WO2008111896A1

WO2008111896A1 - Cleaving device for wood material

Info

Publication number: WO2008111896A1
Application number: PCT/SE2008/000194
Authority: WO
Inventors: Magnus Lagerqvist
Original assignee: Magnus Lagerqvist
Priority date: 2007-03-13
Filing date: 2008-03-12
Publication date: 2008-09-18
Also published as: SE0700604L; SE530652C2

Abstract

The present invention refers to a cleaving device for cleaving wood materials (2), such as e.g. firewood, chunks of wood, boards and said cleaving device (1 ) comprises at least two levers (4), which before the cleaving process are intended mainly to surround the elongated sides (3) of a wood material (2), placed between the levers (4), which then extends in the longitudinal direction (7) of the levers (4), the upper ends (6) of the levers (4) directly or indirectly are turnably connected via at least one revolving axle (5), which extends in a direction (27) across the longitudinal direction (7) of the levers (4) and across the longitudinal direction (28) of the wood material (4), said revolving axle (5) before the cleaving process being situated above an upper wood end (9) of said wood material (2), each of said upper ends (6) is directly or indirectly connected to a cutting edge (8), which extends in the longitudinal direction (27) of the lever (5), each comprising at least an edge (10) arranged side by side and situated next to each other in a distance (14) from the revolving axle (3) counted towards the upper wood end (9) pointing towards/into the same, the opposite, lower wood end (1 1 ) in this case extends below the lower end (12) of the levers (4).

Description

Cleaving device for wood material .

The present invention refers to a cleaving device for cleaving wood materials. The cleaving device comprises two levers, provided to surround the elongated sides of a wood material, which in this position extends in the longitudinal direction of said levers during said cleaving. The levers are turnably connected around a revolving axle, which extends in a direction across the longitudinal direction of the levers at the upper ends of the levers and which are firmly connected to a cutting edge each comprising at least one edge extending in the longitudinal direction of the revolving axle. The edges are arranged side by side in a distance from the revolving axle pointing in a longitudinal direction of the wood material in over the wood end. The opposite, lower end of the wood material extends a bit beyond the lower end of the levers, which during the cleaving operation are angled outwards out from the longitudinal sides.

Structures of this type existing on the market comprise a number of different cleaving devices. Normally the wood materials are cleaved into firewood or smaller sapwoods by aid of an axe towards a chopping block, at the same time as a person by help of one hand is keeping the wood material and the other hand is used to keep the axe if the wood material cannot stand by itself on said chopping block. A danger then arises that one can cut your hand especially if the wood materials are small. According to the US patent specification US 4,381 ,809 a cleaving axe is illustrated having an axe head, which is divided and a spring back element which is arranged in the divided line by aid of a wedge, which during a cutting operation makes that the wedge separates the halves and in this way the wood piece. This structure does not prevent people to cut their hands. The spring counteracts the movement of the wedge and steals power like the friction against the wedge from the pieces, whereby the structure functions bad. According to US 4,440,205 another structure is illustrated, which also this involves a danger to cut ones hand. This one looks like the preceding specification by that a similar spring back device and by that the two elements, which shall give a cleaving effect, steal much power or actually counteract the cleaving effect. DE 3514800 Al illustrates oblique knives provided on a frame intended to put said wood material upon and said knives are then ready to cut through the wood material. This structure is expensive and complicated and cannot function good, since a wood material situated in the middle will be jammed and will easy to be caught between the knives. When the wood material has been cut by the knives, the person which hits also risks to destroy the knives. According to the document DE 201 12840 U l still another cleaving device is illustrated, where a plate is provided by aid of motor power to urge a rigid mounted cleaving tool through a wood material, whereby said wood material is cleaved up into a number of smaller wood pieces. A picking up equipment is connected to this device to take care of the firewood. This is a very expensive and heavy structure intended to cleave and pack firewood in a larger extent.

One object of the present invention is to eliminate those drawbacks existing with the structures mentioned above in providing a cleaving device having levers surrounding said wood material, said cleaving levers comprise cutting knives with edges in their ends. Said ends are turnably connected to a revolving axle, so that when the levers are angled apart from each other around the same, the wood material is cleaved without that a risk occurs that a person is hurting himself.

Thanks to the invention a simple and uncomplicated, cheap and well functioning cleaving device has been provided, which very easy can cleave wood materials such as fire wood and wood splits without that a risk is present for an user to hurt himself. The cleaving device according to the invention comprises two levers, which during the cleaving procedure are intended to contact a wood material placed between the levers, which extends in the longitudinal direction of the levers and which partly or totally surrounds the elongated sides of the wood material. The upper ends of the levers are turnably connected to a revolving axle, which extends in a direction across the longitudinal direction of the levers and across the longitudinal direction of the wood material. Said axle during the cleaving process is situated over and above the upper end of the wood material. The upper ends of the levers each comprise a cutting edge, which extends in the longitudinal direction of the revolving axle and each of which is provided with an edge situated side by side and next to each other in a position just before said cleaving process. The edges are arranged in a distance from the revolving axle and are pointing into the direction of the wood material towards and in over the upper wood end before the cleaving process. The opposite, lower end of the wood material then extends a bit lower below the lower portion of the levers, when these surround the wood material. In order to cleave apart the wood material an user lifts a wood material surrounded by the levers, directs and then strikes the lower end towards a ground e.g a concrete floor, stone plates a chopping block (to obtain a correct working height) in the longitudinal direction of the wood material, whereby the lower wood end stops direct against the support, which presses the upper wood end against the cutting edges. The cutting edges then urges into the upper wood end. Thereafter the lower ends are angled outwards from the elongated sides by an added power from the user. The levers have a length, which is much longer than the distance from the revolving axle to the edges, whereby a moment change occurs of the power supplied, so that a power near the edges is much bigger that the power supplied, which results in that when the edges are angled apart from each other around the revolving axle the wood material is cleaved along its longitudinal direction with a start in the upper wood end and when the levers are further angled apart the cleaving process is going on in the longitudinal direction of the wood material downwards to the lowermost wood end, which rests on the supporting surface until the cleaving process is completed. The cutting edge has a length, which mainly corresponds to the biggest thickness of the wood material, which the cleaving device is capable to cleave, said thickness is limited by a width between the levers across the longitudinal direction of the wood material which is about 15 - 20 cm. The cutting edge cleaves the wood material mainly along a fictive line, which extends across the longitudinal direction of the wood material in the upper wood end mainly through its centre. According to a preferred embodiment example of the invention the cleaving device comprises two levers, which each comprises the mantle surface of a half cylinder made of a sheet unit, e.g. a plate and/or a net in order to surround, support and guide the wood material against the cutting edges, when they contact a tube constituting the elongated sides around the wood material before the cleaving process. That portion of the mantle surfaces, which is situated above the upper wood end turns off and inwards over the upper wood end to reach the revolving axle. There the mantle surface at each lever comprises a recess. When the wood material is cleaved the lower wood end supports against the ground without moving sideways, whereby the upper wood end is cleaved into two wood halves, which are pressed sideways against the recesses, which form openings, which give room for the wood halves at the upper wood end to extend outside the mantle surface more and more the more the lower portions of the levers are pulled apart from each other. In a preferred variant of the invention the mantle surface has an inner wall, which between itself and the long sides of the wood material comprises spring back elements in the form of e.g. steel springs, provided at the inner wall. The spring back element prevents the wood material to fall out from the cleaving device, when the same is lifted from the ground thanks to friction between the spring back element and the longitudinal sides. The revolving axle consists of a hinge pivot with two hinge halves firmly connected to each upper end of the levers. A cutting edge is in this case provided to or near each hinge half. The hinge pivot is stiffened up the cutting edge in its longitudinal direction, which gives a better function during the cleaving process. In order to achieve a still better function and a more controlled cleaving effect, the cutting edge is viewed across its longitudinal direction towards its side, formed in its extension like a "V", turned up and down. Before the cleaving process, when the wood material is hit against the ground, the cutting edges are forced into the outer portions of the wood end and are grasping the same, which counteracts that the wood material tends to turn around its own axle the longitudinal direction of the wood material. The lever or the mantle surface each comprises a handle preferably at their lower ends, said handles extend mainly in parallel to the lever/mantle surface in the longitudinal direction of the levers. The lower portion of the handle is then firmly connected to a projection having a certain length at the same time as the projection is firmly attached to the lever/mantle surface.

The most important advantages with the invention are that a cleaving device is provided, which protects hands to be subjected to cutting damages. The cleaving device is small and easy to bring with oneself. It cleaves above all sap woods quickly and in a simple way without requiring so big places like an axe.

The invention is described closer below with help of an embodiment example with reference to the drawings enclosed, in which

Fig. 1 shows a perspective view of a cleaving device, which has been cut into a wood material before the cleaving process and which is standing on a ground,

Fig. 2 shows a side view of said cleaving device standing on a ground viewed from side, before the wood material is cleaved by that the cutting edge is forced into the upper wood end, and

Fig. 3 shows an upper portion of said cleaving device, when the wood material is going to be cleaved.

As can be seen from fig. 1 a preferred embodiment example is illustrated of a cleaving device 1 according to the invention. The cleaving device 1 , which here comprises two levers 4, surrounds elongated sides 3 of a wood material 2, which extend in the longitudinal direction 7 of the levers 4. The levers 4 each consists of a mantle surface 19 of halves a cylinder, divided in the longitudinal direction 7 of the levers 4. The upper ends 6 of the levers 4 are connected together via a revolving axle 5, which extends in a direction 27 across the longitudinal direction 7 of the levers 4 and the longitudinal direction 28 of the wood material 2. The revolving axle 5 is located above the upper wood end 9 of the wood material 2. In connection to the upper ends 6 the cleaving device 1 is provided with two cutting edges 8 having a length 16, which extends in the longitudinal direction 27 of the revolving axle 5. The cutting edges 8 each comprises an edge 10 provided side by side by side next to each other in a distance 14 from the revolving axle 5. The lower wood end 1 1 of the wood material 2 rests on a ground 13. Before the cleaving process starts the lower ends 12 of the levers 4 are angled outwards from each other in a direction 31 from the elongated sides 3 across the elongated direction 7. The levers 4 have a length 15, which is much longer than the distance 14. The cutting edges 8 cleave mainly along a fictive line 17, which extends across the longitudinal direction 28 of the wood material 2 in the longitudinal direction 27 of the revolving axle 5 in the upper wood end 9 mainly through its centre 18. The thickness of the wood material 2 is a bit smaller than the width 26 existing between the levers 4. The mantle surface 19 has an inner wall 20, which is provided with a spring back element 21 between the inner wall 20 and the elongated sides 3. Respective mantle surface 19 further has a handle 22 fixed to the mantle surface 19 via a projection 32 and each having a recess 23 at the upper end 9 of the levers 4.

As can be seen from fig. 2 the revolving axle 5 consists of a hinge pivot 24 having two hinge halves 25 each firmly connected to its upper end 6 at the same time as a cutting edge 8 is provided in each hinge half 25, whereby the cutting edges 10, which are located in said distance 14 from the revolving axle 5, have been pushed downwards a bit into the upper wood end 9.

As can be seen from fig. 3 it is illustrated how the upper wood end 9 has been pressed apart by the edges 10, whereby two wood halves 30 have been separated from each other in the upper wood end 9, when the levers 4 have been angled apart from each other in a direction 31 , so that the wood halves 30 are urged outwards through recesses 23, which form openings 29, which give room for the wood halves 30.

Claims

1. A cleaving device for cleaving wood materials (2), such as e.g. firewood, chunks of wood, boards, characterized in that the cleaving device (1 ) comprises at least two levers (4), which before the cleaving process are intended mainly to surround the elongated sides (3) of a wood material (2), placed between the levers (4), which then extends in the longitudinal direction (7) of the levers (4), the upper ends (6) of the levers (4) directly or indirectly are turnably connected via at least one revolving axle (5), which extends in a direction (27) across the longitudinal direction (7) of the levers (4) and across the longitudinal direction (28) of the wood material (4), said revolving axle (5) before the cleaving process being situated above an upper wood end (9) of said wood material (2), each of said upper end (6) is directly or indirectly connected to a cutting edge (8), which extends in the longitudinal direction (27) of the lever (5), each comprising at least an edge ( 10) arranged side by side and situated next to each other in a distance (14) from the revolving axle (3) counted towards the upper wood end (9) pointing towards/into the same, the opposite, lower wood end ( 1 1 ) in this case extends below the lower end ( 12) of the levers (4).

2. A cleaving device according to claim 1 , characterized in that the levers (4) have a length (15), which is much longer than the distance (14) from the revolving axle (5) to the edges (10).

3. A cleaving device according to claim 1 , characterized in that the cutting edge (8) has a length (16) across the longitudinal direction (28) of the wood material (2), which is mainly somewhat longer than the biggest thickness of the wood material, the cleaving device (1 ) is capable to cleave, about 15-20 cm or a width (26), which is shorter than a distance between the levers (4) across the longitudinal direction (28) of the wood material (2), said cutting edge (8) cleaves mainly along a fictive line (17), which extends across the longitudinal direction (28) of the wood material in the upper wood end (9) mainly through its centre (18) in the longitudinal direction (27) of the revolving axle (5).

4. A cleaving device according to claim 1 , characterized in that the revolving axle (5) consists of a hinge pivot (24) having two hinge halves (25) each firmly connected to its upper end (6) at the same time as a cutting edge (8) is provided in each hinge half (25).

5. A cleaving device according to claim 3, characterized in that the cutting edge (8) viewed across its longitudinal direction towards its side, has an extension like a "V" turned up and down.

6. A cleaving device according to claim 1 or 4, characterized in that it comprises two levers (4), which each consists of a mantle surface (19) of mainly half a cylinder divided in the longitudinal direction (7) of the levers (4) along the longitudinal direction (27) of the revolving axle in forming a tube, the upper ends (6) are turning off in over the upper wood end (9) towards the revolving axle (5), which each are attached to a hinge half (25).

7. A cleaving device according to claim 6, characterized in that the mantle surface ( 19) has an inner wall (20), which comprises at least one spring back element (21 ) in the form of e.g. a steel spring provided at the inner wall (20), said element (21 ) is arranged between the inner wall (20) and the elongated sides (3).

8. A cleaving device according to claim 1 or 6, characterized in that the lever (4) /mantle surface (19), preferably at its lower end ( 12) each comprises a handle (22), the lower portion of said handles (22) are firmly provided in the lever (4) /mantle surface ( 19) via at least one projection (32).

9. A cleaving device according to claim 6, characterized in that respective mantle surface ( 19) at the upper end (9) of the levers (4) each comprises a recess (23), constituting openings (29), which gives room for the wood halves (30) of the upper wood end (9) to extend outside the mantle surfaces (19) during the cleaving procedure, when the lower ends (12) are angled apart.

10. A method using a cleaving device (1 ) according to claim 1 , characterized in that an user surrounds the levers (4) totally or partly around the elongated sides of the wood material (2) having the upper wood end (9) turned towards the edges (10), whereupon the user is lifting the cleaving device (1 ) containing said wood material (2), directs and thereafter hits the wood lower end (1 1 ) in a direction towards a ground (13), e.g. a concrete floor, stone plates, a chopping block in the longitudinal direction (28) of the wood material, the lower wood end (1 1 ) being stopped immediately against the ground (13) and the upper wood end being pressed (9) towards the cutting edges (8) at the same time as the edges (10) being urged into the upper wood end (9), when the lower ends ( 12) being angled outwards from the elongated sides (3) in a direction (31 ) from one of the user supplied power, the edges ( 10) are angled outwards from each other around the revolving axle (5) and the wood material (6) is cleaved from above and down in the longitudinal direction (28) of the wood material (2).