EP0699022A1 - Method and means for planting of tree plants - Google Patents

Abstract

The invention relates to an apparatus for the planting of tree plants. With a frontal portion (12) of a bucket (10) a planting patch is cleared from humus material and at the same time a scraper blade (30) protruding downwards under the bucket scrapes up a heap of mineral soil (72) below the bucket. After that the bucket is positioned horizontally and a planting device (28) located behind a partition wall (16) in the bucket makes a planting hole (48) in the heap (72) with a mandrel (56). A plant is fed forward to and down into the hole through a hose (52) and finally the earth is pressed together around the plant with a stamp (82, 84).

Description

METHOD AND MEANS FOR PLANTING OF TREE PLANTS.

The present invention relates to a method for planting of tree plants as defined in the preamble of claim 1. It also relates to an apparatus for the performing of the metnod as defined in the preamble of claim 4.

The method and apparatus is above all intended for use at reforestation on clearings. Lack of skilled labour and the hig cost of wages has resulted in that there presently are few possibilities to carry out reforestation of forests in a traditional manner with manual planting. Furthermore, use of machines for treefelling and trimming of branches results in concentrated heaps of branches, which also have to be removed mechanically before planting is possible, otherwise these area will be left unplanted.

At mechanical planting two different operations will be carrie out; preparation of the ground to a suitable planting spot and the actual planting of the tree plants. The object of the invention is primarily to accomplish an improved ground preparation, but it also provides a new and favourable method for the carrying out of the actual planting after completed preparation of the planting spot.

At reforestation it is important not only to plant enough tree plants but also that these plants will get good conditions for survival, such that complementary planting would not be necessary. This is accomplished through some kind of ground preparation, that removes competitive, existing vegetation. This is best accomplished through the scraping away of the vegetation cover and the underlaying decaying plant residues and humus layer, so that the planting can be performed in mineral soil or a mixture of humus- and mineral soil.

One method is to continually or in patches tear away a turf an turn this up-side-down and then plant the new plants in the no exposed mineral soil layer on top, the so called reversed turf method. A similar result is obtained by digging up a number of holes with an excavator in the clearing and putting the soil i a heap at the side of the holes. In all these cases it applies that the heap or the reversed turf ought to/must be given time to stabilize before planting can be carried out to prevent drying out and plant death. In this way the planting must be carried out as two separate operations and one season of growt will be lost.

If you plant in the hole that is created by the patch preparation or plowing instead of on the reversed turf, you face the risk that the hole will be filled with water and that the plant dies. Furthermore, the holes will have a different micro-climate with frequently several degrees lower temperatur than the surroundings, and the plant might then freeze to death.

At a further method you use one or several towed, inclined scarifying wheels, that removes vegetation cover and humus layer and creates a string of mineral soil. In this string of mineral soil a following vertically movable planting device plants tree plants at regular intervals. When meeting obstacle for planting, for example stones and stubs, the planting devic is lifted and new attempts are performed at short intervals until planting can be carried out. This machine is sensitive t broken or stony ground, since planting is done in rows and behind the tow- or carry vehicle. In difficult ground this results in sparse plant populations unless manual complementar planting is carried out.

Another proposed apparatus comprises a towed scarifying wheel for patch preparation followed in the direction of movement by a vertically movable scraper blade for scraping up planting heaps in the patches scraped bare. The blade is suspended in linkage arms and its movements are synchronised with those of the scarifying wheel. A safety system lifts the scraper blade if it runs into an obstacle. The machine can also be fitted with a planting device for tree plants for planting simultaneously with the making of planting heaps. This machine is obviously very sensitive to stubs, stones and uneven ground especially if two or more scarifying wheels are arranged besid each other. In difficult ground you can expect a large amount of unprepared or unplanted planting positions and therefore a poor planting result.

DE 2 854 922 describes a planting device consisting of a planting pipe with a vertically movable mandrel for plant hole making. The mandrel is vibrating so as to be able to glide pas or push away stones and other obstacles. A plant feeding tube is leading obliquely into the planting tube. After completed hole making the mandrel is lifted and a plant is allowed to fall down into the hole. Finally a collar at the orifice of th planting tube compresses the soil around the plant.

This device has the disadvantage that the plant feeding tube i leading into the planting tube in an inclined direction immediately above its opening. The plant is then not given the opportunity to straighten up and fall vertically into the planting hole. Therefore, there is an obvious risk that the plants are disadvantageously planted in a leaning position wit this device. The fact is that it has been shown, that a plant which is planted in a leaning position certainly can survive, but the quality of the lumber will become considerably poorer, since the trunk becomes crooked. This is caused by that the trunk straightens out vertically at the top of the plant while at the same time a considerable additional growth takes place underneath. The result will be that the trunk for the length o two levels of side branches will grow in inclined direction, which can give a loss of straight lumber log at the tree base for 1-2 meters. Leaning plants is also frequently occurring with manual planting.

In particularly stony ground it has been proposed the so calle added soil planting method. The planting apparatus is mounted on an arm from a carrier, often a modified forwarder or harvester. On the carrier there are both a plant feeding devic and a device for feeding of additional soil to create a soil heap around the plant. On the planting apparatus there is a couple of scraper blades intended for the removal of vegetatio and other material thus creating a planting patch. After that this has been done a certain amount of additional soil is deposited through an outer tube, whereupon an inner planting tube is pushed down into the soil heap and deposits a plant into it. The planting tube has a tip consisting of two half cones which are jointed at their top ends and can be opened up. The tip is pushed down into the soil heap until the intended planting depth is reached, then it opens up and the plant is released. According to some machine embodiments the added soil heap can finally be compressed against the plants soil clod with a reversed funnel or rubber cone.

The object of the invention is therefore to provide a new method for tree planting, that enables -a fast planting operation with patch preparation, soil heap making and planting in a continuous operation and at an arbitrary location in relation to the position and driving path of the carrier vehicle. The object is further to accomplish a method, that makes it possible to use the same machine both for soil heap making with existing material and for added soil planting with added external soil.

These objects are achieved with an inventive tree planting method which has essentially the characteristic features set forth in the characterizing clause of Claim 1.

A further object of the invention is to accomplish an apparatus to carry out the above mentioned method, which apparatus has a robust construction with good durability when working in difficult ground, which during the excavation stage exhibits few moving parts, which has low maintenance costs with easily exchangeable wear parts and which is easy to mount on existing forest machines and excavators with no or small constructional changes.

These objects are achieved with an inventive apparatus which has essentially the characteristic features set forth in the characterizing clause of Claim 4. The invention will now be described with reference to non- limiting embodiments thereof and with reference to the accompanying, schematic drawings, in which:

Fig 1 is a cross-sectional side view of an apparatus according to the invention,

Fig 2 is a view from above of the apparatus in fig 1,

Fig 3 is a front view in section of the apparatus in fig 1,

fig 4 is a cross-sectional detail view of the apparatus in a-c fig 1 showing the planting device of the apparatus during different phases of the-course of events in a planting operation,

fig 5 is a front view of a second embodiment of the invention,

fig 6 is a cross-sectional side view of the apparatus in fig 5,

fig 7 are detailed views of an alternative planting device and 8 under different stages of a planting operation and

fig 9 are a schematic side view and a front view of a third and 10 embodiment of the invention.

The inventive apparatus consists of a bucket 10, whose frontal portion constitutes a first digging or scraping means 12. The frontal portion is separated from the buckets rear portion 14 by a partition wall 16. The scraping means 12 exhibits digging teeth 13 at its front edge 15. The bucket 10 is mounted on an arm 18 and is pivotable with a power cylinder 20 and linkage arms 22, 24.

In the buckets rear portion 14 there is arranged a second digging and scraping means 26 and a planting device commonly designated with 28. The digging and scraping means 26 comprise a scraper blade 30, that is guided by a guide 32 and can be pushed down through an opening 34 in the bottom 36 of the bucket with a power cylinder 38. The level of the scraper blade is indicated by a known, schematically shown sensor device 40, for example a limit switch. With the aid of the sensor device and the sensor points 41 on the scraper blade 30 interacting therewith, this level can be sensed and shown on a display in the operators cabin of the carrier. The upper end of the power cylinder is attached to the buckets upper part 42. In order to give additional stability to the scraper blade its guide 32 can be attached in addition to to the bottom of the bucket 36 also to its rear part 44, its sides 45 or its upper part 42 for example with stays 46.

The planting device 28 consists of a piercing mandrel 50, a planting tube 52 and a soil packing means 54 arranged in an opening 55 in the bottom of the bucket 36. The piercing mandrel 50 consists of a mandrel 56 with an exchangeable tip 58. The mandrel is attached to the lower end of a power cylinder 60, the upper part of which is pivotally attached to the buckets upper part 42 or in the upper part of one only in fig 2 shown frame 62, wherein all parts of the planting device 28 are mounted. In use the mandrel 56 is pressed down through an opening 64 arranged in the centre of the soil packing means 54. At the mandrel there are schematically indicated a depth indicators 67, that shows when and if the mandrel have been pressed down to the intended planting depth. It can be a limit switch or a non-contact sensor and also show a completely pulled up position (fig 4c) as well as an intermediate rest position (fig 4a).

When the mandrel 56 is pulled up, it is simultaneously moved sideways by a tension spring 66 along a slanted slide plate 68 for the mandrel tip. In this way the central part of the planting device 28 is exposed for the planting tube 52. This makes it possible to deposit a tree plant 70 substantially vertically down into a hole 48 created by the mandrel 56 in a soil heap 72 made by the scraper blade 30. The planting device itself consist partly of the above mentioned planting tube 52 and partly of an arbitrary plant feeding device known as such. In the described and illustrated example the planting tube consists of a pipe or a ho^-e 74 through which the plant 70 is fed through. During the piercing operation the orifice 76 of the planting tube is situated abov a stop plane 78 against which the plants root clod is intended to rest and be stabilized in its position waiting for a soil heap with a plant hole to be ready for it. In this way the plant transportation portion of the cycle time for the plantin operation is minimized. The planting tube is attached with a linkage stay 80 to the power cylinder 60 of the mandrel 56 or machine part connected therewith, such that when the mandrel has been pulled to the side after completed piercing, the planting tube will be pulled in over the opening 64 and the plant will immediately fall down into the waiting planting hole. To ensure that the plant is being placed as vertically a possible, the orifice part 77 of the planting tube is constructed so as to place itself in a vertical position when brought in over the opening 64.

In figure 7 and 8 there is shown an alternative device to sustain a plant in a waiting position. The hose 74 here exhibits a soft, compressible section 100, that collaborates with a counter-hold 102 in order to create a strangulating hol in the waiting position, such that the plant 70 can not pass. Furthermore, this soft section makes it possible for the orifice part to straighten up during the planting phase (fig 8 to a vertical position to give the plant a long, vertical passage down into the planting hole 48.

The soil packing means 54 consists of a stamp 82, that at the bottom exhibits an work cone 84 being exchangeable, so as to b able to give an appropriate slope of the soil heap around the plant depending on the soil material characteristics. In the centre of the stamp and work cone there is the above-mentioned opening 64 for the passage of the mandrel 56 and the plant 70. On top the stamp 82 exhibits a power cylinder 86, the upper en thereof being attached to the buckets upper part 42 or the upper part of the frame 62.

To ensure that the planting device 28 is standing vertically it is provided with a cross fall indicator 92, that is connected to a control unit and/or a display in the cabin. The indicator 92 measures the tilting angle both in the buckets pivoting plane, and in a plane at right angles thereto. The fact is tha it is not possible to get the bucket entirely horizontal, when the carrier is standing aslant on uneven ground. To eliminate this inconvenience, the frame 62 can be pivotally mounted on a horizontal shaft 88 and can then be placed in vertical positio with the aid of a power cylinder 90 after that the bucket firs has been placed as flat as possible. (See fig 2) In the embodiment of fig 5 and 6 the bucket 10 itself is mounted in a yoke 94 with hinged mounting points 96 on the bucket arranged in the pivoting plane of the bucket arms 18-24. Tilting of the bucket sideways here is done with the aid of two power cylinders 98.

The apparatus operates in the following way. On an appropriate planting spot the bucket is lowered with its front part turned somewhat downwards against the ground. It is pulled towards th carrier and at the same time the bucket toe is turned upwards to horizontal position, the clearing debris, vegetation cover and humus layer A being scraped away under exposure of a patch of mineral soil B. When the bucket is placed in a horizontal position the scraper blade 30, which is protruding downwards under the bottom 36 of the bucket, is pressed down into the mineral soil B. There it begins to dig out a hole 71 and at th same time it makes a heap 72 of mineral soil in front of itself in its direction of movement. At the end of the patch preparation and the soil heap making this growing mineral soil heap will press the bucket upwards, such that the buckets fron edge describes a track ever higher up in the humus layer and vegetation cover.

At this stage the bucket motion is discontinued and the bucket is positioned substantially flat with the planting tube vertical. Thereafter the operator pushes on the start button for the actual planting operation, as shown in fig 4 a-c and fig 7 and 8. This is preferably sequence controlled by a control unit or other control means, such that when a part- operation has been successfully finalized the next one is automatically put in effect. At first the planting apparatus i fine adjusted to a vertical position by the control unit with the aid of the cross fall indicators 92. Thereafter the mandre 56 is pressed down into the soil heap 72 to create a hole 48 with the intended planting depth. If the depth indicator 67 shows, that the mandrel 56 have not reached the intended depth the planting attempt is abandoned. The mandrel is lifted and the bucket is moved a bit, whereupon a new attempt is made. If worst comes to worst you start again and scrape up a new patch and heap as earlier described.

In those cases that the hole making is successful, the mandrel is yet again lifted, its tip being moved to the side by the tension spring 66. At the same time the planting tube 52 is moved in over the hole 64 and a plant 70 is released and is allowed to fall down into the newly created planting hole (fig 8). After an appropriate time lapse to let the plant fall into place, the power cylinder 86 presses the stamp 82 with its wor cone 84 downwards against the soil in the planting heap 72 and compresses this around the plants soil clod. Thereby the walls of the hole 48 are pressed together against the soil clod, suc that a good connection is made against the surrounding soil in the planting heap and cavities are avoided. This is shown with broken lines 104 in figure 8. Finally the bucket is lifted up as vertically as possible and high enough to move clear away from the plant and then the bucket is moved sideways for a new planting operation. Advantageously, this bucket lifting can be a step in the planting sequence with a simultaneous interlocking against side movements, such that a premature sid movement of the bucket will not cause tilting or pulling out o the plant.

In stony or in other ways difficult ground the apparatus according to the invention can be used for planting with the adding soil method on especially difficult places. The adding soil is then taken from a nearby, unplanted point without moving the carrier or from a supply of adding soil transported by the carrier, for example from a cart towed by the carrier. The cart can thereby occasionally during the course of plantin be refilled, for example when the bucket is being used for digging drainage trenches. The planting process is in this case initially started with the filling up of the buckets front part 12 with adding soil for one or several planting operations fro any of the above-mentioned added soil sources. Thereafter the bucket is moved to the intended planting spot with the bucket tip 13 pointed upwards, such that the scraper blade 30 will come into contact with the ground first and by being pulled towards the operator scrapes away at least most of the clearing debris, vegetation and stones on the planting spot. Thereafter the bucket is moved back, the front part is tipped downwards and an appropriate amount of additional soil is poured out onto the cleaned patch. Then the bucket is positioned flat and lowered with its planting device 28 over the deposited soil heap. After that the operator pushes the start button for planting and a planting sequence such as earlier described is started. If the piercing mandrel 56 encounters any obstacles, it is first attempted to move the point of planting. If this does not help more soil is added or another spot is chosen.

The inventive apparatus is not restricted to the use of the planting device of the type described above. The planting device may just as well be one of the initially mentioned type, where the planting tube displays a piercing tip, which can be opened. In this case the special piercing mandrel is omitted. Such a device is however more sensitive and more numerous breakdowns and repairs can be expected. Furthermore, the second digging and scraping means 26 may be a fixed blade 30 attached underneath the bucket 10 instead of a vertically movable blade. Then the bucket becomes less suitable for ordinary excavation work, since the blade is constantly protruding downwards and cannot be lifted out of the way. The different power cylinders are preferably hydraulic cylinders, but can also be pneumatic cylinders or a mechanica or an electrical arrangement for linear movement. The term power cylinder here means an arbitrary arrangement for linear movement.

The carrier for the planting apparatus is suitably an excavat or a so called harvester for tree felling. The bucket is a trenching bucket that has appropriate bucket width or a bucke of special construction. The figures 9 and 10 show a bucket 10 especially intended to be mounted on a harvester. It consists of an extension arm 106 to the vehicles existing boom 18. The arm and a power cylinder 20 are attached to the front leg 108 of the U-shaped yoke 94. The bucket is- tipped sideways in relation to the yoke with a power cylinder 98. Otherwise this bucket corresponds to those earlier described with the same kind of scraping means 26 and planting device 28.

During planting the carrier is moved forwards one planting spacing and plants tree plants in a semicircle behind itself. New repositioning and a new semi-circle. At the circle end parts the planting is done sparser in some rows such that the spacing will not be to dense. ith the bucket it is also possible when the need arises to make smaller excavations for drainage and to clear planting spots also in those big debris banks, that a modern harvester leaves behind. Since the bucke effectively can clear clean cultivation spots also on fresh clearings, it is possible to plant new forest immediately aft deforestation without waiting for the clearing debris to shed its needles. Thereby one growth season is gained.

It will be understood that the invention is not restricted to the described and illustrated embodiments, but that modifications can be made within the scope of the inventive concept as defined in the following claims. For instance, instead of a cylinder operated, movable stamp 54-, the bottom 3 of the bucket can be used as a stamp and be pushed down a little more by the bucket arm 18 after that the plant 70 has been put in place. The bottom has then suitably a funnel shape elevation around its opening 64. Especially when the bucket is used as stamp, but also otherwise it can be suitable to lift the bucket or the stamp 54 before planting such that the planting hole will not collapse before the plant is in place.

Furthermore, according to the invention the apparatus can be used to sow one or several tree seeds in every planting spot. The seeds can either be naked seeds or covered in a soil or peat clod. It is also possible to arrange supply means for fertiliser, pesticides and/or water in connection with the planting apparatus.

The piercing mandrel 50 can advantageously be designed with longitudinal grooves or ridges, that creates planting holes with corresponding ridges and valleys in their walls. Thereby the so called twisted roots syndrome is avoided, i. e. the plants roots only grow round in circles around the walls of th hole instead of penetrating them into the surrounding ground. The roots by container or pot cultivation have already in the nursery got such a growth and if the plant thereafter is planted in a hole with straight walls it can continue to grow around. This especially happens in fine-grained soil types suc as clay and ground moraine.

Claims

1. A method for planting of tree seeds or tree plants comprising creation of a planting spot by ground preparation and planting of one or several tree seeds or a tree plant in the prepared planting spot, characterized in that the ground preparation is performed with two with each other at least during the course of the ground preparation rigidly connected preparation means, in doing which a primary preparation means clears the chosen planting spot from clearin debris, vegetation cover and humus layer etcetera (A) and that a secondary preparation means creates a planting heap (72) of preferably mineral soil (B), whereupon -a planting device (28) puts down said one or several tree seeds or said tree plant

(70) in the heap and presses the soil together around the seed or seeds or the soil clod of the plant with the aid of a soil packing means (36, 54).

2. A method according to claim 1, characterized in that the primary preparation operation is performed by a first digging or scraping means (12) and that the secondary preparation operation is performed by a second digging and scraping means (26), in doing which both the preparation means simultaneously are in intervention with the ground, the first means (12) clearing a patch and the second means (26) being brought to penetrate the patch and dig up a planting heap (72).

3. A method according to claim 1, characterized in that the primary preparation operation is performed by said second digging and scraping means (26) and that the secondary preparation operation is performed by the said first digging and scraping means (12), in doing which during the first preparation operation the first means (12) is held lifted abov the ground while the second means (26) at least passably clear a planting spot, whereupon in the second preparation operation the first means (12) drops down a preferably beforehand in the means (12) deposited amount of adding soil on the exposed planting patch, thus creating a planting heap (72).

4. An apparatus for the performing of the method according to claim 1 for creation of a planting heap (72) for one or several tree seeds or tree plants, characterized in that it comprises a first digging and scraping means (12) and a second digging and scraping means (26), which at least during the creation of the planting heap are rigidly connected with each other; whereby at each operation one of the means (12 or 26) is intended to prepare a patch clear of clearing debris, vegetation cover and humus layer (A), while the other means (26 or 12) is intended to create a planting heap (72) out of mineral soil (B) on the cleared patch; a planting device (28) for tree seeds or tree plants (70) as well as a packing means (36, 54) to press together the soil after planting.

5. An apparatus according to claim 4, characterized in that the first digging and scraping means (12) consists of the front part of a bucket (10) carried by an arm (18), and that the second digging and scraping means (26) is secured in the bucket (10) and at least during its working operations is protruding downwards underneath its bottom (36).

6. An apparatus according to claim 5, characterized in that a shielding partitioning wall (16) is arranged in the bucket (10) and partitions off a not earth—fillable rear space (14), and/or that said planting device (28) for seeds or tree plants (72) is arranged in or on the bucket (10).

7. An apparatus according to any of the claims 4 - 6, characterized in that the second digging and scraping means (26) comprises a scraper blade (30), that is vertically movable with the aid of a power cylinder (38), and that is guided by a guide means (32) and intended to be pushed down through an opening (34) in the bottom (36) of the bucket; and/or that the second digging and scraping means (26) is situated in the digging direction immediately behind the planting device (28), such that a tree plant (70) immediately can be placed in the upscraped heap (72) without moving the bucket (10).

8. An apparatus according to at least one of the claims 4-7, characterized in that the planting device (28) comprises a piercing mandrel (50), that comprises a mandrel (56) with an associated power cylinder (60) and means (66, 68) for lateral movement of the mandrel in its uplifted position; and/or a depth indicator (67) for indication of maximum downstroke of the mandrel; and/or that the planting device (28) comprises a planting tube (52), which exhibits withholding mans (78; 100, 102) intended to retain a tree plant (70) until completion of the hole making by the mandrel (50).

9. An apparatus according to one or more of claims 6-8, characterized in that it comprises cross fall indicators (92) intended to show if the planting device (28) is in a vertical position and/or together with a control unit establis a horizontal setting of the bottom (36) of the bucket in its pivoting plane and/or a vertical setting of the planting devic (28) with the aid of a pivot axis (88; 96) and at least one power cylinder (90, 98).

10. An apparatus according to one or more of claims 6-9, characterized in that the planting device (28) comprises a packing means (54) with a stamp (82) that exhibits a central opening (64) for hole making and planting, and/or that the planting device (28) is arranged at an opening (55, 64) in the bottom (36) of the bucket, whereby one or several tree seeds respectively a tree plant (70) are intended to be brought through said opening and be planted in a soil heap (72) underneath the bottom (36) of the bucket.