GB2322782A

GB2322782A - Tree support

Info

Publication number: GB2322782A
Application number: GB9804700A
Authority: GB
Inventors: Yukio Kida
Original assignee: Toho Leo KK
Current assignee: Toho Leo KK
Priority date: 1997-03-07
Filing date: 1998-03-05
Publication date: 1998-09-09
Anticipated expiration: 2018-03-05
Also published as: GB9804700D0; GB2322782B

Abstract

Apparatus for supporting a tree comprises a retainer 7 placed in the planting hole and locked therein by slidable rods 9, 10 which engage in the walls of the hole; a support member 1 in the form of a flat belt which is wound round the base 18 of the tree and the ends of which are fastened together; and a tensioning member 19 attached to the support member 1 and the retainer 7, thereby holding the rootball 16 in place. The support member 1 is made from hemp coated with thermoplastic polyurethane elastomer so that it will decompose as the tree establishes itself. Alternatively, the support member may be made from rustable iron, or it may have a blade which severs the member as the roots expand, or a timing device which releases the tree after a preset interval.

Description

METHOD OF PROVIDING SUPPORT TO TREE, AS WELL AS TREE BASE SUPPORT MEMBER AND ROOT BALL RETAINER FOR USE IN THE METHOD The present invention relates to a method of providing support to tree which is artificially planted in a park, pavement, exhibition ground or the like, as well as a support member and a root ball retainer for use in the method of providing support to tree.

In accordance with a conventional method of providing support to tree, pole supports 34 are attached to a trunk 33 of a tree 32, and then driven into the earth to provide support to the tree 32, as illustrated in FIGURE 21. As another conventional method, wires 35 each have one end 35a tied the tree 32, and another end 35b equipped with an anchor 36. With this arrangement, the wires 35 are tensioned by driving the anchors 36 into the earth to provide support to the tree 32.

However, in both methods, the trunk of the tree is supported by the pole supports 34 and the wires 35 to provide support to the tree. This arrangement necessarily causes the pole supports 34 and the wires 35 to be exposed outside. Such exposure results in damaging the appearance of the tree being supported.

In view of the foregoing, an object of the present invention is to eliminate tree supporting members such as the pole supports and wires which are exposed outside, prevent the executed state of the tree support from being exposed outside, maintain the appearance of the tree being planted, and provide support to the tree in such a manner as to give sufficient stature and stability to the tree, for which the tree remains and grow in the desired upright position.

Another object of the present invention is to prevent the tree from becoming embedded by any supporting means, while not losing the tension force against the base portion of the tree, as well as maintain a preferable wound state of the tree in accordance with the growth of the tree.

Another object of the present invention is to eliminate the necessity to change a root ball retainer, even if a root ball of a different size is to be supported, so that one root ball retainer is sufficient for the root ball of varying size.

In accordance with the present invention, there is provided a method of providing support to tree including the steps of placing a root ball secured to the base of a tree in a hole which has been previously formed on the ground, fixing the root ball in position by a fixing means, and filling the hole with soil or the like.

The fixing means in the above method may include a tree base support member used to support the base of the tree under tensioned state, and a peripheral surface support member connected to the tree base support member in such a manner as to be positioned around a peripheral surface of the root ball.

In addition to the tree base support member and the peripheral surface support member, a root ball retainer may be used in the above method.

As another aspect of the present invention, there is provided a tree base support member for supporting the base of a tree under tensioned state for use in an operation for providing support to tree, which includes a support member body formed in such a manner as to release the base of a tree from the tensioned state after a predetermined period of time has elapsed.

The support member body la may be coated thereon with a protective member being capable of deteriorating as time elapses to release the base of the tree from the tensioned state after a predetermined period of time. The protective member being capable of deteriorating may be made of, for example, thermoplastic polyurethane. Instead, the support member body may be partially or entirely made of a decomposable material to release the base of the tree from the tensioned state after a predetermined period of time has elapsed.

It is possible to use, as the thermoplastic polyurethane, mixture of polyether thermoplastic polyurethane containing polyether polyol or polyester thermoplastic polyurethane containing polyester polyol and polyether thermoplastic polyurethane.

Further, the releasing of the base of the tree from the tensioned state may be accomplished by providing the support member body with a connection member being capable of breaking into pieces in accordance with the growth of the tree.

Further, the releasing of the base of the tree from the tensioned state may be accomplished by using a time adjusting device having a timer.

The support member body may be formed into a flat-belt shape.

The support member body may be subjected to a process with which the decomposition time can be elongated to correspond to the growth of the tree. The process with which the decomposition time can be elongated to correspond to the growth of the tree is, for example, a water-proofing process or a water repellent process.

Further, the releasing of the base of the tree from the tensioned state may be accomplished by providing the support member body with a breaking means which is actuated by pressure effected by the base of the tree to break the support member body into pieces.

In accordance with the method of the present invention, which includes the steps of placing a root ball secured to the base of a tree in a hole which has been previously formed on the ground, fixing the root ball in position by a fixing means, and filling the hole with soil or the like, it is possible to eliminate a pole support or the like which is required in the conventional method of providing support to tree, and enable the members required in the method of the present invention to is mostly buried in the earth. As a result, the executed state of the tree support is unlikely to be exposed outside, so that the appearance of the tree can be maintained.

In accordance with the tree base support member of the present invention, the support member body releases the tree from the tensioned state after a predetermined period of time, so that the support member is unlikely to become embedded in the base of the tree even if the tree has grown and increased in diameter. Therefore, various problems as a result of that the support member has become embedded in the tree can be prevented. That is, the tree base support member forms no impediment of the growth and well-being of the tree, and omits the necessity to cut the support member in accordance with the growth of the tree to prevent the support member from becoming embedded in the tree as in the conventional manner.

Further, in case of that the decomposable material being capable of deteriorating as time elapses is coated pn the support member body, the protective member can adjust the decomposition time, even if the support member body itself is decomposable prematurely. The support member is, thus, decomposable after a predetermined period of time has elapsed.

In case of that the thermoplastic polyurethane is employed as the protective member, the linkages in the polyol portion can easily be cut if the thermoplastic polyurethane is subjected to a hot and wet state. Although the cut in the linkages does not immediately cause the protective member to be decomposed, the physical properties of the protective member deteriorate. Thus, the protective member gradually deteriorates. Therefore, the support member is not decomposed in a short period of time and the decomposition time can be adjusted as required.

In case of that the support member body is formed into the flat-belt shape, the ends of the support member body can easily be fastened together, as compared with, for example, the case where the support member body has a rounded cross section.

When the support member body is placed on the root ball, the area of the support member body which comes into contact with the root ball is relatively small. If the root ball contains water, it will take a considerable time for water to be permeated into the support member body of this shape. Thus, excessively rapid decomposition owning to rot caused from water can preferably be prevented, and therefore the appearance of the support member can be maintained. Accordingly, it is not necessary to make the support member body thicker. This results in the prevention of damaging the appearance of the support member.

When the support member body is subjected to the process with which the decomposition time can be elongated to correspond to the growth of the tree, permeation of water into the support member body can be somewhat prevented.

As a result, excessive shortening of time at which the support member body is decomposed can be prevented. Thus, the support member body can be decomposed at proper time to correspond to the growth of the tree.

In case of that the support member body is provided with the breaking means which is actuated by the pressure from the base of the tree to break the support member body into pieces, the support member can sufficiently provide support to the tree until the tree root system has developed and the tree itself has obtained sufficient stature and stability to remain and grow in the desired upright position.

In other words, the support member body can securely be broken into pieces before the base of the tree comes into contact with the support member.

A preferred embodiments of the invention will now be described with reference to the accompanying drawings in which: FIGURE lA is a schematic perspective view showing a support member in accordance with one embodiment of the present invention, and FIGURE lB is an enlarged cross sectional view taken along line I-I of FIGURE 1A.

FIGURE 2 is an enlarged cross sectional view showing a fastened portion of the support member body.

FIGURE 3 is a side view with a partial cross section showing a state where a root ball retainer is placed on a bottom surface of a hole for receiving the tree.

FIGURE 4 is a plan view with a partial cross section showing a state where the root ball retainer is placed on the bottom surface of the hole for receiving the tree.

FIGURE 5 is a side view with a partial cross section showing a state where piles are driven into a side wall of the hole.

FIGURE 6 is a plan view with a partial cross section showing a state where the piles are driven into the side wall of the hole.

FIGURE 7 is a side view with a partial cross section showing a state where the root ball is placed on the root ball retainer.

FIGURE 8 is a plan view with a partial cross section showing a state where the root ball is placed on the root ball retainer.

FIGURE 9A is a schematic perspective view showing a support member in accordance with another embodiment of the present invention, and FIGURE 9B is an enlarged cross sectional view taken along line II-II of FIGURE 9A.

FIGURE 10 is an enlarged perspective view showing a fastened portion of the support member body of FIGURE 9.

FIGURE 11 is a cross sectional view showing a support member body in accordance with another embodiment.

FIGURE 12 is an enlarged cross sectional view showing a phenomenon that water moves upward to penetrate into the support member body of the embodiment of FIGURE 11.

FIGURE 13 is a schematic perspective view showing a support member in accordance with another embodiment.

FIGURE 14 is a schematic perspective view showing a support member in accordance with another embodiment.

FIGURE 15 is an enlarged cross sectional view taken along line III-III of FIGURE 14.

FIGURE 16 is a schematic perspective view showing a support member in accordance with another embodiment.

FIGURE 17 is a schematic perspective view with a partial cross section showing another embodiment of the method of providing support to tree.

FIGURE 18 is a schematic plan view with a partial cross section showing another embodiment of the method of providing support to tree.

FIGURE 19 is a schematic plan view showing another embodiment of the method of providing support to tree.

FIGURE 20 is a schematic plan view showing another embodiment of the method of providing support to tree.

FIGURE 21 is a schematic front view illustrating a conventional method of providing support to tree.

FIGURE 22 is a schematic front view illustrating another conventional method of providing support to tree.

Embodiment 1 Before describing a method of providing support to tree, an embodiment of a support member for use in the method will be described.

As shown in FIGURE lA, a support member 1 to be attached to the base of a tree being stabilized includes a support member body la which is made of hemp and formed into a substantially flat-belt shape.

A connection member 2 is provided as a buckle for connecting the opposite ends of the support member body la together to adjust the length of the support member body la. As shown in FIGURE 2, a plurality of the openings 3 are formed in the connection member 2, through which the opposite ends of the support member body la extend to be fastened together via the connection member 2.

A protective member 4 made of thermoplastic polyurethane elastomer is coated on the surface of the support member body la to enable the support member body la to deteriorate as the tree grows.

Specifically, the thermoplastic polyurethane elastomer can be obtained from a raw material composed of polyol, diol and diisocyanate in such a way that polyol and diol are caused to react additionally with diisocyanate so as to be formed into linear polymers. In this case, polyol forms soft portions (soft segments) of the elastomer, while diisocyanate and diol form hard portions (hard segments) of the elastomer.

In this embodiment, 90 % by weight of polyether thermoplastic polyurethane elastomer in a mixture with 10 % by weight of polyester thermoplastic polyurethane elastomer is used as the thermoplastic polyurethane elastomer. The polyether thermoplastic polyurethane elastomer is prepared by using polyether polyol as polyol, and the polyester thermoplastic polyurethane elastomer is prepared by using polyester polyol as polyol.

A root ball retainer used in the method for providing support to tree will be described hereinbelow.

A root ball retainer 5 includes a frame rod 8 of a substantially square shape in plan, a crossing rod 6 extending between diagonally opposite corners of the frame rod 8, both of which constitute a fixing member 7, and slide rods 9 provided as a movable member to be slidable with regard to the fixing member 7, as shown FIGURES 3 and 4. More specifically, the four slide rods 9 are slidably inserted into the respective end portions of the fixing member 7 so that the slide rods 9 are movable with regard to the fixing member 7. The slide rods 9 are provided with piles 10 respectively secured to the upper surfaces of their leading ends, and resistance plates 11 each having a pentagonal shape respectively secured to the lower surfaces thereof.

One embodiment of the method of providing support to tree using the support member 1 and the root ball retainer 5 will now be described.

Initially, soil 8 is placed on a bottom surface 13 of a hole 12 for receiving a tree formed previously as shown in FIGURE 3, and then the root ball retainer 5 is placed on the soil 8, as shown in FIGURES 3 and 4. Then, the four slide rods 9 of the root ball retainer 5 are slid outwards to expand the root ball retainer 5, and then the four piles 10 secured to the upper surfaces of the leading ends of the slide rods 9 are driven into a side wall 15 of the hole 12, as shown in FIGURES 5 and 6.

After the piles 10 have been driven into the side wall 15 of the hall 12 and thus the root ball retainer 5 has been secured in the hole 12, a root ball 16 is placed on the root ball retainer 5, as shown in FIGURE 7. Then, a tension member 19 in the form of a wire is tensioned between a base 18 of a tree 17 and the root ball retainer 5, specifically to the respective base portions of the slide rods 9, which is located substantially just below the root ball 16. To prevent the tension member 19 from becoming embedded in the base 18 of the tree 17, protective pads 20 are attached to the respective shoulder portions of the root ball 16, as shown in FIGURES? and 8.

When the tension member 19 is to be connected to the base 18 of the tree 17, the support member 1 is wound around the base 18 of the tree 17, and then the tension member 19 is stretched to respective detent members 21 attached to the support member 1, as shown in FIGURES 7 and 8. In this case, the support member 1 is relatively loosely wound around the base 18 of the tree 17 so that the support member 1 does not directly contact with the base 18 of the tree 17. Then, the tension member 19 is tensioned by winches 20, turnbuckles or other tension means so that the root ball 16 is supported by the tension force of the tension member 19.

The support member body la is of the flat-belt shape so that the ends of the support member body la can easily be fastened together.

After the base 18 of the tree 17 has been supported as described above, soil or the like is introduced into the hole 12 so that the operation for providing support to the tree 17 is completed.

The base 18 of the supported tree 17 becomes gradually thicker as the time elapses, thus resulting in that the support member 1 is brought into contact with the base 18. However, since the support member body la is made of hemp and the protective member 4 is made of the thermoplastic polyurethane elastomer, which is a soft material, the support member 1 is unlikely to become embedded in the tree 17.

After an additional period of time has elapsed from the above point, the base 18 of the tree 17 become thicker to the point where the support member 1 is brought into contact with the base 18 of the tree 17, and eventually the base 18 of the tree 17 cannot withstand the tightening force effected by the support member 1. However, since the support member body la is made of decomposable material namely hemp, and the protective member 4 is made of the thermoplastic polyurethane elastomer, the support member 1 gradually deteriorates as the time elapses. Therefore, even if the tree 17 becomes thicker, an adverse influence, such as the one that the support member 1 becomes embedded in the base 18 of the tree 17, can satisfactorily be prevented.

More specifically, if the thermoplastic polyurethane elastomer is exposed to hot and wet atmosphere for a prolonged period of time, linkage of the polyol forming soft portions can easily be cut away. Although the cutting of the linkage does not immediately result in decomposition of the protective member 4, the protective member 4 is degraded in physical property so that the protective member 4 gradually deteriorates.

Hydrolysis is able to take place in the ester linkage of the polyester thermoplastic polyurethane elastomer so that the cutting of linkage easily takes place as compared with the polyether thermoplastic polyurethane elastomer.

Moreover, the polyester thermoplastic polyurethane elastomer is decomposable by microorganisms in hot and wet atmosphere. The reason for this can be estimated that enzymes produced by microorganisms act on the ester linkages in the portions of the polyester polyoL As a result, the polyester thermoplastic polyurethane elastomer may deteriorate and decompose before the tree's root system has developed and the tree itself has obtained sufficient stature and stability to remain and grow in the desired upright position. In this viewpoint, the quantity of the polyester thermoplastic polyurethane elastomer is preferably limited to 10 % by weight.

The polyurethane itself gradually deteriorates when exposed to ultraviolet rays.

Therefore, the protective member 4 gradually deteriorate owning to synergistic effect produced by water, microorganisms in the earth, temperatures, ultraviolet rays and the like.

The support member body la is also made of decomposable material namely hemp, the support member body la itself also gradually deteriorates. Thus, both the support member body la and the protective member 4 gradually deteriorate to ease the embedding degree of the support member 1 in the base 18 of the tree 17.

The support member 1 allowed to deteriorate is completely decomposed after a predetermined period of times has elapsed from the point of the operation for providing support to the tree 17.

When the tree's root system has developed, the tree 17 can obtain sufficient stature and stability to remain and grow in the desired upright position. Therefore, even if the support member 1 does not exist any more, the tree 17 is not adversely affected.

The support member 1 is decomposed after a predetermined period of time so that it does not become embedded in the base 18 of the tree 17 and forms no impediment to the growth of the tree 17.

The slide rods 9 are movable with regard to the fixing member 7 so that the root ball retainer 5 is configured to be expandable. This enables the root ball retainer 5 to be adjusted in size in accordance with the size of the root ball being retained.

Therefore, it is not necessary to prepare the root ball retainer 5 of different size for the root ball of different size. This is advantageous in the fact that the only one root ball retainer 5 is enough for retaining varying size of the root ball.

When the root ball retainer 5 is adjusted in size to the point slightly larger than the size of the root ball, the moment becomes larger so that the resistance force against the force allowing the tree 17 to fall down on the ground becomes larger. This is advantageous in the fact that the tree 17 is tolerable against the wind blowing at about 60 meters per second.

The root ball retainer 5 is interposed between the bottom surface 13 of the hall 12 and the root ball 16 of the tree 17 so that the operation for providing support to the tree 17 is carried out without placing the root ball 16 directly on the bottom surface 13 of the hall 12. Therefore, the operation for providing support to the tree 17 can be carried out regardless of the strength of the bottom surface 13 of the hole 12, and the method and the root ball retainer 5 used therein in accordance with the present invention are applicable in varying sites including soft ground such as a rubbish accumulated ground.

As an advantage in the arrangement that the root ball retainer 5 is provided with the piles 10, the piles 10 are driven into the side wall 15 of the hole 12 so that the root ball retainer 5 can be placed at an exact position without being unintentionally moved into a different position, thereby enabling the piles 10 to be driven into a local panel to further improve the supporting force for the tree 17. As a result, the root ball retainer 5 is unlikely to sink in the soil.

Embodiment2 In this embodiment, 95 % by weight of the polyether thermoplastic polyurethane in a mixture of 5 % by weight of polyester thermoplastic polyurethane is used as the thermoplastic polyurethane. Since the other structures of the support member 1 are the same as those according to the first embodiment, description as to details thereof has been omitted.

Embodiment3 In this embodiment, 80 % by weight of the polyether thermoplastic polyurethane in a mixture with 20 % by weight of the polyester thermoplastic polyurethane is used as the thermoplastic polyurethane.

Since the other structures of the support member 1 are the same as those according to the first embodiment, description as to details thereof has been omitted.

Embodiment4 In this embodiment, the thermoplastic polyurethane is solely composed of polyester thermoplastic polyurethane, and 5 % by weight of anti-fungus agent is added.

Thiabendazole is employed as the anti-fungus agent.

Embodiment5 In this embodiment, the thermoplastic polyurethane is solely composed of polyether thermoplastic polyurethane.

Embodiment6 In this embodiment, the support member body la is made of synthetic resin.

Moreover, the connection member 2 is attached to the support member body la in order to fix the opposite ends of the support member body la, as shown in FIGURE 9. The connection member 2 according to this embodiment does not serve as the buckle according to the first embodiment, but is simply formed into an iron plate.

The support member body la is formed so that the opposite ends of the support member body la are inserted into the openings 3 respectively formed at the opposite ends of the connection member 2 to be fixed together, as shown in FIGURE 10. The protective member 4 made of elastic polymer is coated on the surface of the connection member 2 except for the opposite sides which defines the openings 3. Thus, the support member body la is processed in such a manner as to deteriorate as the tree 17 grows.

The elastic polymer is mixture of the polyether thermoplastic polyurethane elastomer and the polyester thermoplastic polyurethane elastomer in the same manner as the first embodiment. It is preferable that mixture ratio be such that the polyether thermoplastic polyurethane elastomer is 50 to 99 % by weight and the polyester thermoplastic polyurethane elastomer is 1 to 50 % by weight.

A half-cut portion 23 having a substantially V-shape in section is formed substantially in the central portion of the connection member 2. The connection member 2 is arranged in such a manner as to be cut along the half-cut portion 23 after a predetermined period of time for the growth of the tree 17 has elapsed.

In this embodiment, the protective member 4 made of the polyester thermoplastic polyurethane elastomer deteriorates after a predetermined period of time has elapsed, thus causing cracks to be generated in the protective member 4. As a result, the connection member 2 made of iron starts rusting.

After the connection member 2 has started rusting, the strength of the connection member 2 is gradually reduced. Since the half-cut portion 23 of the substantially V-shape is formed substantially in the central portion of the connection member 2, the connection member 2 which has gradually deteriorated as time has elapsed loses its strength at the half-cut portion 23 having the smallest thickness. As a result, the connection member 2 is cut along the half-cut portion 23.

As a result, the tree 17 is released from the wound state by the support member 1 so that the tightening force applied to the tree 17 is suspended. Therefore, even if the tree 17 increases in diameter, the support member 1 is unlikely to become embedded in the base 18 of the tree 17, thereby remarkably reducing an adverse effect caused by the support member 1.

Further, the protective member 4 is coated on the connection member 2 so that penetration of water and moisture into the connection member 2 can be prevented.

This prevents the connection member 2 from rusting from the beginning, and cutting into pieces at an earlier point of time than the required point of time.

Even if the protective member 4 is accidentally removed from the connection member 2, the connection member 2 made of iron will not immediately be broken apart.

Other Embodlments It is not necessary to limit the composition of the thermoplastic polyurethane elastomer to that of the above embodiments, in which it is composed of three raw materials including polyol, diol and diisocyanate.

Although the polyol according to the foregoing embodiments is the thermoplastic polyurethane elastomer containing polyether polyol or polyester polyol, the thermoplastic polyurethane elastomer containing another polyol may be employed.

Also the mixture ratio of these components is not limited to the foregoing embodiments. However, it is preferable that the polyether thermoplastic polyurethane is 50 to 99 % by weight and the polyester thermoplastic polyurethane is 1 to 50 % by weight, and it is more preferable that the polyether thermoplastic polyurethane is 70 to 95 % by weight and the polyester thermoplastic polyurethane is 5 to 30 % by weight.

When the polyester thermoplastic polyurethane is solely employed, the anti-fungus agent must be added as described in the fourth embodiment. Although the weight ratio of the anti-fungus agent being mixed is not limited to 5 % by weight as in the fourth embodiment, it is preferable that the anti-fungus agent is contained in the ratio between 0.1 to 15 % by weight.

Also the anti-fungus agent is not limited to the thiabendazole as in the fourth embodiment. Silver ions, etc., may be employed as the anti-fungus agent.

Although the support member body la is made of hemp in the foregoing embodiments, the support member body la is not limited to hemp. For example, the support member body la may be made of decomposable material, such as cotton, jute, rice straw, paper, wool, silk, leather, wood and hemp palm. Mixture of the two or more materials selected from those mater cotton. In this case, the mixture ratio of hemp and cotton may be determined such that the quantity of cotton is 10 % by weight with respect to 90 % by weight of hemp, that of cotton is 20 % by weight with respect to 80 % by weight of hemp, that of cotton is 30% by weight with respect to 70 % by weight of hemp, and that of cotton is 40% by weight with respect to 60 % by weight of hemp.

When the mixed spinning of hemp and cotton is employed, it is preferable that the quantity of hemp is 50 to 100 % by weight and that of cotton is 0 to 50 % by weight.

The decomposable material for forming the support member body la may be photodecomposition material as well as the material which is naturally decomposed in the earth or the like. In this case, the support member body la may be formed by mixing such naturally decomposable material and the photodecomposition material.

In case of that the support member body la is made of the decomposable material, the support member body la is not necessarily made entirely of the decomposable material. Instead, the support member body la may be made partly of the decomposable material.

Although the structure, in which the support member body la is made of the decomposable material, is preferable in viewpoint for easy waste disposal and preventing environmental pollution, the support member body la is not always required to be made of the decomposable material in case of that a timer, a spring mechanism, etc., is provided to release the tree 17 from the tightened state after a predetermined period of time. Therefore, the support member body la may be made of synthetic resin as is employed in the sixth embodiment as well as the above-mentioned decomposable materials.

Alternatively, the support member body la may be made of, for example, a chain, an iron member or a wire type metal member. If the support member body la is made of metal such as iron, the support member body la rusts so that it can be decomposed after a predetermined period of time.

As compared with metal materials, the structure, in which the support member 1 is made of the natural fiber, such as hemp, is able to prevent the problem that the support member 1 becomes undesirably embedded in the tree 17 after the support member 1 has been wound around the base 18 of the tree 17.

The protective member 4 may be applied to the connection member 2 and the support member body la by any conventional methods other than the coating.

In the above embodiments, a tightening means is formed by the support member body la coated thereon with the protective member 4 made of the thermoplastic polyurethane elastomer, the structure is not limited to this. The tightening means may be formed such that the support member body la is made partly of the thermoplastic polyurethane elastomer.

Although elastomer is mainly employed as the thermoplastic polyurethane in the above embodiments, plastomer may be employed instead of elastomer.

To cause the support member body la to deteriorate as the tree 17 grows, the thickness of the support member body la and the thickness of the protective member 4 coated on the support member body la can be varied to adjust a period of time for tightening the tree 17 by the support member 1.

Although the support member body la is, in the above embodiments, coated with the protective member 4, it is possible to employ a different structure in which no protective member 4 is provided and the support member 1 is made solely of the material such as hemp, as illustrated in FIGURE 11. Therefore, the structure, in which the support member body la is coated with the protective member 4, is not essential in the present invention.

Although the above-mentioned preferred effect is obtainable by forming the support member body la into the flat-belt shape, the support member body la is not limited to this shape. For example, the support member body la may have a rounded cross section as shown in FIGURE 13. Alternatively, the support member body la may be formed into a chain or a net shape. Instead of these shapes, the support member body la may be formed into a harp (which is a musical instrument) like shape by disposing hairline members in the manner like a comb. In this shape, the support member body la can be broken apart as a result of several hairline members are cut. However, among various shapes, the support member body la of the flat-belt shape is advantageous in the fact that the operation for connecting the opposite ends of the support member body la together can easily be performed.

Since the support member body la is positioned with its lateral direction perpendicular to the upper surface of the root ball 16 at the time of that the support member 1 has been wound around the base 18 of the tree 17, the lower surface which corresponds to the thickness of the support member body la is smaller than the vertical surface of the support member body la. Therefore, the area where the support member body la in contact with the root ball 16 can be reduced.

Therefore, if water is contained in the root ball 16, it will take an elongated period of time for the water to permeate into the support member body la in the direction of arrow B of FIGURE 12. Thus, a period of time required for decomposition owning to rot caused by water can significantly be elongated as compared with the structure in which the support member body la is formed into a rope shape and, therefore, undesirable rapid decomposition owning to water can be prevented.

If the support member body la is formed into, for example, the rope shape, the support member body la must have a relatively large diameter in order to prevent undesirable rapid decomposition due to water as described above. On the contrary, if the support member body la is formed into the flat-belt shape, the support member body la is not necessarily increased in diameter. Thus, the support member 1 can maintain its quality in appearance.

Moreover, the support member body la is subjected to water-proofing process or water repellent process by coating the support member body la with wax, so that penetration of water into the support member body la is somewhat prevented. As a result, undesirable rapid decomposition of the support member body la can be prevented. That is, decomposition of hemp or other natural fibers forming the support member body la is caused by ultraviolet rays, microorganisms in the earth, water and the like, while the water-proofing process or the water repellent process enables the decomposition speed of the support member body la to be reduced.

Specifically, in this embodiment, a period of time required for the support member 1 to be decomposed was elongated to about five years after the support member 1 has been installed.

Although the above-mentioned embodiment is structured such that the support member body la is coated with wax as the water-proofing or the water repellent process, the water-proofing or water repellent process is not limited to wax coating.

For example, paste, pine resin, tar, vegetable oil, silicon oil or silicon resin may be employed instead of wax.

As an alternative to coating, impregnation means may be employed. The means for applying the materials as mentioned above to the support member body la may arbitrarily be changed to be adaptable to the type of the material being applied.

In place of the water-proofing or water repellent process, a process of rendering a predetermined property to the support member body la to, for example, ultraviolet rays or microorganisms may be employed. That is, it is essential to subject the support member body la to the process with which the decomposition time can be elongated to be adaptable to the growth of the tree 17.

The expression "the decomposition time can be elongated to be adaptable to the growth of the tree" means a fact that decomposition time can be elongated until the root system of the tree has developed and the tree itself has obtained sufficient stature and stability to remain and grow in the desired upright position. The period of time has a certain range within the intended scope of the present invention.

Although the half-cut portion 23 is formed substantially in the central portion of the connection member 2 in the second embodiment, the position of the half-cut portion 23 is not limited to this. The position of the half-cut portion 23 may be arbitrarily determined in the connection member 2.

A mechanical means, for example, a time adjusting device having a timer, may be provided. The timer detects a lapse of predetermined time and a portion of the time adjusting device is detached from the residual portion thereof to release the tree from the wound state by the support member body la at a predetermined point of time.

The time adjusting device may includes a spring or the like so that the time adjusting device works after a predetermined period of time to release the tree from the wound state by the support member body la.

Releasing means may be a mechanism or a material, such as a seat belt for a vehicle, which is stopped with instantaneous and large force and which is extended with small and continuous force.

The description "the tree is released from the wound state after a predetermined period of time in accordance with growth of the tree" means a fact that approximate releasing time is expected to release the tree from the wound state so that the tree is released from the wound state after the root system of the tree has been properly developed and the tree itself has obtained sufficient stature and stability to remain and grow in the desired upright position.

For example, in the first embodiment, the support member body la or the protective member 4 coated on the support member body la is varied in thickness to adjust the time at which the tree is released from the wound state.

In accordance with the sixth embodiment, a period of time for providing support to the tree by winding the tree by the support member 1 is varied by adjusting the half-cut portion 23 of the connection member 2 in thickness.

A breaking means for breaking the support member body la into pieces may be provided on the support member body la. In this arrangement, as the tree 17 grows, the breaking means is gradually pressed by the base 18 of the tree 17.

Such pressure acts on the breaking means to break the support member body la into pieces. This arrangement is formed such that the tree 17 itself acts on the breaking means to break the support member 1 into pieces via the pressure caused by the base 18 of tree 17. That is, the increase of the base 18 in diameter causes the base 18 to apply a pressure to the breaking means for the actuation thereof.

Therefore, the support member 1 can reliably be broken into pieces when the tree 17 has grown into contact with the support member 1.

With the above arrangement, the problem that the support member 1 becomes embedded in the tree 17 can reliably be prevented. Before the support member 1 is broken into pieces by the breaking means, the root system of the tree 17 can develop in the earth. Thus, the tree 17 is unlikely to be subject to the influence caused by the lost of the supporting effect produced by the support member 1.

In the above arrangement, the breaking means is preferably formed by a blade 24 capable of cutting the support member body la into pieces. The reason for this lies in that the blade 23 as the breaking means is simple in structure, which does not require a relatively complicated mechanism. Therefore, the breaking means in this form is free from a fault even if it is buried in the earth for an elongated period of time.

Specifically, the support member 1, as shown in FIGURE 14, includes the support member body la for being wound around the base 18 of the tree 17 and a blade 24 as the breaking means provided on the support member body la. As shown in FIGURE 15, the blade 24 forms therein a cutting part 25 which is capable of cutting the support member body la into pieces, and preferably made of a material such as stainless steel which is unlikely to rust.

More specifically, the blade 24 includes a metal plate member 27 provided on a surface 26a of a buffer member 26 formed by molding expanded polystyrene into a substantially rectangular-parallelepiped shape and the cutting part 25 disposed to project vertically from substantially the central portion of the metal plate member 27 and having a sharpened cutting part formed at the leading end thereof. The blade 24 of this arrangement is secured to the support member body la in such a manner that another surface 26b of the buffer member 26, that is, the surface to which the cutting part 25 of the blade 24 faces, abuts against the support member body la.

The support member 1 having the above arrangement is wound around the base 18 of the tree 17 with predetermined spacing in the same manner as that of the above embodiments, where direct contact is prevented between the base 18 of the tree 17 and the support member 1.

After a predetermined period of time has elapsed and the base 18 of the tree 17 has increased in thickness, the base 18 comes in contact with the plate member 27 of the blade 24. After the base 18 has furthermore thickened, the base 18 presses the plate member 27 of the blade 24, thereby pressing the buffer member 26 to be crushed between the support member body la and the base 18. This causes the cutting part 25 of the blade 24 to come into contact with the support member body la, and the blade 24 to be pressed against the support member body la, as the tree 17 furthermore grows. Therefore, the base 18 of the tree 17 is unlikely to be pressed by the support member 1 so that there does not occur the problem to form impediment to the growth of the tree 17.

When the tree 17 has grown to such a degree as that the support member 1 becomes embedded in the base 18 of the tree 17, the support member body la is likely to be cut into pieces via the pressure produced by the tree 17. Therefore, it is possible to prevent the support member 1 from being cut into pieces before the tree 17 satisfactorily grows. As a matter of course, the support member ldoes not also become embedded in the base 18 of the tree 17 in this arrangement.

Although the buffer member 26 according to this embodiment is made of expanded polystyrene, the buffer member 26 is not limited to the expanded polystyrene. The buffer member 26 may be made of different expanded materials, for example, expanded urethane. Or, bellows which can be expanded can be used for the buffer member 26.

In this embodiment, the blade 24 is made of the material such as stainless steel which does not easily rust, and thus advantageous in the fact that the blade 24 does not easily rust even if it is buried in the earth for an elongated period of time, and the sharpened cutting part formed at the leading end of the blade 24 can be maintained. However, it is not necessary to form the blade 24 by the material such as stainless steel which does not easily rust.

Also the breaking means is not limited to the arrangement according to the above embodiment in which the blade 24 is used to cut the support member body la into pieces. For example, the breaking means may be combined with a coupling member 28 for connecting the opposite ends of the support member body la of a flat-belt shape, as shown in FIGURE 16. Specifically, the support member body la is provided at its opposite ends with a pair of mating portions 28a and 28b which can be interlocked together to fasten the opposite ends of the support member body la together. A releasing button 29 projects towards the base 18 of the tree 17 to allow the opposite mating portions 28a and 28b to be released from the interlocked relationship with each other.

The support member 1 having the above arrangement is wound around the base 18 of the tree 17 and fastened via the coupling member 28 to provide support to the tree 17 in the same manner as that of the above embodiments.

After a predetermined period of time has elapsed and the tree 17 has grown to come into contact with the releasing button 29, the base 18 of the tree 17 presses the releasing button 29 of the coupling member 28 to release the mating portions 28a and 28b from the interlocked relationship with each other. As a result, the support member body la is cut into pieces so that the support member 1 does not become embeded in the base 18 of the tree 17, as indicated by an alternate long and two short dashes line shown in FIGURE 16. In this arrangement, it is possible to employ a plurality of the breaking means.

In the above embodiment, the piles 10 are driven into the side wall 15 of the hole 12 for receiving the tree 17. However, it is not necessary to drive the piles 10 into the side wall 15. For example, means for pressing the side wall 15 may be provided in the slide rods 9 to press the side wall 15.

In the above embodiments, the root ball 16 is placed on the root ball retainer 5, and the tension member 19 which has been wound around the root ball 16 is secured to the root ball retainer 5 so that the tree 17 is supported and secured in position.

However, the means for supporting and securing the tree 17 is not limited to this.

Alternatively, it is possible to employ an arrangement as shown in FIGURE 17, in which the tension member 19 is tensioned between anchors 30 driven into the bottom surface 13 of the hole 12 to support and secure the tree 17 in position.

In the above embodiments, the tension member 19 is in the form of a wire to secure the root ball 16 in position, the tension member is not limited to the wire. For example, the tension member may be formed into plate shape, as shown in FIGURE 18. In the embodiment shown in FIGURE 18, four tension members 19 each having a plate shape are respectively tensioned between the support member 1 and the root ball retainer 5 (more specifically, the base portions of the slide rods 9).

In the above embodiments, the tension member 19 is wound around the root ball 16 to support and secure the tree 17 in position, rod-like members each having a pressing plate may be driven into the earth at positions to surround the root ball 16 and the pressing plates disposed in the upper portions of the rod-like members are used to press the root ball 16 so as to support and secure the root ball 16.

Accordingly, the present invention is not limited to the method of supporting and securing the tree 17 as described above.

In the above embodiments, the support member 1 is wound around the base 18 of the tree 17 to support the same. However, the means for supporting the base 18 of the tree 17 is not limited to this means. For example, an arrangement as shown in FIGURE 19 may be employed in which the tension member 19 is arranged to intersect at the base 18 of the tree 17 so that the intersection portions 19a and 19b of the tension member 19 surround the base 18 of the tree 17.

In the above arrangement, the tree 17 comes into contact with the intersection portions 19a and 19b of the tension member 19 so as to be tightened and supported after the base 18 of the tree 17 has become thicker. In this case, it is possible to enable the tension member 19 to be broken into pieces after a predetermined period of time to release the tree 17 from the tensioned state, or to provide a winch (not shown) which is attached to the tension member 19, and is removable after a predetermined period of time to release the tree 17 from the tensioned state.

In FIGURE 19, the protective pads 20 are placed on a shoulder portion or any other portions of the root ball 16, where the tensioned force from the tension member 19 are concentrated on, to protect such portions from being broken by the tension member 19, and angles 31 are driven into the earth at positions to surround the root ball 16, through which the tension member 19 is tensioned. Since the root ball 16 can have a varying shape, the protective pads 20 may be effective when the root ball 16 has such shoulder portion. However, it is a matter of course that the protective pads 20 are optional and do not constitute an essential part of the present invention.

Further, it is possible to tension the tension member 19 between the angles 31 to secure the root ball 16 in position, as illustrated in FIGURE 20.

In the above embodiments, the support member 1 is disposed with spacing to the base 18 of the tree 17 and above the root ball 16. However, the support member 1 may be wound around the base 18 in contact with the base 18 of the tree 17. In this case, the support member 1 is pressed and supported by the base 18 of the tree 17.

Claims

1. A method of providing support to tree comprising the steps of placing a root ball secured to the base of a tree in a hole which has been previously formed on the ground, fixing the root ball in position by a fixing means, and filling the hole with soil or the like.

2. A method as claimed in Claim 1 where the fixing means comprises a tree base support member 1 fittable around the base of the tree so that the base of the tree is supported under tensioned state, and a peripheral surface support member connected to the tree base support member in such a manner as to be positioned around a peripheral surface of the root ball.

3. A method as claimed in Claim 1 where the fixing means comprises a tree base support member 1 fittable around the base of the tree so that the base of the tree is supported under tensioned state, a peripheral surface support member 19 connected to the tree base support member 1 in such a manner as to be positioned around a peripheral surface of the root ball, and a root ball retainer 5 for receiving the root ball thereon.

4. A tree base support member for supporting the base of a tree under tensioned state for use in an operation for providing support to tree comprising a support member body la formed in such a manner as to release the base of the tree from the tensioned state after a predetermined period of time has elapsed.

5. A tree base support member as claimed in Claim 4 where the support member body la is made of a decomposable material to release the base of the tree from the tensioned state after a predetermined period of time has elapsed.

6. A tree base support member as claimed in Claim 4 where the support member body la is coated thereon with a protective member 4 being capable of deteriorating as time elapses to release the base of the tree from the tensioned state after a predetermined period of time has elapsed.

7. A tree base support member as claimed in Claim 6 where the protective member 4 is made of thermoplastic polyurethane.

8. A tree base support member as claimed in Claim 4 where the thermoplastic polyurethane is used for at least a portion of the support member body la to release the base of the tree from the tensioned state.

9. A tree base support member as claimed in Claim 7 or Claim 8 where the thermoplastic polyurethane is mixture of polyether thermoplastic polyurethane containing polyether polyol or polyester thermoplastic polyurethane containing polyester polyol and polyether thermoplastic polyurethane.

10. A tree base support member as claimed in Claim 9 where the thermoplastic polyurethane comprises 50 to 99 % by weight of polyether thermoplastic polyurethane and 1 to 50 % by weight of polyester thermoplastic polyurethane.

11. A tree base support member as claimed in Claim 7 or Claim 8 where the thermoplastic polyurethane comprises polyester thermoplastic polyurethane and an anti-fungus agent added thereto.

12. A tree base support member as claimed in Claim 11 where the thermoplastic polyurethane contains 0.1 to 15 % by weight of the anti-fungus agent.

13. A tree base support member as claimed in any one of Claims 4 to 12 where the decomposable material for forming the support member body la is hemp, cotton, jute, rice straw, paper, wool, silk or leather.

14. A tree base support member as claimed in Claim 4 where a connection member capable of being broken into pieces after a predetermined period of time has elapsed is attached to the support member body la to release the base of the tree from the tensioned state.

15. A tree base support member as claimed in Claim 4 where a time adjusting device with a timer is provided to release the base of the tree from the tensioned state.

16. A tree base support member as claimed in any one of Claims 4 to 14 where the support member body is formed into a flat-belt shape.

17. A tree base support member as claimed in Claim 4 where the support member body la made of the decomposable material is subjected to a process with which the decomposition time can be elongated to correspond to the growth of the tree.

18. A tree base support member as claimed in Claim 17 where the process with which the decomposition time can be elongated to correspond to the growth of the tree is a water-proofing process or a water repellent process.

19. A tree base support member as claimed in Claim 18 where the water-proofing process or the water repellent process is accomplished by impregnating or applying wax, paste, pine resin, tar, vegetable oil, silicon oil or silicon resin to the support member body la.

20. A tree base support member as claimed in Claim 1 where the support member body la is provided with breaking means, and the breaking means is arranged to be pressed by the base of the growing tree so as to be actuated to break the support member body la into pieces.

21. A root ball retainer for receiving a root ball secured to the base of a tree being placed in a hole which has been previously formed on the ground for use in operation of providing support to tree where the root ball retainer can entirely contract and expand.

22. A root ball retainer as claimed in Claim 21 comprising a fixing member 7, and a slide rod 9 attached to the fixing member 7 to be slidable with regard to the fixing member 7.

23. A root ball retainer as claimed in Claim 21 where a resistance plate 11 is fixed to the slide rod 9 closer to the leading end thereof.

24. A root ball retainer as claimed in Claim 21 where a pile capable of being driven into a side wall 15 of the hole 12 is fixed to the slide rod 9 closer to the leading end thereof.