GB1559343A - Continuous paper tube assembly for seedlings and method ofseparating the same and transplanting apparatus for the same - Google Patents

Description

(54) "CONTINUOUS PAPER TUBE ASSEMBLY FOR SEEDLINGS, AND METHOD OF SEPARATING THE SAME AND TRANSPLANT ING APPARATUS FOR THE SAME" (71) We, NIPPON TENSAI SEITO KABUSHIKI KAISHA, a body corporate organised and existing under the laws of Japan, of No. 6, 2-chome, Kyobashi, Chuo-ku, Tokyo, Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a method of separating and transplanting seedlingaccommodating tubes one by one successively from an assembly of a continuous series of the tubes, to an assembly of a continuous series of upright open-ended tubes adjacent ones of which are interconnected by webs, and to transplanting apparatus for planting seedlingaccommodating upright and open-ended tubes.

The applicants have developed previously a paper tube assembly comprising individual paper tubes connected with each other, as shown in U.K. Patent Specification No. 1,207,858.

When the assembly of seedling-accommodating paper tubes is placed on an automatic transplanting machine and each line of tubes is separated into individual tubes, it is necessary to operate manually or with a cutting blade. In the latter case, the webs connecting the tubes together are cut mechanically when tensioned, so that in the event of breakage of the blade, the cutting is interrupted for a long time. As a result, there has been a disadvantage, when the seedling-accommodating tubes are separated manually or by cutting blade, that continuous planting operation of the assembly of a continuous series of seedling-accommodating paper tubes became impossible, thus resulting in an inefficient operation.

The applicants have completed a very practical invention hereinafter described in order to solve such fault of the prior art operation, as a result of studying the construction method of separation of the paper tubes, and the transplanting machine to operate in conjunction with said method.

The study commenced with the construction of the webs interconnecting adjacent tubes of the assembly. The applicants carried out various experiments about how to rationally sever these webs, and as a result found that in the case of such an assembly wherein the connecting webs had vertically-directed separation lines composed of sewing-machine needle holes or slits formed at certain intervals, they could resist parallel pulling severance in the horizontal direction to a substantial degree, but they could be separated by a small force if only the upper end or the lower end was pulled in one direction, i.e. if the point of separation was moved from the upper end downward or from the lower end upward, as is obvious from Table 1.

Table 1 Construction and Tensile Strength Arrangement of connecting Tensile Strength web Horizontal tensile in the course of (uncut portion) strength (A) time (B) (mm) (point) (kg) (kg) B/A x lOO(!Zo) 2x12 3.38 0.81 24 4 x 6 3.48 0.80 23 6 x 4 3.36 0.84 25 8 x 3 3.53 1.34 38 12x 2 3.30 1.85 56 24x 1 3.45 2.69 78 wherein the paper tubes subjected to the experiment are hexagonal in section with a diagonal length of 19mm, and a height of 130 mm the connecting webs being of breadth 9.5 mm and being made of kraft paper which has been subjected to decomposition resistance treatment.

In Table 1, the horizontal tensile strength (A) means a maximum load at the time of separation of adjacent paper tubes after removal from the latter of the seedlings and the soil and substitution thereof by hexagonal poles made of aluminium having a shape corresponding to the internal shape of the paper tubes, one of the aluminium-pole-accommodating paper tubes being then fixed and the other having applied thereto a horizontal tensile load thereby to cause the separation.

Also, the tensile strength in the course of time (B) means a maximum load at the time of separation of adjacent paper tubes in such a way that one of the aluminium-poleaccommodating paper tubes is fixed as in (A), and the other has applied thereto a tensile load only at its upper end portion thereby to cause separation commencing from said upper end portion and proceeding downwardly. When the distance between the slits of the separation line of the connecting web between adjacent paper tubes is changed appropriately and the joined or unbroken portions of the separation line are distributed from one point to a number of points respectively, the horizontal tensile strength does not change, but the tensile strength in the course of time decreases substantially and it is found that even if the tensile strength in the course of time is about 25% of the horizontal tensile strength, the paper tubes can be readily separated, and there is little difference when the joined or unbroken portion between the slits forming part of the separation line is less than 6 mm. On the other hand, when the unbroken portion between the slits is too long, the tensile strength may become greater than the crushing strength of the paper tubes, and accordingly 2 to 6 mm is the optimum length for the unbroken portion between the slits. Furthermore, it has been found that if the uppermost slit of the separation line extends through the upper edge of the connecting web of adjacent paper tubes, the separation of individual paper tubes becomes very good, the total length of the joined or unbroken portions of the separation line in the web interconnecting adjacent paper tubes being 36 mm and this is divided between six joined or unbroken portions each of length 6 mm, thereby changing the distribution pattern in various ways. The tensile strength when the point of separation moves in the course of time and the tensile strength obtained by pulling horizontally were compared and studied, and the results shown in Table 2 were obtained. As is obvious from Table 2, the slit extending through the upper edge of the connecting web acts as a separation guide portion the length of which is preferably 20-70 % of the height of the connecting web even if in the ideal condition, and for practical purposes it is preferred the separation guide portion be 30-40% of the height of the connecting web, and when the connecting body has such a construction and the paper tubes are connected together thereby, the mechanical separation becomes easy for the first time. The applicants have found, from the results of and the knowledge acquired from said Tables 1 and 2, that in the case of an assembly of a continuous series of paper tubes adjacent ones of which are interconnected by webs so as to permit the continuous pulling-out thereof, if slits of a given length extend through and from the upper edge of each said connecting web in the vertical direction to form guide portions of separation lines and slits are provided at given intervals along said separation lines, whereby the point of separation is moved in the course of time from above downwards, the paper tubes can be separated individually from this assembly by a very small tensile force, and the present invention has been obtained on the basis of such knowledge.

Table 2 Relation between dispersion condition of joined or unbroken portions of separation lines in webs interconnecting adjacent tubes in an assembly of a continuous series of tubes, and separation effeciency (total length of joined or unbroken portions: 36 mm).

Defined dis- Length of Length of Percentage of Number of Tensile Horizontal persion holding unjoined tubes not times of strength tensile condition of part of portion separated breakage of in the strength: total length upper end: within dis- from foremost pulled-out course of kg. of joined or cm. persion: cm. tube or tubes row of tubes. time: kg. unbroken for the assembly portions: 36mm. to separation Dispersion on the whole len- 0 1.56 35 0 1.3 2.5 gth of 13 cm.

Dispersion expect upper end 0.5 1.48 18 0 1.1 2.4 of 0.5 cm. ditto 1 cm. 1 1.40 10 0 1.0 2.5 ditto 2 cm. 2 1.23 5 0 0.8 2.4 ditto 3 cm. 3 1.07 3 0 0.7 2.4 ditto 4 cm. 4 0.70 0 0 0.5 2.5 ditto 5 cm. 5 0.73 0 0 0.4 2.3 ditto 6 cm. 6 0.57 0 0 0.4 2.1 ditto 7 cm. 7 0.40 0 5 0.5 2.0 ditto 8 cm. 8 0.23 0 15 0.6 1.9 ditto 9 cm. 0.06 0 40 0.5 2.0 In accordance with the present invention, we provide a method of separating and transplanting seedling-accommodating tubes one by one successively from an assembly of a continuous series of the tubes comprising forming said assembly from upright open-ended but flattened tubes made of rot-proof film and adjacent ones of which are interconnected by webs so that the tubes can be pulled out thereof in the form of a continuous row, folding the row right and left alternately at every given number of the tubes to form the latter line upon line and pasting the tubes of adjacent lines together by a water soluble paste, expanding said assembled tubes, filling soil into said tubes and sowing therein and raising the seedlings, and, at the time of transplanting, pulling out the seedling-accommodating tubes from one end thereof in the form of a continuous row and successively separating them into individual seedling-accommodating tubes and transplanting them, such separation being facilitated by performing in said interconnecting webs separation lines bisecting the webs and each formed by a sequence of slits alternating with unbroken portions, an end slit or slits of said sequence extending through the upper and/or the lower edge of the connecting web to form a guide portion or portions and the unbroken portions being of a total length between 30% and 80% of the height of the web, whereby they can resist the tensile force by which the weedlingaccommodating tubes are pulled out in the form of a row but can easily be sundered by the application of a mechanical instantaneous tensile force, and inducing the sundering of the unbroken portions starting from the or a said guide portions by applying a mechanical instantaneous tensile force to the adjacent tubes interconnected by the pertaining web, thereby to separate said tubes from one another by progressively dividing the web along said separation line from the bottom to the top or from the top to the bottom.

Also, in accordance with the present invention, we provide an assembly of a continuous series of upright open-ended tubes made of rot-proof film and adjacent ones of which are interconnected by webs which permit the tubes to be pulled out in the form of a row from the assembly, the row being folded right and left alternately at every given number of the tubes to form the latter line upon line; and the tubes of adjacent lines being pasted together by a water soluble paste, the webs having therein separation lines bisecting the individual webs and each formed by a sequence of slits alternating with unbroken portions with an end slit or slits of said sequence extending through the upper and/ or the lower edge of the connecting web to form a guide portion or portions, the total length of the slits of a said sequence being between 20% and 70% of the height of the web, and the unbroken portions being of a total length between 30% and 80% of the height of the web.

Further, in accordance with the present invention, we provide a transplanting apparatus for planting seedling-accommodating upright and open-ended tubes made of rot-proof film by pulling out the tubes in a continuous row from one end of the foremost line of an assembly of a continuous series of tubes adjacent ones of which are interconnected by webs and which series has been folded right and left alternately at every given number of the tubes to form the latter line upon line the tubes of which have been pasted together by a water-soluble paste, said connecting webs having therein separation lines vertically bisecting the individual webs and each formed by a sequence of slits alternating with unbroken portions with an end slit or slits of said sequence extending through the upper and/or the lower edge of the connecting web to form a guide portion or portions, the transplanting apparatus comprising a conveyor system adapted to progress forwards at a constant speed the assembly of seedlingaccommodating tubes loaded thereon with lines of tubes transverse to the direction of progress, said conveyor system being mounted on and spaced above a carrier with the direction of progress of the conveyor system the same as the direction of progress of the carrier, a tube-feeding mechanism comprising at least one pair of rotary bodies clad with elastic material and arranged at the downstream end of said conveyor system both to the right and the left of the seedling-accommodating tubes progressing in a row to nip said tubes, and means to rotate said rotary bodies in the mutually-opposite directions, a separating mechanism at the downstream end of said feeding mechanism and comprising a pair of frusto-conical bodies, or cylindrical bodies mounted at an inclination, clad with elastic material, and means to rotate said separating mechanism bodies in the mutually-opposite directions and at a peripheral speed greater than that of said rotary bodies, said separating mechanism bodies being positioned both to the right and to the left of the progressing seedling-accommodating tubes to nip the tubes, and being so arranged that there is a time differential between the pull exerted on the tubes at the upper and lower portions thereof on being nipped between the conical or cylindrical bodies, and a planting device comprising a tube guide mounted at the upstream end of said separating mechanism, a tube-delivery pipe mounted below said guide and seedling control plate means at the lower end of said tube-delivery pipe.

Hereinafter, the invention will be explained in more detail with reference to the accompanying drawings, wherein: Fig. is a plan view showing the situation in which individual paper tubes are pulled out one after another from an assembly of a continuous series of paper tubes accommodating seedlings and after the completion of nursing of the seedlings; Fig. 2 is a perspective view showing in detail part of the continuous paper tube assembly of Fig. 1; Fig. 3 is a plan view of the main part of one embodiment of separating mechanism from dividing the connecting webs between adjacent tubes of the continuous paper tube assembly of Fig. 1; Fig. 4 is a side view of Fig. 3; Fig. 5 is a plan view showing another embodiment of the separating mechanism; Fig. 6 is a side view of Fig. 5; Fig. 7-a is a side view of an apparatus in accordance with the present invention for separating and transplanting seedling bodies one by one successively; Fig. 7-b is a plan view of Fig. 7-a; Fig. 8 is a detailed plan view showing the separating portion of Figs. 7-a and 7-b; Fig. 9 is a side view of Fig. 8; Fig. 10. is a side view of a seedling planting device; Fig. 10-a is a cross-sectional view taken along the line A-A' of Fig. 10; Fig. 10-b is a cross-sectional view taken along the line B-B of Fig. 10; Fig. 10-c is a cross-sectional view taken along the line C-C of Fig. 10; Figs. 11-a to 1 1-d are perspective views showing various embodiments of the connecting systems of the connecting web between adjacent tubes; and Fig. 11-f is a plan view of Fig. 11-d.

In the drawings, P is an assembly of a continuous series of paper tubes each accommodating a seedling, 1 is an individual paper tube of hexagonal section of many such tubes connected together to form the paper tube assembly, 2 is a film constituting the paper tubes 1 and which is made of a paper material such as kraft paper etc. usually having decomposition resistance of such a degree that decomposition does not occur during the period of the nursing of seedlings.

3 is a web connecting individual paper cylinders 1 to one another, and said connecting web is usually made of the same material as that used for the paper tubes 1, but any material can be used therefor if it can produce the same effect as described above. In order to dispose the connecting webs between the adjacent paper tubes 1, two films 2 forming the paper tubes are pasted thereto at given intervals or as shown in U.K. Patent Specification 1,207,858, previously-formed paper tubes 1 have pasted thereto separate films of a given breadth and either of the same material as that of the paper tubes or of a different material than that of the paper tubes. 4 is a vertical slit which extends through the upper edge 3' of the connecting web 3 and constitutes a separation guide for facilitating the division of the connecting web. 5 are vertical slits below and aligned with the separation guide slit 4 at given intervals. 6 are unbroken portions between the slits 5, and thus the separation line 6', vertically bisecting the web 3 between adjacent tubes 1, is formed by the sequence of slits 5 and unbroken portions 6.

Accordingly, the greater part of the separation line 6' bisecting the connecting web 3 extends along the slit 4 and the slits 5 so that the adjacent paper tubes 1 are connected together only by the relatively short unbroken portions 6. Accordingly, the characteristics of the connected paper tube assembly of the present invention lie in the total length of the unbroken portions 6 and the rupture thereof along the separation lines 6 when the tubes 1 are pulled out from the assembly in a continuous series. Thus, in order to make it possible to pull out the connected paper tubes 1 in a row from the assembly P after nursing of the seedlings, the connecting webs 3 must be of sufficient strength for this purpose, but it is necessary that they can be easily ruptured along the separation lines 6' without any resistance in the subsequent separation of the tubes 1 one after another from the series of interconnected tubes 1. The connecting web 3 which meets these requirements is of the construction hereinbefore described with reference to the experimental examples, wherein the length of the separation guide 4 is within the range of 20 to 70% of the height H of the connecting web 3 even if in ideal status, and is preferably within the range of 30 to 40% of said height H. Also, the slits 5 and the unbroken portions 6 are alternately arranged in alignment with and below the separation guide 4. In this case, the unbroken portions 6 are at appropriately intervals within a range of 30 to 80% of the hiehgt H of the connecting body 3. The vertical slit constituting the separation guide 4 may extend through either the upper edge or the lower edge of the connecting web 3 correspondingly of the separation mechanism individually, or there may be two such vertical slits, one extending through the upper edge and the other extending through the lower edge of the connecting web 3.

In Figs. 3 and 4, the reference numeral 7 denotes seedlings nursed in the paper tubes 1, 8 denotes a paper tube separating device, 9 and 10 are guide rolls which are fixed on shafts 9' and 10' respectively, and each of which covered about its periphery by a cylinder 11 of elastic material such as sponge. The rolls 9 and 10 are axially parallel to one another and the peripheries thereof are spaced apart to provide an interval which allows the rolls to nip a paper tube 1 passing therebetween. The shafts 9', 10' are connected to a source of power whereby they can be driven. 13 and 14 are rolls which are covered about their peripheries by cylinders 11 of material, just as are the guide rolls 9 and 10. 15 and 16 are endless belts, two transversely-spaced belts 15 being stretched between and entrained about the rolls 9 and 13 and two transversely-spaced belts 16 being stretched between and entrained about the rolls 10 and 14. The belts 15 and 16 are driven in the direction indicated by the arrows, and a path 17 for supply of a row of paper tubes 1 is formed between the belts 15 and 16. 18 and 19 are separating rolls which are of truncated conical shape with the larger diameters uppermost, are fixed on spaced and parallel vertical shafts 18' and 19' respectively, and are covered about their peripheries by sheaths 11 of elastic material such as sponge. The drive to the separating rolls 18 and 19 is such that the smaller diameter portions thereof have a peripheral speed greater than the linear speed of the belts 15 and 16, and the separating rolls 18 and 19 are mounted opposite to each other at the exit from the path 17 along which the row of paper tubes 1 is supplied.

With the paper tube separating device 8 constructed as described, the row of paper tubes 1 is progressed uniformly along the supply path 17 by the belts 15 and 16 rotating at a constant speed, and, at the exit from the path 17, the leading paper tube la is nipped by the separating rolls 18 and 19. The rotary speed of the separating rolls is greater than that of the belts 15 and 16 between which is the paper tube supply path 17, and the greater diameter of the frusto-concial separating rolls is uppermost, so that the peripheral speed of the separating rolls progressively increases from the lower to the upper ends thereof and, accordingly, the connecting webs 3 between adjacent paper tubes 1 are progressively ruptured by the separating rolls 18 and 19. The separated paper tubes 1 are progressively planted by means of an appropriate planting machine such as that shown in Figs. 7a and 7b.

In use of the machine shown in Figs. 7a and 7b, the drop pipe 20 is mounted below the separating rolls 18 and 19, whereby the paper tubes 1 can be planted in a field by making use of the force gravity, so that the paper tubes 1 can be automatically separated individually from the continuous series thereof and planted with the seedlings 7 accommodated therein by successive repetition of the operations just described.

Figs. 5 and 6 are similar to Figs. 3 and 4 and, where appropriate, use is made of identical reference numerals. In Figs. 5 and 6, however, the separating rolls are cylindrical and are denoted 18a and 19a. The rolls 18a and 19a are fixed on shafts 18a' and 19a' spaced one to each side of and parallel to the median vertical plane of the path defined between the adjacent runs of the belts 15 and 16, the shafts 18a' and 19a', and hence the rolls 18a and 19a, being inclined such that the distance, at the exit end of said path, between the peripheries of the cylindrical coverings of the rolls 1 8a and 19a-and the cylindrical coverings 11 of the guide rolls 13 and 14, respectively, progressively increases from the upper to the lower ends of the rolls 18a and 19a, thereby producing a substantial difference between the tensile forces at the upper and lower ends of the paper tubes 1 of the row of paper tubes 1 contacting the cylindrical coverings of the rolls 1 8a and 19a, whereby the same effect is brought about as with the cone rolls 18 and 19 of Figs. 3 and 4. It is within the scope of the present invention to use any device which can produce a substantial difference between the upper and lower ends of the connecting webs 3 of the pulling-out force applied to said webs.

Figs. 7a and 7b show a transplanting machine for transplanting the separated seedling 7,21 denoting a machine frame and 22 an endless belt conveyor on which is carried the assembly P of the continuous series of inter-connected paper tubes each accommodating a seedling 7, the conveyor 22 being stretched between and entrained around a drive pulley 22c and a driven pulley 22d, which are fixed on shafts 22a and 22b, respectively, said shafts being respectively supported on support rods 21a and 21b mounted on the machine frame 21.23 denotes wheels which are mounted on a shaft 24 rotatably mounted on the machine frame 21. 25a, 25b... 25f denote chain sprockets, the chain sprocket 25a being mounted on the shaft 24, the chain sprockets 25b and 25c on a shaft 26a, the chain sprockets 25d and 25e on a shaft 26b, and the chain sprocket 25f on the drive pulley shaft 22a, respectively. 27a, 27b and 27c denote endless chains, the chain 27a being stretched between and entrained around the chain sprockets 25a and 25b, the chain 27b between and around the chain sprockets 25c and 25d, and the chain 27c between and around the chain sprockets 25e and 25f respectively.

Considering the transplanting machine as travelling in the direction of the arrow A, the wheels 23 rotate in the direction of the arrow A', and this rotation causes rotation of the chain sprockets 25fin the direction of the arrow A" through the chain sprockets 25a,25b... 25e and the chains 27a, 27b and 27c, and thereby the belt conveyor pulley 22c rotates, resulting in rotation of the belt conveyor 22, so that the paper tube assembly P on the belt conveyor 22 progresses in the direction of the arrow B. 8 denotes a paper tube separating device as hereinbefore described with reference to Figs. 3 and 4, the shafts 9, 10, 13 and 14 of which are journalled on a horizontal plate 28 fixed on the machine frame 21 at the forward end of the belt conveyor 22 and spaced from the latter in co-planar relationship with the upper run of the belt conveyor 22. The separating rolls 1 8a and 19a are constructed and arranged as hereinbefore described with reference to Figs. 5 and 6. In locating the separating rolls 1 8a and 1 9a in relation to the rolls 13 and 14, respectively, it is preferable in order to ensure the separation that the distance (D) between the rolls 1 8a and 13 on the one hand, and between the rolls 1 9a and 14, on the other hand, midway of the length of the rolls, is less than twice a unit length (L) which is the width between opposed flats of a paper tube plus respective halves of the width of the connecting webs associated with an forward and rearward of this paper tube.

29 denotes a bevel gear which is fixed on the lower end of the shaft 10' of the rotary roll 10 and meshing with a corresponding bevel gear (not shown) mounted on the shaft 26b. A bevel gear (not shown) is also mounted on the lower end of the shaft 9' of the rotary roll 9 and is in mesh with said corresponding bevel gear mounted on the shaft 26b. The bevel gear of the shaft 26b driving the bevel gear 29 of the shaft 10' and that of the shaft 9' is arranged so as to rotate the shafts 10' and 9' in the opposite directions, and the rolls 10 and 9 are rotated in the direction of the arrows shown both in Fig. 3 and in Fig. 5, through the rotation of the shaft 26b. Also, owing to the rotation of the shaft 26b, the belts 15 and 16 rotate through the rotary rolls 9 and 10. Chains 32 are stretched between and entrained about the gear 30 mounted on the shaft 10' and the gear 31 mounted on the shaft l9a' of the separating roll 19a, and between and about the gear 30 mounted on the shaft 9' and the gear mounted on the shaft 18a' of the separating roll 18a, and thereby the separation rolls 18a and 19a are rotated in directions of the arrows as shown in Figs. 5. As a result of the construction just described, the rotary rolls 9 and 10 are rotated through the rotation of the wheel 23 and the belts 15 and 16 are thereby rotated so that the paper tube assembly P is progressed in the form of a row of successive tubes along the supply path 17. When the leading paper tube la reaches the exit end of the path 17 and makes contact with the separation rolls 1 8a and 1 9a as hereinbefore described, and since the rotary rolls 13 and 14 and the separation rolls 18a and 19a are located at an interval of D S 2L, the leading paper tube la is nipped and rolled in between the separation rolls 18a and 19a contemporaneously with the second paper tube being firmly nipped between the rotary rolls 13 and 14. Since the peripheral speed of the lower portions of the separation rolls 18a and 19a is greater than the speed at which the seedlings in the row of paper tubes 1 is supplied, the leading paper tube la has applied thereto a force tending to pull it away from the second paper tube and also since the separation rolls 18a and 19a are inclined, as hereinbefore described, with the lower ends thereof leading in the direction of movement of the transplanting machine, the leading paper tube la is nipped initially between the rolls 1 8a and 1 9a at the upper ends of the latter and, progressively therefrom, towards the lower ends of the rolls 18a and 19a, whereby the pulling action varies from the upper to the lower ends of the rolls and the force acting on-the connecting web 3 between the leading paper tube la and the second paper tube gradually increases at the upper portion of the web and gradually decreases at the lower portion of the web, so that the connecting web 3 is divided along the separation line 6' progressively downwards from the vertical slit 4 thereby positively causing V-shaped separation of the connecting web 3. The ratio of the linear speed of the belts 15 and 16 resulting from the rotary rolls 9 and 10 and 13 and 14 to the speed of rotation of the separation rolls 1 8a and 19a can be easily determined by the ratio of rotation of the chain sprockets 30, 30 to that of the chain sprockets 31, 31 mounted on their respective shafts 9', 10' and 18a', 19a'. There is a problem that, upon pul by the separating rolls 1 8a and 19a is positively guided in an upright attitude into the receiving mouth of the drop pipe tube 20 and is dropped in such attitude. 34 denotes a first seedling control plate connected to the lower portion of the drop pipe 20 and composed of a tube mounted so as to incline at a given angle a to the progressing direction of the transplanting machine, or a plate body having a flat plane or curved face to make sliding contact with the side face of the upstanding paper tube in order that' the seedlingaccommodating paper tubes dropping gravitationally through the drop pipe 20 continue so to drop while making sliding contact with the first seedling control plate 34. 35 denotes a second seedling control plate which is mounted opposite to the exit end 34a (Fig. 10) of the first seedling control plate 34 and is at the rear face of an opener 36 having a forward and downward inclination and forming the lower portion of a support rod 37 fixed to the machine frame 21 to depend therefrom forwardly of the drop pipe 20. The upper end of the second seedling control plate 35 is opposite to the first seedling control plate 34 and the lower end thereof has a length corresponding to the depth of the furrow made by the opener 36. The second seedling control plate 35 is adapted to receive the seedling-accommodating tubes 1 slidingly dropped from the exit end 34a of the first seedling control plate 34 and is composed of a plate body having a downwardly-directed flat plane or curved face to make sliding contact with the paper tubes 1. The inclination angle ss of the second seedling control plate 35 is greater than the inclination angle a of the first seedling control plate 34, and thereby the seedling-accommodating paper tubes 1 dropped from the exit end 34a of the first seedling control plate are suitably guided to the ground and are always placed in the furrow at a constant angle to the bottom of the furrow. The second seedling control plate 35 may be attached directly to the rear face of the opener 36 or, alternatively, may be mounted behind the opener 36 at an appropriate interval therefrom. In the embodiment now being described, the first seedling control plate 34 and the second seedling control plate 35 are mounted individually and separately, but they may constitute a single tube formed by connecting them together with each having an appropriate exit portion at a given position. The second seedling control plate may be a slit body providing the paper tubes 1 can slide thereon, and the paper tubes 1 are always controlled by said second seedling control plate 35 to have a constant attitude and thus be placed in the furrow, the soil turned up in making the furrow by means of the opener 36 being replaced in the furrow so that said paper tubes 1 are buried by the replaced soil and then have an almost vertical attitude, thereby completing the transplanting of the paper tubes. 38 denotes a disc coulter which is rotatably supported by a shaft 40 on a bracket 39 fixed to the support rod 37 and is mounted near the front of the opener 36, thereby being adapted to prevent the intertwining of trash, such as thin roots of plants included in the soil of the field, which could obstruct the production of a cut furrow by means of the opener 36.

The continuous series of paper tubes making up an assembly which can be used in the present invention, may be formed in the manners illustrated in Figs. 11-a to 1 1-e. In the series illustrated in Fig. 11-a, two films 2a and 2a' are pasted together by means of a waterproof paste 41 to form the web connecting adjacent paper tubes. In the series illustrated in Fig. 11-b and that illustrated in Fig. 11-c the web is constituted by a single film 2a, and in the series illustrated in Figs. 11-d and 11-f the overlapped portions of two films 2a and 2a' are partly pasted together by means of a water-proof paste 41. These connecting methods forming the webs connecting adjacent paper tubes are known per se, and even if such constructions are adopted, it is possible to attain approximately the same effects as those hereinbefore described. Also, in the series illustrated in Figs. 1 1-d and 11-f wherein two films are partly pasted together, the distribution of the joined portions may be such that the joined portions are distributed slenderly continuously over the length of a defined range in the direction of the height of the webs thereby attaining approximately the same object.

As hereinbefore described, the method and apparatus in accordance with the present invention has made possible very economically the fully automatic separation and transplanting of plant seedlings by means of an assembly of a continuous series of seedlingaccommodating paper tubes, and as a result the productivity of agricultural labour can be considerably increased.

Hereinafter, embodiments of the present inve'ntion will be explained.

Example 1: Kraft paper 60g/m2 had applied thereto hydrated solution of copper 8-hydroxyquinolinolate having 1% of the component on the surface and was dried to make rot-proof paper, and two sheets of this paper were pasted together to make paper tubes intended for beet and of hexagonal cross-section with a diagonal length of 1.9 cm and a height of 13 cm when developed. The adjacent paper tubes of a continuous series were interconnected by webs of width 0.95 mm in which were separation guide lines vertically bisecting the individual webs and made up of vertical slits 4 cm in length and extending through the upper edges of the webs and following thereupon unbroken portions 6 mm in length alternating with slits 2.4 mm in length throughout the height of the webs. Ten successive paper tubes of the series were arranged in line, and then the next ten paper tubes of the series were overlapped therewith with an offset of a half-pitch of a paper tube, the two lines of ten successive tubes being pasted together in such relationship by means of a water soluble paste, and, continuing in this way, 140 lines, each of ten successive tubes, were laminated, thereby making a unit comprising an assembly of a continuous series of paper tubes, including 1400 paper tubes, and a number of the units were so produced.

In such paper tubes, sugar beet were raised in a cold bed, and one assembly of the seedling-accommodating paper tubes was put on the belt conveyor 22 of the transplanting machine shown in Figs. 7-a and 7-b. The wheels 23, the shafts 9' and 10' of the rotary rollers 9 and 10, and the shafts 18a' and 19a' of the separating rolls 18a and 19a were drivingly connected by means of the chain 32, and furrows were produced by means of the opener. The 1400 paper tubes were pulled out from one end of the front line thereof by means of the rotary rollers 9 and 10, upstream of which are the separating mechanisms. The rotary rollers 9 and 10 have a peripheral speed of 9cm/sec., the separating rolls of the separating mechanism have a linear speed ratio of the upper end thereof to the lower end thereof 2:1, and the lower end having a peripheral speed of about 9cm/sec. The separated seedlings of a unit including 1400 paper tubes were transplanted at a speed of 0.9m/sec. by means of a transplanting apparatus as described hereinbefore with reference to and as shown in Figs. 7-a, 7-b, 8, 9, 10, 10-a, 10-b and 10c of the accompanying drawings. The separation of the seedlingaccommodating paper tubes was attained very smoothly, and perfect automatic mechanical separation was performed without cutting-off of the connecting webs during such operation, and there was no mechanical damage of the seedlings and almost all of the seedlingaccommodating paper tubes seedlings were planted in the field in the upright position.

Example 2: Using the same paper material as that in Example 1, a large number of units of the paper tube assembly were made, each unit including a total of 700 paper tubes, having 7 paper tubes in each of 100 lines laminated together. The paper tubes were intended for corn and each had a regular hexagonal shape in section with a diagonal length of 3 cm and a height of 10 cm. The separation guide line vertically bisecting the connecting web between adjacent paper tubes or pots was made up of a vertical slit of length 3.5 cm extending through the upper edge of the web and, following thereupon over the remaining 6.5 cm. length of the separation line, three unbroken portions of 6 mm alternating with slits.

After sweet corn had been nursed in these paper tubes, the paper tube assembly was put on the carrier as a unit without disruption of same, and the seedling-accommodating lines of paper tubes were pulled out in the form of a continuous row, the individual paper tubes were separated from one another, and planted utilizing a transplanting machine similar to that used in Example 1, save that the separating rolls upstream of the rotary rollers 9 and 10 of the paper tube separating device are not of cone shape as in Example 1, but were cylindrical and parallel. The lower ends of the separating rolls are spaced at an interval of 1.6 cm from the rolls 13 and 14, the cylindrical rolls being inclined at about 15 to the progressing direction of the row of seedling-accommodating paper tubes. The cylindrical separating rolls are of diameter 4 cm and height 12 cm and are covered about their peripheries by cylinders of urethane sponge material. 700 of the paper tubes were transplanted fully automatically at a speed of 0.9m/sec., with the result that both the separation and the transplanting were 100% perfect.

Claims (9)

WHAT WE CLAIM IS:

1. A method of separating and transplanting seedling-accommodating tubes one by one successively from an assembly of a continuous series of the tubes comprising forming said assembly from upright open-ended but flattened tubes made of rot-proof film and adjacent ones of which are interconnected by webs so that the tubes can be pulled out thereof in the form of a continuous row, folding the row right and left alternately at every given number of the tubes to form the latter line upon line and pasting the tubes of adjacent lines together by a water soluble paste, expanding said assembled tubes, filling soil into said tubes and sowing therein and raising the seedlings, and, at the time of transplanting, pulling out the seedlingaccommodating tubes from one end thereof in the' form of a continuous row and successively separating them into individual seedling-accommodating tubes and transplanting them, such separation being facilitated by preforming in said interconnecting webs separation lines bisecting the webs and each formed by a sequence of slits alternating with unbroken portions, an end slit or slits of said sequence extending through the upper and/or the lower edge of the connecting web to form a guide portion or portions and the unbroken portions being a total length between 30% and 80% of the height of the web, whereby they can resist the tensile force by which the seedling-accommodating tubes are pulled out in the form of a row but can easily be sundered by the application of a mechanical instantaneous tensile force, and inducing the sundering of the unbroken portions starting from the or a said guide portions by applying a mechanical instantaneous tensile force to the adjacent tubes interconnected by the pertaining web, thereby to separate said tubes from one another by progressively dividing the web along said separation line from the bottom to the top or from the top to the bottom.

2. An assembly of a continuous series of upright open-ended tubes made of rot-proof film and adjacent ones of which are interconnected by webs which permit the tubes to be pulled out in the form of a row from the assembly, the row being folded right and left alternately at every given number of the tubes to form the latter line upon line; and the tubes of adjacent lines being pasted together by a water soluble paste, the webs having therein separation lines bisecting the individual webs and each formed by a sequence of slits alternating with unbroken portions with an end slit or slits of said sequence extending through the upper and/or the lower edge of the connecting web to form a guide portion or portions, the total length of the slits of a said sequence being between 20% and 70% of the height of the web, and the unbroken portions being of a total length between 30% and 80% of the height of the web.

3. A transplanting apparatus for planting seedling-accommodating upright and openended tubes made of rot-proof film by pulling out the tubes in a continuous row from one end of the foremost line of an assembly of a continuous series of tubes adjacent ones of which are interconnected by webs and which series has been folded right and left alternately at every given number of the tubes to form the latter line upon line the tubes of which have been pasted together by a water-soluble paste, said connecting webs having therein separation lines vertically bisecting the individual webs and each formed by a sequence of slits alternating with unbroken portions with an end slit or slits of said sequence extending through the upper and/or the lower edge of the connecting web to form a guide portion or portions, the transplanting apparatus comprising a conveyor system adapted to progress forwards at a constant speed the assembly of seedling-accommodating tubes loaded thereon with lines of tubes transverse to the direction of progress, said conveyor system being mounted on and spaced above a carrier with the direction of progress of the conveyor system the same as the direction of progress of the carrier, a tube-feeding mechanism comprising at least one pair of rotary bodies clad with elastic material and arranged at the downstream end of said conveyor system both to the right and the left of the seedling-accommodating tubes progressing in a row to nip said tubes, and means to rotate said rotary bodies in the mutually-opposite directions, a separating mechanism at the downstream end of said feeding mechanism and comprising a pair of frusto-conical bodies, or cylindrical bodies mounted at an inclination, clad with elastic material, and means to rotate said separating mechanism bodies in the mutually-opposite directions and at a peripheral speed greater than that of said rotary bodies, said separating mechanism bodies being positioned both to the right and to the left of the progressing seedling-accommodating tubes to nip the tubes, and being so arranged that there is a time differential between the pull exerted on the tubes at the upper and lower portions thereof on being nipped between the conical or cylindrical bodies, and a planting device comprising a tube guide mounted at the upstream end of said separating mechanism, a tube-delivery pipe mounted below said guide and seedling control plate means at the lower end of said tube-delivery pipe.

4. A transplanting apparatus as claimed in Claim 3, wherein the speed of progress of the conveyor system and the peripheral speed of the rotary bodies of the feeding mechanism are in a constant ratio.

5. A transplanting apparatus as claimed in Claim 3 or 4, wherein the tube limiter has substantially the same height as that of said separating mechanism bodies.

6. A transplanting apparatus as claimed in Claim 3, 4 or 5, said seedling control plate means comprises a first plate inclined at a given angle to the progressing direction of the carrier, and a second plate mounted opposite to the exit end of said first plate and is inclined at an angle greater than the angle of inclination of the first plate to control the dropping direction and position of the seedlings, the first and second plates defining a seedling guide path, and a soil opener immediately forward of said second plate.

7. A method of separating and transplanting seedling-accommodating tubes, substantially as hereinbefore described with reference to the accompanying drawings.

8. An assembly of a continuous series of upright open-ended tubes, substantially as hereinbefore described with reference to the accompanying drawings.

9. Apparatus for separating and transplanting seedling-accommodating tubes, substantially as hereinbefore described with reference to the accompanying drawings.