INSTALLATION AND METHOD FOR THE TRANSPORT OF GROWTH UNITS AND THE ADJUSTMENT OF THEIR SPACING AND CONTINUOUS CULTIVATION METHOD UTILIZING THE SAME

Abstract: The invention relates to a plant growing arrangement comprising several successive rows of troughs for plants, wherein transport means are provided for transporting said troughs along a cultivation field and successively increasing their spacing as the plants grow. Said transport means comprise successive graspers rows (1, 2, 3) formed of graspers (1a...1c, 2a...2c, 3a...3c) co-acting trough by trough (14). The graspers and/or grasper rows can be brought into engagement with arbitrary groups of troughs for transporting several chosen troughs at a time along the frame. The spacing between successive graspers rows (1, 2, 3) is adjustable by a driving mechanism in connection with the transport. The invention is especially well suited for the automatic cultivation of lettuce grown in separate pots in said elongated troughs (14).

Description: Installation and method for the transport of growth units and the adjustment of their spacing and continuous cultivation method utilizing the same The present invention relates to an installation for cultivating plants, said installation comprising a frame structure, several preferably open cultivation cavities for plants said cavities being provided in common trough means movably mounted in side by side relationship on said frame, and transport means for transporting said trough means along a cultivation field in a direction which is substantially transverse to the longitudinal extension of the individual trough means. The invention also relates to a method for the transport of plant cultivation troughs and/or the adjustment of the spacing between said troughs in accordance with the growth of said plants, said method comprising changing the spacing between parallel troughs by transporting the troughs along said field. The invention is especially well suited for cultivating fast growing plants, such as lettuce in separate pots lodged in elongated parallel troughs. Said troughs are transported along the cultivation field from a planting point to a harvesting point while their spacing is intermittently increased to accommodate for the added space required by the plants as they grow. There are prior known systems for cultivating plants, wherein individual plant units are placed side-by-side in cavities in trough-like devices. In such systems the plant nutrients are generally added in a solution directly into the trough. Immediately after planting or sowing the dimensions of the individual plants are very reasonable and thus the troughs may generally be kept side-by-side in close contact with each other. As the plants grow they demand an ever increasing space and corresponding the parallel troughs must be transported to a greater distance from each other. Another reason for transporting the troughs derives from the fact that the preferred arrangement of the cultivation line often comprises planting at one end of the track and correspondingly harvesting at the other end of the track. A number of constructions are known for performing the above kind of transport. Thus for example US Patent 4, 216, 618 dis¬ closes an arrangement wherein the individual troughs are transported along a frame by the action of a screw member having an ever increasing pitch. The disadvantage of said apparatus lies in the technically complicated screw construction and also in that the spacing between the indivi¬ dual troughs on the bed is very definitely tied to the characteristics of the screw. Thus it is difficult to change the trough spacing for example to adapt the apparatus to the needs of different plant species. NO Patent 149, 527 discloses a construction wherein the troughs rest on successive conveyor belts. The spacing between the troughs may be adjusted when the troughs move from one belt to another by adjusting the speed of the belts to be different. Said construction has the disadvantage among others of placing the troughs on an equidistant spacing on each belt, which makes it difficult to provide for a flexible cultivation. The use of several belts further requires several separately con¬ trolled motors. GB Patent 2,077,082 discloses an arrangement wherein the parallel gullies are transported by a rope from the starting or planting point to the end or harvesting point while nutrient is being added to said gullies along the way. In said construction the spacing of the individual gullies is adjusted by hand, wherefore the amount of manual work in this culti¬ vation method is very high. FI Patent 72029 discloses a construction wherein the troughs gliding on a bed are laterally transported one at a time to a new position by the action of a means engaging the said trough. The transport means moves in a reciprocating manner along the bed and picks one single trough after the other transporting it to a desired position. The apparatus works automatically in the way that the automatically controlled apparatus independently picks one trough at a time and transports it to the desired destination, both the starting point and the end point being determined according to sensor detections. According to the functioning principles of the apparatus the transport means will have to move fairly long distances on an average, the return journey generally being made without a load. The essential disadvantage of the said apparatus lies mainly in its being so slow, since the transporting of each trough requires that the apparatus moves back and forth. The possi¬ bility for increasing the speed is, however, limited since the troughs and the plants as such cannot withstand great trans¬ port speeds. Moreover, since the apparatus works in green house conditions the automatic controls of the apparatus and especially the alignment sensors placed at various positions along the track require specific endurance properties. There¬ fore the sensitivity of the indicators is low and thus the required detection time is correspondingly relatively long, which also affects the handling speed which can be obtained with the apparatus. In practice the slow function of the last mentioned apparatus in larger cultivation sites often leads to a situation, wherein there is not sufficient time for transporting all the troughs during one work shift. On the other hand the apparatus must be very carefully supervised despite its automatic function, since even one leaf of the grown plant coming into the vicinity of the trough engaging means may lead to mal¬ function and stopping of the apparatus. The object of the invention is to provide and installation enabling the individual arrangement of the plants on the frame without the above mentioned disadvantages. The said object is obtained according to the invention in the way defined in the appended claims. Thus, the invention is characterized in that the transport means comprise parallel graspers and/or grasper rows co-acting trough by trough for transporting at a time several chosen trough means of a group of adjoining troughs substantially in the same position and/or to another position on the frame. Hereby the spacing between parallel graspers and/or grasper rows may be changed in connection with the transport, preferably in such a way that the distance between the graspers and/or grasper rows is adapted on one hand to the spacing between the trough means to be transported and on the other hand to the spacing desired between said troughs after the transport phase. According to the method of the invention transport means com¬ prising parallel grasper rows are made to substantially simultaneously engage several parallel troughs at a time, the spacing between the parallel grasper rows being adjusted after said engagement to correspond to the desired trough spacing. In a continuous cultivation the plants are grown in open culti¬ vation cavities provided in successive rows of elongated trough means movably mounted on a frame. The troughs are transported along the cultivation field from a first or planting end to a second or harvesting end while the trough spacing is adjusted to provide for the space required by the growing plants in the individual troughs. The said adjustement is provided by arbitrary troughs or groups of troughs including growing plants being grasped by the individual graspers of successive parallel grasper rows of a transport means and are transported to another position of said field while the spacing between said troughs is changed by adjusting the distance between successive grasper rows during the transport operation and/or immediately thereafter. In the following the invention will be described in more detail by reference to the enclosed drawings, wherein: Fig. 1 shows a schematic front view of one grasper row of one embodiment of the transport means of the invention, Fig. 2 shows a schematic side view of a parallel grasper set of the apparatus of Fig. 1, and Fig. 3 shows a schematic side view of another embodiment of a grasper set for the apparatus of Fig. 1. Fig. 4 shows an axono etric view of an embodiment of the transport means of the invention. Fig. 1 shows a grasper row 1 of the transport means of the invention. In this embodiment said transport means comprises successive graspers la to lc in the longitudinal direction of a trough, said graspers forming together a grasper row 1. The individual graspers are devices according to the prior art and in the shown embodiment the are suitably suspended from a carrier bar (not shown) extending above the frame (not shown). Each trough row 1 is adapted to engage one conventional culti¬ vation trough (not shown). Fig. 1 further shows the work cylinders 6a to 6c arranged for lifting and lowering the grasper sets of the transport means. Said work cylinders are preferably arranged to bring all the graspers of the transport means to simultaneously engage the corresponding troughs. Another embodiment further includes lifting or pivoting means for each individual grasper and/or grasper row by which one or several grasper rows may be brought out of engagement with the trough. Such an embodiment is advantageous especially when the number of parallel grasper rows in the transport means is large and it is still desirable to pick only a few of the parallel troughs. Fig. 2 shows a side view of the grasper rows, said figure showing only the foremost graspers la and 2a, respectively, of the parallel grasper rows 1, 2. In Fig. 3 there are three parallel grasper rows, i. e. the figure shows the grasper 3a in addition the graspers la and 2a. Each grasper row 1, 2, 3 as a whole is capable of engaging one trough at a time. The individual parallel graspers la, 2a, 3a of each grasper row 1, 2, 3, respectively, are preferably combined to form a grasper set 4 and the other graspers correspondingly form grasper sets 5 and 6 shown in Fig. 1. In practice the number of graspers is more or less arbitrary and may be chosen according to the number of troughs to be transported at a time. In case the number of parallel grasper rows is very high it is preferred to provide each grasper set with several lifting cylinders 7. In the embodiments shown in the Figs. 2 and 3 each grasper set is suitably provided with one grasper which is fixed in relation to said set and at least one, preferably several graspers which are movable in respect to said fixed grasper individually of as a group, all graspers situated in the same grasper row 2 and 3, respectively, of the separate grasper sets 4, 5, 6 are arranged for synchronously coupled movement. In the embodiment shown in Fig. 2 grasper row 1 is fixed while grasper row 2 moves along glide rail 9 controlled by cogged belt 8, of which there is one set provided for each grasper set. Cogged belt 8 is mounted to two cogged wheels 10 to 11 and the corresponding driving cogged wheels 10 of all grasper sets 4, 5, 6 in the shown embodiment are connected through the rotation shaft 12 extending through the sets from set to set. One rotating, motor 13 adjusts all the graspers 2a to 2c of the movable grasper row 2 to the correct position. The adjust¬ ment is preferably performed according to a pulse sensor detecting the rotation of the shaft. In case there are several movable grasper rows 2, 3, there are preferably provided respective belt means for each row for moving each grasper row as described above. Providing driving means for each row makes it possible to adjust the trough spacings of a group of troughs being simul¬ taneously transported in order to accommodate for different needs. For example when different plant are cultivated side by side, said plants requiring different space, such as lettuce requiring a relatively large space and chives requiring a relatively small space, it is advantageous to be able to adjust the trough spacings individually. Fig. 4 shows a preferred embodiment of the invention for the cultivation of plants, especially lettuce grown in separate pots in said trough cavities. The troughs 14 are transported three at a time group along the cultivation field by the grasper rows 1, 2, 3. The spacing between successive troughs is intermittently increased from the starting point of the field to the harvesting point by increasing the distance between the parallel grasper rows 1, 2, 3 as said grasper rows transport the troughs along the field. In biological cultivation the apparatus of the invention may preferably be utilized for growing biologically controlling plants between the actual commercial plants. In such cases the plant having a biological controlling effect is generally a plant requiring less growth space and it is either sold separately or it is used several times over, for which purpose the graspers of the transport means may be adjusted to pick certain chosen troughs from the group of troughs and transport them back to the starting end of the cultivation field by lifting said troughs above the growth frame. It is also possible to cultivate slowly growing plants between quickly growing plants for which purpose the graspers may be adjusted to pick certain troughs from the group of troughs and transport them back for example to the starting end of the cultivation field or to the middle of said field for a second growth phase, the space required by said plant in said second growth phase possibly being larger than the space required by said plant in its first growth phase. The apparatus of the invention is capable of accommodating even such a change in the required space for a certain trough. In case the number of parallel grasper rows 1, 2, 3 is very high it is also possible to use a construction, wherein each grasper set 4, 5, 6 comprises separate transport means for each grasper, such as work cylinders 14 or motor assemblies adapted for synchronous movement. The control of the arrange¬ ment preferably utilizes a processor mentioned below, which supervises each movement. When the apparatus is being used the entire transport means is driven to a position determined by the trough group to be moved. The through group comprises the troughs in side-by-side relationship. The transport means simultaneously engages all the troughs of the group, or in specific circumstances only some troughs are chosen. After engagement the transport means is suitably capable of performing three transport functions: First of all the transport means may engage all of the troughs of the trough group, whereafter the spacing between the troughs is changed, while the group remains essentially in its place. Secondly the transport means may engage the whole group and transport it along the frame to a free position, which is situated in an essentially different position from the position of the group at the beginning of the movement, the trough spacing simultaneously being adjusted to obtain the desired distance between the troughs. The said transport operations may take place either in connection with a lifting operation or by gliding along the frame. Thirdly the apparatus is capable of engaging chosen troughs of the trough field, in this case always in a lifting operation, to transport them to a new position, such as to form an extension of the thus thinned out trough group or to be placed at the starting end of the cultivation field. A continuous cultivation is generally performed so that each trough is transported on one hand along the frame from the planting point to the harvesting point the trough spacing being at the same time increased. New troughs are always added to the planting end and emptied troughs are correspondingly removed at the harvesting end. In a conventional cultivation the function of the apparatus is suitably based on the principle that the transport means are made to transport chosen troughs to a distance from the engagement point, suitably to the next free position, free positions along the frame mainly appearing at the harvesting end. The chosen troughs are then the troughs which are situated immediately behind (as seen from the harvesting end of the frame) the positions freed in connection with the previous transport operation. Since the apparatus in the above described manner is capable of transporting several troughs at a time the distance travelled on an average for each trough will be relatively short and the transport operation will be relatively quick. The distance between the adjoining rows of graspers is adjusted during the transport operation and/or immediately thereafter and the graspers are released essentially simul¬ taneously from the troughs at positions determined by the desired trough spacing. A processor is preferably provided to achieve the correct trough spacing as well as to provide control of the release in the desired free position. The said positions and trough spacings depend on the properties of the plants and they may thus be previously determined and programmed into the processor in a known way. As is made evident by the foregoing description, each grasper row 1, 2, 3 comprises graspers la to lc, 2a to 2c and 3a to 3c, respectively, functioning along one corresponding trough means. The distance between the graspers of each grasper row 1, 2, 3 is chosen according to the length of the trough to be handled and according to the required trough spacing. The embodiment of Fig. 1 for simplicity shows a row 1 containing three successive graspers. In case the troughs are very long or their construction is weak, the number of graspers may be significantly higher. In the described case the individual graspers of the successive grasper rows 1, 2, 3 form a grasper field, wherein ' the graspers are provided in essentially fixed predetermined positions in the direction transverse to the track. In the direction of the movement of the transport means, however, all the grasper rows 1, 2, 3 may be substantially freely positioned according to the movement of the transport means. Not counting the one grasper row which is suitable fixedly mounted, the other grasper rows are movable in the direction of movement of the transport means both in relation to each other and in relation to said transport means. In the direction of movement of the transport means the distance between successive grasper rows may be adjusted row by row at a time according to the control of the above mentioned movement assembly 8, 10, 11 or processor. In the preferred apparatus, which is especially shown in Fig. 3, there are three grasper rows 1, 2, 3, the middle row 1 being fixedly mounted in relation to the transport means, while the grasper rows 2, 3 on each side thereof comprise graspers 2a to 2c, 3a to 3c which are movable in relation to the graspers la to lc, respectively of said fixed grasper row 1. In practice the said preferred embodiment is used in such a way that a processor directs the transport means to the position of the troughs which are in turn to be transported and moves the movable graspers 2a to 2c, 3a to 3c in relation to the fixed grasper row 1 so that their mutual distance corresponds to the spacing of the troughs on the frame. Thereafter the graspers la to lc, 2a to 2c and 3a to 3c are simultaneously brought into engagement with a group of three troughs to be transported. When the graspers have become firmly engaged with the troughs the transport means are driven to transport the group of troughs to a chosen position on the frame as controlled by the processor and determined by the fixed grasper row 1, whereafter the cogged belt and other corresponding driving mechanism is actuated to push the movable grasper rows 2, 3 in opposite directions away from the fixed grasper row 1. Thus the first trough in the group of troughs is transported forward, while the last trough of the group of troughs is transported back towards the direction from which it was taken. The pushing of the troughs apart from each other is continued until they have reached the desired distance from each other, whereafter the processor controlled driving mechanism is stopped. Thereafter all the graspers are removed from contact with the troughs and the transport means is ready for fetching the next group of troughs.

Claims: Claims 1. Installation for cultivating plants, said installation comprising a frame structure, several preferably open culti¬ vation cavities for plants said cavities being provided in common trough means movably mounted in side by side relation¬ ship on said frame, and transport means for transporting said trough means along said frame in a direction which is substantially transverse to the longitudinal extension of the individual trough means, c h a r a c t e r i z e d in that said transport means comprise graspers (la...3c) successive in the transport direction and/or transversely extending successive grasper rows (1, 2, 3) formed of graspers (la... lc, 2a...2c, 3a...3c) respectively, co-acting trough by trough, said graspers and/or grasper rows being alignable with arbitrary groups of trough means for transporting several chosen trough means at a time along the frame, the spacing between successive graspers (la...3c) and/or grasper rows (1, 2, 3) being .adjustable by a driving mechanism in connection with the transport operation. 2. Installation according to claim 1, c h a r a c t e ¬ r i z e d in that each grasper row (1, 2, 3) comprises several graspers (la... lc, 2a...2c, 3a...3c) which respectively operate along one trough means at a time in a direction which is transverse to the transport direction. 3. Installation according to claim l or 2, c h a r a c t e ¬ r i z e d in that said transport means comprise a common carrier rail moving along the frame, preferably above said frame. 4. Installation according to any of the preceding claims 1...3, c h a r a c t e r i z e d in that out of the grasper rows (1, 2, 3) formed of parallel graspers (la... lc, 2a...2c and 3a...3c, respectively) and extending transversely to the direction of movement of the transport means, one row (1) is fixed in relation to said transport means, and one or several rows (2, 3) is/are correspondingly arranged to be movable at least in the direction of movement of the transport means. 5. Installation according to any of the preceding claims 1...4, c h a r a c t e r i z e d in that the movable graspers (2a...2c, 3a...3c) are functionally connected in such a way that the distances between the successive grasper rows (1, 2, 3) are adjustable by the row at a time. 6. Installation according to any of the preceding claims 1...5, c h a r a c t e r i z e d in that the distances between the successive grasper rows (1, 2, 3) are increased by moving at least one grasper row (2) backwards and at least one grasper row (3) forwards with respect to the fixed grasper row (1). 7. A method for the transport of plant cultivation troughs and the adjustment of the spacing between said troughs in accordance with the growth of said plants, said method com¬ prising changing the spacing between adjacent troughs by transporting the troughs along said frame in a direction transverse to their longitudinal extension, c h a r a c t e ¬ i z e d in that the individual graspers (la... lc, 2a...2c, 3a...3c) of the successive grasper rows (1, 2, 3) of a transport means are made to substantially simultaneously engage at a time arbitrary troughs of a group of troughs, the spacing between said successive grasper rows (1, 2, 3) being adjusted after said engagement to correspond to the desired trough spacing. 8. A method according to claim 7, c h a r a c t e r i z e d in that the transport means are made to transport the chosen troughs to a distance from the engagement point, that the distance between successive grasper rows (1, 2, 3) is adjusted during the transport operation and/or immediately thereafter and that the graspers (la... lc, 2a...2c, 3a...3c) are released from the troughs substantially simultaneously in positions determined by the desired trough spacing. 9. A method for the continuous cultivation of plants, wherein said plants are grown in open cultivation cavities provided in successive rows of elongated trough means movably mounted on a frame, said troughs being transported along the cultivation field from a first or planting end to a second or harvesting end while the trough spacing is adjusted to provide for the space required by the growing plants in the individual troughs, c h a r a c t e r i z e d in that arbitrary troughs or groups of troughs including growing plants are grasped by the individual graspers (la... lc, 2a...2c, 3a...3c) of successive parallel grasper rows (1, 2, 3) of a transport means and are transported to another position of said field while the spacing between said troughs is changed by adjusting the distance between successive grasper rows (1, 2, 3) during the transport operation and/or immediately thereafter. 10. A method according to claim 9, c h a r a c t e r i z e d in that the cultivated plants comprise lettuce grown in separate pots in said trough cavities and in that the spacing between successive troughs in groups of troughs is intermittently increased from the starting point of the field to the harvesting point by increasing the distance between the parallel grasper rows (1, 2, 3) as said grasper rows transport groups of successive troughs along the field.

Inventors: RAPILA TIMO MIKKO, TENHUNEN MARTTI TAPANI, RAPILA, TIMO, MIKKO, TENHUNEN, MARTTI, TAPANI
Applicants: FAMIGRO OY
Application year: 1990
Main classification: A01G9
IPC codes: A01G9, A01G31