FI79815B - LARVMATTA FOER LARVFORDON. - Google Patents

Description

7981 5 1 Track of the tracked vehicle Larvmatta för larvfordon 5

The invention relates to a track for a tracked vehicle, which consists of successive track parts which are at least to some extent flexible plastic material or the like and which can be connected at their edges to form a closed loop track.

It is already known that both the so-called The track mats of track vehicles that are controlled by pivot rollers and by means of the speed difference of skis or adjacent track belts consist of successive track parts which are connected to each other, e.g. by tapping pins.

15

As is already known, the track mat and the roller parts are generally made of a plastic material, e.g. by a mold casting method, into elongate flat pieces.

20 Known track tracks have shown breakages in use, especially in severe frosts. The inventor has found that carpet grooves are caused in particular in turntable vehicles but also in fixed-track tracks controlled by skis because the track pieces on the end rolls of the track have to repeatedly bend to a relatively small radius of curvature determined by the end roll. The resulting repetitive load breaks the tracks more frequently the lower the operating temperature. In addition, for the reasons mentioned, the rolling resistance of the track mat becomes high in frost. These constraints have even become a limiting factor for the use of tracked vehicles in frost.

The object of the present invention is to provide a simple solution by which the above-mentioned drawbacks can be largely avoided.

It is a further object of the invention to provide a track mat for a track vehicle with which the durability of the track can be substantially improved, especially in frost, while at the same time significantly reducing the rolling resistance of the track.

The object of the invention is to provide such a track mat, by means of which the maximum permissible speed of the vehicle can be increased, if necessary.

2 79815 1 In order to achieve the above and later objects, the invention is mainly characterized in that the track parts of the track are made curved in the direction of movement of the track in the same direction as the track parts bend or curve with end rolls or similar , and that the roll parts are then placed on a mold bench or the like, after which they are heated.

The invention will now be described in detail with reference to an embodiment of the invention shown in the figures of the accompanying drawing, to the details of which the invention is in no way narrowly limited.

Figure 1 shows a top view of a separate track of a revolving roller vehicle from a roll track.

Figure 2 shows a part of a track assembled from the roll parts according to Figure 1.

Fig. 3 shows a section III-III in Fig. 1 and this figure shows the curvature of the roll parts according to the invention.

First of all, it should be emphasized that although the invention will now be described with reference to a reversible roller track, in which the advantages of the invention are highlighted, the track is also suitable for ski-guided and non-reversible end roller tracks.

The figures show a roll part 10 which is elongate, plate-shaped and which is joined side by side to form a roll mat of a swivel roll vehicle according to the invention. The roller parts 10 are made, for example, of suitably elastic and wear-resistant plastic. The roller part 10 has a central part 12 and corrugated and / or accordion-like parts 11a 35 and 11b on both sides, which on one side of the central part 12 expand and contract on the spring side and return when the track is turned by guide rollers (not shown) 1 to the resulting curved position. The successive central parts 12 of the roller parts 10 form a central part on the track, which is substantially inextensible but nevertheless such that it can bend to the curvature corresponding to the radius of curvature of the vehicle as smoothly as possible.

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In Figures 1 and 2, the track mat and the roller stacks 10 are shown schematically, and the central part 12 of the track sections 10 has a protruding portion 13 and / or corresponding openings through which the traction is transmitted to the track. Adjacent roll members 10 are connected to each other at their edges by a joint 14 consisting of, for example, loop portions 15a and 15b on the long edge sides of the roll members 10, with steel pins inserted through holes 16a and 16b in the middle connecting adjacent roll members 10 into a track. The edges of the roll portions 10 have interleaved finger portions (not shown) with the aforementioned loop portions 15a, 15b and holes 16a, 16b shown in Fig. 3.

15

According to Figure 1, the dimension of the edges of the roll particles 10 is smaller than the corresponding average dimension. Thus, when the roller parts 10 are connected to each other, the edge areas 11a and 11b are prestressed so that the edge areas of the track do not bag on the side of the track of the vehicle equipped with the track.

20

Figure 3 shows the curvature of the track according to the invention and a structural example of the shrinkable and stretchable shank-like part of the track. The altar-like parts 11a, 11b have strip-like parts 17 which are on the outer side 20 of the track and which correspond to the running gear when the track is in use.

Correspondingly, on the inner side 21 of the track there are planar sides 18 connecting the accordion-like parts, which correspond to the end rollers of the track as they pass. The side portions 11a and 11b are substantially corrugated in cross-section so that they can stretch and contract smoothly. The contraction is aided on the inner arc side by the above-mentioned prestress provided by the structure 30 of Figure 1.

According to the invention, the roll parts 10 are made curved in the vertical plane in the direction of movement of the roll so that they have a certain suitable radius of curvature R. The radius of curvature R is parallel to the curvature to which the roll parts are bent by the roll end ends, The main shape of the roller parts 10 is, for example, in the form of a part of a circular cylinder (radius R). Thus, the section shown in Fig. 3 of 4,79815 1 is in a situation where the track el is not under tension. Said curvature R may be in both the central part 12 and the side parts 11a and 11b of the track, and suitably the curvature is substantially recessed.

5

The curvature of the roll parts 10 is more conveniently achieved by first making the roll parts 10 from planar pieces of a suitable plastic material as a mold casting, since the planar mold is less expensive than a curved mold. The roll particles are pressed into a mold bench where they bend to the curvature R mentioned above, after which the roll particles are heated, for example in a water bath, to a temperature of about 80-100 ° C for about 0.2-2 h. When the heating effect acts when the roll particles 10 are in a tensioned state in their mold, a permanent deformation and curvature are obtained.

15 Example

An example of a track according to the invention is the production of a roll part 10 in a flat mold from a plastic material marketed by Dupond under the trade name "Hytrel" (trademark). The roll parts 10 sl-20 are then placed on a curved mold bench. The roll parts 10 are then placed with their molds for 30 min. for a time in a water bath at a temperature of 95 ° C, where they are bent to a radius of curvature equal to the radius of curvature of the end roller of the roller vehicle in question. The roll particles are kept in the mold bench long enough for them to cool. After the roll parts are removed from the mold bench, their radii of curvature R return slightly larger.

By bending the planar roll part after heating, the curvature R according to the invention has a significant advantageous effect in that the molecular chains in the roll material are placed in such a position that the plastic raw material becomes even more inclined with respect to the bending direction.

For example, in a normal-sized swivel vehicle, a radius of between n is generally used as said radius of curvature R.

70-250 mm, preferably about 80-100 mm, which latter area gives the roll piece a final curvature which is about twice as large as the radius of curvature Rq of the corresponding end roll. Thus, the rollers in the straight runs of the track due to the tensioning stress are straightened almost straight and the end rollers are correspondingly slightly bent so that their radius of curvature R is reduced by half (Rq) of the normal unstressed radius of curvature.

The following are claims within the scope of which the various details of the invention may vary and differ from those set forth above.

10 15 20 25 30 35

Claims (7)

A track for a tracked vehicle, consisting of successive track sections (10) of at least somewhat flexible plastic material or the like and connectable at their edges to form a closed loop track track, characterized in that the track sections (10) of the track are made trackless. curved in the direction of movement (R) in the same direction as the roll parts (10) bend or curve with end roll guiding rollers or the like so that the roll parts (10) are made of planar pieces of suitable plastic material, preferably in a mold casting step, and then or the like, after which they are heated. 1 Claims Roll mat according to claim 1, characterized in that the roll parts (10) made in flat pieces are heated in a water bath or the like for about 0.2-2 h to a temperature of about 80-100 ° C, where they are kept pressed in a mold bench to said curvature or final curvature to a slightly steeper curvature. Track according to Claim 1 or 2, characterized in that the track parts of the track are mainly parts of a circular cylinder whose radius of the circular cylinder is equal to the curvature (R) of the roller part (10) according to the invention. Roller mat according to one of Claims 1 to 3, characterized in that said radius of curvature (R) of the roll parts (10) is greater than the radius of curvature (Rq) of the end roller or rollers guiding them. Track according to Claim 4, characterized in that said radius of curvature (R) of the roller parts (10) is of the order of curvature (Rq) of the end roll guiding the track about twice. Roller mat according to one of Claims 1 to 5, characterized in that the radius of curvature R of the roll parts (10) is between R 70 and 250 mm, 35 mm R R 80-100 mm. 7 79815