GB1570902A

GB1570902A - Tyre chains

Info

Publication number: GB1570902A
Application number: GB2064177A
Authority: GB
Original assignee: Eisen und Drahtwerk Erlau AG
Current assignee: Erlau AG
Priority date: 1975-06-13
Filing date: 1977-05-17
Publication date: 1980-07-09
Also published as: AU507486B2; FR2361231A2; FR2361231B2; BE855036R; ATA276977A; AU2559877A; AT362994B; DE2623827A1

Description

(54) TYRE CHAINS (71) We, EISEN- UND DRAHT WERK ERLAU AKTIENGESELL SCHAFT, a Company organised under the Laws of the Federal Republic of Germany, of Erlau 16, 7080 Aalen-Württ, Federal Republic of Germany, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to tyre chains and is an improvement in or modification of the invention of our British Patent No. 1 544 291.

In the aforesaid earlier Patent Application there is described a type chain having a tread part and side parts which have a tensioning device comprising a housing, a compression spring disposed in the housing, two supports arranged on opposite ends respectively of the spring, a link member connected to one of the supports, the other support being provided by the housing, the link member being movable, relative to the housing, and a locking device operable to lock the link member in an extended position against the action of the compression spring and a second link member supported by the housing.

With the above mentioned tyre chain, the link members of the tensioning device are moved into their stretched-out position before the tyre chain is fitted and are then locked so that the tyre chain can be fitted on to the tyre without traction stressing being caused by the tensioning device. In order to achieve a high degree of tensioning and a large tensioning path or spring path, the tensioning device is comparatively long and cannot be used without trouble with narrow mesh tyre chains in which the side of each mesh consists only of a few chain links.

An object of the present invention is to provide a tyre chain of the kind described above having a tensioning device suitable for use in the context of narrow mesh tyre chains.

According to the invention there is provided a tyre chain having a tread part and side parts which have a tensioning device for the tensioning of the tyre chain in the operating state and which device is linked to members of the tyre chain, the device comprising two link members movable relative to one another against the action of spring means up to a stretched-out position, the link members in the stretched-out position being held in position relative to each other by a releasable locking means characterised in that, the spring means comprises at least two compression springs which are coextensive.

With the construction of the present invention, the tensioning device need have only a short length and can therefore be used in narrow mesh tyre chains or in tyre chains with small spacing, as for example, is the case with tyre chains having a bridge piece-ring system. With the use of at least two compression springs the tensioning device according to the invention can produce in spite of a short constructional length thereof, a comparatively high degree of tensioning so that the tyre chain when fitted can be satisfactorily tensioned and can be located securely on the tyre. With the aforesaid detachable locking, the tensioning device can be secured in its stretched-out position before fitting the tyre chain on the tyre so that the tyre chain, in spite of the high degree of tensioning can be easily fitted on to the tyre.

The invention will now be described further by way of example only and with reference to the accompanying drawings in which: Figure I shows in longitudinal section a tensioning device of one form of a tyre chain according to the invention; Figure 2 shows in longitudinal section an alternative form of a tensioning device; Figures 3 and 4 shows in section a part of the tensioning device according to Figure 2 with alternative means for locking the link members in a stretched-out position; Figure 5 shows in section a further form of a tensioning device; and Figure 6 shows a section along the line VI-VI of Figure 5.

The tensioning device 1 shown in Figure 1 has two link members 2 and 3 movable towards one another with which the tensioning device 1 is suspended in chain links 4 and 5 of a tyre chain. The two link members 2 and 3 are movable in the direction away from one another against the force of two compression springs 6 and 7. The two compression springs 6 and 7 are supported at their ends on counter bearings 8 and 9 which bearings are connected respectively to the link members 2 and 3 facing away from the appropriate ends of the compression springs 6, 7. The link members 2 and 3 are respectively connected by means of guide parts 10 and 11 to the appropriate counter bearings 8 and 9. The guide part 10 of the link member 2 is formed by a cylindrical housing which surrounds and is spaced from the guide part 11 of the other link member 3, which is formed as a shaft.

The cylindrical housing 10 is closed at one end with a closure plate 12 which is welded to the housing 10. The other end of the housing 10 is closed with the counter bearing 8 which is formed as a ring, which counter bearing is likewise welded to the end of the housing. Through the central opening 13 of the annular counter bearing 8 the shaft-like guide part 11 is guided and in position shown in Figure 1 the part 11 projects through the opening 13 from the housing 10 with an end section 14 which is screw-threaded. The other end 15 of the shaft-like guide part 11 is widened conically and carries the counter bearing 9 which is also formed as a ring and has a corresponding conical opening 16. The counter bearing 9 is located on the shaft-like guide part 11 such that the flat front face 17 of the guide part 11 and the corresponding outer face 18 of the counter bearing 9 lie in one plane so that the shaft-like guide part in the position shown in Figure 1 is supported satisfactorily via a comparatively large face on the inside 19 of the closure plate 12.

In the embodiment, the shaft-like guide part 11 is surrounded by the two compression springs 6 and 7 which are formed as helical compression springs. The compression spring 7 is surrounded by the other compression spring 6 over its entire length.

The two compression springs 6, 7 lie inside the housing 10 and are thus supported by the shaft-like guide part 11 as well as also by the housing 10 over their entire length.

Thereby in advantageous manner a danger of bending of the compression springs is obviated so that a jamming of the two link members 2 and 3 against one another cannot occur. The pitch of the two compression springs is different. Thereby, advantageously, the shaft-like guide part 11 has a constant cross-section over its entire length surrounded by the compression springs so that the compression springs can be compressed and released without hindrance. The compression springs are securely protected in the housing 10 from contamination and from premature wear so that the tensioning device even after long use can ensure a satisfactory tensioning of the tyre chain. In consequence of the special arrangement of the compression springs 6 and 7 the tensioning device 1 has only a short constructional length without thereby however the tensioning pressure being reduced. The tensioning device has in spite of its short constructional length a high degree of tension pressure so that the tyre chain can be tensioned satisfactorily and thus can sit securely on the tyre.

The use of compression springs for the tensioning device has the great advantage that these cannot be overloaded. With high loading of the springs their windings lie on one another and prevent a further loading likely to lead to destruction of the springs.

The tensioning device can therefore be used to a certain extent wherever particularly strong stresses arise, for example, in the context of car chains in mine works or in stone breaking. The counter bearings 8, 9 respectively are disposed on the ends of the compression springs 6 and 7 turned away from the appropriate link members 2 and 3 and the link members are movable towards one another whereby the tensioning device, in spite of its small constructional length, has a comparatively large adjustment path.

With the embodiment of Figure 1, the two compression springs 6 and 7 surround the shaft-like guide part 11. It is also possible to arrange compression springs in the region between the shaft-like guide part 11 and the housing wall diametrically opposite one another. Several compression springs may also be used on a circle, at positions spaced around the shaft-like guide part 11. In this way also with short constructional length for the tensioning device 1, a high degree of tension pressure can be produced.

The two link members 2 and 3 are forked and have two legs 20 to 23 which are freely projecting and run parallel to one another.

The legs 20 and 21 of the link member 2 are of equal length and are welded directly onto the outer face 24 of the closure plate 12. The legs 22 and 23 of the other link member 3 are also of equal lengths and merge into one another via a bridge-piece 25 running per pendicularly thereto. In the bridge-piece 25 there is provided a screw-threaded bore 26 so that the link member 3 in a simple manner can be screwed on to the end section 14 of the shaft-like guide part 11. In order to prevent an unintended loosening of the link member 3 from the guide part 11, the link member 3 may be connected additionally to the guide part 11 by welding. In both legs of each link member 2 and 3 there are provided openings 27 to 30 in alignment with one another in which a cross piece 31 and 32, in the embodiment shown, a clamping sleeve is fixed. The ends of the clamping sleeve 31 s 32 lie in the outer faces 33 to 36 of the legs 22, 23 turned away from one another. In the region between the two legs of each link member 2 and 3 there is located on the clamping sleeve 31 and 32 respectively a wear piece 37 and 38 respectively which is formed as a roller and has a recess 39 and 40 respectively corresponding in crosssection to the outer profile of the chain link 4, 5 to be suspended, which recess runs around the whole periphery of the wear piece 37, 38. The chain link 4 and 5 respectively lies with a section thereof projecting in the recess 39, 40 respectively over the whole width of the recess on the base 41 and 42 respectively of the recess. The width of the wear piece 37 and 38 respectively corresponds to the inner spacing of the legs of the two link members 2 and 3 respectively from one another so that the wear piece cannot be pushed along the clamping sleeve 31 and 32 respectively. As the chain links 4 and 5 suspended in the link members 2, 3 lie in the recesses 39 and 40 of the wear pieces 37 and 38 and, in addition, the wear pieces are mounted immovably on the clamping sleeves 31 and 32 the chain links 4 and 5 cannot vary their position in relation to the link members 2 and 3. Thereby the traction force exerted by the chain links always acts approximately in the direction of the longitudinal axis of the tensioning device 1 so that this is loaded uniformly in use. In an advantageous manner it is thereby achieved that the shaft-like guide part 11 in the drawn-out position does not tilt in respect of the housing 10 which can lad to an adverse effect on the tension action of the tensioning device. The link members 2 and 3 are protected against premature wear to a large extent by the wear pieces 37 and 38 respectively. The distance of the tension sleeves 31 and 32 respectively from the free leg ends and the diameters of the wear pieces 37 and 38 respectively are selected such that the suspended chain lins 4 and 5 respectively as shown in Figure 1 are also spaced apart from the closure plate 12 of the housing 10 and from the bridge piece 25 of the connection member 3 so that the mobility of the suspended chain links 3 and 5 is not obstructed. The wear pieces 37 and 38 do not project further beyond the legs 22, 23 of the two link members 2 and 3.

In the embodiment according to Figures 2 to 4 the cylindrical housing 10a is cupshaped. With this construction instead of the closure plate 12 according to Figure 1 the housing 10a is provided with a bottom 12a. The two link members 2a and 3a of the tensioning device la are hook-shaped.

Chain members 4a and Sa of the tyre chain to be suspended lie in the suspension openings 45 and 46 bounded by the hooks 43, 44 of the two link members 2a and 3a. The two link members 2a and 3a are respectively provided with supporting parts 47 and 48 respectively which run perpendicularly to the legs 49 and 50 respectively of the link members 2a and 3a respectively, forming parts of the hooks 43, 44 respectively, and are formed in one piece with these. With these supporting parts 47, 48 two link members 2a and 3a can be fixed simply to the appropriate guide parts 10a and 11a.

The supporting part 47 of the link member 2a is with its flat outer side 51 welded onto the outside of the bottom 12a of the housing 10a. The supporting part 48 of the link member 3a has over about half its length a screw-threaded bore 26a so that the link member in a simple manner can be screwed onto the threaded end section 14a of the likewise shaft-like formed guide part 11a.

For securing the suspended chain links 4a and 5a against unintended dropping out from the suspension openings 45, 46 of the two link members 2a and 3a, securing members 52 and 53 respectively are provided which are fixed in openings 34, 35 respectively in the legs 49, 50 respectively.

The securing members are advantageously clamping pins which are inserted first of all loosely into the openings 54 and 55 respectively and only after the suspension of the chain links 4a and 5a in the link members 2a and 3a are locked into the openings 54 and 55.

The securing members 52, 53 extend perpendicularly to the legs 49 and 50 of the two link members and project as far as the gaps 56 and 57 formed between the free ends of the hooks and the supporting parts 47, 48. As the diameters of the securing members 52, 53 in addition are smaller than the widths of the link members 2a and 3a the securing members are protected securely in operation against damage and wear. The tensioning device according to Figures 2 to 4 is moreover formed similar to the tensioning device according to Figure 1.

In order that the tyre chain may be drawn onto the tyre with the tensioning devices in a simple and rapid manner, the tensioning device may be stretched out before placing onto the tyre chain and secured in this stretched-out position. For this purpose there is provided in the shaft-like guide part tla a passage opening 58 which is arranged approximately midway along the length of the guide part. The distance a of this passage opening 58 from the outer face 59a of the counter bearing 8a is equal to the smallest spring path of one of the two compression spnngs 6a, 7u. The passage opening 58 in the position of the guide part I la shown in Figure 2 lies inside the housing l()a. For placing on the tyre chain the two link members 2a, 3a are pulled away from one another until the passage opening lies outside the housing l()a (Figure 4). Then a bolt may be pushed into the passage open ing 58 so that the link member 3a is secured against displacement. The bolt 60 then lies, under the force of the two compression springs 6a, 7a which are tensioned in the position of the link member 3a shown in Figure 4, on the outer face 59a of the counter bearing 8a. After the securing of the tensioning device in the stretched-out posi tion the tyre chain may be drawn simply and rapidly onto the tyre without traction load ing of the side part. After the drawing on the tyre chain the locking means is released so that the link members of the tensioning device under the force of the two springs 6a, 7a move in the direction towards one another until the side part and thus the tyre chain is tensioned. The bolt 60 may be inserted into the passage opening 58 and subsequently removed from this in a simple manner.

In Figure 3 a further possibility is shown.

Instead of the passage opening 58 the shaft-like guide part 1 la may also have an annular groove 61 as shown in Figure 1 for the guide part 11. This annular groove likewise has a distance from the outer face 59 of the counter bearing 8 which at the most is equal to the smallest spring path of one of the two compression springs 6, 7.

Thereby it is ensured that the annular groove 61 at least with completely tensioned compression springs emerges from the hous ing 10 and 10a respectively so that in this annular groove there may be inserted, for example, a ring 62. Under the force of the two springs this rings then lies likewise on the outer fact 59 and 59a respectively of the counter bearing 8 and 8a respectively of the tensioning device and secures the tensioning device in the stretched-out position. After drawing on of the tyre chain the ring 62 is again released so that the two link members in consequence of the force of the compress ion springs are moved in the direction towards one another until the tyre chain is tensioned.

In the shortest position of the tensioning device the link member 3 and 3a respectivei lies on the outer face 59 and 59a respec- tively of the counter bearing 8 and 8a respectively as shown in Figures 1 and 2. In addiction, the shaft-like guide part lies with its front face on the counter bearing 9 and 9a respectively with the outer face 18 and 18a respectively on the inner face 19 of the closure plate 12 and on the inner face 19a respectively of the housing bottom 12a.

Due to wear of the chain links on their contacting places, the tyre chain becomes widened with lengthy usc. By means of the tensioning device the tyre chain is continually re-tensioned so that always a satisfactory seating of the tyre chain on the tyre can be ensured. Overloading of the tyre chain which for example may be brought about by jerking due to turning of the vehicle wheels, variation of the angle of attack of the vehicle wheels, are obviated as the parts of the tyre chain provided with the resllient tensioning device are stretched elastically and can yield with the loadings. By suitable arrangement of the tensioning device it may also be prevented that the tyre chain lifts off from the tyre due to centrifugal force and thereby becomes damaged. In the tyre chain there may be arranged several tensioning devices each of which may be locked individually upon drawing on of the tyre chain. In accordance with the number of tensioning devices which are unlocked after drawing on of the tyre chain the tensioning of the tyre chain may be determined.

The tensioning device may be arranged on the inside and/or outer side part and/or on a centre chain of a double row chain lying between two tread parts. A tyre chain with two tread parts is provided for twin wheels in which on the two tyres a respective tread part contacts each. With such a tyre chain the tensioning devices may also be arranged next to one another between the two treads on two adjacent lying middle chains or the like, such that adjacent to the two tyre flanks turned towards one another respectively at least one tensioning device lies.

When the whole possible tensioning path of the tensioning devices upon subsequent tensioning of the tyre chain has been utilised, at least one tensioning device may be removed from the tyre chain and replaced by a shorter chain link. Thereby the diameter of the pertinent part of the tyre chain may be reduced so far that the remaining tensioning devices may again be used for subsequent tensioning.

In Figures 5 and 6 one embodiment of a tensioning device is shown which for example may be used on the outer side part of the tyre protection chain. This tensioning device 1b is formed substantially the same as the tensioning device la according to Figures 2 to 4. On the casing of the cylindrical housing 10b which surrounds the two compression springs 6b and 7b as well as the shaft-like guide part 11b there is firmly welded a wear part 63 which runs in the peripheral direction of the housing 10b over an angle region of, for example, about 1050. In the embodiment, the wear part has over its entire width a constant thickness and runs almost over the whole length of the housing 10b. Due to the wear part 63 the housing 10b is to a high degree protected so that the duration of use of the tensioning device ib is substantially prolonged. The tensioning device as arranged on the outer side part of the tyre chain is easily accessible and may therefore be contained without difficulties. The tensioning device 1b may, for example, also be inserted in the middle part of a double tyre chain in order to be able to take up the enormous centrifugal forces additionally to the outer and inner side part of the tyre chain. The wear part according to requirements, may also be designed with other shapes.

The tensioning devices as shown in Figures 1 to 6 consist of simple constructional parts which may be assembled rapidly and simply. Both compression springs in the tensioning device are respectively supported on common counter bearings. The tensioning devices may be locked rapidly and simply in the stretched-out position and after the drawing on of the tyre chain can again be unlocked. The tensioning devices are suitable in particular for tyre protection chains which provide armour-like protection of the tyre against damage due to the road.

Such tyre chains are, for example, used in mining in which the tyres may be damaged easily due to stony ground.

WHAT WE CLAIM IS: 1. A tyre chain having a tread part and side parts which have a tensioning device for the tensioning of the tyre chain in the operating state and which device is linked to members of the tyre chain, the device comprising two link members movable relative to one another against the action of spring means up to a stretched-out position, the link members in the stretched-out position, being held in position relative to each other by a releasable locking means characterised in that, the spring means comprises at least two compression springs which are coextensive.

2. A tyre chain according to claim 1 characterised in that the compression springs are supported on counter bearings which are connected to the link members of the tensioning device, the counter bearings being respectively arranged on the ends of the compression springs of the tensioning device turned away from the pertinent link members.

3. A tyre chain according to claim 2 characterised in that the two link members are connected to the counter bearings by means of a guide part.

4. A tyre chain according to claim 3, characterised in that the compression springs are accommodated in a common housing.

5. A tyre chain according to claim 4, characterised in that the housing forms the guide part of one of the link members which is connected rigidly to the housing.

6. A tyre chain according to claim 4 or claim 5, characterised in that the guide part for the other link member is formed as a shaft and is supported movable on the housing.

7. A tyre chain according to claim 6, characterised in that on the end turned away from the appropriate link member a ring is located on the shaft-like guide part as a counter bearing.

8. A tyre chain according to claim 6 or 7, characterised in that the other link member is arranged on one end of the shaft-like guide part and is preferably screwed on to the end.

9. A tyre chain according to any one of the claims 6 to 8, characterised in that the housing is formed cylindrically and is closed at both ends with closure plates one closure plate of which has an opening for the passage of the shaftlike guide part.

10. A tyre chain according to claim 9, characterised in that a link member is fixed on the outside of one closure plate and that the outer side of the other closure plate forms a stop for the other link member.

11. A tyre chain according to any one of the claims 6 to 10, characterised in that the compression springs are formed as coil compression springs which surround the shaft-like guide part and that one compression spring is surrounded by the other compression spring.

12. A tyre chain according to any one of the claims 1 to 11 characterised in that each link member is forked with two legs projecting freely and running parallel to one another, which legs in the region between their ends, are connected to one another by means of a cross-piece, preferably a clamping sleeve, which is provided as a suspension bridge piece for links of the tyre chain.

13. A tyre chain according to claim 12, characterised in that the cross piece is surrounded by a wear piece preferably a wear roller which has a recess running around adapted in cross-section to the outer profile of the link to be suspended.

14. A tyre chain according to claim 12 or claim 13, when appended to claim 6, characterised in that the legs of the link member connected to the shaft-like guide part are connected to one another at one end by a bridge-piece and that in the bridge piece there is provided a screw-threaded bore for the corresponding end of the shaft-like

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. guide part 11b there is firmly welded a wear part 63 which runs in the peripheral direction of the housing 10b over an angle region of, for example, about 1050. In the embodiment, the wear part has over its entire width a constant thickness and runs almost over the whole length of the housing 10b. Due to the wear part 63 the housing 10b is to a high degree protected so that the duration of use of the tensioning device ib is substantially prolonged. The tensioning device as arranged on the outer side part of the tyre chain is easily accessible and may therefore be contained without difficulties. The tensioning device 1b may, for example, also be inserted in the middle part of a double tyre chain in order to be able to take up the enormous centrifugal forces additionally to the outer and inner side part of the tyre chain. The wear part according to requirements, may also be designed with other shapes. The tensioning devices as shown in Figures 1 to 6 consist of simple constructional parts which may be assembled rapidly and simply. Both compression springs in the tensioning device are respectively supported on common counter bearings. The tensioning devices may be locked rapidly and simply in the stretched-out position and after the drawing on of the tyre chain can again be unlocked. The tensioning devices are suitable in particular for tyre protection chains which provide armour-like protection of the tyre against damage due to the road. Such tyre chains are, for example, used in mining in which the tyres may be damaged easily due to stony ground. WHAT WE CLAIM IS:

1. A tyre chain having a tread part and side parts which have a tensioning device for the tensioning of the tyre chain in the operating state and which device is linked to members of the tyre chain, the device comprising two link members movable relative to one another against the action of spring means up to a stretched-out position, the link members in the stretched-out position, being held in position relative to each other by a releasable locking means characterised in that, the spring means comprises at least two compression springs which are coextensive.

guide part.

15. A tyre chain according to any one of the claims 1 to 11, characterised in that the link members are formed hook-like and that the suspension opening formed by the hooks is blockable by means of a securing member.

16. A tyre chain according to claim 15, characterised in that the securing member is a clamping pin which is to be fixed in an opening in a leg of the link member forming a part of the hook.

17. A tyre chain according to any one of the claims 6 to 11, and 15 or 16, when appended to claim 6, characterised in that the link member has a supporting part connecting at right angles with the legs, in which supporting part the threaded bore for the corresponding end of the shaft-like guide part is provided and that the supporting part lies parallel to the securing member.

18. A tyre chain according to claim 6 or any one of the claims 7 to 17, when appended to claim 6, characterised in that in the region between the ends of the shaft-like guide part there is provided at least one receiving means for a locking bar with which the link members are lockable in at least the stretched-out position.

19. A tyre chain according to claim 18, characterised in that the distance of the receiving means from the outer side of the closure plate having the opening for the shaft-like guide part is at the most equal to the smallest spring path of one of the compression springs.

20. A tyre chain according to claim 18 or 19, characterised in that the receiving means is a passage opening provided in the shaftlike guide part.

21. A tyre chain according to claim 18 or 19, characterised in that the receiving means is an annular groove provided in the shaftlike guide part.

22. A tyre chain according to claim 4 or any one of the claims 5 to 21 when appended to claim 4, characterised in that on the housing there is fixed a wear part which runs over a part of the periphery of the housing, preferably a part subtending an angle of about 105 .

23. A tyre chain according to claim 22, characterised in that the wear part runs approximately over the entire length of the housing.

24. A tyre chain substantially as hereinbefore described with reference to and as illustrated in Figure 1, Figures 2-4, or Figures 5 and 6 of the accompanying draw ings.