FIELD

The invention relates to a rocker assembly for coupling links of a transmission chain, to a transmission chain comprising said rocker assembly, to a transmission comprising said transmission chain, including a continuously variable transmission, to a driveline for mechanical equipment comprising said transmission, and to a vehicle comprising said transmission.

BACKGROUND

EP 2034215 B1 (EP’215) discloses rocker assemblies for coupling links of a transmission chain wherein each rocker assembly, in operation has an inner side which is at an inwardly directed side of the transmission chain and an outer side which is at an outwardly directed side of the transmission chain. Each rocker assembly comprises a first elongated pin extending in a longitudinal direction between two ends and a second elongated pin extending in a longitudinal direction between two ends. The two ends of the first elongated pin are configured to cooperate in a force transmitting way with two opposite cone discs of a pair of pulley sheaves. The first elongated pin has a curved longitudinal surface which, in operation, rolls over an opposite longitudinal surface of the second elongated pin. EP’215 also discloses a transmission chain comprising a plurality of links mutually coupled by said rocker assemblies, wherein each link of the plurality of links comprises a first opening and a second opening, through which openings the rocker assemblies extend.

In the transmission chain disclosed by EP’215 (see Figs. 1-3) the first elongated pin 20 is confined in the first opening 16 of a first hnk 12 and can rock within the confinements of a contour of a second opening of a neighboring second link 12’ through which the rocker assembly 14 extends. The second elongated pin 22 can rock within the confinements of a contour of the first opening 16 of the first link 12 through which the rocker assembly 14 extends and is confined in the second opening of the neighboring second link 12”. Of course, the second opening 18 of the first link 12 confines a second pin 22’of a second rocker assembly 14’. A first pin 20’ of this second rocker assembly 14’ can rock within the confinements of a contour of the second opening 18 of the first link 12. Both contours mentioned above are configured to correspond with the envelope of the path which is described by rolling movement of the first and second elongated pin with respect to each other. The movement of the second pin 22 of the first rocker assembly 14 in the first opening 16 and first pin 20’ of the second rocker assembly 14’ in the second opening 18 is indicated in Fig. 3.

SUMMARY OF THE INVENTION A disadvantage of the transmission chain of EP’215 is that the rocking of the second elongated pin during use of the transmission chain causes friction with its corresponding contour in the link. As a consequence energy is lost and the friction and accompanying wear can ultimately result in a breaking of a link and consequently breaking of its neighboring links and final in a fracture of the transmission chain during high loads.

An object of the invention is to provide a transmission chain which alleviates the above mentioned problems. To that end, the invention provides a rocker assembly for coupling links of a transmission chain according to claim 1. More particular, the invention provides a rocker assembly for coupling links of a transmission chain wherein the rocker assembly, in operation, has an inner side which is at an inwardly directed side of the transmission chain and an outer side which is at outwardly directed side of the transmission chain. The rocker assembly comprises a first elongated pin extending in a longitudinal direction between two ends, and a second elongated pin extending in a longitudinal direction between two ends. The two ends of the first elongated pin are configured to cooperate in a force transmitting way with two opposite cone discs of a pair of pulley sheaves. The first elongated pin has a longitudinal contact surface which, in operation, rolls over an opposite longitudinal surface of the second elongated pin. At least one of the longitudinal contact surface and the opposite longitudinal surface includes a curved portion when viewed in a cross sectional plane, perpendicular to the longitudinal direction. The first elongated pin has a longitudinal protrusion which is positioned at a side of the first elongated pin which is closest to the inner side of the rocker assembly and which is configured to engage and guide the second elongated pin.

Due to this construction, a force transmitting contact between a pin and a link only takes place via contact surfaces between the link and the pin which are stationary relative to each other. The only contact surfaces which move relative to each other and which transmit force upon each other during use are surfaces of the pins of the rocker assembly. In particular, the force transmitting surfaces that move relative to each other are the longitudinal contact surface of the first elongated pin and the opposite longitudinal surface of the second elongate pin as well as a surface of the longitudinal protrusion which is configured to engage and guide the second elongated pin. Consequently, the wear of the link through which the rocker assembly extends is minimized because no friction occurs between the rocker assembly and the link in view of the fact that the contact surfaces between these parts do not move relative to each other. This configuration is also advantageous for the transferal of force from the second elongated pin to the link and from the link to the first elongated pin, and for the distribution of the force within the link. In view of the above, the risk of a chain break is reduced. The invention also provides a transmission chain according to claim 12. More particular, the invention provides a transmission chain which comprises a plurality of links mutually coupled by rocker assemblies according to the invention. Each hnk of the plurality of links comprises at least one opening defining a first retaining contour and a second retaining contour, wherein the rocker assemblies extend through the at least one opening.

The effects and the advantages of the transmission chain according to the invention are the same as the effects and advantages of the rocker assembly according to the invention.

The invention further provides a transmission comprising the transmission chain according to the invention, a driveling for mechanical equipment comprising the transmission according to the invention, and a vehicle comprising the transmission according to the invention. The effects and the advantages of the transmission, the driveline, and the vehicle according to the invention are the same as the effects and advantages of the transmission chain and the rocker assembly according to the invention.

The present invention will be further elucidated with reference to figures of exemplary embodiments. The embodiments may be combined or may be applied separately from each other.

BRIEF DESCRIPTION OF THE FIGURES

Fig. 1 shows a perspective view of a part of a prior art transmission chain.

Fig. 2 shows a side view of a part of a prior art transmission chain in a straight and bent configuration.

Fig. 3 shows a prior art transmission chain hnk with a first rocker assembly and a second rocker assembly.

Fig. 4 shows a side view of an example of a rocker assembly according to the invention. Fig. 5 shows an example of a transmission chain link according to the invention comprising two openings for cooperation with the pins of the rocker assembly of Fig. 4, with the first pin of a first rocker assembly of Fig. 4 in the first opening and the second pin of a second rocker assembly of Fig.

4 in the second opening.

Fig. 6 shows a part of a chain including the rocker assemblies and transmission chain links of Fig. 4 and Fig. 5 in a straight configuration.

Fig. 7 shows a part of a chain including the rocker assemblies and transmission chain links of Fig. 4 and Fig. 5 in a bent configuration.

Fig. 8 shows a side view of another example of a rocker assembly according to the invention.

Fig. 9 shows another example of a transmission chain link according to the invention comprising two openings for cooperation with pins of a rocker assembly according to the invention, with the first pin of a first rocker assembly in the first opening and the second pin of a second rocker assembly in the second opening.

Fig. 10 shows views of a longitudinal side and an end of an example of a second elongated pin according to the invention.

Fig.11 shows another example of a rocker assembly according to the invention.

Fig. 12 shows another example of a transmission chain link according to the invention comprising two openings for cooperation with the rocker assembly of Fig. 11, with the first pin of a first rocker assembly of Fig. 11 in the first opening and the second pin of a second rocker assembly of Fig. 11 in the second opening.

Fig. 13 shows a part of a chain including the rocker assemblies and transmission chain links of Fig. 11 and Fig. 12 in a straight configuration.

Fig. 14 shows a part of a chain including the rocker assemblies and transmission chain links of Fig. 11 and Fig. 12 in a bent configuration. Fig. 15 shows an example of a transmission chain link according to the invention comprising a single opening for cooperation with the rocker assembly of Fig.4, with the first pin of a first rocker assembly of Fig. 4 engaged to the first retaining contour and the second pin of a second rocker assembly of Fig. 4 engaged to the second retaining contour.

Fig. 16 shows an example of a transmission chain link according to the invention comprising a single opening for cooperation with the rocker assembly of Fig.11, with the first pin of a first rocker assembly of Fig. 11 engaged to the first retaining contour and the second pin of a second rocker assembly of Fig. 11 engaged to the second retaining contour.

Fig. 17 shows cross-section view of a transmission according to the invention, comprising two pulley sheaves each comprising two opposite cone discs.

Fig. 18 shows a schematic, partially cut-away view of an example of a transmission chain according to the invention between two cone disks of a pulley sheave

Fig. 19 shows a schematic, partially cut-away view of another example of a transmission chain according to the invention between two cone disks of a pulley sheave.

DETAILED DESCRIPTION OF THE FIGURES

In this application similar or corresponding features are denoted by similar or corresponding reference signs. The description of the various embodiments is not limited to the examples shown in the figures and the reference numbers used in the detailed description and the claims are not intended to limit the description of the embodiments, but are included to elucidate the embodiments by referring to the examples shown in the figures.

In general, the invention relates to a rocker assembly 14 for coupling hnks 12 of a transmission chain 10. The rocker assembly 14, in operation, has an inner side 38 which is at an inwardly directed side 40 of the transmission chain 10 and an outer side 42 which is at an outwardly directed side 44 of the transmission chain 10. The rocker assembly 14 comprises a first elongated pin 20 extending in a longitudinal direction between two ends 46, 48 (see Figs.16- 18), and a second elongated pin 22 extending in a longitudinal direction between two ends. The two ends 46, 48 of the first elongated pin 20 are configured to cooperate in a force transmitting way with two opposite cone discs 58, 60 of a pair of pulley sheaves 54, 56. Examples of the rocker assembly 10 according to the invention are shown in Fig. 4, Fig. 8 and Fig. 11. These figures are side views of the rocker assembly 14, i.e. viewed in the longitudinal direction of the rocker assembly 14. The first elongated pin 20 has a longitudinal contact surface 21 which, in operation, rolls over an opposite longitudinal surface 23 of the second elongated pin 22. At least one of the longitudinal contact surface 21 and the opposite longitudinal surface 23 includes a curved portion when viewed in a cross sectional plane, perpendicular to the longitudinal direction. The first elongated pin 20 has a longitudinal protrusion 24 which is positioned at a side 26 of the first elongated pin 20 which is closest to the inner side 38 of the rocker assembly 14 and which is configured to engage and guide the second elongated pin 22.

Both of the first elongated pin 20 and the second elongated pin 22 preferably have a constant cross section between their respective ends 46,

48, 50, 52. The elongated pins 20, 22 having a constant cross section can be manufactured in long lengths by a rolling process with high precision and relatively low costs. After the rolling process, the required lengths of the elongated pins 20, 22 between their respective ends 46, ,48, 50, 52 can be obtained by standard mechanical machining operations.

Further effects and advantages of rocker assembly 14 have been described in the summary section and these effects and advantages are inserted here by reference. In an embodiment, of which examples are shown in figures 4-9, the first elongated pin 20 further comprises a second longitudinal protrusion 34 which is positioned at a side of the first elongated pin 20 which is closest to the outer side 42 of the rocker assembly 14 and which is configured to engage and guide the second elongated pin 22.

The second longitudinal protrusion 34 has the effect that the second elongated pin 22 engages the first elongated pin 20 at a side which is closest to the outer side 42 of the rocker assembly 14. The second elongated pin 22 does not have a moving contact point with the link 12 in the transmission chain 10 and thus friction and resulting wear between the second pin 22 and the link 12 is prevented.

In an embodiment the first elongated pin 20 is longer than the second elongated pin 22.

As a result of this configuration the two ends 46, 48 of the first elongated pin 20 may engage the two opposite cone disks 58 60, while the two ends 50, 52 of the second elongated pin 18 do not. This enables the pulley sheave 54,56 to transmit force to the transmission chain 10 via the first elongated pin 20 and not via the second elongated pin 22. It also allows the second elongated pin 22 to have play in its longitudinal direction with respect to the first elongated pin 20 when said first elongated pin is engaged in a force transmitting way with the two opposite cone disks 58, 60 of one of the pulley sheaves 54, 56.

In an embodiment of which an example is shown in fig. 10, the second elongated pin 22 comprises grooves 68 configured to retain a hydraulic fluid to lubricate the rocker assembly 14. The hydraulic fluid may comprise oil.

The grooves 68 enable the hydraulic fluid to flow between the longitudinal contact surface 21 and the opposite longitudinal surface 23 and may there form a protective film which may reduce the friction between said surfaces. Furthermore, the hydraulic fluid may also serve as a coolant. An example of such a hydraulic fluid is oil.

In an embodiment the longitudinal contact surface 21 of the first elongated pin 20 includes a curved portion having an involute shape when viewed in the cross sectional plane. Additionally, or alternatively, the opposite longitudinal surface 23 of the second elongated pin 20 includes a curved portion with an involute shape when viewed in the cross sectional plane.

The consequence of the involute shape is that the curvature of each point along the curved portion is not the same. The involute shape may be chosen such that the curvature at an edge of the curved portion nearest the inner side 38 of the rocker assembly 14 is the smallest, whereas the curvature at an edge of the curved portion nearest the outer side 42 of the rocker assembly 14 is the largest. Such an involute shape facilitates the rolling over of the longitudinal contact surface 21 over the opposite longitudinal surface 23 thereby reducing the impact noise of the chain pulley contact.

In an embodiment the surface 21, 23 of the longitudinal contact surface 21 and the opposite longitudinal surface 23 having the curved portion, also comprises a first flat portion when viewed in the cross sectional plane adjacent the curved portion. The other surface 21, 23 of the longitudinal contact surface 21 and the opposite longitudinal surface 23 comprises a first opposite flat portion when viewed in the cross sectional plane which first opposite flat portion is configured to directly oppose the first flat portion. Additionally, the surface 21, 23 of the longitudinal contact surface 21 and the opposite longitudinal surface 23 having the curved portion, may comprise a second flat portion when viewed in the cross sectional plane adjacent the curved portion and opposite of the first flat portion. The other surface 21, 23 of the longitudinal contact surface 21 and the opposite longitudinal surface 23 may comprise a second opposite flat portion when viewed in the cross sectional plane which second opposite flat portion is configured to directly oppose the second flat portion.

The first flat portion and the first opposite flat portion of the longitudinal contact surface 21 and the opposite longitudinal surface 23 may engage and together act as a stop for the rolhng movement of the second elongated pin 22 with respect to the first elongated pin 20. Said stop creates a first extreme position of the rolling movement of the second elongated pin 22 with respect to the first elongated pin 20. Likewise the second flat portion and the second opposite flat portion of the longitudinal contact surface 21 and the opposite longitudinal surface 23 may engage and together act as a stop for the rolling movement of the second elongated pin 22 with respect to the first elongated pin 20. Said stop creates a second extreme position of the rolling movement of the second elongated pin 22 with respect to the first elongated pin 20. The rolling movement of the second elongated pin 22 with respect to the first elongated pin 20 is thus confined within said two extreme positions.

In an embodiment an end surface of each of the two ends 50, 52 of the second elongated pin 22 has a spherical shape, a crowned shape or a straight shape.

The end surfaces of the two ends 52, 52 may be perpendicular or beveled to the longitudinal direction of the second elongated pin 22. When beveled they may e.g. be parallel to a contact surface of the cone disks 58, 60 of one or both of the pulley sheaves 54, 56. An example of a straight shape parallel to a contact surface of the cone disks 58, 60 is shown in Fig. 18.

In an embodiment an end surface of each of the two ends 46, 48 of the first elongated pin 20 has a crowned shape.

The end surfaces of each of the two ends 46, 48 of the first elongated pin 20 are the surfaces which are configured to engage the two opposite cone disks 58, 60 of the pair of pulley sheaves 54, 56. It are these end surfaces which facilitate the cooperation in a force transmitting way. The crowned end surface may be an ellipsoidal crowned surface with a first and a second curvation radius. The first curvation radius may be in a first direction which may be parallel to a radial direction of the to be engaged cone disks 58,60, The second curvation radius may be in a second direction which may parallel to a tangent of the cone disks 58,60 to be engaged. Such a crowned shape having these two curvation radii is very suitable to improve the Hertz contact surface between the first elongated pin 20 and the two to be engaged opposite cone disks 58, 60 of the pair of pulley sheaves 54, 56.

The invention further relates to a transmission chain 10 comprising a plurahty of links 12 mutually coupled by rocker assemblies 14 according to the invention. Each hnk 12 of the plurality of links 12 comprises at least one opening 16, 18 defining a first retaining contour and a second retaining contour. The rocker assemblies 14 extend through the at least one opening 16, 18.

The transmission chain 10 forms an endless transmission chain 10 which is closed in itself. In operation, the transmission chain 10 will be wrapped around the two pulley sheaves 54, 56, transferring a force from a first pulley sheave 54 of the two pulley sheaves 54, 56 to a second pulley sheave 56 of the two pulley sheaves 54, 56. The first pulley sheave 54 forms the prime mover and exerts a force on the ends of one or multiple first elongated pins 20 which are in contact with the cone discs 58, 60 of the first pulley sheave 54. These first elongated pins 20 will exert a force on the second elongated pin 22 of their respective rocker assemblies 14 thereby pushing these second elongated pins 22 forward. These second elongated pins 22 exert a force on the second retaining contour through which they extend, thereby pushing the hnks 12 forward. Because the links 12 are pushed by the second elongated pins 22, the first retaining contours are pushed against the first elongated pin 20 which extends through said first retaining contours. All links 12 may be equal to each other. But this need not be. E.g. a distance of the first retaining contour to the second retaining contour on each link 12 may differ. With different distances between the first retaining contour and the second retaining contour, a pitch of the rocker assemblies in the transmission chain 10 may also differ. By randomly variating this pitch an otherwise monotonous run-in frequency of the rocker assemblies 14 in the pulley sheaves 54, 56 is prevented, resulting is less impact noise.

Further effects and advantages of transmission chain 10 have been described in the summary section and these effects and advantages are inserted here by reference.

In an embodiment, of which examples are shown in figures 5, 9 and 12, the at least one opening 16, 18 comprises a first opening 16 and a second opening 18. The first retaining contour bounds the first opening 16, and the second retaining contour bounds the second opening 18. In an alternative, of which examples are shown in figures 15 and 16, the at least one opening 16, 18 comprises a single opening which is bounded by the first retaining contour and the second retaining contour.

The first retaining contour retains a first rocker assembly 14 and the second retaining contour retains a second rocker assembly 14’. The first and second retaining contours do not necessarily extend all the way around their retained rocker assembly 14, 14’. It may be sufficient to only partially extend around the rocker assemblies 14, 14’ in order to retain them. This means that an intermediate portion of the link 12 in between the first opening 16 and the second opening 18 can be omitted without impeding the functioning of the first and second retaining contours. The at least one opening 16, 18 may thus comprise one or two openings 16, 18.

In an embodiment, of which examples are shown in figures 5, 9, 12, 15, and 16, the first elongated pin 20 is non-rotatable enclosed by the first retaining contour such that, in operation, the first retaining contour prevents the first elongated pin 20 to move with respect to the link 12 in a direction from the inwardly directed side 40 towards the outwardly directed side 44 of the transmission chain 10 and in a longitudinal direction of the transmission chain 10.

The first retaining contour, which is on the left side of the single opening 16, 18, or the first opening 16, forms a form closed engagement with the first elongated pin 20, preventing movement with respect to the link 12. The effect is that the first elongated pin 20 is held in place during operation. This is advantageous for the transferal of force from the link 12 to the first elongated pin 20, and for the distribution of the force within the link 12. Relative movement between the first elongated pin 20, 20’ and the first retaining contour of the link 12, 12’ is prevented, thereby avoiding associated friction which would lead to wear of the link 12, 12’.

In an embodiment, of which examples are shown in figures 5, 9, 12, 15, and 16, the second elongated pin 22 has a profiled contour which is complementary to the second retaining contour such that, in operation, the second retaining contour prevents the second elongated pin 22 to move with respect to the link 12 in a direction from the inwardly directed side 40 towards the outwardly directed side 44 of the transmission chain 10 and in a longitudinal direction of the transmission chain 10. The second elongated pin 22, 22’ may comprise a longitudinal cam 28, 28’, which longitudinal cam 28, 28’ is configured to engage a corresponding recess 30 in a side of the second retaining contour of the link 12. Alternatively, as shown in the example of Figs. 8 and 9, the second elongated pin 22, 22’ may comprise a longitudinal recess 70, 70’, which longitudinal recess is configured to engage a corresponding protrusion 72 on a side of the second retaining contour of the link 12.

Advantageously the longitudinal cam 28, 28’ or recess 70 is placed on an opposite side of the second elongated pin 22, 22’ with respect to the opposite longitudinal surface 23, as is depicted in Fig. 5 and Fig. 11. Again, the effect is that the combination of cam 28 and recess 30 or, alternatively, the combination of recess 70 in the second elongated pin 22 and a protrusion 72 on the link 12 allow the second elongated pin 22 to be held in place with respect to the link 12 during operation. This is advantageous for the transferal of force from the second elongated pin 22 to the link 12, and for the distribution of the force within the link 12. The second pin 22, 22’ is stationary confined in the second opening 18, 18’ of the link 12, 12’ thereby avoiding relative movement and associated friction which would lead to wear of the link 12, 12’.

As another alternative, a side of the second retaining contour adjacent the outer side 42 of the rocker assembly 14 may be provided with a recess 82 (see Fig. 16) which is configured to confine the second elongated pin 22. A similar retaining effect is reached as with combination of the longitudinal cam 28, 28’ on the second elongated pin 22, 22’ and the recess 30 in the side of the second retaining contour of the link 12, and/or the combination of the recess 70 in the second elongated pin 22 and the protrusion 72 on the link 12, i.e. to allow the second elongated pin 22, 22’ to be held in place with respect to the link 12 during operation.

In an embodiment, a side 36 of the first retaining contour adjacent the outer side 42 of the rocker assembly 14 is provided with a recess 32 (see Fig. 12) which is configured to confine the first elongated pin 20 to form a form-closed engagement between the link 12 and the first elongated pin 20.

The effect is that the first elongated pin 20 is held in place during assembly of the chain. Consequently, even during assembling of the chain, i.e. in absence of a chain pulling force in the longitudinal direction of the transmission chain 10, the first elongated pin 20 is kept in place.

In an embodiment, the first elongated pin 20 is prevented from moving in its longitudinal direction through the retaining contours of the links 12 through which the first elongated pin 20 extends by means of a transition fit. Alternatively, as shown in the example of fig. 18, the first elongated pin 20 may be prevented from moving in its longitudinal direction through the first retaining contours of the links 12 through which the first elongated pin 20 extends by means of clips or circlips 64 attachable to both ends 46, 48 of the first elongated pin 20, or holding extensions 66 welded to both ends 46, 48 of the first elongated pin 20, preferably by spot welding. An example of is this shown in figure 18. Though holding extensions 66 are drawn on both the upper and lower side of the first elongated pin 21 only one of these per end 46, 48 is needed. Additionally, the longitudinal protrusion 24 may comprise bended end parts 74, 76 at the ends 46, 48 of the first elongated pin 20 which bended end parts 74, 76 are bent towards the outer side 42 of the rocker assembly 14. An example of this is shown in figure 19. The bended end parts 74, 76 may be configured to engage ends 52, 52 of the second elongated pin 22 such that the engagement of the ends 52, 52 of the second elongated pin 22 with the bended end parts 74, 76 may prevent the second elongated pin 22 from moving in its longitudinal direction through the retaining contours through which the second elongated pin 22 extends. The ends 50, 52 of the second elongated pin 22 may comprise chamfered edges 78, 80 which are configured to engage the bended end parts (74, 76). Alternatively, the second elongated pin 22 may also be prevented from moving in its longitudinal direction through the second retaining contours of the links 12 through which the second elongated pin 22 extends by means of clips or circlips 64 attachable to both ends 50, 52 of the second elongated pin 22, or holding extensions 66 welded to both ends 50, 52 of the second elongated pin 22, preferably by spot welding.

If a force applied to the first or second elongated pin 20, 22 tries to induce a movement in their respective longitudinal directions, the above mentioned holding means will prevent such a movement. The clips or circhps 64 or holding extension 66 attached to the ends 46, 48, 50, 52 of the elongated pins 20, 22 may abut against an outer link 12 preventing any further movement of the elongated pin 20, 22. Of course, the clips or circlips 64 or holding extension 66 may be placed such that a small movement or play in the longitudinal direction is allowed. For the second elongated pin 22 this play may be chosen such that the travel in the longitudinal direction is limited by an abutment against one of the cone disks 58, 60 of the pulley sheaves 54, 56, and not an abutment against the placed clips or circlip 64 or holding extension 66. A obliqueness of the chamfered ends 78, 80 may also be chosen such that a small movement or play in the longitudinal direction is allowed. Such play prevents a statically indeterminate construction within the transmission chain 10. Any of the abovementioned holding means for the first elongated pin 20, 22 may be used in combination with any one for the second elongated pin 22.

The invention further relates to a transmission 62 comprising the transmission chain 10 according to the invention, to a driveline for mechanical equipment comprising the transmission 62 according to the invention, and to a vehicle comprising the transmission 62 according to the invention. The transmission 62 may be embodied as a continuously variable transmission (CVT), as is shown in figure 17.

The effects and advantages of the transmission 62, the drivehne, and the vehicle have been described in the summary section and these effects and advantages are inserted here by reference. In summary, the main advantage is that no friction forces are exerted by the rocker assemblies 14, 14’ on the links 12, 12’ thereby avoiding wear of the links 12, 12’ and reducing the chance of breakage of the chain 10.

The various embodiments which are described above may be used implemented independently from one another and may be combined with one another in various ways. The reference numbers used in the detailed description and the claims do not limit the description of the embodiments nor do they limit the claims. The reference numbers are solely used to clarify. Legend

10 - transmission chain 12 - link 14 - rocker assembly

16 - first opening 18 - second opening

20 - first elongated pin

21 - longitudinal contact surface 22 - second elongated pin

23 - opposite longitudinal surface

24 - longitudinal protrusion

26 - side of the first elongated pin which is closest to the inner side of the rocker assembly 28 - longitudinal cam of the second elongated pin

30 - recess in a side of the second retaining contour

32 - recess in a side of the first retaining contour adjacent the outer side of the rocker assembly

34 - second longitudinal protrusion 36 - side of the first retaining contour adjacent the outer side of the rocker assembly

38 - inner side (of the rocker assembly)

40 - inwardly directed side of the transmission chain 42 - outer side (of the rocker assembly) 44 - outwardly directed side of the transmission chain

46 - first end of the first elongated pin 48 - second end of the first elongated pin 50 - first end of the second elongated pin 52 - second end of the second elongated pin 54 - pulley sheave 56 - pulley sheave 58 - cone disk of pulley sheave 60 - cone disk of pulley sheave 62 - transmission 64 - clip/circlip

66 - holding extension 68 - groove

70 - longitudinal recess (in the second elongated pin) 72 - corresponding protrusion 74 - bended end part (of the longitudinal protrusion)

76 - bended end part (of the longitudinal protrusion) 78 - chamfered end (of the second longitudinal pin) 80 - chamfered end (of the second longitudinal pin) 82 - recess in a side (of the second retaining contour)