TRACK ASSEMBLY

FIELD OF TECHNOLOGY

[001] The present invention relates to tracks for all-terrain vehicles equipped with wheels with tyres or similar. Such vehicles are, for example, forestry forwarders and harvesters. The invention can be applied to rubber tyres or a solution with other similar wheels.

BACKGROUND

[002] Forestry machines are generally equipped with wide rubber tyres. In some conditions, tracks are required to improve traction and climbing ability. Tracks reduce the surface pressure, thus also reducing damage to the ground of the forest. Special tracks are designed for wet and marshy conditions, as well as for snow and ice. Such a track must produce good flotation and good cleaning properties with the aid of snow and mud removal. Because tracks designed to improve traction may become clogged and jam in marshy or snowy conditions, they are not suitable for terrain where good flotation is required. On the other hand, tracks producing good flotation generally do not have good traction. Each machine must therefore have two sets of tracks, if the device is used in varying conditions and terrain, as is generally the case. An investment in two sets of tracks is naturally a great financial burden.

[003] The tracks of off-road vehicles equipped with rubber tyres comprise a track plate, which is oriented over the width of the tyre, and in which there are guide plates at each end. The guide plates are oriented over the edge and to the sides of the tyre, in such a way that the tyre remains between them. This construction is typical of tracks designed for rubber tyres, as guide plates are required to hold the tracks on the tyres. For this reason rubber-tyre tracks differ from those used, for example, in excavators. At the ends of the track plates there are also lugs, which point at right-angles over the length of the track plates. In these lugs, there are holes for the chain links that join the track plates together to form one complete track. In such a construction, wear is concentrated in the lugs and the chain links. When these parts are worn out, they must be replaced by cutting them off the track plates. New parts can then be welded in place of the old parts. This repair method demands much time, work, and expense.

[004] All-terrain vehicles equipped with tracks are disclosed in publications WO 2015/053689 and WO 2009/040472.

SUMMARY OF THE INVENTION

[005] The invention is defined by the features of the independent Claims. Some specific embodiments are defined in the dependent Claims. [006] According to a first feature of the present invention, a track assembly is created for an all-terrain vehicle equipped with wheels. The track assembly comprises at least two track plates, each of which has a body that is dimensioned to extend over the width of the tyre, and which has guide plates that point away from the body in such a way that they can be arranged to extend over the edge of, and to the sides of the tyre, at each end of which track plate there are lugs, which are oriented transversely to the length of the track plate on each side of the track plate, in each of which lug there is a hole for a link, which joints the track plates together to form an entire track. In addition, there is in the track at least one link, comprising a link body, which has length, and the link body of which comprises, at least at one end, two lugs and a slot between them, and in the lugs there are holes for pins, and a groove, parallel to the holes and transverse to the pins and the length of the link body, in the portion of the link body between the lugs, on at least one side of the link body.

[007] According to a second feature of the invention, in the link body there are grooves parallel to the holes, transverse relative to the length of the link body, in the portion of the link body between the lugs of the link body, on both side of the link body.

[008] According to a third feature of the invention, the pins are welded to the link body.

[009] According to a fourth feature of the invention, the pins are attached to the link body by nuts. [0010] According to a fifth feature of the invention, the link body comprises tow side plates, which are joined together by pins.

[0011] According to a sixth feature of the invention, the link body is a single piece.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIGURE 1 shows a tyre set, which is equipped with a first track assembly according to at least any of the embodiments of the present invention;

[0013] FIGURE 2 shows a tyre set, which is equipped with a second track assembly according to at least some of the embodiments of the present invention;

[0014] FIGURE 3 shows a partly exploded view of the track assembly according to at least some of the embodiments of the present invention;

[0015] FIGURE 4 shows the track assembly of Figure 3 from another angle;

[0016] FIGURE 5 shows a link used in at least some embodiments of the invention;

[0017] FIGURE 6 shows a side view of the link of Figure 5;

[0018] FIGURE 7 shows an end view of the link of Figure 5; and [0019] FIGURE 8 show a second view of the link of Figure 5.

EMBODIMENTS

[0020] DEFINITIONS [0021] In the present context, the term "track assembly" comprises complete entire tracks and portions of such tracks.

[0022] The longitudinal direction of a track assembly is the direction of the centre line of the longitudinal direction of the track. [0023] The transverse direction of the track assembly is at right angles to the longitudinal direction and the same as the direction of the longitudinal direction of the track plates.

[0024] Forestry machines are generally equipped with wide rubber tyres. In some conditions, tracks are required to improve traction and climbing ability. Different types of tracks are required in different terrain conditions. One characteristic of the present invention is to produces a track assembly, which can be adapted to different terrain conditions simply by attaching accessories to a basic track. These components can be designed to produce better flotation in marshy or snowy conditions, or better traction when required, or a combination of these properties. Additional plates can be also be shaped in such a way that they prepare the ground. This property is suitable, for example, for land improvement and preparation work. The additional plates can be shaped in such way that they automatically prepare the ground as they drive over it.

[0025] The idea of altering the properties of a track assembly by adding or removing accessories permits very good flexibility and reduces costs, as in this way only one track is needed with suitable accessories, instead of two or more tracks. A second characteristic of the invention is the use of links and locking pins to make a crawler track. By locking the rotation of the pins, wear can be concentrated in easily replaced components. The maintenance and repair of the track assembly will then be cost-effective and quick, when compared to previous methods.

[0026] FIGURE 1 shows a set of tyres, which is equipped with a track assembly according to at least some of the embodiments of the present invention. In this case, there are two tyres 1 in the tyre set, which in forestry vehicles are generally two rubber all- terrain tyres installed on metal rims. The track assembly 2 comprises track plates 3, which are at right angles to the longitudinal direction of the track assembly 2. The track plates 3 are intended to provide good traction on the ground or whatever surface the vehicle is moving on. The track plates 3 are generally made from steel and different manufacturers have their own definitions for the shape of the plate. The length of the track plate 3 is set in such a way that it is oriented across the width of the tyre and thus depends of the dimensions of the tyres. There are guide plates 4 at each end of the track plates 3. The guide plates 4 are intended to keep the track assembly 2 on the tyres 1. Because the tyres 1 do not have guide surfaces or grooves, as is the case in the wheels used in a bulldozer, the track assembly fitting the tyres must be guided from the edges of the tyres 1, so that they hold the track assembly 2 on the tyres, even on difficult terrain.

[0027] Track assemblies implemented according to various embodiments of the invention can be applied to different applications, in which there are wheels that require guiding the track from the edges of the wheel or tyre. Such tyre and wheel arrangements are in, for example, in agricultural machines and tractors, or in mining machines, or in work machines in peat excavation, as well as in car tyres as a new snow chain, or in quad bikes. In a set of wheels or tyres there may be only a single wheel, around which the track rotates, or instead in the set there can be three or more wheels instead of two. The number of wheels or tyres is limited mainly by the limited steering of a long set of wheels and a long track. In agricultural machines, there are generally four wheels, or individual wheels are used. The wheels can be of different sizes and they can be two or even more next to each other as in a twin-wheel solution.

[0028] FIGURES 2 and 3 show the same track as FIGURE 1, but equipped with infill plates 5. The infill plates 5 are fitted between two parallel track plates 3. Generally, the infill plates 5 are used in all the gaps between two parallel track plates 3, but it can be envisaged that a smaller number of infill plates is used and some gaps remain empty. In this way, traction and surface pressure can be adjusted when necessary or when desired.

[0029] In the following, the construction of the track assembly 2 is described with reference to FIGURES 3 and 4. For example, according to these figures, the track assembly of an all-terrain vehicle equipped with tyres 1 comprises at least two track plates 3, in each of which is a body 6, which is dimensioned to extend over the width of the tyre 1. The body 6 is curved in such a way that it follows the profile of the tyre 1 and produces an extension in the direction transverse to the direction of rotation of the wheel. The transverse direction and detailed shape of the body 6 can vary according to the manufacturer’s design principles. In the body 6 are guide plates 4, which point away from the body 6 in such a way that they can be set to extend over the edge of the tyre 1 and to the sides of the tyres 1. The guide plates 4 are flat plates, which extend at an obtuse angle from the extreme ends of the body 6, in such a way that the body 6 and guide plates 4 form an open U-shape, into which the tyre 1 fits. The shape of the guide plates 4 can vary.

[0030] The body 6 comprises lugs 7 at each end of the track plate 3, which are oriented transversely to the track plate 3. The lugs 7 are set on each side of the body 6 of the track plate 3, in such a way that the lugs 7 are on opposite sides of the ends of the body 6. The lugs 7 are oriented to extend in the longitudinal direction of the track assembly. In each lug 7 there is at least one hole for a link 11, which joints the track plates 3 together to form one entire track assembly. In the link 11, there is a link body 12, which has length and at least one link hole 13 in each opposite end of the link body 12. The track assembly 2 is formed by joining the track plates 3 together with the aid of the links 11 and pins 14. The pins 14 are set to run through a pair formed by a hole 13 in the body 12 of the link and at least one hole in the lug 7 in the track plate 3, in order to form the crawler track. The pins 14 are locked relative to the hole 13 in the link 11, so that the rotation of the pins 14 in the hole 13 is prevented. The locking of the pins 14 can be implemented simply by welding the pins to the link body 12. Alternatively, locking can be implemented by using locking grooves and keys, or other shapes that prevent the pin 14 from rotating in the hole 13. The pins 14 can also be attached using nuts, closure pins, or other method of attachment known in machine construction. Alternatively, the pins 14 can be freely rotating and it can be envisaged that they are equipped with sleeve bearings in the manner of roller chains.

[0031] In the example of Figure 5, the link body 12 is formed of two side plates 8, which are simply flat plate pieces. There are holes 13 for pins 14 at the longitudinal ends of the side plates 8. The pins 14 can be ready attached to one of the side plates 8 and in assembly the pins 14 are set in the holes in the lugs 7 and the opposite (counter side plate) 8 is fitted to the ends of the pins 14. The pins 14 can be secured as described above. The pins 14 and side plates 8 can also be separate parts, which are attached to each other when assembling the track.

[0032] The link body 12 comprises at least at one end two lugs and between them a slot and holes 13 in the lugs for pins 14, and pins 14. In the embodiment of Figure 5, the slot is formed by the gap in the side plates 8 and the lugs by the ends of the side plates 8, in which the holes 13. In the link body 12, there are grooves 9, 10 for attaching the infill plates, which are transverse to the length of the link body 12, and parallel to the holes 13, over at least part of the link body 12, between the lugs, on at least one side of the link body. In the example of Figure 5, in the link body 12, there are grooves 9, 10, which are transverse to the length of the link body 12 and parallel to the holes 13 in the part of the link body 12 between the lugs, on both sides of the link body 12. On the track outer surface of the link body 12, i.e. on the side pointing in the direction of the track plates, there is a guide groove 9, and on the side opposite to it, i.e. on the side lying in the direction of the tyres there is a locking groove 10. The locking groove is not essential, if guiding is otherwise implemented sufficiently in structurally.

[0033] Alternatively, the link body 12 can be a single piece. Such a link body can be made, for example, by casting, forging, or machining. In a link body made from a single piece, the middle part of the body can be a uniform filled piece, at the ends of which are slots equipped with holes 13 for attaching the track plates 3 to the lugs 7. In one exemplary alternative, one side of the link body can be, for example, a unified piece with the pins, made by forging, and the other side is formed of a side plate like that in Figure 5.

[0034] The grooves in the link body, the guide groove 9 and the locking groove 10, are for attaching the infill plates 5. Figures 3 and 4 show one example of an infill plate 5. In the infill plate 5, there is an elongated body part 18, at one end of which is a hook 15, which is formed of a hook body 16 and a recess 17, which points towards the opposite end of the elongated body part 18. At the opposite end of the elongated body part 18 to the hook 15 is a locking attachment 19, which comprises a locking protrusion 20, with a locking hole 21, extending to the same side of the elongated body part 18 as the hook 15. Next to the locking protrusion 20 is a support flange 22 on the side of the end of the elongated body part 18. The locking protrusion 20 extends outwards from the plane of the surface of the support flange 22 at least enough for the locking hole 21 to fit in it. A locking pin 23, which can be a pin or a threaded bolt, can be fitted into the locking hole 21. A pin can be attached by riveting or welding, and a bolt correspondingly using a nut or thread formed in the locking hole. The locking protrusion 20 can be formed alternatively rotated in the longitudinal direction of the elongated body part, so that the support flange is on the side of the hook 15. Correspondingly, the hook 15 can be rotated to point towards the end of the body part 18, or it can be transverse to the body part 18. The attachment of the additional plates 5 to the track assembly can be implemented with the aid of many kinds of attachment elements. One alternative is that the attachment elements are a fixed part of the link body and the body part of the additional plate is attached to the link body, for instance, by bolts, rivets, or welding.

[0035] The track assembly is formed in such a way that a link body 12 is fitted to the lugs of the track plates 3 and the pins 14 to the holes in the lugs in the order determined by the structure of the link 11. After assembly, the part are locked to each other, for example, in one of the aforementioned ways. With the aid of the invention, a new track assembly can be formed, or worn lugs can be removed from used track plates and replaced with lugs suiting the links 11, in order to form a renovated track assembly. If the track plate attachments are usable, only the worn link parts need be replaced with a link according to any of the embodiments of the invention.

[0036] With the aid of the links described above, a new of renovated track assembly can be formed, to which infill plates like those described above or infill plates described in the international patent application PCT/FI2017/050676 can easily be attached. In the link is a guide groove 9 and an attachment groove 10 for attaching the infill plates. The infill plate 5 is placed on the link, in such a way that the support surfaces in the infill plate 5 lie against the bottom of the guide groove 9 and the guide groove extends to the sides of this support surface. In an infill plate of Figures 3 and 4, the support surface are the surface on the side of the recess 17 of the elongated body and the support flange 22. For its part, the hook 15 extends to the attachment groove 10 at the first end of the infill plate and a locking pin 23 is placed at the attachment groove 10 at the second end. In a corresponding manner, infill plate equipped with, for example, attachment forks, which are disclosed in patent application PCT/FI2017/050676, can be added to the assembly of the track assembly.

[0037] In the link 11 there can be either a guide groove or an attachment groove. The best support and guiding for an infill plate is obtained using two grooves, but it is also possible to use only one. At least one groove is need to support the infill plate, so that it will not bend to the side and possible between the track plates when pressed by the surface of the ground.

[0038] The track assembly and its part are preferably made from steel. However, the invention is not limited to any manufacturing material, instead various materials, such as plastics, reinforced composites, and similar can be used for different purposes and applications.

INDUSTRIAL APPLICABILITY

[0039] The invention can be industrially applied in agricultural and forestry equipment as well as in the manufacture, maintenance, and repair of all-terrain vehicles.

LIST OF REFERENCE NUMBERS

1 tyre 2 track assembly

3 track plate

4 guide plate

5 infill plate

6 body

7 lug

8 side plate

9 guide groove

10 attachment groove

11 link

12 link body

13 attachment hole

14 pins

15 hook

16 hook body

17 recess

18 elongated body part

19 locking attachment

20 locking protrusion

21 locking hole

22 support flange

23 locking pin

LIST OF REFERENCE PUBLICATIONS Patent literature:

WO 2015/053689

WO 2009/040472