Field of the invention

The present invention relates to a seedling planting tool and a dispenser for automatic dispensing of a predetermined dosage of granular fertilizer during a planting operation.

Background of the invention

Forest planting is to a large degree done by manual labour. Planting tools are available that speed up and make the work easier. A well known planting tool is Pottiputki ^tm [https:/ / shop.pottiputki.se/]. A Pottiputki planting tool, and similar designs, consists of a tube that can be forced into the soil or ground and a jaw -like structure that can be opened up after being forced into the ground. A seedling is introduced into the tube and dropped into the hole made by the jaw-like structure.

Fertilization is an important part of forestry, not at least at or in close connection to planting. For a number of reasons, not at least to avoid leakage of fertilizing substances or overuse of fertilizers, it is desirable to provide the fertilizer to each seedling individually and in a controlled dosage. This could be done by introducing a fertilizer into the planting tube in connection with the planting. This adds a number of time consuming steps manual steps in the procedure. In addition the manual handling of the fertilizer is often unwanted.

A number of dispensers are available for using in when planting the seedlings. Also these dispensers introduce a number of additional steps. In addition the dispenser may fail in that they do not provide the fertilizer at the optimum position, i.e. in close proximity to the root system. The commercially available dispenser are often difficult to combine with the planting tools of Pottiputki-type. Summary of the invention

The object of the invention is to provide a dispenser and a planting toll and dispenser assembly which provides an effective fertilization of a seedling at planting without introducing additional operations for a user to perform. A further object is to provide equipment that can withstand the often harsh environment associated to forest planting.

This is achieved by the dispenser as defined in claim 1 and the planting tool and dispenser assembly as defined in claim 5.

The dispenser according to the invention is adapted for providing a dosage of granulated fertilizer to a seedling upon planting of the seedling and to be mounted on a planting tool with a hollow tube. The dispenser comprises a housing with an inlet for receiving a container with granulated fertilizer and a dosage mechanism for providing a predetermined amount of granulated fertilizer from the inlet to an outlet. The outlet is arranged to provide the predetermined amount of fertilizer into the tube of the planting tool.

According to one embodiment the dosage mechanism comprises a dosage wheel with a dosage space. The dosage space has a wedge bottom so that the dosage space on one side is in line with the outer cylindrical surface of the dosage wheel and the opposite side of the dosage space is depressed from the cylindrical outer surface. Tthe dosage wheel may further comprises a cut out positioned opposite on the cylindrical surface of the dosage wheel from the dosage space.

According to one embodiment the dispenser a bolt for operating the dosage wheel is arranged fixed to the dosage wheel. The bolt extends through an opening in the dispenser housing, the opening having a semi-circular shape.

The planting tool and dispenser assembly according to the invention comprises a dispenser as described above and a planting tool with a hollow planting tube of the type wherein the seedling is introduced into the tube.

According to one embodiment of the invention the planting tool and dispenser assembly comprises a release rod in connection with a movable jaw and controlling the retraction of the movable jaw, an arm attached to the release rod. The arm is acting on the bolt for actuating the rotation of the dosage wheel, thereby providing a simultaneous action of opening the movable jaw and releasing a dosage of fertilizer from the dispenser outlet into the tube.

According to a further embodiment of the planting tool and dispenser assembly the arm is arranged to be able to expand and contract following the transverse movement of the bolt in the opening. The arm may be spring loaded to expand in- between the bolt and release rod.

Thanks to the invention a precise and predetermined dosage of granulated is automatically provided to each seedling during planting.

One advantage of the present invention is that the dispenser may be mounted on existing planting tools, such existing planting tools being proven and appreciated in the field.

A further advantage is that the operator does not need to handle the fertilizer manually.

A still further advantage is the modular design of the dispenser. It can be readily adapted to different sizes and shapes of the planting tool and also to different dosages of granular fertilizer.

The invention optimizes the uses of fertilizer which has both economical and environmental implications.

The planting tool and dispenser assembly according to the invention is particularly useful for planting seedlings of spruce, pine and fir.

In the following, the invention will be described in more detail, by way of example only, with regard to non-limiting embodiments thereof, reference being made to the accompanying drawings.

Brief description of the drawings

Fig. la-b are perspective schematic views of the dispenser according to the invention, a) in an a exploded view and b) illustrating the housing in a view showing the opposite side;

Fig. 2 a-b are schematic illustrations of the dosage wheel of the dispenser according to the invention, a) perspective view and b) frontal view;

Fig. 3 is a schematic illustration of the a part of the dispenser according to the invention;

Fig. 4 a-b are schematic illustrations of the planting tool and dispenser assembly according to the invention; and

Fig. 5 is a schematic illustration of the planting/ fertilizing operation using the planting tool and dispenser assembly according to the invention.

Detailed description

Terms such as’’top”,“bottom”, upper”, lower”,“below”,“above” etc are used merely with reference to the geometry of the embodiment of the invention shown in the drawings and/or during normal operation of the planting tool with a dispenser and are not intended to limit the invention in any manner.

Figures 1 a-b schematically illustrate the dispenser 10 according to the invention. The dispenser is designed to be mounted on a planting tool as illustrated in Figures 4 a-b. The planting tool 40 comprises a hollow tube 41. Typically the tube 41 has a circular cross section, but also oval, rectangular and polygon shapes are possible. The dispenser 10 comprises a housing 11 with an inlet 12 for receiving a container (not shown) providing fertilizer in granulated form to the dispenser 10. The inlet 12 may be threaded and the container provided with a corresponding thread. The container may alternatively be fitted to the dispenser with a bayonet coupling, a snap lock, or just friction, for example. The dispenser 10 has an outlet 13 for letting out a dosage of granular fertilizer. Preferably the outlet 13 has a downward inward direction corresponding to an opening in the tube 41 for providing the dosage of the granular fertilizer on the inside of the tube 41. Alternatively the outlet 13 is directed downward to deliver the granular fertilizer outside the tube 41. In this embodiment the dispenser 10 may be equipped with a tube or hose attached to the outlet 13 to better direct the granular fertilizer close to a seedling when planting.

The inlet 12 and outlet 13 are connected via a cylindrical cavity 14. A dosage wheel 15 is fitted in the cylindrical cavity 14. As illustrated in figure 2 the dosage wheel 15 has a dosage space 16 on, and contained in, the cylindrical surface. The dosage space 16 occupies preferably an area of the cylindrical surface that corresponds to the area of the inlet 12. The depth, and hence the volume of the dosage space should preferably be chosen as to result in the desired dosage of the granular fertilizer. It is possible to provide exchangeable dosage wheels 15 with different volumes of the dosage space 16 in order to comply to different requirements of fertilizer dosage. According to one embodiment the bottom surface 17 of the dosage wheel 15 is weedged so that the front side 18, the side being in front with regards to the rotational direction of the dosage wheel 15, is in line with the cylindrical surface and the opposite side 19 is depressed the distance YY mm from the cylindrical surface. This design facilitates that the granular fertilizer is delivered out from the dispenser with a minimal risk of getting stuck to the dosage wheel.

The dosage wheel 15 may have a cut out 9 reducing the radius in the order of a few millimetres and positioned approximately opposite the dosage space 16. The cut out 9 should not stretch too close to the dosage space 16 in order to secure a sufficient sealing of the dosage wheel 15 with the cylindrical cavity 14, so that fertilizer grains do not leak out of the dosage space 16. The purpose of the cut out is to lower the friction of the dosage wheel against the cylindrical cavity.

A central axis 20 of the dosage wheel 15 may, as depicted, be an integral part of the dosage wheel 15 or alternatively an axis is provided as a separate unit. The housing 11 is provided with a hole 21 centred in the cylindrical cavity 14 for accommodating the central axis 20. A cover plate 30 is fixed to the housing, for example with screws, and covers the cylindrical cavity 14 and is provided with a hole

accommodating the central axis 20 of the dosage wheel 15. The housing 11 has here been described as closed on one side and open to the cylindrical cavity 14 on the opposite side, covered by the cover plate 30. As apparent to the skilled person, the housing could be open to the cylindrical cavity 14 on both sides and the dispenser having cover plates on both sides. The housing has an opening 22 extending in a circular direction centred at the hole 21, i.e. having a semi-circular extension. A pin or bolt 23 for manoeuvring the dosage wheel 15 is provided through the opening 22 and is fixed to the dosage wheel 15, for example screwed into a threaded hole 31 in the dosage wheel.

Alternatively the bolt 23 is an integral part of the dosage wheel 15 and extending through the opening 22 out from the housing 1 1. The extension of the opening 22 is such that at a first end point the dosage space 16 will be positioned under the inlet 12 and at the other endpoint the dosage space 16 will be positioned at the outlet 13. A washer 24 may be provided to cover the opening 22 and the hole 21 , the washer 24 fixed with a screw 25, for example. The bolt 23 will provide the rotary translation of the dosage wheel 15 from the first position with the dosage space under the inlet 12 to the second position with the dosage space positioned at the outlet 13.

Figures 4 a-b schematically illustrate the planting tool and dispenser according to the invention. The dispenser 10 is mounted on the planting tool 40, preferably so that the outlet of the dispenser 10 corresponds to an opening in the tube 40 of the planting tool 40 so that a dosage of granular fertilizer may be released into the tube.

The tube 41 of the planting tool 40 is at a top end provided with a handle 46 and in the opposite end, ending in a fixed jaw 42 which together with a moveable jaw 43 forms a cone that can be forced into the ground. The moveable jaw 43 is via a hinge 44 attached to a pedal 45 arranged to move the movable jaw 43 outwards when it is pressed down. A release rod 47 is attached to the movable jaw 43 and hence arranged to move in the opposite direction from the pedal 45. The release rod 47 is in connection with a locking mechanism close to the handle 46. The locking mechanism is arranged to fix the release rod 47 in an upper position and thereby keep the moveable jaw 43 in an open position until the locking function is deactivated.

As illustrated in the schematic drawing of figure 4a, an arm 26 is attached to the release rod 47 at a position given by the position of the mounted dispenser 10. The arm 26 extends from the release rod 47 to the bolt 23 manoeuvring the dosage wheel 15 of the dispenser 10. The bolt 23 is rotably connected to the arm 26, for example going through a through hole in the arm 26. The arm 26 is fastened to the release rod 47 at a position so that the bolt 23 abutting or being close to the downward end of the opening 22 corresponds to the rod being in its relaxed position, i.e. the planting tool being closed. The other extreme position, the pedal 45 being pushed down and the release rod 47 being locked in an upper position, corresponds to the bolt 23 being close to or abutting the upper end of the opening 22. The length of movement in the vertical direction of the bolt 23, which in turn is set by the dimensions of the dispenser 10, must correspond to the movement of the release rod 47. Hence, as appreciated by the skilled person, the dimensions of dispenser 10 must be chosen so as to match the planting tool 40. The planting tool 40 is typically manufactured in a few different sizes and the dispenser 10

accordingly needs to be available in corresponding sizes. Given the information herein the skilled person knows how to design a dispenser suitable for a particular size and/or model of a planting tool 40.

The opening 22 being in the shape of a semicircle will force the bolt 23 to move in a direction transverse to the vertical direction and the direction of the moment of the release rod 47. This transverse movement may be taken up by tolerances in the design and/or the flexibility of the parts, for example the release rod 47 being somewhat flexible. Alternatively the hole in the arm 26 accommodating the bolt 23 is extended in the transverse direction, thereby taking up the transverse movement of the bolt 23.

According to one embodiment the arm 26 comprises of two or more parts that are spring loaded with an outward force as seen from the release rod 47. Thereby the arm 26 may expand and retract depending on the position of the bolt 23 in the opening 22 and mitigate the transversal tension on the release rod 47.

According to one embodiment the upper end of the opening 22 is positioned at around 8° or more from a thought vertical line passing thorough the centre of the central axis 20, to accommodate that there will be an inward force on the bolt 23 from the release rod 47 as the bolt 23 follows the semi-circular path of opening 22.

Figure 5 schematically illustrate the use of the planting tool and dispenser assembly. A planting action comprises the steps of:

1) The planting tool 40 is forced into the ground.

2) The pedal 45 is pushed down resulting in the simultaneous actions of

opening the jaws of the planting tool and activating the dispenser to deliver a dosage of the granulated fertilizer into the tube. ) The seedling is dropped down into the tube 41.

) The planting tool 40 is lifted up from the ground and the release rod

released, which causes both the jaws to close and the dispenser to be loaded with a new load of granulated fertilizer.