GB2231775A

GB2231775A - Electric domestic appliance for chopping solid-flesh fruit and vegetables

Info

Publication number: GB2231775A
Application number: GB9009243A
Authority: GB
Inventors: Leo Bertram; Hugo Schemmann; Romuald Leander Bukoschek
Original assignee: Philips Gloeilampenfabrieken NV
Current assignee: Koninklijke Philips NV
Priority date: 1989-04-29
Filing date: 1990-04-25
Publication date: 1990-11-28
Anticipated expiration: 2010-04-25
Also published as: GB2231775B; IT9021080V0; IT9021080U1; GB9009243D0; FR2646361B3; ES1013672U; FR2646361A3; DE3914370A1; IT220204Z2; ES1013672Y

Description

PHD 89.064 1 05.04.1990 Small electric domestic appliance for chopping

solid-flesh fruit and vegetables, more specifically onions.

The invention relates to a small electric domestic appliance for chopping solid-flesh fruit and vegetables, more specifically onions, comprising a counterblade locked against rotation in a jug-shaped container and rotating blades fixedly arranged on a shaft driven by an electric driving motor.

A device of this type is known from German Patent No. DE-PS 12 19 641. It discloses a container in which blades rotate which are driven by an electromotor. The material to be chopped is fed to the container and chopped by the blades rotating at high speed. A counterblade is arranged on the blade shaft and its end is positioned in a vertical groove of the container wall.

In the prior-art devices high-speed universal motors are used having noload speeds of approx. 10,000-20,000 r.p.m. and power consumptions of approx. 100 W. Accordingly, they are bulky and expensive. Recently, also high-speed brush motors with permanent-magnet excitation have been used. The no-load speed of these motors is approx. 10,000 r.p.m.

The prior-art devices have in common that the blade is directly coupled to the shaft of the motor so that the blade has the same high speed as the driving motor. This results in the fact that, for example, when chopping onions in a small container, a pulpy mash arises which soon loses its taste and becomes unsavoury. If a larger container is used, the chopping result will be better. Small pieces of onion will be obtained as desired, but they are slung against the container wall by the blade and are hard to collect for further processing.

When chopping fruit and vegetables one should take care that the material is not moved along ahead of the blade or stuck between the container wall and the blade. This requires adequate blade speed. If the foodstuff is desired to be chopped into small pieces and not mashed, however, the blade speed should not be too high.

For practical reasons the container should be large enough for fruit and vegetables such as apples and onions of normal PHD 89.064 2 05.04.1990 size to be fed uncut. This leads to a container diameter of approx. 10 cm.

It is an object of the invention to provide a small handy domestic appliance of the type mentioned in the opening paragraph, with which fruit and vegetables such as apples and onions can be chopped into small pieces and with which the motor output is reducible.

According to the invention the object is achieved in that the shaft rotates at a speed of 200 - 500 r.p.m.

The arrangement of an additional counterblade provides that a fruit to be chopped can no longer be moved along ahead of the rotating blade; the fruit will be pressed against the stationary blade by the rotating blades. However, it will specifically be possible to reduce the speed of the blades. Since the counterblade stops the fruit, the speed can be reduced to 200 - 500 r.p.m. So far one has not recognised the possibility of reducing the operating speed by means of a counterblade to obtain well-cut pieces.

According to a further embodiment of the invention the counterblade is pivoted to the shaft and on the inner wall of the container a stop is provided for the counterblade, which stop restricts the free rotation of the counterblade to a maximum of 3600. The counterblade can thus be taken along for as much as one full turn and will then remain stationary.

According to a further embodiment of the invention the counterblade is arranged on the inner wall of the container. This variant of the embodiment has the same effect as a counterblade which is pivoted to the shaft and stops against a stop on the inner wall of the container. The pivoting to the shaft may be omitted.

According to a further embodiment of the invention, in an arrangement comprising blades positioned in a mutually displaced manner along the axis of the shaft and driven by this shaft, the counterblade is located between the blades driven by the shaft. Thus, a two-sided cutting of the fruit is realised as a result of which the cutting effect is improved. The stationary counterblade first stops the fruit and the rotating blades cut the fruit above and below the stationary blade.

According to a further embodiment of the invention the counterblade is an unsharpened blade. Such an unsharpened blade retains the fruit better than a counterblade arranged as a cutting blade.

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PHD 89.064 3 05.04.1990 According to a further embodiment of the invention the driving motor drives the shaft at a speed of 200 - 500 r.p.m. by means of an inserted drive unit. If the driving motor does not drive the shaft directly, the motor may rotate at a higher speed and it is possible to work with a motor having less driving power.

According to a further embodiment of the invention the driving motor is a bipolar single-phase synchronous motor having a permanent-magnet rotor. Such a single-phase synchronous motor having a permanent-magnet rotor provides sufficient power at very small dimensions. Since this motor has no preset direction of rotation, either a symmetrical arrangement with double-sided sharpened blades or the use of a return stop is necessary.

A specific embodiment of a compact and attractive form may be realised if, according to a further embodiment of the invention, the driving motor is constructed as a bipolar single-phase synchronous motor that has an output power of approx. 10 W if two blades are used that rotate together with the shaft and one counterblade in a container having an inside diameter of approx. 10 cm. The rotational speed of the shaft is then preferably adjusted to approx. 500 r.p.m. 20 The invention will be further explained with reference to the drawing, in which: Fig. 1 shows an embodiment of a small onion chopper having a stationary additional counterblade; Fig. 2 shows a variant of the arrangement of the counterblade.

In the embodiment as shown in Fig. 1 a small onion chopper is driven by a bipolar single-phase synchronous motor 1 arranged in a motor housing 3 which is fit into a cover of the chopper. The cover of the chopper can be put onto a container 7.

The single-phase synchronous motor having a bipolar permanent-magnet rotor drives a shaft 10 by means of a drive unit 9 that has a step-down ratio of 1:12, to which shaft two blades 11 are centrally fixed. The blades 11 have a mutual distance along the axis of the shaft. A counterblade 13 is pivoted to the shaft 10 between the clamps 12 of the blades 11. The pivoting is shown as a plane bearing 13a for simplicity. on the inner wall 14 of the container 7 a stop 15 is provided against which the counterblade may be retained. The stop 15 PHD 89.064 4 05.04.1990 or retains the counterblade after no more than one rotation of approx. 3600.

Between the shaft 10 and a gearwheel 16 of the drive unit 9 driving this shaft a freewheel clutch 17 known per se is provided enabling the motor 1 to start running before the shaft 10 is engaged. A return stop 18 allowing the driving motor 1 to start rotating in only one direction acts on the gearwheel 16. If the two blades 11 are sharpened on both sides, the return stop may be omitted.

In the embodiment of the invention as shown in Fig. 2 the counterblade 13 is fixedly attached to the inner wall 14 of the container by means of a stop 19. The counterblade is thus rigidly arranged in the container.

The domestic appliance has an utterly favourable design when constructed as follows: the driving motor is an a.c. powered single- phase synchronous motor having a bipolar permanent-magnet rotor operating at 3,000 r.p.m. The container has an inside diameter of approx. 10 cm. The motor output is designed to be approx. 10 W. The speed of the shaft is adjusted to approx. 250 r.p.m.

Such an electric domestic appliance used as an onion chopper is very small and handy. The onions fed to the container are chopped into small pieces which can easily be removed from the container.

PHD 89.064.. 5 20.04.1990

Claims

CLAIM(S)

1. Small electric domestic appliance for chopping solid-flesh fruit and vegetables, more specifically onions, comprising a counterblade locked against rotation in a jug-shaped container and rotating blades fixedly arranged on a shaft driven by an electric driving motor, characterised in that the shaft rotates at a speed of 200-500 r.p.m.

2. Domestic appliance as claimed in Claim 1, characterised in that the counterblade is pivoted to the shaft and on the inner wall of the container a stop is provided for the counterblade, which stop restricts the free rotation of the counterblade to 3600.

3. Domestic appliance as claimed in Claim 1 or 2, characterised in that the counterblade is arranged on the inner wall of the container.

4. Domestic appliance as claimed in Claim 1,2 or 3, characterised in that in an arrangement comprising blades positioned in a mutually displaced manner along the axis of the shaft and driven by this shaft, the counterblade is located between the blades driven by the shaft.

5. Domestic appliance as claimed in Claim 1,2,3 or 4, characterised in that the counterblade is an unsharpened blade.

6. Domestic appliance as claimed in any one of the preceding claims, characterised in that the driving motor drives the shaft at a speed of 200-500 r.p.m. by means of an inserted drive unit.

7. Domestic appliance as claimed in Claim 6, characterised in that the driving motor is a single-phase synchronous motor having a bipolar permanent-magnet rotor.

8. Domestic appliance as claimed in Claim 6 or 7, characterised in that the driving motor has an output power of approximately 1OW if two blades are used that rotate together with the shaft and one counterblade in a container having an inside diameter of approximately 10cm.

PHD 89.064 6 20.04.1990

9. Domestic appliance as claimed in any one of the preceding claims, characterised in that the rotational speed of the shaft is adjusted to approximately 250 r.p.m.

10. Small electric domestic appliance for chopping solid-flesh fruit and vegetables, more specifically onions, substantially as hereinbefore described with reference to andlor as illustrated in the accompanying drawings.

R Published 1990 a. The 71 High Rolborr,.LrndonWC1R4TP-F-,irther copies rnay be obtained frornThe Patent Office- Sales Branch. St Mary Cray. Orpington, Kent BR5 3RD- Printed by Multiplex techmques ltd, St Mary Cray. Kent, Con- 1W