AU1971792A - Apparatus for splitting wood - Google Patents

Description

TITLE: Apparatus for Splitting Wood

FIELD OF THE INVENTION

This invention relates to apparatus for splitting wood. In this specification, the term "splitting" comprehends other ways of cutting blocks of wood into smaller pieces including chopping.

BACKGROUND OF THE INVENTION

In conventional wood splitting operations, trees are felled and then "blocked", i.e. sawn into lengths of about 200-400 mm face to face. The blocks are then split longitudinally into pieces of, very roughly. between 75 × 75 to 150 × 150 mm. The localities where trees are felled are seldom accessible by truck. The felled logs are therefore conventionally usually dragged to an accessible site before being blocked. This is costly. Moreover dirt is rubbed into the logs and this bluntens the saw rapidly. It would be better if the logs were blocked and split at the site where they are felled but this is impractical using known apparatus and methods for these purposes.

The output of split blocks is measured and traded in "metres", i.e. cubic metres. Workers are also paid by the "metre".

DESCRIPTION OF PRIOR ART There are two types of conventional splitters known to the applicant. The first is derived from a postrammer. The second consists of an an:, which pivots at its centre, a cutting tool being mounted at one end of the arm and a hydraulic ram mounted at the other end. Extension of the hydraulic ram raises this end and lowers the end with the cutting tool. A table is located under the tool. The tool comes down to split a block placed on the table.

In both known systems the splitting operation is much slowed down by the fact that the finished split blocks end up scattered over the ground. Moreover the apparatus used in both systems is dangerous. The postrammer derived machines split the block into many pieces in one hit but have no means of preventing the split pieces flying off under the sudden release of energy, particularly when the block has a knot which tends to hold it together. The hydraulic machines lack rigidity and operation is further slowed since they have only a single cutting blade. The semifinished blocks must be retrieved and put through the machine a second time. Typical production rates are 2-3 metres per hour. SUMMARY OF THE INVENTION

According to the invention apparatus for splitting wood comprising a splitting device, a table for supporting wood to be split by the splitting device, a bin for receiving wood which has been split, mounting means for mounting the apparatus on a vehicle provided with lifting means for lifting the apparatus, and means to unload the bin after it has been lifted by the lifting means to an unloading position.

In one form of the invention the splitting device comprises an arm arranged to carry a blade for splitting the wood and a hydraulic ram arranged to apply reciprocating motion to the arm towards and away from the table

In one aspect of the invention the cutting device comprises an arch disposed over the table, the hydraulic ram being suspended from the arch above the arm. In a second aspect of the invention, the apparatus is provided with means for guiding the motion of the arm towards and away from the table. Advantageously the means for guiding the motion of the arm includes a rail with which at least one end of the arm is siidably engaged.

In one form of the invention the apparatus includes mounting means for pivotably mounting the opposite end of the arm on the apparatus.

The apparatus is advantageously mountable on the three point hitch of a tractor or on a similar lifting device with which the vehicle is equipped. The apparatus could for example be mounted on the lifting arms of a front end loader. In one aspect of the invention the apparatus includes a frame, the bin being hinged to the frame and the means to unload the bin comprising tipping means for tipping the bin over.

The tipping means advantageously comprises a second hydraulic ram mountable between the frame and the bin. The second hydraulic ram is connected to the hydraulic system of the tractor.

In another aspect of the invention the table is pivoted to the apparatus and spring means is provided for urging the table to move to a working position, the table being arranged to pivot away from the working position against the force of the spring under pressure applied to the table by a block of wood being split, damping means being provided for damping return movement of the table to the working position. The yielding of the table helps to ensure that the block of wood is securely seated on the table and does not bind the cutting blade as it penetrates the block. Moreover the yielding of the table combined with damping of the return motion helps to prevent cut pieces of wood from shooting away from table when, as already mentioned, energy which built has up in a block of wood is suddenly released.

Advantageously the ram for applying reciprocating motion to the arm is double acting and a hand operable valve is provided for actuating the ram. Such valves are commonly provided with an operating handle which can be moved in one direction to extend the ram and in the opposite direction to retract the ram. The handle has a neutral position in which the valve is closed so that no hydraulic fluid can pass into or out of the ram. The ram is thus locked in position when the operating handle is in the neutral position. The valve is preferably mountable on the end of the arm which is pivoted to the arch and the handle is connected by means of a light chain or the like to the arch adjacent the opposite end of the arm. The valve is orientated so that when an operator at the table pulls the chain the ram drives the arm towards the table. BRIEF DESCRIPTION OF THE DRAWINGS

The invention is further discussed with reference to the accompanying drawings in which:

Figure 1 is a somewhat schematic side view of a wood chopping or splitting apparatus; Figure 2 is a rear end view of the apparatus;

Figure 3 is a detail of part of the apparatus;

Figure 4 is a view, similar to Figure 1, of a modified apparatus;

Figure 5 is a view, similar to Figure 2, of the apparatus shown in Figure 4; Figure 6 is a plan view of a part of the apparatus shown in Figures 4 and 5; and

Figure 7 is a detail of part of the apparatus shown in Figures 4 to 6. DETAILED DESCRIPTION OF THE EMBODIMENTS SHOWN IN THE DRAWINGS

In Figures 1 to 3 wood splitting apparatus 10 comprises a rectangular frame 12 made up of heavy walled, 10 cm × 10 cm square steel tubing. The frame 12 surrounds a bin 14 which is hinged to the rear cross member 16 of the frame. The bin rests horizontally in the frame as shown in the drawings but the front end thereof can pivot upwardly on the cross member 16. Legs 20 are mounted on the forward cross member of the frame and carry upper and lower lugs 21 for mounting the frame on the conventional three point hitch of a tractor. An arch 22 is mounted on one side of the frame. The arch comprises a front leg 24 and a rear leg 26 which are joined together at an apex 28. Each leg comprises a pair of parallel, 50 mm x 50 mm rolled steel angle bars 30a, 30b positioned with a space 32 therebetween. The arch is braced by downwardly angled struts 33 which are welded to the angle bars 30a, the frame 12 and to each other where they meet. An arm 34 in the form of a heavy walled 75 mm diameter steel tube is located in the spaces 32. The front end of the arm is pivoted to the arch by means of a pin 36 mounted in lugs welded to each bar 30a, 30b of the front leg. The rear end of the arm is a close sliding fit in the space 32 between the bars of the rear leg 26 which thus acts as a rail for guiding the arm 34. A first hydraulic ram 40 is suspended from a bracket 42 which joins the legs of the arch at the apex. The lower end of the ram 40 is pivoted to the arm by means of a pin 44 mounted in lugs 46 welded to the arm close to its longitudinal centre. For the sake of clarity the ram 40 is not shown in Figure 2.

A cutting tool 50 is mounted on the arr 34, aisc close to its longitudinal centre. The cutting tool comprises a first blade 52 disposed parallel to the arm and projecting directly downwardly therefrom; and a second blade 54 disposed transversely to the first blade and projecting from the inner side thereof. The arm and hence the cutting edge of the first blade 52 is angled at about 15° to the horizontal when the arm is at its lowest point. The cutting edge of the transverse blade 54 is spaced upwardly from the cutting edge of the first blade as can best be seen in Figure 3. A cutting table 56 is mounted on the frame below the cutting tool. The table comprises a flat steel plate 58 welded to a stiffening flat bar 60. The flat bar is hinged to the fore-and-aft member 62 of the frame 12 by means of pins 63 at the forward and aft ends of the bar 60 which are received in channels 61 welded to the fore-and-aft member 62. A strong compression spring 64 is mounted between the member 62 and the lower face of the plate 58 near its outer edge. A telescopic damper 66 is mounted inside the spring. (A spring and shock-absorber assembly from a motor cycle or light motor car may conveniently be used for the spring 64 and the damper 66). The table 56 can thus pivot downwardly from the horizontal working position shown in the drawings if sufficient downward force is applied to the plate between the line of the hinge pins and the outer edge of the plate.

The arm 34 and the cutting tool 50 are positioned so that the cutting edge of the blade 52 moves in a plane which lies just inside the inner edge of the upper face of the cutting table 56. This is shown schematically in Figure 3. A flat bar 67 is welded to the inner face of the member 62, angled downwardly at about 15º to the horizontal. This bar acts as a slide over which the split pieces of wood slide into the bin. A short length of round bar 68 is welded to the side face of the member 62. The round bar 68 is located just above the flat bar 67 and directly below the transverse cutting blade 54. It is also angled downwardly at about 15º to the horizontal and its highest point is flush with the upper face of the member 62. It acts as an anvil, to assist a wood block to be split by the transverse blade without binding the blade.

The geometry of the various components, as described, is chosen so that when the cutting tool 50 first engages a wood block of predetermined height, say 16 cm, the cutting edge of the first blade 52 is substantially parallel to the upper face of the cutting table. Both blades will thus bite into the wood block almost immediately so that the chances of the block slipping or flying off the table are minimal.

The ram 40 is connected to the hydraulic system of the tractor through a conventional control valve 70 having an operating handle 72. The valve is mounted on the forward end of the arm 34 and so pivots with the arm. A light link chain (indicated by the chain dotted line 74) is connected between the operating handle and a connecting point on the rear leg 22 of the arch. The chain thus hangs in an approximately horizontal position. A return spring (not shown) is mounted between the operating handle and the forward leg 24 of the arch. This spring urges the operating handle to the ram retracting position. The position of the chain is selected so that the weight of the chain by itself is just able to overcome the force of the return spring and hold the operating handle in the neutral position when the arm is in a preselected raised position. If the chain is pulled the operating handle will be moved to the ram advancing position (against the force of the return spring) and the arm will be pivoted downwardly by the ram. If the chain is now released, the return spring will move the operating handle to the ram retracting position and the arm will be moved back to the raised position. The raised position of the arm can be changed by altering the connection point of the chain on the rear leg 22. The bin 14 is tipped by means of a second hydraulic ram 80 located on the side of the bin opposite the arch. The ram 80 is mounted between the frame 12 and a trunnion 82 welded to the bin. The bin is preferably raised and tipped from the drivers seat of the tractor.

A cross member 90 is welded to the angle bars 30b of the arch. The member 90 is upwardly cranked as shown at 94 to accommodate the transverse cutting blade 54 when the arm 34 is raised. Occasionally a block of wood will become jammed on the cutting tool. The member 90 is positioned to act as an abutment which pushes such a jammed block off the cutting tool when the arm is lifted higher than its normal raised position.

In a variant of the machine, further sets of lugs 46 can be mounted on the arm 34 at varying distances from the pivot pin 36. If the ram is mounted on lugs which are closer to the pivot pin the speed of operation of the arm will increase although the force applied to the wood block will diminish. The opposite will happen if the ram is mounted on lugs which are further from the pivot pin.

The apparatus has a number of advantages over conventional wood splitting machines. The provision of a transverse blade ensures that a block can usually be completely split in a single operation. The blade operates vertically with the block resting on a horizontal table. The table can pivot to allow the block to open as it is split. As already mentioned, the return motion of the table is damped. The split pieces fall into a bin which in the present example is conveniently of one (cubic) metre capacity. When the bin is full the tractor is driven to a tip-truck and the bin is lifted by operation of the three point hitch mechanism of the tractor and positioned over the body of the truck by maneouvring the tractor. The ram 80 is then extended, causing the bin to pivot upwardly and rearwardly and tip its contents into the truck. Production rates can be substantially improved.

The location of the chain 74 minimises operator fatigue and increases safety of operation. A dump counter can be mounted on the apparatus to record production.

In the apparatus 10' shown in Figures 4 to 6 many components are substantially identical to those of the apparatus 10 and will not be described and in some cases not illustrated. Those components which are described and which are equivalent to similar components in the apparatus 10 will be identified by the same numerals as used in Figures 1 to 3 but with a dash (') appended.

The apparatus 10' comprises a frame 12' which is located on one side of a bin 14' and carries an arch 22' which is substantially similar to the arch 22. For the sake of clarity the frame 12' is shown by itself in Figure 6. At its front end the frame 12' is provided with a cross sub-frame 100 including downwardly depending legs 20' which carry lugs 21' for mounting the frame on the three point hitch of the tractor. In order to allow the apparatus to be raised to a higher level when the bin is to be discharged it is desirable to use a hydraulic upper link in the three point hitch. For this purpose the upper lug 21' is shorter than the lower lugs.

A transversely disposed heavy walled steel pipe 102 is welded to the rear end of the frame 12'. A steel pipe 104 is welded to the rear upper edge of the bin 14'. The pipe 104 is of larger diameter than the pipe 102 and can slide thereover so that the bin 14' is pivotably supported on the pipe 102.

The ram 80' which tilts the bin 14' is located between the frame 12' and the bin 14' below the table 56. One end of the ram is connected to a lug 106 which is welded to the pipe 104. A lug 108 is welded to the cylinder of the ram 80' about halfway along its length. This lug is mounted on a pin 110 which is supported on the struts 33' of the arch 22'.

In the apparatus 10' the bin can be lifted higher and tilted through a greater angle for unloading. The ram 80' is less susceptible to damage and the bin is more accessible from the side opposite the arch.

It is not intended that the scope of a patent granted in pursuance of the application of which this specification forms a part should exclude modifications and/or improvements to the embodiments described and/or illustrated which are within the scope of the invention as defined in the claims or be limited by details of such embodiments further than is necessary to distinguish the invention from the prior art.

Claims (9)

1.

Apparatus for splitting wood CHARACTERISED IN THAT it comprises a splitting device [10, 10'], a table [26, 26'] for supporting wood to be split by the splitting device, a bin [14, 14'] for receiving wood which has been split, mounting means [21, 21'] for mounting the apparatus on a vehicle provided with lifting means for lifting the apparatus, and means [80-82, 80'-82'] to unload the bin after it has been lifted by the lifting means to an unloading position.

2.

Apparatus according to claim 1, CHARACTERISED IN THAT the splitting device comprises an arm [34] arranged to carry a blade [52-54] for splitting the wood and a hydraulic ram [40] arranged to apply reciprocating motion to the arm towards and away from the table.

3.

Apparatus according to claim 2, CHARACTERISED IN THAT the cutting device comprises an arch [22, 22'] disposed over the table, the hydraulic ram being suspended from the arch above the arm.

4.

Apparatus according to claim 2 or claim 3, CHARACTERISED IN THAT it is provided with means [30a-30b, 32] for guiding the motion of the arm towards and away from the table.

5.

Apparatus according to claim 4, CHARACTERISED IN THAT the means for guiding the motion of the arm includes a rail [30a, 30b] with which at least one end of the arm is slidably engaged.

6.

Apparatus according to claim 5, CHARACTERISED IN THAT it includes mounting means [36] for pivotably mounting an opposite end of the arm on the apparatus.

7.

Apparatus according to any one of claims 1 to 6, CHARACTERISED IN THAT it includes a frame [12, 12'], the bin being hinged to the frame and the means [80-82, 80'-82'] to unload the bin comprising tipping means for tipping the bin.

8.

Apparatus according to claim 7, CHARACTERISED IN THAT the tipping means comprises a second hydraulic ram [80, 80'] mountable between the frame and the bin.

9.

Apparatus according to any one of claims 1 to 8, CHARACTERISED IN THAT the table is pivoted to the apparatus and spring means [64] is provided for urging the table to move to a working position, the table being arranged to pivot away from the working position against the force of the spring under pressure applied to the table by a block of wood being split, damping means [66] being provided for damping return movement of the table to the working position.