Manually drivable apparatus for comminuting foods

[0001] The invention relates to a manually drivable apparatus for comminuting foods, in particular vegetables.

[0002] In an Applicant's apparatus of the generic type which is marketed as ‘der Häxler’, the drive part is in the form of a crank mounted centrally in the cover. The shaft has two blades which project at right angles in opposite directions and which in each case are provided with a cutting edge only at the front edge, so that the crank always has to be turned clockwise. Both are arranged relatively closely above the base, although staggered relative to one another in the direction of the shaft. Although the apparatus has generally proved its worth, it is possible for cut solid material, e.g. onions, to be carried by the blades owing to the constant direction of rotation. This can be counteracted to some extent only by a relatively high speed of the blades, which however, particularly when cutting onions, can easily lead to a satisfactory degree of homogeneity being reached only with a high degree of comminution. The apparatus can be used conveniently only if it is supported on a level work surface, which entails a relatively large space requirement during use.

[0003] DE-A-39 14 372 discloses an electrically driven vegetable cutter of otherwise similar design, in which the shaft likewise has two blades which project at right angles in opposite directions and are staggered relative to one another in the direction of the shaft. In order to ensure that the carrying of the cut material, which also occurs here, does not have a disadvantageous effect, a counter-knife which is stationary or rotatable only to a limited extent is arranged in the vessel, between said blades. The blades are provided with cutting edges on both longitudinal edges, but this only has the purpose of making it possible to dispense with a startup lock for the electric motor. Controlled reversal of the direction of rotation of the shaft is not envisaged.

[0004] Another generic type of apparatuses for comminuting foods, as used in particular for comminuting onions, is evident from EP-A-1 232 840. This apparatus has a knife with a cutting edge which is curved in a serpentine manner on the underside and is mounted at the lower end of a ram which carries an actuating button at its upper end. By impacts on the latter, the knife is caused repeatedly to strike a firm substrate on which the material to be cut lies, against the restoring force of a coil spring. These apparatuses are relatively inconvenient to operate, and moreover pieces of the material to be cut can easily become jammed in the knife, which prevents further comminution of said pieces.

[0005] It is the object of the invention to provide an apparatus of the generic type which ensures high uniformity of the cut material even with a moderate degree of comminution, in particular when cutting onions. Moreover, it should be convenient to operate.

[0006] This object is achieved by the features in the characterizing clause of Claim 1. The apparatus according to the invention can be held in the hands during use and the shaft which carries the blades can be caused to execute alternately opposite rotational movements by movement of the drive part back and forth relative to the other parts of the apparatus. The spatial position of the apparatus may vary, it generally being tilted by about 90°. In any case, the apparatus is usually not supported during use and therefore requires no free space on a work surface.

[0007] In particular, however, it has been found that the material to be cut, in particular onions, is very rapidly and uniformly comminuted. A further advantage of the apparatus is that it is equally convenient to operate for right-handed persons and left-handed persons.

[0012] The substantially rotationally symmetrical apparatus has a round cover 1 which comprises a base 2 and a cap 3 as drive part, between which a gear 4 is arranged. The cap 3 has a plurality of indentations distributed at regular intervals over its edge. A beaker- or dish-like vessel 5 of transparent material can be connected to the underside of the base 2 in such a way that a toothed system on the outer edge of the underside of the base 2 engages a complementary tooth system on the inside of the upper edge of the vessel 5 so that the two parts are nonrotatably connected.

[0013] Located along the axis of the vessel 5 is a hollow shaft 6 which has an operative connection through the base 2 to the gear 4 on which the cap 3 acts on the other side so that rotations thereof relative to the base 2 are converted into rotations of the shaft 6. The latter carries two approximately rectangular blades 7a, 7b which project approximately at right angles on opposite sides and are oriented perpendicular to the axis and extend up to close to the wall of the vessel 5. The blades 7a,b are staggered relative to one another in the direction of the axis in such a way that the axial distance from the lower blade 7a to the base approximately corresponds to the axial distance from the upper blade 7b to the edge of the vessel 5, while the distance between the two blades 7a, 7b is slightly larger. Each of the blades 7a,b has a cutting edge 8 in each case on two parallel longitudinal edges.

[0014] The gear 4 comprises a plurality of gear wheels lying in a plane and mounted so as to be rotatable in the cover. A central wheel 9 located in the centre of the cover 1 has a central orifice which is nonrotatably engaged by a sleeve 10 which projects through a central orifice 11 in the base 2 into the interior of the vessel 5. There, it carries at its lower end a peg 12 which has a hexagonal cross-section and engages a corresponding recess in the upper end of the shaft 6 so that the sleeve 10 and, via this, the central wheel 9 are nonrotatably connected to the shaft 6. At the lower end, the shaft 6 is mounted on the base of the vessel 5 by virtue of the fact that a bearing journal 12 formed there projects into it. At its upper end, where it widens in a dish-like manner and surrounds the lower part of the sleeve 10, it extends up to the base 2 so that penetration of cut material between the sleeve 10 and the shaft 6 is not possible.

[0015] The sleeve 10 is mounted on a hollow axle journal 14 which projects downwards from the centre of the cap 3 and engages an orifice in the sleeve 10, which orifice is concentric with the central wheel 9. It has a plurality of fingers 16 which are separated by slots 15 and carry at their ends hooks 17 which grip behind an all-round ledge 18 in the interior of the sleeve 10 and thus limit its axial displaceability in a downward direction. The latter is at the same time limited in an upward direction by a stop ring 19 on the cap 3, which stop ring surrounds the axle journal 14 at a distance, so that the sleeve 10 has only slight axial play.

[0016] The central wheel 9 is surrounded concentrically by three identical intermediate wheels 20a,b,c which engage it at points uniformly distributed over its circumference. They are mounted similarly to the sleeve 10 on axle journals 14 which in this case project upwards from the base 2 but are otherwise formed correspondingly and engage concentric orifices, and once again are limited in their axial displaceability by hooks 17 and stop rings 19 surrounding the axle journals 14 at a distance, so that they too have only slight axial play.

[0017] The cap 3 carries, on the inside of a skirt 21 running around its edge and projecting downwards, a gear ring 22 which engages the intermediate wheels 20a,b,c from the outside. A rotation of the cap 3 relative to the base 2 therefore results, via the gear ring 22, in identical rotational movements of the intermediate wheels 20a,b,c, which in turn cause the central wheel 9 to rotate, which rotation is transmitted via the sleeve 10 to the shaft 6. The transmission ratio is preferably from 1:3 to 1:5. In the apparatus shown here, it is 1:4.

[0018] The blades 7a,b are produced from stainless strip steel, their surface is electrolytically polished and the cutting edges 8 are sharpened burr-free. All other parts of the apparatus consist of plastic, preferably the cap 3 of ABS, the vessel 5 of SAN and the other parts of POM. They are produced by the injection moulding process.

[0019] The dimensions of the apparatus correspond to its intended use as a manually operated apparatus. The diameter is about 108 mm and the height about 75 mm. The length of the blades 7a,b is 52 mm. Of course, deviations from these values are possible. Diameters of from 80 mm to 120 mm and heights of from 60 mm to 120 mm are readily possible without the handling and operating properties of the apparatus being substantially impaired. In the case of a greater height of the vessel, it may be necessary to provide more than two blades axially staggered relative to one another.

[0020] The material to be cut—e.g. an onion cut beforehand into quarters—is introduced into the vessel 5, and the cover 1 is then mounted. The vessel 5 is then gripped, for example with the left hand, and the cap 3 with the right hand, its indentations improving its grip, and the apparatus is tilted by about 90° so that its axis is approximately horizontal. The vessel 5 and the base 2 of the cover 1 which is nonrotatably connected to it, on the one hand, and the cap 3, on the other hand, are rotated relative to one another, for example 10 times in alternately opposite directions of rotation, each time by about one full revolution. After about 20 to 30 seconds or 40 to 60 revolutions, which corresponds to 160 to 240 revolutions of the shaft 6 relative to the shaft 5, the onion has been comminuted. The vessel 5 can then be removed and emptied.

[0021] Owing to the regular reversal of the direction of rotation, there is virtually no carrying of the cut material by the blades. The generally tilted position of the apparatus during the use thereof leads to a better distribution of the cut material in the vessel 5 and to more uniform processing thereof by the blades 7a,b.

[0022]

List of reference symbols
	1	Cover
	2	Base
	3	Cap
	4	Gear
	5	Vessel
	6	Shaft
	7a, b	Blades
	8	Cutting edges
	9	Central wheel
	10	Sleeve
	11	Orifice
	12	Peg
	13	Bearing journal
	14	Axle journal
	15	Slot
	16	Finger
	17	Hook
	18	Ledge
	19	Stop ring
	20a, b, c	Intermediate wheels
	21	Skirt
	22	Gear ring