The present invention relates to the use of plant cutting trays of the type comprising one or preferably two parallel rows of planting cells. Typically, these longish tray units are shaped with carrier plate portions projecting from the opposite ends of the trays.

Such tray units are used extensively in plant nurseries, where the cells of the trays are filled with earth and the cuttings are placed therein, whereafter the trays are placed in parallel on long tables closely next to each other.

The method has proved to be economical and rational, as the cutting trays may be produced in plastics at relatively low costs and provide for just the required planting spaces with a minimum of surrounding waste space, such that many cuttings can be watered and fertilised concurrently.

Typically, the single cells exhibit an area of only some 3x3 cm, and during an initial phase the trays may be brought closely together, i.e. with a high concentration along the tables.

As the cuttings grow, it is necessary to displace the trays away from each other in order to provide sufficient space for the remaining plant growth until the planting out of the plants. The tight location of the two rows in each tray is still acceptable, when only the plants in each row can expand to one side. The said displacements are effected manually and normally without aids of any kind, and since the number of trays is usually very large there is not time to really measure out the displacements. These may then be more or less incidental, despite instructions as to a desired spacing of e.g. 3 cm between the trays. The desired spacing is rather critical, as it has of course been chosen as an ab¬ solute minimum for the benefit of both the plants and the to¬ tal space requirement after the displacements, and problems may arise in both respects if the measure is not observed. On this background it is difficult for the staff to carry out the work in a satisfactory manner with respect to both speed

and accuracy, and it is well known that this may cause some friction in the nurseries.

With the present invention it has been realised that this problem may be widely counteracted by arranging the trays not as entirely loose units, but as groups of such units inter¬ connected in such a manner that the units may be drawn from each other from closely juxtaposed positions into parallel positions with a predetermined mutual spacing, e.g. in that the neighbouring trays are interconnected by flexible and thus also straightenable wires of the desired length. For the operators it will be a great relief that the correct spacing can be obtained merely by pulling out the trays to a stop, as this will render special attention to the spacing superflu- ous.

It could well be possible to produce or preassemble the trays with a large number of units in such a group, but for various reasons this is not particularly practical, so ac¬ cording to the invention it is even preferred to include only four units in each group. This choice is partly associated with the preferred design of the spacer means, but in general it is preferable to include only relatively few units in the groups. Then, a remaining problem will be that the spacing between neighbouring pairs of units should also be correct, but for one thing the total problem has been reduced consid¬ erably, and for another thing it will promote a correct posi¬ tioning that the operator can directly watch the correct spacing between displaced nearby units.

In a preferred embodiment of the invention there is still made use of loose tray units, which are only mounted on crosswise extending beam portions at the ends, where the tray units have shortly projecting gripping plate portions. These portions are made with downwardly projecting pins, which are connected with the beam in being lowered into respective slots therein, such that the tray units can be mounted closely juxtaposed and from these positions be displaced out¬ wardly from the middle until the pins abut respective outer ends of the slots. The desired result is thus achievable when

the slots are suitably located and dimensioned. At least in connection with four tray units the system may be laid out such that the beam elements have the same length as the width of the closely juxtaposed trays, i.e. without the beams re- quiring space in projecting from the tray group, while the beams may also effectively engage all the units in the ex¬ panded positions thereof.

With the use of the said beams it is also achieved that each of the tray groups will be easy to carry as a unit, which greatly facilitates the general handling.

Typically, the discussed trays are used once only, but it will be appreciated that the carrier and spacer beam elements will be reusable, whereby the tray manufacturer should not necessarily take any measures of actually coupling the trays together, e.g. with flexible or foldable interconnections. The new technique so far described only requires a simple modification of the trays themselves, in addition to the lo¬ cal use of the spacer beams, but in fact the invention can be realized even without any modification of the trays. To the extent the spacer beam elements can be regarded as qualified reusable elements they may realistically be made as more com¬ plex and more expensive units enabling an expansion of their own, whereby they may cooperate with non-modified trays, as further discussed below. In the following the invention is described in more de¬ tail with reference to the drawing, in which:

Fig. 1 is a perspective view of a known and only slightly modified tray unit;

Fig. 2 is a sectional view of one end thereof; Fig. 3 is a perspective view of four such units forming a group with associated carrier and spacer beams;

Fig. 4 is a top view of the tray group with the trays closely juxtaposed;

Fig. 5 is a similar view with the trays in drawn-out po- sitions;

Fig. 6 is a perspective view of a special spacer beam structure;

Fig. 7 is a similar view of this structure in an expanded state, and

Fig. 8 a lateral view of Fig. 1 , shown with inserted tray units. The cutting tray 1 shown in Fig. 1 is commonly known in nurseries and consists of two parallel rows of pockets 2 for receiving earth and cuttings. At both ends, the tray has pro¬ jecting plate portions 3 adapted as finger grips.

The cutting trays are typically made in ther o shaped plastic sheet material. The material thickness is small, only a fraction of a millimeter, but the shaping of the trays is optimised such that they have the necessary material thick¬ ness and structure for enabling them to be moved and carried when filled with earth and with cuttings therein. This is done by means of the plate portions 3, which are easy to grip by the fingers and are reinforced by spatial end ribs 4 on the trays. In use, the trays as filled with earth and cut¬ tings are placed closely juxtaposed on a long table. When the cuttings have grown to a certain size it is necessary to move the trays from each other, such that the plants can have the required space for growing until they are planted in pots or the like.

The trays are modified only in being provided with down¬ wardly projecting pins 5 at both end plates 3, made as local depressions of the sheet material and having a narrow widen¬ ing 6 at their lower ends. The pins 5 are located offset from the longitudinal middle of the tray unit, to the same side at both ends.

As shown in Fig. 3, the spacer member 7 is an oblong plate provided with four displacement slots, of which there are two outermost, long slots 8 and two innermost, shorter slots 9, corresponding to four pins 5 in the trays 1. In use, a spacer member is arranged underneath the ends of four trays, such that in the group of four trays the two pins 5 at one end will be located oppositely to the two in the other end. With this design, the spacer member 7 will be symmetri¬ cal in the longitudinal direction, so it does not matter which end is forwardly or rearwardly directed, respectively.

when connected with the trays, and the trays may be uniformly shaped.

As shown in Fig. 4 the spacer members have the same length as four closely juxtaposed trays 1, and the respective pins 5 are placed at the innermost ends of the slots 8 and 9. Thus, such groups of four trays may, themselves, be placed in a long row without spacing between them. When the time is ready, the trays 1 can now just be pulled away from each other until the pins engage with the opposite ends of the slots 8 and 9 as shown in Fig. 5, whereby the trays will automatically assume correct mutual positions.

For the production of the spacer member 7, a relatively stiff plate can be used, whereby it is made possible to carry and move groups of cutting trays, in this instance four at a time. This is advantageous when the purpose is to create a distance between the individual cutting trays, as it will then be easy to remove e.g. every fourth group and thereby achieve precisely the necessary space for the other trays. The design of the spacer members and the depressions may be otherwise as here disclosed.

By way of example, the tray may be formed with elements at each end which are connected by a film hinge or the like and are pivotable between two positions, viz. the close and the spaced, respectively. A further possibility will be to use distance members of a type having two holes or the like which are suited for en¬ gagement with depressions or the like in the respective trays. This may be effected by means of a piece of flexible material, which is bent when the trays stand close to each other and is stretchable to the desired spacing between the trays.

The pin and slot engagements may be inverted. The system may be modified so as to enable the use of non-modified trays, e.g. in being made of expansible tray carrier elements as shown in Figs. 6-8. Such elements could also be made of wire material, with integral guiding and stop eyelets. The elements may be designed such that the long and short displacements are coupled with each other.