WO1999064214A1

WO1999064214A1 - A device for splitting wood blocks

Info

Publication number: WO1999064214A1
Application number: PCT/SE1999/000984
Authority: WO
Inventors: Edvard SÖRENSEN
Original assignee: Soerensen Edvard
Priority date: 1998-06-09
Filing date: 1999-06-08
Publication date: 1999-12-16
Also published as: SE9802031L; SE512236C2; AU4669099A; SE9802031D0

Abstract

A wood splitting device comprises a stand (1), a knife device (2) having a horizontal main knife (12) and a plurality of help knives (14) on the underside thereof, a holder (3) for wood blocks having a lying fibre direction as well as means for achieving longitudinal relative motion between the knife device (2) and the holder (3). The stand (1) comprises a horizontal table (7) along which a frame (3) serving as holder is, together with a block lying therein, movable to and fro along with a pressing device (22) which is pressable against an end surface of the block, more precisely by means of a hydraulic cylinder (4). The knife device (2) is mounted on free ends of a pair of arms (16), which are turnable in relation to the table (7) via hinges (17) and placed in a position outside a front edge of the table (7).

Description

A DEVICE FOR SPLITTING WOOD BLOCKS

Technical Field of the Invention

This invention relates to a device intended for splitting wood blocks, which comprises a stand, a knife device having a main knife wr.ich on an underside presents a plurality of mutually spaced-apart secondary knives, a holder for blocks having a lying fibre direction as well as means for bringing about a longitudinal relative motion between the knife device and the holder with tne purpose of cleaving the block in the fibre direction of the wood, more precisely by the fact that the main knife detaches a bottom part which m turn is, at the same time, divided into a plurality of smaller wood pieces by means of tne secondary knives.

Prior Art

A wood splitting device of the above-mentioned type is previously disclosed in CH 237 565. In this case, the knife device is articulateαly connected to a piston rod which is movable to and fro in relation to a stationary holder in the shape of a vertical box open at the top as well as at the bottom, whicn may be loaαed with wood blocks via the upper opening thereof. At a certain level under the lower ooemng of the box a support plate is arranged, against which the bottom part of the individual wood diock may rest in order to hold the block m position until the knife device starts a work operation, during whicn a lying main knife splits a substantially horizontal main cut tnrough the block at the same time as secondary knives on the underside of the main knife divide the block into a plurality of wood pieces having a limited size.

Although the known device has the general advantage of dividing more than one single piece of wood from the block during eacn splitting operation, the same is associated with disadvantages. One disadvantage is that the distance between the lower feedmg-out opening of the wood block box and the support plate is given once for all. This means that the dimensions of the separated wood pieces cannot be varied. An additional disadvantage is that the wood clocks has to have a certain smallest diameter in order not to risk to be distanced from the space between tne feeding-out opening of the box and the support plate without being processed by the knife device. Another disadvantage is based on the fact that the box is stationary while the knife is movable, more precisely by means of a crank mechanism together with a piston rod. In order for such a mechanism to generate the force, which is required to effectively cleave in particular knot-rich and cross-grained wood blocks, it has to be powerfully dimensioned. This is something that, among other things, limits the possibilities of manufacturing the splitting device in mobile embodiments. By the fact that the knife is movable and the block holding box is stationary, it is furthermore required that the box is made in a particularly strong and resistant embodiment order to reliably resist the forces whicn are applied to the box when the Knife device initiates a splitting operation.

Objects and Features of the Invention

The present invention aims at obviating the above- mentioned disadvantages of the device known by CH 237 565 and at providing an improved wood splitting device. Therefore, a primary object of the invention is to provide a wood splitting device which, with simple means, enables considerable variation of the dimensions of the wood pieces separated from a wood block, more precisely in respect of tne thickness thereof. Thus, the device should be able to separate wood pieces, which are useable not only for coimoustion purposes, but also for other purposes, in particular roofing purposes. Another object is to provide a device whicn may be manufactured of components having moderate dimensions without lower- mg the capacity and efficiency of the device, and which, in that manner, may be realized in mobile embodiments, which m a simple way may be transported between various sites.

According to the invention, at least the primary object is attained by the features defined the characteriz- mg clause of claim 1. Preferred embodiments of the invention are furthermore defined n the dependent claims. Brief Description of tne Appended Drawings

In the drawings : Fig 1 is a perspective exploded view of a device according to the invention, Fig 2 is a schematic side view of the device according to fig 1, more precisely in a functional state m which the device detaches comparatively thick wood pieces from a block, Fig 3 is a cut detailed side view showing the device in another functional state in which the same detaches thinner wood pieces, Fig 4 is an enlarged detailed side view illustrating a knife device included in the device, Fig 5 and 6 are side views showing the device without and with a wood blocκ, respectively,

Fig 7 and 8 are enlarged cross-sections through the device, and Fig 9 is a cross-section corresponding to fig 7 showing an alternative embodiment of the device.

Detailed Description of Preferred Embodiments of the Invention

The device shown fig 1 comprises a stand designated 1 m its entirety, a knife device 2, a holder 3 as well as a force generator generally designated 4. The stand 1 includes a central beam 5 and two long side beams 6, which together carry a table 7. Furthermore, two front support legs 8 and two rear, V-positioned legs 9, which are provided with wheels 10, are included the stand. The front support legs 8 may advantageously consist of telescopic tubes, the length of which is adjustable, more precisely individually for each support leg. In that manner, the table 7 may always be located horizontally even if the device is put on uneven ground. The legs can be tipped-up via hinges 11 to an upper, inactive position n which they do not block transportation of the device, e.g. as a trailer behind a traction vehicle.

The knife device 2 includes a horizontal ma knife 12 in the shape of a long and wide plate having an edge 13 extending along the entire width of the plate. Underneath the plate 12, a plurality of secondary knives or help knives 14 are arranged. In the example, more precisely five such help knives are shown. The edges on these help knives are designated 15. As may be seen in fig 4, the edge 13 of the main knife 12 is situated at a certain distance from the edges 15 of the help knives 14. This means that the edge 13 will cut in a distance in a wood block before the edges 15 of the help knives initiate their splitting operation in the block. The edge 13 is provided along the rear edge of the plate 12 and situated near, although at a certain distance from the front edge 7' of the table 7.

As may be seen in fig 1, the main knife 12 is mounted on free ends of a pair of arms 16, which are connected to the stand via hinges 17. In the direction backwards from the hinges 17, the arms 16 transform into a common rear yoke 18, which extends under the central beam 5 and has a finger-like plate 19. A diagonal member 6' extends between the central beam 5 and a long side beam 6. In the finger plate 19, there is a threaded hole for a set screw 20, which with an upper end is pressed against the underside of the stand, more precisely against the central beam 5 thereof. When the set screw is adjusted so that the distance between the finger plate 19 and the central beam 5 is large, the level difference between the main knife 12 and the table 7 is also large. If the distance between the finger plate 19 and the central beam is reduced by rotation of the set screw, the level difference between the main knife 12 and the table 7 is decreased correspondingly. In practice, the level difference between the main knife and the table may be varied from the range of 80-100 mm (in order to give relatively thick wood pieces for combustion purposes) down to about 10 mm as is shown in fig 3. In the last-mentioned case, the device may thus be used for the separation of thin, flat wood pieces, which may be used as roof shingles.

In order to maximise the angle of deflection of the support arms 16 in the direction upwards, a stop element 21 (see also fig 8) is arranged in the shape of a U-shaped member, which is attached to the central beam 5 and has a hori^¬ zontal branch situated under the finger plate 19.

A pressing device 22 is movable backwards to and fro along the table 7 by means of the force generator 4. In the shown embodiment example, this pressing device consists of a cross-section-wise L-shaped cross piece having a horizontal flange 23 and a vertical flange 24 for pressing against a wood block (which in fig 2 is designated 25) . This cross piece is controlled in relation to the table in such a way that the same cannot lift from the table. Thus, in the example is shown how two vertical dowels 26 (see, at the same time, fig 1 and fig 8) engage in longitudinal groove 27 in the table and are provided with washers and nuts 28, 29 underneath the table. Underneath the horizontal flange 23 of the cross piece, there are friction plates 30 of a material, e.g. plastic, having a low coefficient of friction.

Although the force generator 4 could consist of an arbitrary mechanism having an intermittently variable length (e.g. a screw together with a rotatable nut) per se, a double- acting hydraulic cylinder is preferred for the purpose. Thus, in the example according to the drawings a hydraulic cylinder is shown, the cylinder part 4 ' of which is articulatedly connected to the rear end of the stand via a hinge 31, while a rod piston 4" projecting out of the cylinder part is, via a hinge 31', connected to the cross piece 22 serving as a pressing device. The oil supply to the hydraulic cylinder takes place in a conventional way by means of a tank and a pump, which may be driven, for instance, by means of an electric motor 32.

The holder 3 is in the shape of a quadrangular frame, the purpose of which is to bring back the wood block in question to the table after each splitting operation which is carried out by the pressing device 22 in co-operation with the knife device 2. In the example, the frame 3 is composed of two transverse end walls 33, 33' being vertically oriented, as well as two long side walls 34, 34', both of which are oblique in the direction upwards/outwards in relation to the table. Means are associated with the frame to guide the same linearly along the arms 16. In the example, these means consist of dis- mountable claws 35 having horizontal, lower flanges which engage under the undersides of the arms 16. On the outside of the rear end wall 33, a vertical, central U-profile 36 is arranged, which forms a guide for receipt of a dog 37, con- nected with the pressing device 22, in the shape of an upright plate which is articulatedly connected with the horizontal flange 23. Thus, when the arms 16 move vertically in relation to the table, the frame 3 is movable vertically in relation to the table 7 and the pressing device 22 movable along the table. On the inside of the end wall 33, a strip or flat- shaped insert 38 is arranged, which fills out the space above the vertical flange 24 of the cross piece 22 (see fig 2) and the inturned surface of which is situated approximately in the same vertical plane as the front surface of the flange 24. In practice, the insert 38 may be made of a relatively soft, vibration absorbing material, such as plastic. By the presence of this insert, the risk is cleared away that the rear end of the block 25 by misadventure is hitched against the upper edge of the flange 24 in connection with the down-feeding of the block in the holder frame 3.

The Function and Advantages of the Invention

In fig 5, the device is shown in a starting position in which the frame 3 is empty and withdrawn to a rear end position by the fact that the hydraulic cylinder 4 is contracted to a minimal length. As is seen by the double arrows, the horizontal main knife 12 of the knife device may be adjusted in various height positions in relation to the table 7 by means of the set screw 20. In fig 6 is shown how a wood block 25 has been loaded in the frame 3 after that the knife device has been adjusted to the desired level position. In the next step, which is illustrated in fig 2, the hydraulic cylinder 4 is extended by the fact that the rod piston 4" is pushed out of the cylinder part 4 ' while driving the cross piece 22 serving as pressing device. When this longitudinal displacement of the cross piece is initiated, the backwardly directed edge 13 of the main knife 12 will cut into the end surface of the wood block a short moment before the edges 15 of the help knives 14 penetrates into the same end surface. During the continuing displacement movement, the main knife 12 will separate a lower part from the block, which in turn is divided into a plurality of individual wood pieces 25' by means of the help knives 14. As may be seen in fig 7, the help knives 14 are mounted in such a way that adjacent help knives diverge in the direction downwards in relation to each other. In that manner, it is guaranteed that the wood pieces do not get pinched between adjacent help knives. When a given splitting operation has been executed in the way described above, the holder frame 3 is returned to the starting position thereof by the fact that the rod piston 4" is again inserted in the cylinder part 4 ' while shortening the hydraulic cylinder. In doing so, the holder frame 3 brings the wood block 25 towards the rear end position, the block falling down again from the position thereof on top. of the main knife 2 to the table 7 situated lower. Hereafter, the splitting operations alternating with the return movements are repeated until the wood block has in its entirety been split into indi- vidual wood pieces.

As is shown in fig 3, the knife device may be adjusted with the main knife 12 situated very low in relation to the table 7, whereby flat and thin wood pieces may be separated from the wood block. Such wood pieces may advantageously be used as roof shingles for roofing purposes.

Reference is now made to fig 9, which illustrates an alternative embodiment of the device according to the invention. In this embodiment, the main knife 12' of the knife device is cross-section-wise V-shaped. More precisely, the main knife includes two edge-provided, plane part plates together forming an obtuse angle. In practice, the obtuse angle between the part plates may be within the range of 100- 140°, and attain for instance 120°, such as is exemplified in the drawing. Although the part plates in the example together form a sharp angle, it is also feasible to form the central transition section between the same softly rounded or curved. Also the table 7' is correspondingly cross-section-wise V- shaped. By this shape of the table as well as the main knife, the wood block or wood blocks to be split will automatically be centred in the direction towards the middle of the table and the main knife.

In the embodiment according to fig 9, the holder and the appurtenant pressing device are also given a V-like basic shaoe . A substantial advantage of the invention is that the holder frame may be loaded with wood blocks of most disparate dimensions, from very thick blocks to very slender blocks or wood pieces. In other words, the holder frame may be loaded with an unsorted batch of wood objects without risking that the smallest objects fall away without first having passed the set of help knives. By the fact that the knife device is axi- ally stationary (although movable vertically) at the same time as the pressing device is movable, a force interaction is obtained during the splitting which makes minimal demands on the dimensioning of the components included in the device. In other words, such components as the knife device, the pressing device, the force generator and the holder frame do not need to be made extremely solid to endure de stresses which arise even when particularly knot-rich and cross-grained wood blocks are split. Hence, as a result, the device may be realized in structurally simple, smooth and light embodiments of a mobile character. Another advantage is that the thickness of the separated wood pieces may be varied within wide bounds by means of the simple measure to readjust a set screw.

Claims

Claim

1. Device for splitting wood blocks, including a stand (1), a knife device (2) having a mam knife (12) which on an under- side presents a plurality of mutually spaced-apart secondary knives (14), a holder (3) for bloc╬║s (25) navmg a lying fibre direction as well as means for bringing about a longitudinal relative motion between the knife device (2) and the holder (3) with the purpose of cleaving the block in the fibre direc- tion of the wood, more precisely by the fact that the mam knife (12) detaches a bottom part, which in turn is, at the same time, divided into a plurality of smaller wood pieces by means of the secondary knives, c h a r a c t e r i z e d in that the stand (1; comprises a taole (7) along which a frame (3), serving as a holder, is, together with at least one block (25) lying therein, are movable to and fro along with a pressing device (22) which is pressable against an end surface of the bloc╬║, more precisely by means of a force generator (4) having an intermittently variable length, and that the knife device (2) is mounted on free ends of a pair of arms (16) which are turnable m relation to the table (7) via hinges

(17) and placed in a position outside a front edge (7') of the table.

2. Device according to claim 1, c h a r a c t e r i z e d that the arms (16) are interconnected via a mutual, rear yoke

(18) whicn is located under a beam (5) included in the stand (1) and includes means (20) for varying the angle adjustment thereof in relation to the stand, more precisely with the pur- pose of enabling adjustment of the mam knife (12) in starting positions at various levels relative to the plane of the table (7) in order to be able to vary the thickness of the split and detached wood pieces.

3. Device according to claim 2, c h a r a c t e r i z e d m that said means is a set screw (20), one end of which is pressed against parts of the stand.

4. Device according to claim 2 or 3, c h a r a c t e r i z e d in that a stop element (21) is connected to the stand (1), the purpose of which element is to maximise the angle of deflection of the yoke (18) in relation to the stand so as to preset an upper end position for the main knife (12) .

5. Device according to any one of the preceding claims, c h a r a c t e r i z e d in that the force generator is a double-acting hydraulic cylinder (4).

6. Device according to any one of the preceding claims, c h a r a c t e r i z e d in that the pressing device consists of a cross-section-wise L-shaped cross piece (22) having a vertical flange (24) for pressing against the block (25) as well as a horizontal flange (23) with which the force generator (4) is articulatedly connected, and that members (26) are arranged to always detain the cross piece against the table during the reciprocating motions of the cross piece.

7. Device according to any one of the preceding claims, c h a r a c t e r i z e d in that the frame (3) has claws (35) which are in engagement with said arms (16) in order to guarantee that the frame always moves linearly along the arms.

8. Device according to claim 6 and 7, c h a r a c t e ri z e d in that a carrier plate (37) is articulatedly connected with the cross piece (22) which plate is inserted in a socket (36) in the frame (3), the frame being movable vertically in relation to the cross piece.

9. Device according to any one of the preceding claims, c h a r a c t e r i z e d in that vertical edges (15) of the secondary knives are further distanced from the front edge (7') of the table (7) than the edge (13) of the main knife (12).

10. Device according to any one of the preceding claims, c h a r a c t e r i z e d in that the main knife (12') of the knife device (2) is cross-section-wise V-shaped and arranged to co-operate with a cross-section-wise V-shaped table (7') in order to automatically centre individual blocks towards the centre of the table and the main knife.