The invention relates to a shackle device for show-shackles mounted periodically on tyres of vehicles, which includes a shackle shank and one or more shackle profile connected to the shackle shank, having said shackle shank a contact surface borne at least partly on the shoe of the tyre while the shackle shank has a cogged part serving for the connection to the hub assembly provided with adjusting and fastening mechanism

Duπng winter periods, a number of solutions aimed at contπbuting to the traffic safety on snow-covered and icy roads became known One of them consists of the snow-chain made from chain-links and provided with flexible fastening elements, that are mounted on the driven wheels of vehicles

The disadvantage of show-chains is that, due to its difficult handling and fastening, they are uncomfortable, therefore, other substituting solutions were developed, 1 e fixed shackle mechanisms fastened on the tyres in order to promote the clinging to the road surface

A mechanism of this kind is described among others in the patent descriptions US 4 209 049 and HU 210 372

The common feature of show shackles used at present is, that the part of shackle in contact with the tire shoe that promotes the clinging and the cogged shackle shank connected to the central hub assembly is formed as a single part made preferably of bar- steel, thus ensuring the rigid connection to the hub assembly of the shackle mechanism

However, the snow-shackles have the disadvantage that, due to their rigid structure, the central hub assembly of the shackle device mounted on the tyre performs an irregular roaming motion as a result of the "flattening" of tyre under the load, which causes a harmful dynamic stresses during progression As a result of roaming motion, the contact between the shackles and the tyre shoe will be loosened and, with larger and smaller displacement, will be re-established on each revolution of the wheel

The phenomena described above and the associated dynamic effects have negative influence on the traveling features of the vehicle and, together with other disadvantages of the fixed shackle design, they also endanger the safety in use which, in turn, is unacceptable in respect of life- and material safety.

A further disadvantage of the fixed shackle design is that the part of shackles in contact with the tyre shoe will be unable to follow the declination of road surface from the horizontal plane and its roughness. In extreme cases, this disadvantage of the rigid shackle structure may lead to the permanent deformation of shackle shanks, or even, breaking of the hub assembly.

The "shackle insertion" described in the patent description HU T 55.684 aimed at reducing the imperfection found, however, without obtaining complete solution.

The invention is aimed at eliminating the insufficiencies of known structures provided with fixed shackle shanks, and developing a show-shackle that enables the shackle profiles to follow the deformation of tyre during travel without any harmful effect, thus ensuring a more coordinated motion of the shackle profiles with the tyre shoe.

The invention is based on the recognition that, by inserting a particular sliding subassembly between the shackle shank and the shackle profiles, the harmful consequences due to the flattening of tyre can be avoided by appropriate shortening the shackle shank and, as the case may be, by bending the shackle profiles and the shackle shank relative to each other, thus enabling the task to be solved.

According to the objective set, the shackle device for show-shackles mounted periodically on tyres of vehicles according to the invention - which includes a shackle shank and one or more shackle profiles connected to the shackle shank, having said shackle shank a contact surface borne at least partly on the shoe of the tyre while the shackle shank has a

cogged part serving for the connection to the hub assembly provided with adjusting and fastening mechanism - is designed in a manner that a sliding subassembly that allows the shackle profile to displace towards the hub assembly is inserted between the shackle shank and the shackle profile

A further cπteπon of the shackle device according to the invention may be that a spπng bundle is fastened to the sliding subassembly at its outer end facing the shackle profile, while the spring bundle is connected either directly or by inserting a connecting plate to the shackle profile

In an exemplary embodiment of the shackle device, the shackle shank has one or more guide grooves machined in it and the sliding subassembly includes side plates in contact with the side faces of the shackle shank, at least one spacer inserted into the guide grooves of shackle shank and allowing a limited displacement, as well as fastening elements connecting the side plates with the spacers together

In another embodiment of the invention, a restoπng element e g a compression spπng is arranged in at least one of the guide grooves of the shackle shank, and the restoπng element is inserted between the shackle shank and the spacer

In another embodiment of the shackle device, holes of diameter same as the diameter of rivets fastening the spring bundle together are at both ends of middle spπng plate in the spπng bundle that is fastened to the sliding subassembly movable on the shackle shank, and openings of diameter larger than the diameter of the rivets are arranged at one end of the outer spπng plates each mounted on both sides of the middle spπng plate within the spπng bundle

In a further embodiment of the shackle device according to the invention, the contact surface of the shackle profile is completed with a shoe plate of size and form adapted to the tyre shoe and the shoe plate is provided with elements improving the clinging capability

The shoe plate is mounted with grasping ribs suitable to improve the clinging capability and the grasping πbs are fastened to the shoe plate parallel to the shackle profile section borne on the tyre shoe

In another design of the shackle device, exsections are formed on the shackle profile section in contact with the tyre shoe and or on the grasping ribs mounted on the shoe plate The shoe plate and/or the grasping ribs are fastened bv means of cone-head rivets to the shackle profile

The advantage of the shackle device according to the invention is that, by using a structure allowing the shackles to be shortened and bent, the operation of self-adjusting character of the shackle profiles that adapt itself to the deformation of the tyre shoe can be significantly improved, thus also making the operational features of the snow-shackle more favourable

In the following, the invention is described in connection with an exemplary embodiment, based on drawings In the drawings

Fig 1 shows the front view of the snow-shackle provided with the shackle device according to the invention

Fig 2 shows the device of Fig 1 from the direction II

Fig 3 shows the part-sectional front view of the sliding subassembly

Fig 4 shows the sectional view along the plane IV-IV of device shown in Fig. 3

Fig 5 shows the sectional view along the plane V-V of device shown in Fig 3

Figs 1 and 2 show the snow-shackle design provided with the shackle device according to the invention It is well shown that the flexible shackle device is composed of the 2

shackle shank connected to the 1 hub assembly, the 3 sliding subassembly, the 4 spπng bundle, the 5 shackle profile and the 6 connecting plate that connects the 5 shackle profile to the 4 spπng bundle The spring bundle is fastened by means of the 10 πvets to the 3a outer end of the 3 sliding subassembly and to the 5 shackle profile The 2 shackle shank is connected by means of its end provided with 2c cogging to the 1 hub assembly, while the other end of the 2 shackle shank is connected to the 3 sliding subassembly The 2c cogging enables the position of 2 shackle shank to be modified by displacing it within the 1 hub assembly, thereby altering the protruding length of the shackle device, while the 3 sliding subassembly allows the distance between the 2 shackle shank and the 5 shackle profile to be shortened and restored to its original size automatically according to the deformation of the tyre

The Fig also shows the 1 1 shoe plate mounted on the 5a contact surface of the 5 shackle profile as well as the 12 grasping ribs fastened to the 1 1 shoe plate that serve for improving the clinging capability Similarly, the 13 exsections also serving for improving the clinging capability are arranged on both the 5b shoe surface of 5 shackle profile and the 12 grasping ribs in this embodiment, as shown in Fig 2

The clinging capability is also improved by the 14 cone-head πvets that fasten the 5 shackle profile and the 12 grasping ribs to the 1 1 shoe plate It shall be noted here that the 14 cone-head rivets can also be used in themselves, or even, any other element improving the clinging capability by ensuring the better engagement of the 5 shackle profile with the snow-covered and icy road surface and the tyre shoe can also be used

Figs 3 and 4 shows the arrangement and connection of component parts of 3 sliding subassembly movable on the 2 shackle shank It is shown that the 31 side plates in contact with the 2a side faces of 2 shackle shank and the 7 spacers are fastened together by means of the 9 fastening elements, thus forming the covered space in the 3 sliding subassembly in which the 2 shackle shank is inserted

The 2 shackle shank is provided with the 2b guide grooves passing through between the 2a side faces In the 2b guide grooves, the 8 restoπng elements serving for resetting the 3 sliding subassembly to its outer end position - compression spπngs in this embodiment - are arranged, on the one hand, and the 7 spacers are also inserted and guided in the 2b guide grooves, on the other hand It is also well shown that, in this embodiment, the 8 restoπng elements are arranged between the 2b guide groove formed in the 2 shackle shank and the 7 spacer fastened to the 3 sliding subassembly, thus ensuring the 2 shackle shank and the 5 shackle profile to be stretched out

Of course, the 5 shackle profile can be retained in its outer end position by means of 8 restoring elements arranged in a different manner, thus, the embodiment shown in the Figures is only one of the possible solutions without being considered to be exclusive

Fig 5 shows the arrangement of the 4 spπng bundle composed of the 4a middle spπng plate and the 4c outer spring plates surrounding it on both sides It is shown that the size of 4b holes formed in the 4c outer spring plates - that are forced to slide if the 4 spπng bundle is bent - at their 41c ends connected to the 31 side plates is the same as the diameter "D" of the 10 rivets, while the 4c outer spπng plates at their 42c ends fastened to the 6 connecting plates are provided with 4d openings of size larger than the diameter "D" of the 10 rivets, in order to allow the possibility of sliding

However, the 4b holes at both ends - 41 a and 42c - of the 4a middle spring plate are of diameter equal to the diameter "D" of the 10 rivets

The shackle device according to the invention fulfills its function while performing complex movement within the snow-shackle fastened to the tyre

Basically, the rest position of the 3 sliding subassembly, I e the maximum length of the shackle, is ensured by the reaction exerted by the tyre The force exerted by the 8 restoπng elements - also acting towards the end position that determines the maximum length of the shackle - is negligible as compared to the reaction exerted by the tyre

During the rotation of the wheel, the tyre rolls over the 5 shackle profiles borne on the road surface as well as the 11 shoe plate and its components When the flattening tyre rolls over the 5 shackle profile, the 3 sliding subassembly slides along the 2a side faces of the 2 shackle to a distance determined by the extent of flattening, while the 1 hub assembly of the snow-shackle remains stable essentially at the centre. The method of operation described eliminates the unfavourable dynamic impacts and the irregular roaming motion of the 1 hub assembly to an unacceptable extent together with its harmful consequences described above, that would occur in the case of rigid shackle design

During the use of the shackle device, the 5 spπng bundle enables the 5 shackle profile borne on the road surface as well as the elements improving the clinging capability to be function in a self-dependent manner.

The operation of the 4 spring bundle shows hysteresis, as a result of the friction due to the compression force of the 10 rivets As a result of the hysteresis, the 5 shackle profile and the elements improving the clinging capability while resting on the tyre shoe "preserve" their setting according to the lateral angular offset of the road surface and, at the same time, they also stand any extreme deviations due to the roughness of the road surface without damage Thus, the use of the 4 spring bundle eliminates the risks that occur in the case of snow- shackles provided with rigid shackles

The shackle device according to the invention is well suitable to be used under winter circumstances in order to improve the traffic safety of various vehicles using tyres.

List of references

hub assembly shackle shank 2a side face 2b guide groove 2c cogging sliding subassembly 3 a outer end 31 side plate spring bundle 4a middle spring plate 1a end

42a end 4b hole 4c outer spring plates

41c one end

42c other end 4d opening shackle profile 5a contact surface 5b shoe surface connecting plates spacer restoring element fastening elements 0 rivets "D" diameter 1 shoe plate 2 grasping ribs 3 exsections 4 cone-head rivet