AN ARRANGEMENT FOR VIBRATING PLANTS

Abstract: An arrangement for vibrating simultaneously a large number of plants (2) preferably plants grown in a greenhouse (1), for artificial pollination of the plants. The plants are supported by support means (3) carried by longitudinally extending plant carriers, each of which is common to a group of plants. Vibration of the plants (2) is effected by causing the plant carriers to move backwards and forwards in a movement transversally to their longitudinal extension. This movement of the plant carriers is effected by means of rigid vibrator rods (15) which are connected to the plant carriers and extend transversally thereto. The vibrator rods are free from all load from the plants (2) and the fruit carried thereby. The vibrator rods (15) are preferably supported by the plant carriers.

Description: An arrangement for vibrating plants The present invention relates to an arrangement by means of which a large number of plants can be vibrated spontaneously, preferably plants grown under glass, in order to cause pollination. In the case, for example, of tomatoes grown in green¬ houses, where natural agitation of the air does not occur to an extent sufficient to ensure pollination of the flowers on the vines , or where pollination by insects cannot be relied upon, it is necessary to pollinate the flowers with the aid of artificial means. The tomato vines are normally held with cord hanging from a system of lines, which extend along or across the greenhouse. Artificial pollination of the flowers is normally effected in this case by vibrating the cord, lines etc. used to support the vines, by striking the cords with the aid of a stick, or by means of a hand- operated vibrator. Since large greenhouses can contain as many as 3,000-5,000 tomato plants, the task of pollinating- the flowers is extremely time-consuming, even though it may take only 5-10 seconds to shake each separate plant. Moreover, this task should be carried out at least once every calendar day during the whole of the growing season. The physical movements required in this regard are highly monotonous and may easily result in so-called industrial injury. In addition, present day techniques for the artifi¬ cial pollination of plants do not give optimum results. Pollination should be effected over a relatively short period during the day, at times when conditions relating to temperature, humidity and light are at an optimum with regard to pollination. Comprehensive efforts have been made to mechanize the work of pollination without meeting any great success. In this regard attempts have been made to set the whole of the plant suspension system in vibration. For example, there is described in DE-B 12 18 205 an arrangement for simultaneously vibrating a large number of plants, prefer- - ably plants grown in greenhouses, for the purpose of pollinating the plants, the plants being supported by support means carried by an elongated plant carrier, each of which is common to a group of plants, the plants being caused to vibrate by moving the plant carriers backwards and forwards transversely of their longitudinal extension. In this known arrangement the plant carriers, which have the form of lines, are set in motion ' with the aid of transverse lines which support the plant-carrying lines and which are adapted to be moved reciprocatingly by means of excentric means mounted on a rotatable shaft extending through the whole of the greenhouse. It is not possible with such an arrangement to shake all plants uniformly, among other things because the transverse lines intended to transmit the vibratory movements to the plant-carrying lines are loaded by the weight of the plants and the fruit thereon. This means that the vibratory movement in the transverse lines will die away very quickly. This is due, among other things, to the fact that the load on respec- ' tive plant-carrying lines cauaes the lines to sag, and hence when the transverse lines are pulled to move the plant-carrying lines sideways the sag in the transverse lines is taken up instead of moving the aforesaid plant- carrying lines to mutually equal extents. As a result hereof, the plant-carrying lines furthest from the rotat¬ ing shaft are hardly moved at all. Furthermore, the use of a rotating shaft which extends through the whole of the greenhouse is unsuitable from the safety aspect. Moreover, it would seem that a relatively high power input is requi- red to rotate the shaft, in view of the heavy weight, several tons, which must be supported by the transverse lines activated by the motor. The main object of the present invention is to provide an arrangement of the aforesaid kind in which, inter alia, the aforesaid disadvantages and drawbacks of the known arrangement are eliminated. This is achieved by means of a modified arrangement according to the aforegoing, this modified arrangement being characterized in that for the purpose of causing the plant carriers to move in the aforesaid manner there are provided substantially rigid vibrator rods which extend transversally to the plant carriers and are connected there- to, and which are free from the weight of the plants and the fruit carried thereby. With an arrangement of this kind all plant carriers are imparted the same degree of movement, irrespective of the distance to the drive means, these vibration movements being well sustained. In addition, vibration is effected effectively with the use of low drive power, since the aforesaid vibrator rods do not in themselves support any load. Due to the fact that the rods are rigid, movement of the rods in their longitudinal direction will be fully converted to a corresponding transversal movement of the plant carriers. In a preferred embodiment of the invention the vibrator rods are supported by the plant carriers, there¬ with enabling the rigidity of the rods to be used for equalizing the load between the plant carriers. According to one embodiment, the vibrator rods are arranged in pairs, with a respective rod on each side of a centre shaft which is imparted a longitudinal, reciproca- tory movement by means of a drive motor, and means are arranged for converting movement of the shaft to a reci- procatory longitudinal movement of the vibrator rods extending at right angles to the shaft, in this case, the vibrator rods in each pair of rods are suitably driven in a push-pull relationship. The central shaft is preferably divided into two sections and the drive motor located between said sections and adapted to drive the shaft sections in a push-pull relationship. According to one alternative embodiment of the inven- tion, the vibrator rods are arranged in pairs, there being arranged between the rods of each pair a drive motor adap¬ ted to drive said rods in a push-pull relationship. In accordance with a preferred embodiment of an 86/03095 __ arrangement according to the invention, two circular cam discs are mounted excentrically on the motor shaft and displaced in relation to one another through 180°, each of these discs being arranged to rotate in a respective surrounding annulus, which is used for driving the shaft sections and vibrator rods in a respective push-pull relationship. A compensating means is preferably coupled between each vibrator rod and a drive means therefor, in order to enable the height of the vibrator rod to be adjusted automatically in dependence on the plant carriers. This will ensure that the vibrator rods themselves carry no part of the load exerted by the plants. The connection between the vibrator rods and respec- tive plant carriers suitably has the form of a spring element, which, inter alia, has been found to improve the transmission of vibrations between the transverse lines and the plant carriers. The spring element suitably comprises a bent leaf spring. The invention will now be described in more detail with reference to embodiments thereof illustrated in the accompanying drawings. Figure 1A is a schematic cross-sectional view of a greenhouse provided with an arrangement according to the invention. Figure 1B is part of a schematic horizontal view of an arrangement according to Figure 1. Figures 2A and 2B are respectively a side view and a horizontal view of the drive means for the arrangement illustrated in Figure 1. Figures 3A and 3B are respectively a side view and a horizontal view of a movement conversion mechanism used in the arrangement illustrated in Figure 1. Figure 4A is a cross-sectional view of a greenhouse provided with an alternative embodiment of an arrangement according to the invention. Figure 4B is part of a schematic horizontal view of an arrangement illustrated in Figure 4A. Figures 5A and 5B are respectively a side view and a horizontal view of drive means used in the arrangement illustrated in Figure 4. Figure 6 illustrates a connecting element incorpora- ted in the arrangement according to the invention. Figure 7 illustrates part of a movement transmitting mechanism incorporating the arrangement according to Figure 6. ' Fig. 1A illustrates in cross-section a greenhouse 1 in which, for example, tomato plants 2 are supported by support means 3, suitably consisting of wires. The wires 3 hang from horizontal wires 4 or the like (cf. Fig. 1B) which serve to carry the plants and which extend in the longitu¬ dinal direction of the greenhouse 1. The wires 3 are con- nected directly to the wires 4 in spaced relationship there- along. The horizontal wires 4 are suitably stretched be¬ tween the ends of the greenhouse and support the whole of the weight of the plants and the fruit carried thereby. The horizontal wires 4 extend between the end walls of the •r .greenhouse through holders whiςh serve as line supports and which are carried by structural beams 6. The beams 6 are connected centrally thereof to a longitudinally extending beam 7. The reference 8 identifies two shafts which extend in the longitudinal direction of the greenhouse 1 and which are journalled on the beam 7 to impart a longitudinal, reciprocatory movement to the shafts. The shafts 8 are driven by a motor 9, Fig. 2, having an output shaft 10 on which two excentric discs 11 are mounted, of which discs only one is shown. Each of the excentric discs 11 rotates in its respective outer annulus 12, each of which is connected, via a joint 13, with its respective shaft 8, which is guided by a pair of guide rollers 17. The two excentric discs 11 rotate in mutually opposite directions, and hence the forces acting in the two shafts 8 substan¬ tially balance out one another, so that no resultant forces act on the motor. In Fig. 1B the reference 14 identifies drive knuckles by means of which the longitudinal reciprocatory movement of the shafts 8 is converted to a longitudinal reciproca¬ tory movement of transverse vibratory rods 15 connected to the longitudinally extending plant carriers 4 at locations 16. The rods 15 are suitably supported by the plant carriers 4 without being subjected to any load therefrom. Because the rods 15 are rigid they are able to assist in equalizing the load between the various plant carriers 4 without supporting any of this load themselves. As illustrated in Fig. 3 each drive knuckle 14 includes a journal pin 18 and a surrounding sleeve 19 pro¬ vided with three arms. A first arm 20 is pivotally connec¬ ted to the shaft 8, while the two remaining arms 21 extend in mutually different directions and are each pivotally connected to a respective link arm 22 coupled to a respec- tive vibrator rod 15. As will be seen from Fig. 3A, the coupling to respective vibrator rods is effected in a manner which permits the vertical height of the vibrator rod to adjust to the position of the plant carriers 4. To this end, the outer ends of the arms 22 are provided with sleeves which movably surround a vertical part of respec¬ tive vibrator rods 15. The vibrator rods 15 are able to rest directly on the plant carriers 4, via the connecting means 23 of said rods. When the motor 9 used in an arrangement according to the above, is started-up, the rotational movement of the motor will be converted to longitudinal, reciprocatory movement of the shafts 8 by the excentric discs 11 and the annuli 12 surrounding said discs. In turn, the longitudinal reciprocatory movement of the shafts 8 is converted by the drive knuckles 14 into longitudinal, reciprocatory movement of the vibrator rods 15. Each pair of rods 15 will thus move in mutually opposite directions, i.e. in a push-pull relationship, and hence no unbalanced forces will occur in the drive knuckles 14. Since the rods 15 are rigid all of the plant carriers 4 connected thereto will be subjected to the same degree of lateral movement, via the rod connect¬ ing means 23, therewith causing the plants held by the plant carriers 4 to vibrate. This ensures that all plants are vibrated with equal vigorousness, irrespective of their distance from the driveshaft 8. Because the vibra¬ tor rods 15 are totally ree from the load exerted by the plants, the rods can be driven at a relatively low power. In addition, the arrangement obviates the need for long rotating shafts. Good results were obtained in tests using a motor 9 of 2.2 kW and a rotary speed of 930 r.p.m., the vibration amplitude being 5-10 mm and operating times as short as 3-7 seconds. Because of the short operational times pollination can be effected at precisely that point in time when con¬ ditions are right for a successful result. This point of time can be determined with aid of conventional measuring instruments intended, inter alia, for temperature and 5 humidity measurements, and the arrangement can also be adapted to be controlled automatically from such instru¬ ments. The number of operational periods and the duration thereof can be adapted, inter alia, in accordance with the time of year and prevailing light conditions. o Figures 4 and 5 illustrate an alternative arrangement according to the invention, those components whose func¬ tion corresponds to the function of similar components in the arrangement of Figs. 1-3 being identified by the same references. In the arrangement illustrated in Fig. 4A the 5 plant-carrying lines 4 extend transversally of the green¬ house 1 , between the central support beam 7 and side beams 24. In this arrangement a pair of vibrator rods 15 extend in the longitudinal direction of the greenhouse 1 on each side of the central beam 7. The number of rods provided is 0 contingent on the size of the greenhouse complex and require ments. As with the previous embodiment, the rods 15 are rigid and free of all load, and are suitably supported by the plant carriers 4. In this embodiment a motor 9 having excentric discs 11 is provided for each pair of longitudi- 5 nally extending vibrator rods 15. This obviates the need for the separate drive knuckles 14 of the previously described embodiment. Figs. 5A and 5B illustrate the drive motor 9 together with its shaft 10 on which the excentric discs 11 are mounted. Similar to the Fig. 3 embodiment, the vibrator rods 15 are coupled to associated drive arms, here referen¬ ced 25, via a coupling which permits movement in the ver- tical direction. The drive arms 25 are supported by double pairs of guide rollers 26 and are pivotally connected to the rings or annuli 12 driven by the excentric discs 11. As with the previous embodiment, the vibrator rods 15 are ' provided with connecting means 23 for connection to the plant carriers 4. Fig. 6 illustrates a highly advantageous embodiment of the connecting means between a vibrator rod 15 and a plant carrier 4. This connecting means comprises a bent leaf spring 23, which permits movement in the vertical direction and which has been found highly suitable for transmitting movement of the vibratory rods 15 to the plant carriers 4. Fig. 7 illustrates the height-compensating coupling between the vibrator rod 15 and the drive arm 25, .the - vibrator rod ^ 15 being provided with the connecting element 23 according to Fig. 6. The manner in which this height adjustment is carried out is illustrated in broken lines in Figs. 6 and 1 , from which it will be seen that the spring elements 23 enable the various plant carriers 4 to be located at mutually different levels, depending on the load exerted on respective plant carriers, without loading the vibrator rods 15 to any appreciable extent. The afore-described arrangements shall be seen solely as preferred embodiments of the invention, since modifica- tions can be made within the scope of the claims. Thus, the excentric mechanisms, drive knuckles, coupling elements, height-adjustment means and other components of the illu¬ strated and described arrangements can be varied as desired and as required, while retaining the advantages afforded by the invention. Although it has been said in the aforegoing that the plant carriers consist of wires, it will be under¬ stood that successful application of the invention is not dependent on the type of plant carriers used. The vibrator rods need not extend solely above the plant carriers, but may also be arranged to hang beneath the same. The plant carriers can also be arranged to be vibrated in other directions.

Claims: ^ . . . CLAIMS 1. An arrang'ement for vibrating simultaneously a large number of plants (2), preferably plants grown in a green¬ house (1), for pollinating said plants, said plants being supported by support means (3) carried by longitudinally extending plant carriers (4) , each of which is common to a given group of plants, said plants (2) being vibrated by subjecting the plant carriers (4) to a reciprocatory move¬ ment transversally to their longitudinal extension, charac¬ terized in that for the purpose of thus moving the plant carriers (4) the arrangement further includes substantial¬ ly rigid vibrator rods (15) which extend transversally of the plant carriers and are connected thereto, and which are free from the weight of the plants (2) and the fruit carried thereby. 2. An arrangement according to Claim 1, characterized in that the vibrator rods (15) are supported by the plant - carriers (4) . 3. An arrangement according to Claim 1 or 2, charac¬ terized in that the vibrator rods (15) are arranged in pairs, with one rod on each side of a central shaft (18); in that a drive motor (9) is provided for effecting reci¬ procating movement of the shaft (8) in its longitudinal direction; and in that means (18-20) are provided for converting movement of the shaft (8) to a reciprocating longitudinal movement of the vibrator rods (15) extending at right angles to the shaft (8) . 4. An arrangement according to Claim 3 , characterized in that the vibrator rods (15) in each pair are driven in a mutually opposed push-pull relationship. 5- An arrangement according to Claim 3 or 4, charac¬ terized in that the central shaft (8) is divided into two sections; and in that said drive motor (9) is arranged between these sections and arranged to drive said sections in a mutually opposed push-pull relationship. 6. An arrangement according to Claim 1 or 2, charac¬ terized in that the vibrator rods (15) are arranged in . 1 1 pairs; and in that a drive motor (9) is arranged between the rods (15) of each pair and arranged to drive said rods in a mutually opposed push-pull relationship. 7. An arrangement according to Claim 5 or 6, charac- terized in that two circular cam discs (11) are mounted excentrically on the motor shaft (10) at an angular dis_^ placement of 180°, each of said discs (11) being arranged to rotate in a respective surrounding annulus (12) which is used to drive said shaft sections (8) and said vibra- tor rods (15) in mutually opposite directions. 8. An arrangement according to any one of Claims 1-7, characterized in that a compensating means is connected between each vibrator rod (15) and a drive means (14; 9) therefor, in order to permit automatic adjustment of the height level of the vibrator rod (15) in dependence on the plant carriers (4) . 9. An arrangement according to any one of Claims 1-8, characterized in that the vibrator rods ( ' 15) are connected to respective plant carriers (4) via a spring element (23) . 10. An arrangement according to Claim 9, characterized in that the spring element comprises a bent leaf spring (23) .

Inventors: VITANS LEO, VITANS, LEO
Applicants: VITANS LEO, VITANS, LEO
Application year: 1985
Main classification: A01G9
IPC codes: A01H1