523622D0; DE19543802A1; SE9404147L; NL1001782C2; GB2295532B; DE19543802B4

Description

1 A knife ipeeling machine for veqetable products 2295532 The present

invention relates to a knife peeling machine for vegetable products, especially potatoes.

Machine peeling of vegetable products, for example potatoes, can be provided by means of a peeling machine comprising a container in which the vegetable products are placed and in which peeling means are positioned for removing the peel of the vegetable products at relative movement and engagement between the vegetable products and the peeling means, the peeling means being constituted typically by knives or by a cutting coating or surface consisting of for example carborundum grits.

Peeling machines in which the peeling means consist of a cutting coating or surface of for example carborundum grits are of a simple construction and work relatively quickly. A drawback of peeling machines of this kind is that the cutting coating or surface provides scratches in the pulp of the vegetable products causing the cells of the pulp to release melanin which in turn causes the vegetable products to be discoloured at a relatively short time after the peeling. Peeling machines working by means of knives provide the vegetable products with a smoother surface causing less damage to the cells of the vegetable products and thereby less tendency to discolouring of the vegetable products. Knife peeled vegetable products can be stored without discolouring for a much longer time than vegetable products which have been peeled by means of for example a carborundum coating.

A drawback of prior art knife peeling machines is that they either work at a low speed with low efficiency or are of a complicated and expensive construction which is unfavourable from the investment as well as the maintenance point of view.

The object is to provide a knife peeling machine for vegetable products which is of simple and reliable 2 construction and in spite thereof is able to peel the vegetable products at a high speed.

According to the present invention, a knife peeling machine for vegetable products comprises a container for receiving the vegetable products, knives positioned in the container for peeling the vegetable products during relative movement between the knives and the vegetable products, and agitators arranged in the container for promoting the relative movement between the vegetable products and the knives, with the knives and the agitators being rotatably journalled and being adapted to be rotated to give a relative movement between the knives and the agitators.

A knife peeling machine constructed in accordance with is the invention can be of simple construction and provides in spite thereof an extremely rapid and well accomplished peeling of the vegetable products - for example, the peeling operation may avoid the peel being broken from the vegetable products and may thus avoid the vegetable products having uneven surfaces.

It is, of course, also possible to let the knife peeling machine according to the invention work in cooperation with a peeling machine of the kind having a cutting coating or surface consisting of carborundum grits, the vegetable products being first peeled by means of the peeling machine having the cutting coating or surface consisting of carborundum grits whereupon the final peeling is conducted in a knife peeling machine according to the invention in order to provide a final product lacking such scratches and damaged cells which cause discolouring of the vegetable products.

It is preferred that the knives and the agitators of the knife peeling machine according to the invention are adapted to be rotated in opposite directions but it is also possible to design the knife peeling machine so that the knives and the agitators rotate in the same direction but at different speeds.

3 It is preferred that the bottom of the container of the knife peeling machine according to the invention is constituted by a rotatable disk on which the knives are radially directed and that the agitators are constituted by arms which are also radially directed and are supported above the knives by means of a rotatable, vertical shaft. The agitators can be supported by means of a tubular shaft in which the shaft for supporting the disk constituting the bottom of the container is rotatably journalled. The disk constituting the bottom of the container can be formed with radially extending slots, the knives being releasably fastened to edge portions of the slots with the knife edges positioned in the central portions of the slots. In this construction the peel removed from the vegetable products is by means of the knives will leave the container through the slots in the disk.

The arms constituting the agitators of the knife peeling machine can be designed in different ways. For example an arm can have an upper surface which is inclined in relation to the bottom of the container at an angle amounting to for example 1350. It is also possible to design the leading edge of an arm, which is positioned at the front in the direction of movement thereof, in different ways so as to provide the desired movement pattern of the vegetable products in the container during the peeling operation.

The container of the knife peeling machine can be designed so that the shape of the container contributes to such a movement pattern of the vegetable products which are peeled that the peeling action is improved. In accordance therewith the container can have a peripheral wall having an inner surface of angular shape in horizontal section, the inner surface being for example generally octagonal.

The invention shall now be described in more detail with reference to the accompanying drawings in which:- Fig. I is an axial section of an embodiment of a knife peeling machine according to the invention; 4 Fig. 2 is a plan view of the knif e peeling machine shown in Fig. 1; Fig. 3 is a section of a detail of a modified embodiment of the knife peeling machine according to the invention; and Fig. 4 is a plan view of a container included in another modified embodiment of the knife peeling machine according to the invention.

The knife peeling machine shown in Figs. 1 and 2 is intended for the peeling of potatoes and is of the type for batchwise peeling, i.e. the peeling machine is supplied with a certain amount of unpeeled or pre-peeled product, whereupon the peeling operation is conducted and the peeled product is then removed from the peeling machine, whereupon a new batch of unpeeled or pre-peeled product is supplied and so on.

The knife peeling machine comprises a support 2 which is only partly shown and supports a container 4 consisting of a peripheral side wall 6 and a bottom 8 designed as a disk. The side wall 6 has a cylindrical portion 10 which by means of a flange 12 is connected with the support 2 and a lower, conical portion 14. The disk 8 constituting the bottom of the container 4 is supported by a shaft 16, the upper portion 18 of the shaft 16 being rotatably journalled in a tubular shaft 20 by means of bearings 22. At its lower end the shaft 16 has a pulley 24 which by means of a belt 26 is connected with a driving motor, not shown.

The disk 8 has at its periphery four radially directed slots 28. Four knives 30 are releasably fastened at edge portions of the slots 28 in such a way that sharp edges 32 of the knives are positioned in the central portions of the slots 28. The knife edges 32 are positioned a short distance above the upper surface of the disk 8 and constitute the peeling means of the knife peeling machine.

At its lower portion, the tubular shaft 20 has outwardly directed fastening lugs 34 which are equally distributed around the periphery of the tubular shaft 20 with each supporting one radially outwardly directed arm 36. The arms 36 are positioned close above the upper surface of the disk 8 and at their end portions 38 are inclined so as to complement the lower conical portion 14 of the side wall 6. The tubular shaft 20 at its upper end is connected with a driving shaft 40 which in turn is connected possibly via appropriate gearing with either the same or a different driving motor, not shown.

During the peeling operation the knife disk 8 and the agitators constituted by the arms 36 are driven in such a way that there is provided a relative movement between the knives 30 and the arms 36. The knife disk 8 is of course rotated in such a direction that the knife edges 32 move forwards which means that the knife disk 8 is rotated counter-clockwise while the arms 36 are preferably rotated in the opposite direction, i.e. in clockwise direction. Suitable numbers of revolutions are for the knife disk 200 rpm and for the arms 100 rpm. It is possible also to rotate the arms 36 in the same direction as the knife disk 8 but at a different rotational speed.

A knife peeling machine of the embodiment shown in Figs. 1 and 2, wherein the diameter of the peeling machine amounts to about 500 mm, can be suitable to peel potatoes in batches of 10 kg. Such an amount of potatoes is peeled in the knife peeling machine in a time of about two minutes. The potatoes can be peeled directly from a washed condition but can alternatively be subjected to a subsequent peeling in the peeling machine starting from potatoes which have been pre-peeled in a peeling machine working with a grinding coating of for example carborundum grits. The peeling machine in which the potatoes are prepeeled can for example be constituted by a step peeling machine of the kind shown and described in US Patent 5,351,610.

The invention can be modified in various ways.

In Fig. 3 there is shown a section of a detail of a modified embodiment of the knife peeling machine according 6 to the invention. The knife disk 8 including the knife 30 shown in Fig. 3 is of the same design as in the embodiment according to Figs. 1 and 2 but the agitators are of different shape. Thus, the agitators are constituted by arms, one arm 42 being shown in section in Fig. 3. As is appears from Fig. 3 the arm 42 is inclined in such a way that the upper surface 44 of the arm forms an angle of about 1350 with the plane of the knife disk 8. Because of this design of the arms 42 there is provided an improved movement of the potatoes peeled in the peeling machine leading to an improved peeling efficiency.

Moreover, the design of the agitators formed by the arms can be arched so that the front edges of the arms in the direction of movement are of concave shape and the outer end portions of the arms form an angle with the tangent of the side wall of the container exceeding 900.

As appears from Fig. 4, it is possible to design the inner surface of the side wall 6 of the container in such a way that the desired movements of the potatoes are improved. Thus, such improved movements can be provided by giving the inner surface of the container an angular shape in horizontal section. The round container according to Figs. 1 and 2 is according to Fig. 4 provided with f our flat wall portions 46 which are arrange as chords in the container 4 to give a generally octagonal shape.

7

Claims

1. A knife peeling machine for vegetable products, comprising a container for receiving the vegetable products, knives positioned in the container for peeling the vegetable products during relative movement between the knives and the vegetable products, and agitators arranged in the container for promoting the relative movement between the vegetable products and the knives, with the knives and the agitators being rotatably journalled and being adapted to be rotated to give a relative movement between the knives and the agitators.

2. A knife peeling machine according to claim 1, in which the knives and the agitators are adapted to be rotated in opposite rotational directions.

3. A knife peeling machine according to claim 1 or claim 2, in which the knives and the agitators are rotatably journalled at the bottom of the container.

4. A knife peeling machine according to any preceding claim,in which the bottom of the container is constituted by a rotatable disk on which the knives are radially arranged.

5. A knife peeling machine according to claim 4, in which the disk constituting the bottom of the container is formed with radially extending slots having edge portions to which the knives are releasably fastened such that the knife edges are positioned in the central portions of the slots.

6. A knife peeling machine according to claim 4 or claim 5, in which the agitators are supported by a tubular shaft in which a shaft for supporting the disk constituting the bottom of the container is rotatably journalled.

7. A knife peeling machine according to any preceding claim, in which the agitators are constituted by arms which extend radially and are supported above the knives by means of a rotatable, vertical support.

8. A knife peeling machine according to claim 7, in which the upper surfaces of the arms are inclined.

is 8

9. A knife peeling machine according to claim 8, in which the upper surfaces of the arms form angles of about 1350 with the bottom of the container.

10. A knife peeling machine according to any one of claims 7 to 9, in which the f ront edges of the arms in the direction of movement are of concave shape.

11. A knif e peeling machine according to any preceding claim, in which the container has a peripheral wall having an inner surface of angular shape in horizontal section.

12. A knife peeling machine according to claim 11, in which the inner surface of the peripheral wall is generally octagonal.

13. A knife peeling machine according to any preceding claim, in which the knives and the agitators are driven by the same or different driving motors.

14. A knife peeling machine substantially as hereinbefore described with reference to Figures 1 and 2, or Figures 1 and 2 as modified by either Figure 3 or Figure 4.