A JIB-MOUNTED SUSPENSION DEVICE FOR A TIMBER HARVESTER

Abstract: Suspension device for suspending a felling processor (1) to be installed at the end of the jib (13) of a loader by means of an upper joint (12, 18, 17), which suspension device includes a turning motor (11) to turn the frame (6, 9) of the suspension device and with it the harvester (1), an operating device e.g. a hydraulic cylinder (7) to turn the harvester to the desired vertical or horizontal position and in which the suspension of the harvester from the frame (6, 9) of the suspension device is realized by means of a transverse joint (4) and the aforementioned operating device is secured between the frame (6, 9) of the suspension device and the frame of the harvester (1). By means of the suspension device in accordance with the invention an attempt is made to achieve a short length of the device and nevertheless to achieve a sufficient vertical rise. The turning shaft (10) of the suspension device in accordance with the invention is adapted so that its extension essentially goes behind the centre of gravity of the harvester (1) i.e. on the saw (15) side.

Description: A Jib-mounted Suspension Device for a Timber Harvester The object of the invention is a suspension device to be installed at the upper end of the jib of a timber harvester by means of the upper joint, to suspend a harvester, the suspension device consisting of a turning motor to turn the frame of the suspension device and with it the harvester, on operating device, e.g. a hydraulic cylinder, to turn the harvester to the desired vertical or horizontal position, and in which the suspension of the harvester from the frame of the suspension device is carried out by means of a transverse joint and the aforemen¬ tioned operating device is connected between the frame of the suspension device and the frame of the harvester. Timber harvesters, which carry out all stages of the work except felling, are called timber processors. Nowadays most of them can be equipped with a so-called felling head. The purpose of this felling head is to bring the processor to a vertical position. The vertical position is required in order to take hold of the tree. In practice it is sufficient if the processor is even roughly in a vertical posi¬ tion so thatthe tree can be taken hold of. Felling sawing in carried out by the cutting saw of the porcessor. . When the harvester is hanging freely it naturally tends to take a horizontal position, i.e. the centre of gravity in the middle of the machine tends downwards. By means of the cylinder in the suspension device the harvester is turned in the direction of the suspension de- vice by pushing the frame of the suspension device towards the stripping blades and the harvester now moves into a nearly vertical position, for the centre of gravity tries to move under the upper joint. After the felling stage the stripping and cutting of the tree take place with the treee in a horizontal position. The harvester hangs freely from its felling head and in addition a so-called grab turner is located on the felling head. The harvester is directed round its vertical shaft by this turner. Really this felling head is a suspension device, by which the harvester is made to rise to a vertical position advantageously by means of a hydraulic cylinder. The problem with these felling heads or suspension devices is their great weight, great length, and also price. These problems are due to the fact that ordinary grab turners are used in these suspension devices. Because the diameter of the grab turners is large the turner must be located at the extreme top of the suspension device and further the turner should be in the felling position above the harvester. This is so that the harvester is able to turn sufficiently vertically. But now the length of the suspension device becomes great because the turner must be entirely situated in front of the stripping blades of the harvester. In the suspension device in accordance with the invention an attempt Q is: made to achieve a short length for the suspension device and neverthe¬ less achieve a sufficient vertical rise. In addition the invention at¬ tempts to achieve as light and easily used construction as possible. The- characteristics of the invention appear in the accompanying patent claims. S Even in the stage where the harvester is taking hold of the tree the jib of the crane can push the harvester against the trunk without the harvester in the vertical position trying to much to move away from the lower part of the tree as happened with earlier suspension devices. In m a suspension device in accordance with the invention the upper joint is 0 located during the felling stage close to the upper stripping blade. Thus a turning moment creating a horizontal pushing movment away in the lower part of the harvester is nonexistent. Further, by placing the cylinder that tilts the suspension device in the centre of the device it " is possible to ---inimize the length of the stroke of the cylinder. By 5' - selecting suitable securing points for the cylinder when the suspension device at one stage tilts towards the cutting saw the piston rod of the cylinder begins once again to push out of the cylinder. This kind of situation appears for example when the tree being stripped is prevented from moving backwards when the feeding device begins to drive the 0 entire harvester forwards i.e. in the direction of the stripping blades. Because when the harvester is hanging freely it tends towards a horizontal position, it is sufficient when, starting from this horizontal position the cylinder is able to develop even a small amount of the moment required to make the harvester rise to the vertical. 5 In what follows the invention is illustrated by reference to the accom¬ panying figures, which show one form of application of the invention. Figure 1 shows the suspension device and harvester taking hold of a standing tree. Figure 2 shows the suspension device and harvester during the stripping and cutting stage of work. Figure 3 shows a cross-section of the suspension device along the line II -II shown in Figure 2. Securing lugs are attached to the frame 1 of the harvester by pins 4 and 5- Pin 4 secures the sub-frame 6 of the suspension device to frame 1 in such a way that the sub-frame 6 is able to turn about 140° around pin 4« The turning movement can be controlled by cylinder 7- Cylinder 7 is attached to frame 1 by pin 5 and to the sub-frame 6 by pin 8. The attachment of cylinder 7 thus permits sub-frame 6 to turn past the short¬ est position i.e. the lower dead centre of cylinder 7~ Tube 9 is secured to the sub-frame 6. Inside tube 9 is axle 10, which is secured by bearing axially and radially to tube ~ . Axle 10 is secured by pin 17 to cross-piece 18. Cross-piece 18 is further secured by pin 12 in the crane jib 1 . The cross-piece 18, and pins 12 and 17 permit the frame 1 of the harvester to hang freely independently of the mutual posi- tion of frame 1 and sub-frame 6. Turning motor 11 is secured to tube 9- A second possibility would be to attach the motor to the sub-frame of the suspension device. Further cutting and felling saw 15 ? feeder rollers 3 and stripping bl-tdes 2 are secured to frame 1. In Figure 1 the sawing to fell tree 14 to be felled has not yet been carried out. The centre of * gravity of the harvester is located at point 19, Figure 1. The operation of the suspension device: In Figure 1 the piston rod of cylinder 7 is pushed out when sub-frame 6 is clsoe to frame 1. At the same time tube 9 guides the front edge of frame 1 at point 10. It is also noticed that the straight line between pins 4.and 12 does not go through centre of gravity 19. but that centre of gravity 19 remains closer to the tree 14. But the straight line, which is in the line of axle 10 is located still further from centre of gravity 19- It is also nώticed that angle A, which is between axle 10 and the horizontal level, is significantly smal¬ ler that 90°. Up till now in previous suspension devices this correspond- ing angle is close to 90°. By locating the turning motor 11 in a slanting position on the suspension device is is possible to locate cylinder 7 partly parallel to turning motor 11, which saves in the overall length of the suspension device. In Figure 1 point 20, in which tube 9 and frame 1 meet, is marked. But now tube 9 can be made cosniderably thinner than turning motor 11. By 5' placing axle 10 and at the same time thin tube 9 at an angle (angle A), securing point 12 can have a very advantageous position. As can be seen pin 12 is located only a little above point 16. The significance of point 16 is empahasized when jib 13 pushes the harvester in the felling position against the tree. Only an insignificant turning moment between pin 12 and 10 point 16 moving the lower part of the harvester away from the tree arises. -Or the- stripping and cutting position in Figure 2 the harvester hangs freely from pin 12, when pin 12 and pin 14 are more or less in the same vertical line. Without the tree the centre of gravity 19 would be more or less, in the line joining pins 12 and 4« 15 The- size of angle A between axle 10 and the horizontal can be reduced to ev,en 45°. It would then be advantageous that axle 10 would be suspended from jib 13 by a constant angular velocity joint. This is because when turning motor 11 turns the harvester the moment requirement varies un¬ reasonably when using a normal universal i.e. cardan joint, especially if 20 pins 17 and 18 cannot for structural reasons be brought close together in the direction of axle 10. In. Figure 3 the securing point of cylinder 7 in relation to frame 1 is seen.. Because pin 5 is shorter than the inside dimension of frame 6 frame 6 is able to turn past pin 5- When pin 5 is passed pins 8, 5, and 4 are 25". in the same staight line. At this stage the piston rod of the cylinder begins to push out again is frame 6 still turns around pin 4 towards saw 15- Thus it is possible to have a very short length of stroke in cylinder 7 " . In the position in Figure 2 the passing situation has not yet taken place. 30 35.

Claims: rece ve y e nternat ona ureau on st cto er 198 01.10.87 ; original claims 1-6 replaced by amended claims 1-5 (1 page)] 1. A suspension device installed by means of an upper joint (12,18, 17) at the end of a loader jib (13) for suspending a felling processor (1), which suspension device includes a turning motor (11) suspension device - frame (6, 9) and with it an operating device, e.g. a hydraulic cylinder (7) for turning the harvester to the desired vertical or horizontal posi¬ tion and in which the suspension of the harvester from the frame (6, 9) is realized by means of a transverse joint (4) and the aforementioned operating device (7) is connected between the frame (6, 9) of the suspen- 10 sion device and the frame (1) of the harvester, characterized in that the frame of the suspension device includes a sleeve or tube (9), and that in this is placed an axle (10) connected to the upper joint (12, 18, 17), which axial bearing, essentially that bearing carrying the entire suspension device and the turning motor (119)is placed below the afore- 15 mentioned sleeve or tube (9) and that the extension of the turning axle (10) of the suspension device is adapted to go essentially behind the centre of gravity (19) of the freely handling harvester (1) seen from the feeding direction i.e. from the side of the saw (15). 20 2. A suspension device in accordance with Claim 1, characterized i that the axle of continuation (10) of the turning motor (11) is secured to the upper joint (12, 18, 17) and the frame of the turning motor (11) to form the frame of the suspension device (6, 9). 25 3- A suspension device in accordance with Claims 1 or 2, charac¬ t eriz ed in that the aforementioned carrying bearing is separate from the turning motor (11). 4. A suspension device in accordance with one of Claims 1-3, char- 30 acterized in that the upper joint (12, 18, 17) is of the constant angular velocity joint type. 5. A suspension device in accord.ance with one of Claims 1 -4, in which * the sub-frame (6) is of a forked model, characterized in that 35 the operating device, e.g. a hydraulic cylinder (7) is located between the sub-fork in such a way that the attachment permits the turning of the sub-frame (6) to pass the lower dead centre to the other side.

Inventors: KETONEN LAURI KALERVO, KETONEN, LAURI, KALERVO
Applicants: KETONEN LAURI KALERVO, KETONEN, LAURI, KALERVO
Application year: 1987
Main classification: A01G23
IPC codes: A01G23