Bamboo handle

Abstract

The invention relates to a handle which consists substantially of block-shaped rectangular bamboo elements which are glued together in a plurality of layers, said elements being laid next to one another and against one another substantially in the longitudinal direction of the fibers of the elements and said elements being laid next to one another and against one another on the horizontal plane and forming vertical longitudinal seams between the elements laid next to one another and against one another. At least three layers of the elements are glued together using an adhesive, at least one first layer being glued to a second layer and the second layer being glued to a third layer of the elements. The elements are arranged in an assembly in which the majority of the vertical longitudinal seams of the first layer are substantially offset with respect to the vertical longitudinal seams of the subsequent layer.

Description

[0001] BAMBOO STRIP

[0002] DESCRIPTION

[0003] The invention relates to a handle made of bamboo elements glued together in several layers. Handles manufactured in this way can be used to attach tools such as a shovel, spade, hammer, or axe.

[0004] TECHNOLOGICAL BACKGROUND

[0005] Traditional timber-based construction techniques typically involve the use of logs, boards, beams, rafters, composite timber products, and other components made from wood in the form of sawn timber or laminated elements. The use of wood for a variety of applications is increasing, as wood is in many cases a sustainable alternative to, for example, concrete and brick in construction.

[0006] Consequently, global demand for timber is high, which often results in harvesting quotas being higher than replenishment quotas.

[0007] Bamboo, especially giant bamboo, also known as wood bamboo, is increasingly used for various applications. Bamboo is a type of grass that grows worldwide and offers many advantages over wood as a building material, including lower material costs, greater strength, faster growth, higher carbon sequestration, and greater durability, making wood bamboo an attractive alternative to timber. Using wood bamboo as a substitute for wood is highly desirable. However, the size of wood bamboo—typically exceeding 10 meters in length but less than 30 cm thick and hollow with relatively thin walls and multiple nodes along its length—means it is not a direct replacement for tree timber.

[0008] The longitudinal compressive strength of bamboo is primarily due to the orientation of the fibers, which run lengthwise within the culm. The fiber orientation is generally parallel, with the exception of some transverse fibers in the node regions. Therefore, unprocessed bamboo poles made from whole culms are suitable to a certain extent for applications such as scaffolding, columns, or posts. Failures in bamboo poles are typically caused by splitting along the length of the culm, with the parallel fibers separating. This type of failure is also evident when fasteners such as screws are driven through the culm, resulting in poor pull-out performance when bent along the grain. Consequently, natural bamboo is not readily a good substitute for wood, which contains additional transverse fibers.

[0009] To produce traditional dimensional building materials, such as lumber and beams, from bamboo, the bamboo culm is typically shredded, and the chips are then processed with resins to create dimensional lumber. However, this shredding process destroys the natural fiber orientation and lignin bonds, thus compromising the natural strength properties of the bamboo culm, and usually results in materials that are less strong and / or heavier than natural bamboo.

[0010] Instead of shredding, bamboo wood is also produced by pressing bamboo fibers. In this case, (giant) bamboo is sawn into long strips. To kill parasites and make the bamboo pliable, the strips are boiled in water and then glued together under high pressure. The thickness can be varied by using multiple layers. By laying the layers diagonally across each other, a board or panel is created that is, among other things, more resistant to warping.

[0011] The following section discusses some patent specifications relating to the use of bamboo instead of wood.

[0012] US Patent US 10,442,111 B1 can be summarized as a laminated bamboo wood for replacing tree wood. The bamboo-laminated wood consists of laminated bamboo elements glued together to form composite wood components. The laminated bamboo wood comprises a combination of linear bamboo boards made from longitudinally halved halves of woody bamboo poles, which are flattened and laminated in alternating layers of half-bamboo poles along the grain, alternating with half-bamboo poles positioned at an angle so that the grain runs diagonally to the longitudinally positioned half-bamboo poles. A disadvantage of this solution may be that production can be comparatively complex, and a relatively large amount of bamboo waste is to be expected when manufacturing boards from this form of bamboo wood.

[0013] Finally, the construction of block-shaped bamboo strips (hereinafter referred to as bamboo elements) in several layers is known on the bamboo wood market. The bamboo elements are arranged in a bond known in the construction industry as a brick bond, in which bamboo elements of the same width are stacked directly on top of each other and glued together, thus forming blocks of bamboo elements. These blocks are then placed next to and against similar blocks, creating vertical seams between the adjacent blocks. The seams are glued.Although this has the advantage of allowing boards of various sizes to be produced relatively efficiently by varying the number of blocks placed side by side and the number of layers, this construction has the inherent problem that when a board made using this construction, or a product sawn from this board, is subjected to stress, the weakest points of the bamboo are, firstly, the seams between the blocks and, secondly, the connection between the different layers. The use of such bamboo is therefore mostly limited to constructions where the stress occurs primarily or exclusively along the grain, and where the blocks cannot break lengthwise or the layers cannot separate.

[0014] REVELATION OF THE INVENTION

[0015] The invention relates to a bamboo handle made from a plate of bamboo elements. The plate consists of bamboo processed into block-shaped elements arranged side by side in at least three layers, with the fibers or veins oriented lengthwise and the layers glued together. Vertical longitudinal seams are located between the adjacent and opposing elements. The arrangement of the elements is such that the vertical longitudinal seams of a first layer are offset from the vertical longitudinal seams of a third layer, and preferably also from a second, fourth, and subsequent layers.The offsetting of seams in this way is also called free or random stitching, whereby it should be noted that this is a form of free or random stitching in which careful attention is paid to ensuring that as few as possible vertical longitudinal seams lie in a line, but that in any case no or as few as possible seams of a first layer lie in the extension of a third layer.

[0016] To ensure that the staggered joints occur in as many layers as possible, bamboo elements of varying widths are preferably used. Using bamboo elements of the same width increases the likelihood of a recurring "brickwork pattern," where vertical joints of a first layer align with vertical joints of a layer above or below, similar to half-brick masonry. The closer layers with vertical joints are to other layers with aligned vertical joints, the greater the chance of a fracture occurring at the point where the joints overlap. Joints are the weakest point in a timber structure, often even when they are glued.

[0017] This staggered seam construction results in a bamboo plank structure that is more resistant to stress from multiple directions.

[0018] The production of the invented bamboo handles from this plate construction therefore results in handles that are particularly suitable for applications as garden and construction tools, as listed above.

[0019] The manufacturing process involves sawing a beam lengthwise with a cross-cut just large enough to allow for subsequent rotation into a round piece of wood. The resulting round piece is therefore much more stress-resistant than currently available bamboo handles and is at least as stress-resistant, or even more so, than tool handles made from conventionally used woods such as beech, ash, or hickory.

[0020] The invention demonstrates its value particularly in the following application.

[0021] For ergonomic reasons, tool handles are often designed with a curved shape. From the end of the handle facing the user, the part without the tool (like a shovel or bat), an ergonomically sound handle in this case initially runs straight and then curves towards the tool part. Creating such a handle presents a challenge in the manufacturing process, as the curve must not compromise the handle's strength and stress resistance. A common technique involves sawing or milling the shape, including the curve, from a piece of wood. If we consider the curved handle with the tool part facing forward in the working position, the curve is in the vertical plane. However, the cut-out shape is in the horizontal plane when the wood is laid flat.

[0022] If the plate is made from a single section of a tree trunk, the handle is sawn out as precisely as possible so that the fibers / veins of the wood structure run in the same longitudinal direction as the handle. However, this presents the problem that the fibers "fly out of alignment" relative to the curved section, meaning they don't follow the curve. This can create points in the material where fracture lines can develop because stress isn't effectively absorbed. Therefore, such a handle can split lengthwise or break in the curved section with long-term and / or intensive use.

[0023] The application of the current panel construction therefore requires very careful planning, the selection of optimal pieces of lumber for sawing, and consequently also results in a significant amount of waste from unusable parts. The same problem occurs when bamboo elements are used, particularly when these bamboo elements are placed in a tile pattern or a diagonal pattern.

[0024] In the present invention, the location where a stem is sawn out is much less critical, and a curved stem sawn out in this way results in a much stronger and more reliable product.

[0025] When cutting production parts from a sheet, it is important to utilize the sheet optimally, minimizing waste. This leads to lower handling costs, such as those associated with international transport, and more efficient internal logistics flows, resulting in reduced material consumption and clearly positive environmental impacts. Using sheets according to the invention allows for optimal processing. The so-called nesting process becomes simpler, and smaller cavities can be cut out, for example, to create T-shaped handles for the poles, as well as poles of various shapes and sizes. After the shape of the curved pole has been cut out in the flat plane, the bamboo pole is subjected to further processing according to the invention, such as turning into a round log with a curvature.

[0026] An important process that must be mentioned here is the tapering of the tool end of the bamboo handle, so that the handle can be fitted into a socket (handle attachment) of, for example, a shovel. The socket is the round, hollow, metal part of a metal tool into which the handle can be secured.

[0027] To align the outer surface of the stem with the outer surface of the socket, the stem must be tapered over the length that will be inserted into the socket (resulting in a slightly smaller diameter of the stem in that area). This tapering is typically achieved through a machining process. Material removed in this way creates a potentially weaker point in the stem. Therefore, it is even more important that the bamboo element structure is inherently strong, so that the tapering results in only a negligible reduction in strength.

[0028] The invention relates to a handle consisting essentially of block-shaped rectangular bamboo elements glued together in several layers, wherein the elements are placed side by side and opposite each other substantially in the longitudinal direction of the fibers of the elements, and wherein the elements are placed side by side and opposite each other in the horizontal plane, forming vertical longitudinal seams between the adjacent and oppositely placed elements. Furthermore, at least three layers of the elements are glued together with an adhesive, wherein at least a first layer is glued to a second layer, and the second layer is glued to a third layer of the elements. The elements are arranged in a staggered pattern, with most of the vertical longitudinal seams of the first layer being significantly offset from the vertical longitudinal seams of any other layer of the at least three layers.

[0029] The invention can be summarized in the following embodiments or features:

[0030] - The vertical longitudinal seams of each layer are significantly offset from the vertical longitudinal seams of the next adjacent layer.

[0031] - The elements are arranged in a pattern where most of the vertical longitudinal seams of the first layer are significantly offset from the vertical longitudinal seams of the second and third layers. - The block-shaped rectangular elements vary in at least two different widths per layer.

[0032] - An association comprises one association from the group:

[0033] - Half-brick bond;

[0034] - free or wild association;

[0035] - Runners Association;

[0036] - Bamboo elements of essentially the same dimensions, placed in a free or wild bond or runner bond.

[0037] - The vertical longitudinal seams are glued with adhesive.

[0038] - Elements of the elements per layer of the multiple layers are placed with their end faces against each other, forming vertical width seams between the elements placed against each other, with the majority of the vertical width seams of the first layer being substantially offset from the vertical width seams of the second layer and / or the third layer.

[0039] - The vertical width seams are glued together with adhesive.

[0040] - The stem refers to a cutout from a block, beam or plank, consisting essentially of elements of bamboo placed in the aforementioned arrangement.

[0041] - The handle is configured as a round piece of wood or an oval.

[0042] - The handle is suitable for use as a handle for a tool.

[0043] - The tool includes one tool from the group: rake, shovel, bat, spade, hoe, edger, axe, hammer, fork or fork.

[0044] - The adhesive comprises an adhesive from the group: melamine-based synthetic resin, wood glue (PVA adhesive), epoxy adhesive or polyurethane adhesive.

[0045] The present invention is also related to a method for manufacturing a handle from bamboo elements. The method comprises the following steps:

[0046] A. Production of elements from bamboo;

[0047] B. Forms of a plate consisting of several layers of elements in a bond according to one of the preceding claims;

[0048] C. saw the board into lengthwise sections; D. form one lengthwise section of the lengthwise sections into a round piece of wood by applying a machining technique such as turning or milling.

[0049] In one embodiment, in step C the length parts are sawn in a relatively long straight part that transitions into a curved part.

[0050] Summary: The present invention relates to a handle consisting essentially of block-shaped rectangular bamboo elements glued together in several layers, wherein the elements are laid side by side and adjacent to each other substantially in the longitudinal direction of the fibers of the elements, and wherein the elements are laid side by side and adjacent to each other in the horizontal plane, forming vertical longitudinal seams between the adjacent and adjacent elements. At least three layers of the elements are glued together with an adhesive, wherein at least a first layer is glued to a second layer and the second layer to a third layer of the elements. The elements are arranged in a staggered pattern in which the majority of the vertical longitudinal seams of the first layer are substantially offset from the vertical longitudinal seams of the subsequent layer.

[0051] BRIEF DESCRIPTION OF THE FIGURES

[0052] The accompanying drawings illustrate various embodiments of the invention. The element boundaries shown are an example of such boundaries. In some examples, one element may be designed as multiple elements, or multiple elements as one element. The elements are not necessarily drawn to scale, but relative dimensions may be indicated if necessary. Non-restrictive and non-exhaustive descriptions are provided with reference to the following drawings:

[0053] Fig. 1 shows a front view or cross-section of a bamboo wood construction.

[0054] Fig. 2 shows the view of Fig. 1 after material has been abbreviated.

[0055] Fig. 3 shows the view of Fig. 2 with possible saw cuts.

[0056] Fig. 4 shows a sawn-out round piece of wood that can serve as a bamboo stem.

[0057] Fig. 5 shows a top view of a bamboo wood structure with a possible saw cut for producing a round log or bamboo stalk with a curve. Fig. 6 shows a detail view of Fig. 5.

[0058] Fig. 7 shows a front view or cross-section of a bamboo wood construction with cut-out projections of a round timber with a curvature.

[0059] Fig. 8 shows a front view or cross-section of a bamboo wood construction with cut-out projections of an oval round timber.

[0060] DETAILED DESCRIPTION OF THE FIGURES

[0061] Exemplary embodiments of the invention are described in more detail below with reference to the accompanying drawing figures, in which numbers represent similar elements in the various drawing figures, and in which exemplary embodiments are shown.

[0062] Fig. 1 shows a front view or cross-section of a bamboo wood structure 101. The structure 101 is built from layers of bamboo elements placed side by side. In Fig. 1, 5 layers can be distinguished (see also Fig. 2), but more or fewer layers are also possible. The invention is based on a minimum of 3 layers. In the Fig., 3 widths of bamboo elements are used, which are designated as the narrowest width 110a,b, the medium width 111a,b, and the widest 112a. The widths used can be found again in the subsequent layers in any combination. By staggering the vertical width seams 120, the cohesion between the different layers is increased, and fracture lines are less likely to occur, since vertical width seams like 120 do not have any vertical width seams in their extension, at least in two further layers.

[0063] To produce processable panels from the bamboo wood construction 101, parts to the left of saw cut 190a and to the right of 190b can be shortened.

[0064] Fig. 2 shows the view of Fig. 1 after material abbreviation. Reference numbers 131 ae have been added to identify the layers, each representing one layer. Fig. 3 shows the view of Fig. 2 with possible saw cuts 191 a,b, resulting in blocks from which round timber in cross-section 192a,b,c can be produced.

[0065] Fig. 4 shows a sawn-out round timber that can serve as a bamboo stem 100 according to the invention. The layers 131 ae are shown, with the vertical seams being offset in each layer, at least between two layers, between which a layer is located. To illustrate this, virtual dividing lines 19a-d have been drawn. In the optimal case, no single vertical seam lies in the extension of another vertical seam, but in order to achieve significant reinforcement, the invention proposes that, at least in the first and third layers, the majority of vertical seams should not lie in the extension of each other.

[0066] Another arrangement of the bamboo elements using a single width of bamboo elements is a design in which, in each layer, the vertical width seams are regularly slightly offset in the same direction, such that no two vertical width seams lie in the same roundwood in the extension, at least considered in a first and a third layer.

[0067] Another arrangement relates to an arrangement as a free association or so-called wild association, but according to a variation that meets the requirements of the invention.

[0068] Fig. 5 shows a top view of a bamboo wood construction 101 with possible saw cuts 192 for the production of a production part from which round timber or bamboo stalk 100 with a curvature can be produced.

[0069] Fig. 6 shows a detail view of Fig. 5. Bamboo elements 110a, 111a and 112a are part of the possible cutout 192.

[0070] Fig. 7 shows a front view or cross-section of a bamboo wood structure 101 with cut-out projections of a curved roundwood piece. Dashed lines 193a,b show a cross-section 194a as the roundwood would be sawn from the structure 101 if it were a straight bamboo stalk. Dashed lines 193c,d show the cross-section 194b as it appears when following the curve of the production part 192 from which the bamboo stalk 100 can be formed. This illustrates how the various bamboo elements are and remain connected, even in the case of a curved bamboo stalk.

[0071] Fig. 8 shows a front view or cross-section of a bamboo wood structure 101 with cut-out projections of an oval round timber. Dashed line 194c shows a cross-section 194c as the round timber would be sawn from the structure 101 if an oval round timber were used instead of a round cross-section of a round timber as in Fig. 7. Element 11a is an exemplary representation of a bamboo element with a vertical longitudinal seam 120.

[0072] It should be noted that the embodiments described above illustrate rather than limit the invention, and that a person skilled in the art will be able to design many alternative embodiments without deviating from the scope of the appended claims. The use of the verb "comprise" and its conjugations does not preclude the presence of elements or steps not listed in a claim. The term "and / or" includes all combinations of one or more of the related listed articles. The indefinite article "a" before an element does not preclude the presence of several such elements. The definite article "the" before an element does not preclude the presence of several such elements. In apparatus claims that list various means, several of these means may be embodied by one and the same piece of hardware.The mere fact that certain measures are listed in independent claims does not mean that a combination of these measures cannot be used.

Claims

PROTECTIVE CLAIMS 1. Stem (100) consisting essentially of block-shaped rectangular elements (110a, 111a, 112a) of bamboo glued together in several layers (131a, 131b), wherein: - the elements are essentially laid side by side and next to each other in the longitudinal direction of the fibers of the elements; - the elements are placed next to and next to each other in the horizontal plane, forming vertical longitudinal seams (120) between the elements placed next to and next to each other, characterized in that - that at least three layers of the elements are glued together with an adhesive, wherein at least a first layer is glued to a second layer and the second layer is glued to a third layer of the elements; - that the elements are arranged in a bond, wherein most of the vertical longitudinal seams (120) of the first layer are significantly offset from the vertical longitudinal seams of another layer of the at least three layers.

2. Stem according to claim 1, characterized in that the vertical longitudinal seams of each layer are arranged substantially offset from the vertical longitudinal seams of the immediately adjacent following layer.

3. Stem according to claim 1 or 2, characterized in that the elements are arranged in a bond in which the majority of the vertical longitudinal seams of the first layer are substantially offset from the vertical longitudinal seams of the second and third layers.

4. Stem according to one of the preceding claims, characterized in that the block-shaped rectangular elements vary in at least two different widths per layer.

5. Stem according to one of the preceding claims, characterized in that the bandage comprises a bandage from the group: - Half-brick bond; - free or wild association; - Runners Association; - Bamboo elements of essentially the same dimensions, arranged in a free or wild bond or a runner bond.

6. Handle according to one of the preceding claims, characterized in that the vertical longitudinal seams are glued with the adhesive.

7. Stem according to one of the preceding claims, characterized in that elements of the elements per layer of the several layers are placed together with their end faces and thereby form vertical width seams between the placed elements, wherein the majority of the vertical width seams of the first layer are substantially offset to the vertical width seams of the second layer and / or the third layer.

8. Handle according to claim 7, characterized in that the vertical width seams are glued with the adhesive.

9. Stem according to one of the preceding claims, characterized in that the stem represents a section of a block, a beam or a plate consisting essentially of elements made of bamboo arranged in the said arrangement.

10. Handle according to one of the preceding claims, characterized in that the handle is configured as round wood or as oval wood.

11. Handle according to one of the preceding claims, characterized in that the handle is suitable for use as a handle for a tool.

12. Handle according to one of the preceding claims, characterized in that the tool comprises a tool from the group: - Rake; - shovel; - mallet; - Spade; - Hoe; - Edge cutter; - Axe; - Hammer; - Fork; - Pitchfork.

13. Stem according to one of the preceding claims, characterized in that the adhesive comprises an adhesive from the group: - Melamine-based synthetic resin; - Wood glue (PVA adhesive); - Epoxy adhesive; - Polyurethane glue.

14. Handle according to one of the preceding claims, manufactured by the following steps Production of elements from bamboo; A. Forms of a plate consisting of several layers of elements in a bond according to one of the preceding claims; B. Sawing the board into lengthwise sections; C. Shaping a length of the lengths into a round log by applying a machining technique such as turning or milling.

15. Tool with a handle (100) according to one of the preceding claims.

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