IE50939B1 - Tree harvesting apparatus - Google Patents

Abstract

A tree harvesting apparatus comprises a wheeled frame 10 with means 14 at the front for connection to a tractor 15 or the like. The frame 10 supports a push-over bar 18 at a substantial height above the ground and laterally offset from the means 14 for engaging and bending forward small trees for harvesting. The frame 10 further supports a pair of generally horizontal cutting discs 21 side-by-side close to the ground for cutting the trunk of each tree near ground level, and conveying means 23, 27 and 32 for feeding the cut trunks to a billeting mechanism 34. A flailing mechanism 35 is disposed immediately behind the billeting mechanism, and a cross-conveyor at the rear of the frame 10 conveys the cut billets to an elevator 39. A hopper 40 disposed laterally adjacent the cutting discs 21 receives the billets from the elevator 39. The cutting discs 21 are adjustable at a small angle to the horizontal, and the frame 10 is pivotable intermediate its length to permit adjustment of the height of the discs 21 above the ground.

Description

This invention relates to a tree harvesting apparatus, and is particularly but not exclusively concerned with the harvesting of small trees (10 to 12 ft high and 4” in diameter) which have been grown over a four year cycle in harvested bog land or arable land: Year 1: Trees planted in staggered rows 1 metre apart with the trees in each row also spaced one metre apart. At the end of- the first year the trees are coppiced.

Years 2/3: Trees allowed to grow.

Year 4: Trees harvested during October to April. According to the present invention there is provided a harvesting apparatus for small trees comprising a wheeled frame with means at the front end for connection to a tractor or the like, the harvesting apparatus further comprising (all supported by the frame) a push-over bar disposed at a substantial height above ground level and laterally offset from the tractor connection means for engaging and bending forward small trees for harvesting, a pair of generally horizontal cutting discs disposed side-byside close to the ground rearwardly of the push-over bar for cutting the trunk of each tree near ground level, a billeting mechanism disposed rearwardly of the cutting discs, means for conveying cut trees readwardly from the cutting discs and feeding such trees into the billeting - 3 mechanism, said conveying means consisting of a pair of generally horizontal collectors in the form of rearwardly convergent endless bands having collecting fingers, the horizontal collectors being located immediately above the cutting discs, a pair of generally vertical feed rollers located behind the horizontal collectors, and endless conveyor means behind the feed rollers, a hopper, and further means for conveying the billets from the billeting mechanism to the hopper.

Preferably the harvesting apparatus frame further supports a flailing device rearwardly of the billeting mechanism, the billets being passed into the flailing device for separation, trimming and splitting prior to conveyance to the hopper.

The wheels of the frame may comprise a respective pair of bogey-mounted tracked wjieels on either side of the frame, and all the apparatus components may be conventionally powered from the power take-off of the tractor.

An embodiment of the invention will now be described, by way of example with reference to the accompanying drawings, in which: Figure 1 is a side elevational view of an apparatus according to an embodiment of the invention; Figure 2 is a plan view of the apparatus; Figure 3 is a rear view of the apparatus; and Figure 4 is a schematic view of part of the flailing device forming part of the apparatus.

Referring to the drawings, the harvesting apparatus comprises a main frame 10 which supports all the operational components of the harvester to be described. The rear of the frame 10 comprises on each side a respective pair of wheels 11, each pair of wheels 11 having a track 12 and being pivotted on the frame at 13 in the manner of a bogey mounting. The front end of the frame 10 has means 14 (figure 1) for connection to a tractor or the like generally indicated at 15.

A sub-frame 16 is pivotally mounted about a horizontal axis at 17 to the frame 10 and rigidly supports a horizontal push-over bar 18 at a substantial height above ground level, the bar 18 being slidably adjustable forwardly of the sub-frame 16 on the upper, downwardly inclined portions 19a of a pair of rearwardly convergent tubular steel side members 19 bolted to the sub-frame 16. The sub-frame 16 and pushover bar 18 are laterally offset from the connection means 14 so as to provide sufficient clearance to simultaneously harvest two rows of young trees 20. The trees 20 are typically 10-20 foot high and up to 4 in diameter, and are planted 1 metre apart along each row with the rows themselves being 1 metre apart (see figure 2).

The function of the push-over bar 18 is to engage and bend' forwardly the trees 20 as the harvester is - 5 pulled forwards by the tractor 15, thereby to present the base of the trunk of each tree to one or other of a pair of generally horizontal cutting discs 21 disposed side-by-side close to the ground rearwardly of the push-over bar 18, the slidable adjustment of the pushover bar 18 on the side members 19 permitting both the height of the bar and its position forwardly of the sub-frame 16 to be adjusted for different average heights of tree. Each disc 21 is similar to a large circular saw blade and is mounted at the bottom of the sub-frame 16 for high speed rotation about a generally vertical axis by means of a hydraulic motor 22 and its associated hydraulic pump 22a. The pump 22a is driven from a main drive shaft 42 through a gear box 42a.

Immediately above the discs 21 the sub-frame 16 supports a pair of generally horizontal collectors 23 disposed side-by-side in the form of endless bands having collecting fingers 24, each band passing around a pair of front and rear guide wheels 25 and 26 respectively. The sub-frame 16 further supports a pair of generally vertical feed rollers 27 having longitudinal serrations or fingers 27a. The vertical rollers are driven by a further hydraulic motor 28 via a chain drive 29. The hydraulic motor 28 has associated therewith a hydraulic pump 28a. The horizontal collectors .23 are also driven by a further hydraulic motor 28b. The mountings for the rollers 27 - 6 are spring-loaded towards one another in conventional manner for accommodating variations in the diameter of the tree trunks. Finally, the sub-frame 16 supports two pairs of rearwardly convergent tubular steel guide bars 19b and 19c which embrace the front edges of the discs 21 as shown to prevent the cut ends of trees being thrown inwardly by the discs 21, and also supports a protective plate 30 below the rear edges of the cutting discs 21.

The horizontal pivotting at 17 of the sub-frame 16 on the main frame 10 permits the angle of inclination of the sub-frame to the vertical, and thus of the cutting discs 21 to the horizontal, to be adjusted typically from about 0° to 10°. This adjustment is achieved by a rigid coupling member 31 of manually adjustable length connected between the sub-frame 16 and the main frame 10.

The components thus far described operate as follows. As the harvester is drawn slowly forwards by the tractor successive trees 20, alternately from each row, are engaged by the bar 18 which bends them forwardly for presentation of the base of their trunks to the cutting discs 21. The latter saw through the trunks of the trees near ground level, with the trees in each row being cut by a respective one of the discs 21, whereupon the lower ends of the cut trunks spring up from the root trunk portion in the ground under the spring action imparted by the forward bending imparted to the trees prior to cutting. The cut trees, whose cut ends are guided rearwardly by the pairs of guide bars 19b and 19c, are collected by the fingers 24 of the horizontal collectors 23 and passed between the vertical feed rollers 27 whose serrations grip the tree trunk and continue to feed them rearwardly. Since the trees are spaced at 1 metre intervals in each row, and each tree is 10-20 ft in height, it is clear that the rollers 27 must be able to accommodate ten or more tree trunks simultaneously, and are therefore provided with sufficient vertical height for this purpose.

Behind the vertical feed rollers 27 upper and lower rearwardly convergent endless feed conveyors, of which only the lower conveyor 32 is shown, channel the cut trunks rearwardly to a billeting mechanism 34 which may be of the kind described in Brifcisl, Application No. 8210017. From the mechanism 34 the billets pass to a flailing device 35 of generally known type consisting of a rotatably mounted rotor bar 36 having a plurality of flail blades 37 freely mounted thereon. However, the present device 35 differs from conventional flailing devices in respect of the blades 37. In the present case (fig 4) narrow chisel-like blades 37’ alternate along the length of the bar 36 with broad flat blades 37. The broad flat blades 37 separate the billets if they are not quite severed from one another by the billeting mechanism 34, and the chisellike blades 37' trim and split the billets. The flailing device is driven by a hydraulic motor 50.

From the flailing device, primarily under the 5 impetus of the broad blades 37, the billets pass to a slightly upwardly inclined cross-conveyor 38 at the rear of the frame 10, and thence to a steeply inclined elevator 39 for deposition in a hopper 40. The hopper is mounted directly behind the tractor coupling 14 and laterally adjacent the sub-frame 16, thereby providing a compact overall arrangement.

The conveyors 32 and 38, the elevator 39, and the billeting mechanism 34 are all driven mechanically from the power take-off 41 of the tractor by the longitudinal drive shaft 42, gear boxes 43 and 44, drive shaft 43a and various chain drives 45,46,47,48, 48a and 49, figure 2. The hydraulic motors 22,28,28b (figure 1) and 50 (figure 2) are driven, if necessary via suitable gearing, from a hydraulic system also powered by the drive shaft 42.

It will be appreciated that the frame 10 comprises various housing members, such as those shown at 51,52 supporting the conveyors 32, which laterally confine the wood along the desired path to the hopper 40.

These are generally conventional in construction and are therefore not described in detail but can be seen in the drawings.

The hopper 40 is itself pivotally mounted at 53 (figure 3) to members 54 upwardly slidable in guides 55 rigidly secured to the frame 10, and is also connected to the frame 10 by hydraulic rams 56,57 (see also figure 1) disposed at the front and rear of the hopper. When the rams 56,57 are extended the hopper 40 is raised upwardly and pivotted sideways as shown at 58 for discharging the harvested billets of wood.

Finally, the frame 10 is provided with a known 10 type of depth control wheel 60 which is hydraulically connected to a hydraulic ram 61 (figure 1). The wheel, which is a sensor, sends a hydraulic signal to the ram 61 which retracts/extends as appropriate in response to the signal to pivot the frame 10 about pivot 62 to maintain a constant height above ground of the cutting discs 21 as required. The frame 10 also pivots about points 63 and 13 (figure 1) to facilitate the pivotting about point 62. Xn order to lift the machine to a transport position one overrides the sensor wheel and operates the ram 61 direct to lift the cutting discs 21 well clear of the ground.

Claims (10)

1. A harvesting apparatus for small trees comprising a wheeled frame with means at the front end for connection to a tractor or the like, the harvesting apparatus further 5 comprising (all supported by the frame) a push-over bar disposed at a substantial height above ground level and laterally offset from the tractor connection means for engaging and bending forward small trees for harvesting, a pair of generally horizontal cutting discs disposed side-by10 side close to the ground rearwardly of the push-over bar .for cutting the trunk of each tree near ground level, a billeting mechanism disposed rearwardly of the cutting discs, means for conveying cut trees rearwardly from the cutting discs and feeding such trees into the billeting 15 mechanism said conveying means consisting of a pair of generally horizontal collectors in the form of rearwardly convergent endless bands having collecting fingers, the horizontal collectors being located immediately above the cutting discs, a pair of generally vertical feed rollers 20 located behind the horizontal collectors, and endless conveyor means behind the feed rollers, a hopper, and further means for conveying the billets from the billeting mechanism to the hopper.

2. A harvesting apparatus according to claim 1, wherein 25 the push-over bar, the horizontal collectors, the vertical feed rollers and the cutting discs are pivotable as a unit about a horizontal axis so as to permit the cutting discs to be adjusted at a small angle to the horizontal.

3. A harvesting apparatus according to claim 1 or 2, further including rearwardly convergent guide means adjacent

4. A harvesting apparatus according to claim 1, 2, or 3, wherein the push-over bar is adjustable in height above ground level. 10 5. A harvesting apparatus according to any preceding claim, further including a flailing device immediately behind the billeting mechanism.

5. Cutting discs a constant distance above the ground. 5 the front edges of the cutting discs for guiding the cut ends of trees between the horizontal collectors.

6. A harvesting apparatus according to claim 5, wherein the flailing device comprises a rotatably mounted rotor bar 15 with a plurality of flail blades freely mounted thereon, the flail blades comprising both narrow chisel-like blades and broad flat blades.

7. A harvesting apparatus according to any preceding claim, wherein the further conveying means comprises an 20 upwardly inclined cross-conveyor at the rear of the frame and an elevator extending forwardly to the hopper which is disposed laterally adjacent the first mentioned conveyor means.

8. A harvesting apparatus according to any preceding 25 claim, wherein the frame comprises front and rear portions relatively pivotable about a horizontal axis permitting adjustment of the height of the cutting discs above the ground. - 12

9. A harvesting apparatus according to claim 8, further comprising a sensor wheel in contact with the ground for providing a signal which controls the degree of pivotting of the front and rear frame portions for maintaining the

10. A harvesting apparatus according to claim 1, substantially as described with reference to the accompanying drawings. F.R. KELLY & CO.,