FIELD OF TECHNOLOGY

This invention is connected with forestry machinery and relates to equipment used in the working of forestry land. The invention can be used especially in the so-called scarifying process in which the land surface is worked for the purpose of sowing or planting.

TECHNOLOGICALBACKGROUND

In renewing forests the so-called scarifying process is used, in which the land surface is worked favorably for the purpose of growing seeds or small plants.

Scarifying can be carried out as desired with an excavator or equivalent machinery. This kind of work is, however, slow, demands precision and is expensive. In addition, for example, an excavator turning while stationary can cause harmful hollows and heaps.

The most general scarifying is done by harrowing, for example, with machinery in which there are two rotating discs set at an angle. For example, in Finnish patent number 63317 a harrow of this kind is presented. Harrowing forms continuing furrows. This leads to the problem that melt and rain water flow along these furrows and seeds and plants are easily washed away along with the water. In addition, harmful erosion can be caused where fine soil ingredients are washed away leaving infertile stony ground. The ingredients washed away block the ditches and burden the waterway systems. Especially on land that is sloping and otherwise susceptible to erosion, harrowing is not recommended. It is, in any case, very difficult to achieve good furrows in areas which are fresh and contain a lot of logging waste.

Proper scarifying equipment is also known with which shorter sowing or planting strips are formed in the land surface. For example, in Finnish patent number 34910 a scarifier, which is pulled along, is presented which has two simultaneously rotating four-bladed dressing units whose rotating

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movement can be stopped hydraulically whenever desired. The wheels are stopped such that the tool is perpendicular to the ground. In this way the land surface is peeled off and forms a sowing strip. When the dressing unit is allowed to turn freely strips are not formed.

In Finnish patent number 84414 a tussocky scarifying apparatus is presented which presses against the ground under its own weight. It contains one rotating four-bladed scarifying unit whose blades are directed strongly in a forward direction. In this way, when the scarifying unit is stopped, the blade digs deeply at an angle into the ground whilst at the same time ploughing a large tussock in front of it. This kind of scarifier, which digs deep into the ground and forms tussocks, is not, however, recommended.

A particular scarifier is also presented in Finnish patent number 88849. This apparatus consists of two wheel discs fitted with bearings to the shaft coupled to an ordinary tractor, in whose frame are scarifier blades formed by radial pegs. The wheels press against the ground under the weight of the equipment. The equipment is fitted with brakes with which each wheel can be locked in turn. The wheels also contain storage containers from which seeds or fertiliser can be fed into the strip as it is being formed. The opening of the container is guided by the pressure formed in front of the blade with the help of the weight of the piled up earth layer. In Finnish patent number 90488 an alternative braking system is presented intended for this scarifying equipment with which the wheels can be locked simultaneously.

One weakness of existing scarifying equipment is their poor working efficiency.

DESCRIPTION OF THE INVENTION

General description

Equipment is now invented according to patent claim 1. The advantageous arrangements of the invention are presented in the other claims.

In the first feature of the invention the equipment contains two or more rotating dressing units moving along the ground in the direction of travel, and equipment to hold the rotating movement in a locked position, when the dressing unit works the surface of the land. Each dressing unit is attached to a shaft and the equipment contains a device for raising and lowering each of the shafts independently of the other shafts. In this way the land can be worked effectively since the dressing units can be pressed against the ground surface independently of the others optimally whilst taking account of the variations in the ground surface. According to the second feature of the invention, the equipment is connected to machinery and the weight of the machinery is utilised in pressing the dressing units against the ground. Also in this way, the working of the ground is effective when the dressing unit can be pressed against the ground with the respective optimal weight.

A particular feature of the invention is that there are one or several dressing tools in the dressing unit projecting from the frame of the dressing unit. The equipment also contains devices for setting the desired angle between the dressing tool in the locked position and the ground surface. In this way the working effectiveness ofthe dressing tool can be regulated. The dressing tool is especially advantageously slanted backwards with respect to the direction of travel. The inclining angle can be, for example, as much as up to 20 degrees. The backwards slanted tool works the land surface evenly and only to the desired depth. Mineral soil does not need to be broken, neither is it mixed with the humus. Large tussocks are not formed either. A backwards slanting tool also automatically follows the surface of the ground and does not lift stones and stumps up from the ground.

The dressing tool can contain several claws, side by side. When there are three or more claws, the outside claws are advantageously longer than the middle ones. In this way slightly deeper furrows are formed on the sides of the strip, in which rain water collects without damaging the plants growing in the center.

Another particular feature of the invention is that the equipment contains breaking equipment for stopping the movement of the dressing units, in

which there is a bracket on the dressing unit and a counterpart on the frame which, when set to the locking where the bracket meets the counterpart, the dressing unit is prevented from revolving and, when the counterpart is free from the locking position the dressing unit can revolve freely. In this way, equipment can be constructed which is durable, reliable and easily guided and adjusted.

A third particular feature ofthe invention is that the dressing unit contains two or more radial forks, at the head of which there is a dressing tool. A hollow can be formed between the forks into which the material pushed by the dressing tools can be collected.

Drawings

The following drawings form part of the description of the invention. In the drawings

• figure 1 shows the scarifying equipment from above

• figure 2 shows equipment equivalent to figure 1, viewed from the rear, in which the dressing tools are shaped differently • figure 3 shows one shaft and dressing unit of the equipment in figure 1, viewed from the outside

• figure 4 shows a shaft and dressing unit of the equipment in figure 2, viewed from the inside

• figure 5 shows the counterpart for the dressing unit rotation breaking equipment, viewed from the side and partly in cross-section

• figure 6 shows the counterpart from above.

Specific description

The equipment has a frame 1, which is attached to the rear part of the forestry machine with the attaching device 2. The frame has two shafts 3, which are coupled to the attaching device. The shafts are coupled such that the centrelines of the joints are in a v-angle. In this way the shafts turn towards each other when they are lifted so that the equipment occupies the least amount of space in the transverse direction. This means that the equipment can also be taken along narrow paths in the forest.

A hydraulic cylinder 4 is connected to the outside of each of the shafts 3 with one end connected to the attaching device 2. The free ends of both shafts have a dressing unit 5, attached with a bearing and rotating in the direction of travel. The hydraulic cylinder can be used to raise and drop each of the dressing units independently of the other. In this way, each of the dressing units can be held on the surface of the ground at the required depth regardless of the variation in the shape of the terrain.

In the dressing unit 5 there are four radial forks, at the end of which is a dressing tool 6. Each dressing tool has 4 parallel claws for dressing the ground. The claws are angled backwards, for example, about 10°, where they scrape the ground evenly without any tendency to dig into the ground.

The outer claws are slightly longer so that a slightly higher area within the strip is formed for the plants where the rainwater will not stand (see figure 2). The ideal claws are shaped in an arc in the transverse direction (e.g. in the form of a rounded curve) such that the center area surface of the strip is also formed into the equivalent arc. The outside edges of the outer claws are also ideally straight (see figure 2), so that the strip becomes the same width as the whole tool.

The dressing unit 5 is fixed with a sleeve bearing to the shaft 3 and to the axle 7, which does not rotate in a transverse direction. The outside end of the axle is fixed to the outer fork of the shaft.

The rotation breaking equipment is attached to the dressing unit 5 in which there is a counterpart 8 and operating device 9 in the frame 1 and a bracket 10 on each of the forks of the dressing unit. The bracket is a plate extending from the dressing unit towards the center of the equipment. The counterpart is a bar, whose lower end is fixed with a bearing to the frame turning in the direction of the rotation direction of the dressing unit. When the counterpart is in the forward position the bracket hits the end of the counterpart and the rotation of the dressing unit is obstructed. When the counterpart is turned to the rear position the dressing unit can turn freely. In this way the dressing unit dressing tool 6 which is against the ground either turns the surface of the ground or rotates freely without essentially breaking the surface.

The operating device 9 is a hydraulic cylinder, one end of which is attached with a bearing to the frame 1 and the other end to the counterpart 8.

By using the breaking equipment, it is possible to control both the length ofthe strips and their intervals. Control and use ofthe equipment are best arranged with electrically pre-programmed hydraulics. The breaking of the rotating of the dressing unit 5 then occurs, for example, hydraulically/mechanically by means of control by a microprocessor. Between the forks of the dressing unit 5 there are relatively deep and spacious areas 5a into which the branches, etc. which are pushed from in front of the dressing tools can collect. During the rotating stage, the front edge of the fork presses the collected material against the ground and the land surface remains neat and even.

The equipment is measured such that it is possible to work with it also in difficult conditions such as stony ground or slash heaps. Steadiness is also increased by the weight which assists effective working of the ground. The weight of the equipment can be, for example, 3500 kg. The hydraulic cylinders 4 can be used to direct to each shaft a further, for example, 4000 kg in addition to the weight of the equipment. The width of the dressing tool can be, for example, 70 - 100 cm.

In the counterpart 8 there is a sleeve-like frame 8a whose lower end is attached with a bearing to the frame 1. A stem 8b is fitted into the sleeve whose upper end is a roller 8c which meets against the bracket 10, and is fixed with a bearing to the axle 8d rotating in the direction of movement of the counterpart. This roller reduces wear on the parts.

The lower end of the counterpart 8 stem 8b has a transverse hole and several equivalent holes in the frame into which the stem can be locked, using the pin 8e. In this way the length of the counterpart can be adjusted and also, therefore the rake angle of the fork ofthe locked dressing unit 5, with respect to the ground. The dressing angle can be selected according to the type of ground and the degree of working required. With ground that is easily worked the dressing unit fork can be angled backwards quite

a lot with respect to the direction of travel and still work the ground sufficiently.

In order to adjust the length of the stem 8b of the counterpart 8, extension pieces 8f can be fitted between the lower end of the stem and the base of the frame 8a, such that no strain is placed on the pin 8e. In addition, there can also be a shock-absorber (e.g. an elastic object) between the extension piece and the frame, where movement tolerance is created in the lengthways direction for the pin (in this case in stem 8b). Wear on the parts caused from impacts is reduced as a result of the shock-absorber.

The dressing unit 5 is attached with one or more bearings 1 1 to the axle 7 (see figure 2). The bearing is tempered to endure wear and it is press-fitted into the hole in the middle of the dressing unit. There is a gasket 12 on the outside of the bearing, advantageously a stefa gasket, which allows lubricants out but prevents dirt from entering. The gasket is kept in place with a mounting flange 13. The mounting flange is press-fitted into the dressing unit.

Between the mounting flange 13 and the shaft 3 there is a slip- washer 14, tempered to resist wear, which keeps the dressing unit 5 in place in a sideways direction. The slip-washer moves against the mounting flange and in between comes lubricant from the bearing 11 through the gasket 12.

The axle 7 is shorter than the external width of the shafts 3. On the end of the axle, on the mounting flange 15 side, there are adjusting discs 16 between the end of the axle and the collar 17 (see figure 1). The adjusting discs function as an extension to the axle. By removing them it is possible to reduce the distance between the shafts (when the shafts 3 are flexible) by tightening the fixing device and in this way compensate for the play in the slip- washers 14 when they wear.

A suitable sowing equipment can be attached to the equipment with which it is possible to feed seeds into the strips being formed. In the same way the equipment can contain fertiliser or other additive feed equipment. The functioning of the feed equipment is co-ordinated with the rotation of the dressing unit.