GB2194431A - Halving apparatus and process - Google Patents

Abstract

An apparatus for aligning objects and for then cutting them into two segments comprises: two laterally spaced feed conveyor belts 23 mounted so as to be capable of feeding objects 28a placed thereon into the vicinity of a pair of cutting blades 22, two guide belts 26 mounted above the feed belts and capable of motion in the same general direction as the feed belts, the two cutting blades each being mounted for rotation in a vertical plane between the feed and guide belts, the arrangement of feed and guide belts in the vicinity of the cutting blades being substantially symmetrical about a vertical plane passing midway between the feed belts, and the cutting blades being mounted so as to exercise their cutting action during the operation of the apparatus substantially in the said vertical plane of symmetry. The apparatus may be used to halve plant bulbs before they are fed to a bulb segmenting machines. <IMAGE>

Description

SPECIFICATION Halving apparatus and process The present invention relates to an apparatus for cutting objects, especially plant bulbs substantially into halves and to a process using the apparatus.

There are at present various machines capable of cutting objects such as food and plant tissue into two or more segments eg for the purposes of propagation. It is however a pre-requisite of some of these for example the machine described in UKPA 8611791 that if plant bulbs are being segmented then they must be cut as to include one and preferable two specific portions of the plant bulb.

It is vital to the propagative capabilities of individual bulb segments no matter what their size that each segment should contain a region from the base or stem of the bulb from which region the new (adventitious) bulbs grow. As a matter of efficiency, so as to produce as many segments from one plant bulb as possible it is also preferable that a cutting axis also runs through or substantially close to the apex of the bulb to be segmented so that the segments produced are of equal or substantially equal size.

Some bulb-segmenting machines, eg that described in UKPA 8611791 are fed by bulbs which have been previously halved or substantially halved, ie cut into two segments with a cut passing as close as possible along the axis referred to above.

To achieve cutting of bulbs etc into two equal or substantially equal halves, with a cut passing through an axis as described above, it is necessary to align the bulbs etc prior to halving. Some such aligning and/or centering devices are known, eg as described in UKPA 2010077A which uses a number of radially arranged feed belts to centre approximately cylindrical food articles prior to cutting into a number of segments. A centering device of this type would probably not be suitable for objects the shape of plant bulbs.

Consequently there is a requirement for an apparatus which is capable of cutting objects such as plant bulbs and plant tissues of a similar shape substantially into halves in a fast and efficient manner.

According to the present invention there is provided an apparatus for aligning objects and for then cutting them into two segments which comprises: two feed conveyer belts mounted so as to be capable of feeding objects placed ther eon into the vicinity of a pair of cutting blades, two guide belts mounted above the feed belts and capable of motion in the same general direction as the feed belts, the two cutting blades each being mounted for rotation in a vertical plane between the feed and guide belts, the arrangement of feed and guide belts in the vicinity of the cutting blades being sub stantially symmetrical about a vertical plane passing midway between the feed belts, and the cutting blades being mounted so as to exercise their cutting action during the operation of the apparatus substantially in the said vertical plane of symmetry.

The feed and guide belts are preferably made of a soft but resilient material with a high coefficient of friction such as rubber or plastics, and are preferably circular in cross section. Objects are carried thereon by resting the object on both belts with the central portion of the object fitting into the space between the belts, but without any possibility of the object falling through the gap between them.

The feed belts preferably run on guides, such as rails or pulley wheels, over substantially the whole length over which they carry the objects, to prevent excessive lateral movement of the objects.

The guide belts may be present for the whole length of the feed belts over which the latter carry the objects or alternatively over only the length close to the cutting blades.

They should at least be present in the immediate vicinity of the blades so as to align the objects whilst they are being cut. Although resilient there is less necessity for guides, but the degree of resilience should be such that there is as little likelihood as possible of the objects losing their alignment during cutting.

The guide belts are preferably angled downward toward the cutting blades so that they gradually engage with the objects to be aligned and cut as the objects move along the feed belts. Their horizontal spacing is determined by the shape and size of the objects to be cut, and may conviently be the same as that of the feed belts. Their vertical spacing from the feed belt is similarly determined by the shape and size of the objects to be cut.

At least the feed belts must be driven, and the guide belts may be freely rotating or preferably are also driven. The direction of the drive guide belts in this latter case must of course be such as to convey the objects in the same direction as the feed belts.

The two cutting blades are preferably circular discs with circumferential cutting edges.

They preferably rotate in opposite directions to each other and in directions which cause objects on the feed belts to be drawn into their cutting field. They are preferably made of metal eg steel.

The blades are mounted so as to exercise their cutting action substantially in a vertical plane. The blades are therefore mounted on either side of the vertical plane of symmetry with their cutting edges overlapping in the horizontal plane and as close together as possible without contact. The overlap may be up to one-third of the disc diameter and if the thickness of the discs decreases in the radial direction they may be mounted coplanar whilst maintaining overlap.

It is also preferred that one of the cutting blades makes contact with the object to be cut before the other, so that the object to be cut is drawin into the cutting field of the blades.

The contrarotating and overlapping discs give a better cutting and shearing action than unidirectional edge to edge blades and this means throughput of materials can be fast and the halved materials have cleanly cut edges.

The contrarotating and overlapping blades can as a result of the improved shearing action over the conventional unidirectional edge to edge blade and other systems be operated at lower speeds for the same diameter of disc if this is necessary.

The dimensions and operating speed of such an apparatus will depend upon the shape, size and nature of the objects to be cut, in a preferred form of the apparatus the spacings of the feed and guide belts may be made variable, by for example lockable bosses on drive wheels or pulley wheels over which the feed and guide belts travel, and by similar bosses on the cutting blades. Cutting blades about 180mm in diameter have been found suitable for cutting most plant bulbs, with a rotation speed of around 600 rpm providing a suitable velocity of the cutting edges, which speed is of course related to the blade dia meter. An edge overlap of about 2mm on such blades has been found suitable.

In use, objects such as plant bulbs to be cut about a pre-defined plane are placed onto the moving feed belts so that the plane passes between the feed belts and between the guide belts or between the projection of the line of the guide belts. As the objects travel along the feed belts they come into contact with the guide belts, which girdle them into a position such that the plane is vertical or substantially vertical and if the guide belts are angled downward they gradu ally grip the objects at the same time so as to hold them firmly in alignment as they reach the vertically mounted cutting blades.

It will be appreciated from the use of resili ent materials for the belts, and from the often irregular shape of eg plant bulbs that the pro cess of halving achieved by the apparatus will not be geometrically precise, hence the term "substantially" has been used with reference to directions etc. The degree of accuracy achieved is however entirely satisfactory for cutting bulbs and for use of the apparatus as a feeder for the halved bulbs used in the seg menting apparatus described in UKPA 8611791.

Various additional refinements may be pre sent on an apparatus according to the inven tion. For example a plate, with a slot through which the lower cutting blade passes may be mounted below the feed belts to prevent cut objects from falling away. In some cases the resilient nature of the belts may prevent the cut objects from separating into segments, so a deflector, eg prongs may be used to force them apart. If the gap between the feed belts widens after the cutting blades, then these separated segments may then be caused to fall through the bottom of the machine into a suitable collector.

The apparatus of the invention may be used for cutting a wide range of plant bulbs, and is particularly suitable for cutting the bulbs, corms rhizomes and stem tubers as appropriate of plants such as Daffodils, Narcissi, Iris, Crocus, Snowdrop, Bluebells and Lily of the Valley etc.

In accordance with a further aspect of the invention there is provided a process for cutting objects using an apparatus as described herein.

The invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 shows a cross section of a typical plant bulb Figure 2 is a perspective view of the cutting apparatus and belt system Figure 3 is a sectional view throng A-A of the apparatus of Fig. 2.

Referring to Fig. 1 a typical plant bulb consists of condensed shoots and leaves (not shown) one or more lateral buds (11) and a very short stem (12) at the base of the bulb.

Shown is a possible cutting axis which runs through the stem (12) or base of the bulb and through the bulb apex (13) which is preferable.

Referring to Figs. 2 and 3 these show generally an apparatus for halving bulbs.

Two disc-shaped steel blades (21) with circumferential cutting edges (22) are mounted on axles (not shown) for drive by an electric motor (not shown) and gearing arrangement (not shown). The blades (21) are positioned substantially in a vertical plane with their cutting edges (22) overlapping and ail but in contact.

The blades (21) are mounted with their plane midway between a pair of feed belts (23), mounted horizontally and capable of being driven by an electric motor (not shown) acting through pulleys (24). Along their upper run (23A) the feed belts (23) run through guides (25) (omitted from Fig. 2 for clarity).

Above the feed belts (23) are mounted guide belts (26) driven by an electric motor (not shown) acting through pulleys (27). The guide belts (26) slope downwards towards the cutting blades (21). The guide belts (26) extend for only a portion of the upper run (23A) of the feed belts.

A bulb (28) has been placed on the upper run of the feed belts (23A) with the plane (14) passing between the feed belts (23A) and the guide belts (26). When the bulb (28) reaches the position (28A) the lower run (26A) of the guide belts engage with the bulb (28A) guide it into a position in which the plane (14) of the bulb is substantially coplanar with the plane of the blades (21), and hold it in that position until it engages with the blades (21) and is cut into two segments of substantially equal size (not shown).

These segments are prevented from falling away by means of a plate (29) mounted be iow the upper run (23A) of the guide belts, in which there is a slot (210) through which passes the blade (21). These two segments are then separated by deflector prongs (not shown) and collected.

Claims (18)

1. An apparatus for aligning objects and for then cutting them into two segments which comprises: two feed conveyer belts mounted so as to be capable of feeding objects placed ther eon into the vicinity of a pair of cutting blades, two guide belts mounted above the feed belts and capable of motion in the same general direction as the feed belts, the two cutting blades each being mounted for rota tion in a vertical plane between the feed and guide belts, the arrangement of feed and guide belts in the vicinity of the cutting blades substantially symmetrical about a vertical plane passing midway between the feed belts, and the cutting blades being mounted so as to exercise their cutting ac tion during the operation of the apparatus substantially in the said vertical plane of symmetry.

2. An apparatus according to claim 1 wherein the feed and guide belts are made of a soft but resiliant material with a high coefficient of friction.

3. An apparatus according to claim 1 or 2 wherein either or both of the feed and guide belts are circular in cross section.

4. An apparatus according to any of the preceding claims wherein the feed belts run on guides.

5. An apparatus according to claim 4 wherein the guides are rails or pulley wheels.

6. An apparatus according to any one of claims 1 to 5 wherein the feed belts diverge from one another past the cutting blades so that cut objects fall between the feed belts.

7. An apparatus according to any one of claims 1 to 6 wherein the guide belts are angled downwards towards the cutting blades

8. An apparatus according to any one of claims 1 to 7 wherein the feed and/or guide belts are driven.

9. An apparatus according to any one of the preceding claims wherein the spacing of the feed and guide belts is variable.

10. An apparatus according to any one of the preceding claims wherein the two cutting blades are circular discs with circumferential cutting edges.

11. An apparatus according to any one of the preceding claims wherein the discs rotate in opposite directions to each other.

12. An apparatus according to any one of the preceding claims wherein the blades are made of metal.

13. An apparatus according to any one of the preceding claims wherein the blades exercise their cutting action substantially in a vertical plane.

14. An apparatus according to any one of the preceding claims wherein one of the cutting blades makes contact with the object to be cut before the other.

15. An apparatus according to any one of claims 10 to 14 wherein the cutting blades have a diameter of about 180 mm.

16. An apparatus according to anyone of claims 10 to 15 wherein the speed of blade is around 600 revolutions per minute.

17. An apparatus according to any one of claims 10-16 wherein the edges of the blades overlap by about 2 mm.

18. An apparatus substantially as herein described with reference to the accompanying figures and drawings.