CROSS-LINKS FOR A TRACK OF A TRACKED VEHICLE

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 USC 119(e) of U.S. Provisional Patent Application No. 60/980,166 filed by F. Paquet et al. on October 15, 2007 and hereby incorporated by reference herein.

FIELD OF THE INVENTION

The invention relates generally to tracks for tracked vehicles and, more particularly, to cross-links for such tracks.

BACKGROUND

Certain types of tracked vehicles, such as tractors and carriers used in various industrial or military applications, are propelled by a pair of tracks each comprising belts that are interconnected by a series of cross-links distributed longitudinally along the track.

Cross-links are typically made of metal, such as so-called "D-dent" cross-links and "flat track" cross-links which are forged into shape. These cross-links may be suitable when a tracked vehicle on which they are provided is on soft terrain (e.g., earth, mud). However, due to the tracked vehicle's weight, they are often unsuitable and/or unacceptable for use on hard surfaces (e.g., paved surfaces) as they tend to damage such hard surfaces.

Some flat track cross-links have been permanently embedded in a rubber envelope to reduce their impact on hard surfaces. However, in view of the rubber envelope's

permanent presence, these cross-links often prove inadequate in situations or applications where enhanced traction of metallic cross-links is desired or required, such as on very soft terrain.

Other flat track cross-links have been provided with urethane shoes bolted thereon to reduce their impact on hard surfaces. However, urethane is relatively expensive, thus discouraging mass production of such shoes. Furthermore, stones and other small hard objects typically become easily trapped in bolt holes of the urethane shoes such that subsequent use of a tracked vehicle equipped with such cross-links on a hard surface can still inflict damage on that surface. Moreover, urethane has a relatively low friction coefficient which can lead to poor traction capability in some applications.

Accordingly, there is a need for improvements in cross-links for tracks of tracked vehicles.

SUMMARY OF THE INVENTION

According to a first broad aspect, the invention provides a cross-link for a track that comprises belts spaced apart to accommodate a plurality of wheels of a tracked vehicle on which the track is mounted, the belts having a ground-facing side. The cross-link comprises an elongate member for mounting to the belts to interconnect the belts, the elongate member having a belt-engaging face contacting the belts on the ground-facing side when the elongate member is mounted to the belts. The cross-link also comprises a wheel guide comprising a pair of projections spaced apart from one another, the projections extending from the belt-engaging face and opposite the ground-facing side.

The wheel guide is capable of engaging the wheels of the tracked vehicle as the tracked vehicle travels over the track such that, when the wheel guide engages a given one of the wheels, the given one of the wheels is received between the projections.

According to a second broad aspect, the invention provides a cross-link for a track that comprises belts spaced apart to accommodate a plurality of wheels of a tracked vehicle on which the track is mounted, the belts having a ground-facing side. The cross-link comprises an elongate member for mounting to the belts to interconnect the belts, the elongate member having a belt-engaging face contacting the belts on the ground-facing side when the elongate member is mounted to the belts. The elongate member defines a channel including a bottom portion and a pair of sidewalls extending from the bottom portion, each of the sidewalls having a height, measured relative to the belt-engaging face, of at least 30 mm.

According to a third broad aspect, the invention provides a cross-link for a track that comprises belts spaced apart to accommodate a plurality of wheels of a tracked vehicle on which the track is mounted, the belts having a ground-facing side. The cross-link comprises an elongate member for mounting to the belts to interconnect the belts, the elongate member having a belt-engaging face contacting the belts on the ground- facing side when the elongate member is mounted to the belts. The elongate member defines a channel including a bottom portion and a pair of sidewalls extending from the bottom portion. Each of the sidewalls has a height and a thickness, the height being measured relative to the belt-engaging face. Each of the sidewalls has a height-to-thickness ratio of at least 3.0.

According to a fourth broad aspect, the invention provides a cross-link for a track that comprises belts spaced apart to accommodate a plurality of wheels of a tracked vehicle on which the track is mounted, the belts having a ground-facing side for facing a ground surface on which the tracked vehicle travels. The cross-link comprises an elongate member for mounting to the belts to interconnect the belts, the elongate member having a belt-engaging face contacting the belts on the ground-facing side when the elongate member is mounted to the belts. The elongate member defines a channel including a bottom portion and a pair of sidewalls extending from the bottom portion, each of the sidewalls having a terminating edge for engaging the ground surface to form a region of localized pressure on the ground surface.

According to a fifth broad aspect, the invention provides a sole for a cross-link of a track that comprises belts spaced apart to accommodate a plurality of wheels of a tracked vehicle on which the track is mounted. The cross-link comprises an elongate member having a first end and a second end, the elongate member defining a channel including a bottom portion and a pair of sidewalls opposite one another on either side of the bottom portion. The sole is mountable in the channel and comprises a pair of sidewall-engaging surfaces for engaging the sidewalls when the sole is mounted in the channel, the sidewall- engaging surfaces being generally parallel to one another.

According to a sixth broad aspect, the invention provides a sole for a cross-link of a track that comprises belts spaced apart to accommodate a plurality of wheels of a tracked vehicle on which the track is mounted. The cross-link comprises an elongate member for mounting to the belts to interconnect the belts, the elongate member defining a channel including a bottom portion and a pair of sidewalls opposite one another on either side of the bottom portion. The sole comprises a base portion for mounting in the channel of the elongate member and a ground-engaging portion comprising elastomeric material for engaging a ground surface on which the tracked vehicle moves.

According to a seventh broad aspect, the invention provides a sole for a cross-link of a track that comprises belts spaced apart to accommodate a plurality of wheels of a tracked vehicle on which the track is mounted. The cross-link comprises an elongate member for mounting to the belts to interconnect the belts. The sole comprises: an inner side for facing the elongate member to mount the sole to the elongate member; an outer side opposite the inner side for engaging a ground surface on which the tracked vehicle moves; and a plurality of blind holes extending from the inner side without reaching the outer side, the sole being mountable to the elongate member via a plurality of fasteners received in the blind holes.

According to an eighth broad aspect, the invention provides a cross-link for a track that comprises belts spaced apart to accommodate a plurality of wheels of a tracked vehicle

on which the track is mounted, the belts having a ground-facing side. The cross-link comprises an elongate member for mounting to the belts to interconnect the belts, the elongate member having a belt-engaging face contacting the belts on the ground-facing side when the elongate member is mounted to the belts. The elongate member defines a channel including a bottom portion and a pair of sidewalls opposite one another on either side of the bottom portion. The cross-link also comprises a sole mountable in the channel for engaging a ground surface on which the tracked vehicle travels, the sole comprising a pair of sidewall-engaging surfaces for engaging the sidewalls when the sole is mounted in the channel.

These and other aspects of the invention will now become apparent to those of ordinary skill in the art upon review of the following description of embodiments of the invention in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A detailed description of embodiments of the invention is provided below, by way of example only, with reference to the accompanying drawings, in which:

Figures IA and IB respectively show a side view and a front view of an example of a tracked vehicle comprising a pair of tracks each comprising a plurality of cross-links in accordance with an embodiment of the invention;

Figure 2 shows one of the tracks arranged in an endless path around a plurality of wheels of the tracked vehicle;

Figures 3 and 4 show different perspective views of one of the cross-links;

Figures 5 and 6 respectively show a front view and a side view of the cross-link shown in Figures 3 and 4;

Figures 7 and 8 show different perspective views of an elongate member of the cross-link shown in Figures 3 and 4;

Figures 9 to 12 respectively show a front view, a top view, a bottom view and a side view of the elongate member shown in Figures 7 and 8;

Figures 13 and 14 show different perspective views of a sole of the cross-link shown in Figures 3 and 4;

Figures 15 to 18 respectively show a front view, a top view, a bottom view and a side view of the sole shown in Figures 13 and 14; and

Figure 19 shows a front cross-sectional view of the sole shown in Figures 13 and 14.

It is to be expressly understood that the description and drawings are only for the purpose of illustrating certain embodiments of the invention and are an aid for understanding. They are not intended to be a definition of the limits of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

Figures IA and IB show a tracked vehicle 10 comprising a pair of tracks 12 _1; 12 ₂ in accordance with an embodiment of the invention. The tracked vehicle 10 comprises a prime mover (e.g., an internal combustion engine) in a driving relationship with a pair of drive wheels 18 _1? 18 ₂ (in this case, sprockets) each driving a respective one of the tracks 12i, 12 ₂ to propel the tracked vehicle 10 on a ground surface. As it is driven by the respective one of the drive wheels 18 _l5 18 ₂ , each of the tracks 12 _1; 12 ₂ moves in an endless path around that drive wheel as well as a respective one of a pair of idler wheels 19i, 19 ₂ (in this case, sprockets) and a respective one of two sets of support wheels 2Ij _-1 -

2Ij _-4 , 21 _2-1 -2l2- ₄ of the tracked vehicle 10. The tracked vehicle 10 can be used in various industrial, military and/or other applications over various types of terrain.

As shown in Figure 2, in this embodiment, each track 12 _j (j = 1 or 2) comprises a pair of belts 2O ₁ , 2O ₂ spaced apart from one another to accommodate the drive wheel 18 _j , the idler wheel 19 _j and the support wheels 21^-2I _j-4 of the tracked vehicle 10. hi addition, the track 12j comprises a series of cross-links M ₁ -H _N distributed longitudinally along the track 12 _j and extending transversally to interconnect the belts 2O ₁ , 2O ₂ .

Each of the belts 2O ₁ , 2O ₂ has an inner side 24 facing the wheels 18 _j , 19 _j , 21^-2I _j-4 and defining an inner area 15 of the track 12 _j in which these wheels are located. Each of the belts 201, 2O ₂ also has an outer, ground- facing side 25 opposite the inner side 24 and facing the ground surface on which the tracked vehicle 10 travels, hi this embodiment, each of the belts 2O ₁ , 2O ₂ comprises a continuous length of rubber closed to form the belt. In other embodiments, the belts 2O ₁ , 2O ₂ may have various other constructions. For example, each of the belts 2O ₁ , 2O ₂ may comprise a plurality of parts (e.g., rubber and/or metallic sections) interconnected to one another to form the belt. Also, while in this embodiment the track 12 _j comprises the two belts 2O ₁ , 2O ₂ , in other embodiments, the track 12j may comprise three or more such belts.

The cross-links H ₁ -H _N interconnect the belts 2O ₁ , 2O ₂ and interact with the wheels 18 _j , 19 _j , 21j-i-21j_4 as the track 12 _j moves in the endless path around these wheels, hi particular, the cross-links H ₁ -H _N interact with the drive wheel 18 _j to cause the track 12 _j to be driven by the drive wheel 18 _j . More specifically, in this case, as the drive wheel 18 _j rotates, individual ones of the cross-links H ₁ -H _N engage recesses in the drive wheel 18, which causes the track 12 _j to be driven in the endless path around the wheels 18 _j , 19,-, 2I _j- 1-2I ₎ A- In addition, as the track 12j moves around the endless path, individual ones of the cross-links H ₁ -H _N located on a lower run of the track 12 _j engage the ground surface and thus contribute to traction of the tracked vehicle 10 on the ground surface.

With additional reference to Figures 3 to 19, in this embodiment, each cross-link 14j (1 < i ≤ N) comprises an elongate member 30, a sole 40, and a pair of backing parts 50i, 5O ₂ . As further discussed below, the sole 40 can be used when the tracked vehicle 10 is to travel on a hard surface (e.g., a paved surface) in order to minimize an impact of the cross-link 14{ on that surface. When the tracked vehicle 10 is to travel on a soft surface (e.g., mud, earth), the sole 40 can be removed to allow the elongate member 30 to provide enhanced traction on that surface.

The elongate member 30 is configured to be mounted to the belts 2O ₁ , 2O ₂ to interconnect the belts 20i, 2O ₂ . In addition, the elongate member 30 also serves to transmit forces resulting from rotational motion of the drive wheel 18 _j to the track 12 _j in order to cause motion of the track 12 _j .

More particularly, the elongate member 30 comprises a first end 3I ₁ , a second end 3I ₂ and a central portion 32 therebetween. The central portion 32 of the elongate member 30 comes into contact with and engages the drive wheel 18 _j , which applies force to the cross-link 14; and causes motion of the track 12 _j in the same general direction as the rotational direction of the drive wheel 18i-

The elongate member 30 comprises a belt-engaging face 33 that is in contact with the ground-facing side 25 of the belts 2O ₁ , 2O ₂ , when the elongate member 30 is mounted to the belts 2O ₁ , 2O ₂ . In this embodiment, the belt-engaging face 33 is mainly flat, which may allow the weight of the tracked vehicle 10 to be distributed across the entire elongate member 30, providing the tracked vehicle 10 with a generally low ground pressure that may prove advantageous on certain ground surfaces.

The elongate member 30 also comprises a bottom portion 34 and a pair of sidewalls 3O ₁ , 36 ₂ that lie opposite to one another on either side of the bottom portion 34 to create a channel 35. As further discussed later on, the channel 35 helps to receive and retain the sole 40 when the sole 40 is used as part of the cross-link 14j.

The bottom portion 34 comprises a sole-engaging surface 37 that extends from the first end 3I ₁ to the second end 3I ₂ of the elongate member 30 and that is in contact with the sole 40 when the sole 40 is used as part of the cross- link 14j. In this case, the sole- engaging surface 37 is generally flat such that, as the sole 40 contacts the sole-engaging surface 37 when mounted in the channel 35, there is a planar interface (i.e., contact points lying in a common plane) between the sole 40 and the bottom portion 34 from the first end 3I ₁ to the second end 3I ₂ of the elongate member 30, which may allow a more uniform distribution of forces when the tracked vehicle 10 travels.

A plurality of holes 73i-73 ₆ pass through the bottom portion 34 to receive fasteners that allow mounting of the elongate member 30 to the belts 2O ₁ , 2O ₂ . More particularly, in this embodiment, the holes 73i-73 ₆ are divided equally between two (2) sets. Each set is located in one lateral portion of the elongate member 30, so that a first set with the holes 73]-73 ₃ is located in a first lateral portion proximate the first end 3I ₁ , while a second set with the holes 73 ₄ -73 ₆ is located in a second lateral portion proximate the second end 31 ₂ . In other embodiments, the elongate member 30 may have a different number of holes and/or a different arrangement of such holes.

The sidewalls 36 _1? 36 ₂ are configured to, on the one hand, enhance retention of the sole 40 when it is used as part of the cross-link 14i and, on the other hand, enhance a traction effect of the elongate member 30 in the ground surface on which the tracked vehicle 10 travels when the sole 40 is not used. Each of the sidewalls 3O ₁ , 36 ₂ extends from the bottom portion 34 to a terminating edge 39.

More particularly, in this embodiment, the sidewalls 36i, 36 ₂ are configured such that the channel 35 has a substantially constant width W _c from the first end 3I ₁ to the second end 3I ₂ (while in practice there may be some slight variation in the width W _c of the channel 35 due to manufacturing of the elongate member 30, the width W _c is substantially constant in that it does not change from a macroscopic point of view). Specifically, in this case, the sidewalls 36 _ls 36 ₂ have inner surfaces that are generally parallel to one another such that the width W _c of the channel 35 is substantially constant. Maintaining this

substantially constant width W _c throughout the channel 35 along its entire length allows the elongate member 30 to be sturdier, facilitates its manufacturing, and provides a better interface with and retention of the sole 40 within the channel 35 when the sole 40 is used as part of the cross-link 14;.

Each of the sidewalls 36], 36 ₂ has a height H (measured from the belt-engaging face 33 to its terminating edge 39) providing the channel 35 with an internal height that enhances retention of the sole 40 therein when the sole 40 is mounted therein. The height H of each of the sidewalls 36 _1; 36 ₂ also allows that sidewall to act as an aggressive traction element on the ground surface on which the tracked vehicle 10 travels, when the sole 40 is not used as part of the cross-link 14i. For example, in some embodiments, the height H of each of the sidewalls 3O ₁ , 36 ₂ may be of at least 30 mm, and in some cases 35 mm or more, to provide such desired enhanced retention of the sole 40 when it is used and aggressive traction effect when the sole 40 is not used. The height H may take on various other values in other embodiments.

In addition to the height H of the sidewalls 3O ₁ , 36 ₂ , when the sole 40 is not used as part of the cross-link 14;, the terminating edge 39 of each sidewall engages the ground surface on which the tracked vehicle 10 travels to form a region of localized pressure on the ground surface which enhances traction of the tracked vehicle 10.

Also, in this case, the height H of the sidewalls 36 _ls 36 ₂ is such that, when the sole 40 is not used as part of the cross-link 14i, any fasteners that are used to secure the elongate member 30 to the belts 20i, 2O ₂ remain recessed within the channel 35, i.e., do not extend higher than the sidewalls 36 _l5 36 ₂ . Since repeated contact between any part of a fastener that extended outside of the channel 35 and a hard ground surface (e.g., a paved road or sidewalk) could cause impact on the ground surface, the height H of the sidewalls 3O ₁ , 36 ₂ helps reduce potential damage from the cross-link 14j on such a surface. Moreover, such contact between any part of a fastener outside of the channel 35 and a hard ground surface could also cause unnecessary wear to and decrease operational life of such

fasteners, and thus the height H of the sidewalls 36i, 36 ₂ also helps to extend the operational life of the fasteners when the sole 40 is not used as part of the cross-link 14;.

In this embodiment, the sidewalls 3O ₁ , 36 ₂ decrease in height proximate the first end 3I ₁ and the second end 3I ₂ of the elongate member 30. That is, each of the sidewalls 3O ₁ , 36 ₂ has a first tapering end portion leading to the first end 3I ₁ and a second tapering end portion leading to the second end 3I ₂ . These tapering end portions can facilitate turning of the cross-link 14{ when the tracked vehicle 10 and the track 12 _j turn. Thus, in this and other embodiments where the sidewalls 3O ₁ , 36 ₂ vary in height along their length, the height H of each of the sidewalls 36 _ls 36 ₂ can be taken as a maximum height of that sidewall along its length. Also, although in this embodiment both of the sidewalls 36 _l5 36 ₂ have the same height H, in some embodiments, the sidewalls 3O ₁ , 36 ₂ may have different heights H.

Each of the sidewalls 3O ₁ , 36 ₂ also has a thickness T (taken as its average thickness along its height H) which provides sufficient strength and rigidity to that sidewall to allow it properly retain the sole 40 when the sole 40 is mounted in the channel 35 and to allow it to withstand forces exerted thereon while acting as a traction element when the sole 40 is not used as part of the cross-link 14{. For example, in some embodiments, the thickness T of each of the sidewalls 3O ₁ , 36 ₂ may be of 7.5 mm, and in some cases of at least 9.5 mm, to provide such desired enhanced retention of the sole 40 when it is used and aggressive traction effect when the sole 40 is not used. The thickness T may take on various other values in other embodiments. Also, while in this embodiment both of the sidewalls 36 _1? 36 ₂ have the same thickness T, in other embodiments, the sidewalls 36 _l3 36 ₂ may have different thicknesses T.

The height H and the thickness T of each of the sidewalls 3O ₁ , 36 ₂ can thus be selected to allow the sidewalls 36 _1? 36 ₂ to both enhance retention of the sole 40 when it is used as part of the cross-link 14i and act as an aggressive traction element when the sole 40 is not used as part of the cross-link 14i. For example, each of the sidewalls 36 _1; 36 ₂ may have a height-to-thickness ratio H/T of at least 3.0, and in some cases 3.5 or more, to provide

such desired enhanced retention of the sole 40 when it is used and aggressive traction effect when the sole 40 is not used, while maintaining sufficient strength and rigidity.

In this embodiment, the elongate member 30, including the bottom portion 34 and the sidewalls 3O ₁ , 36 ₂ , is created by stamping, in this case bending, a single piece of material to form the elongate member 30. More particularly, in this embodiment, the single piece of material is a flat piece of metal, in this case high-strength steel, which is bent into shape. Various bending techniques, involving plastic deformation of the single piece of metal about a linear axis with little or no change in its surface area, are well known can be used for this process. These bending techniques can facilitate manufacturing of the elongate member 30 and allow proper formation of the sidewalls 36 _1? 36 ₂ with a height- to-thickness H/T ratio as described above.

While in this embodiment the elongate member 30 comprises a single metallic component that is formed and shaped through a stamping process, in other embodiments, the elongate member 30 may be produced using various other processes and may comprise a plurality of components that are interconnected to one another, such as through welding, and that are made of the same material or different material. For example, in some embodiments, the sidewalls 36 _l5 36 ₂ and the bottom portion 34 may each be produced separately and then welded together to form the elongate member 30.

With continued reference to Figures IA to 19, in this embodiment, the cross-link 14; comprises a wheel guide 60 to engage individual ones of the wheels 18,-, 19 _j , 21^-2I _j-4 as the track 12 _j moves in the endless path around these wheels. The wheel guide 60 comprises a pair of projections 62 \, 62 ₂ that are spaced apart from one another and that extend from the belt-engaging face 33 and opposite the ground-facing side 25, i.e., from the belt-engaging face 33 towards the inner area 15 of the track 12 _j .

As the track 12 _j moves along its endless path, each of the wheels 18 _j , 19 _j , 21^-2I _j-4 passes through the wheel guide 60, and in particular, between the projections 62 _l9 62 ₂ that are located on either side of these wheels. The projections 62 _l9 62 ₂ can interact with the

wheels 18 _j , 19j, 21 _j .i-21 _j _ ₄ to keep the cross-link 14i centered by opposing any lateral movement outside of a space between these projections. As a result, the projections 62 _1? 62 ₂ help to laterally guide the track 12 _j as it moves along its endless path.

hi this embodiment, when viewed from a front or rear of the elongate member 30, each of the projections 62 _1; 62 ₂ has a triangular shape, in this case resembling a right-angle triangle, with a wheel-facing face 63 that faces individual ones of the wheels 18j, 19 _j , 2Ij- _! -2I _j-4 as the track 12 _j moves along its endless path. The wheel-facing face 63 of each of the projections 62 _\ , 62 ₂ lies at an obtuse angle relative to the belt-engaging face 33, which can help center the elongate member 30 (and therefore the cross-link 14;) as it comes into contact with any of the wheels 18 _j , 19 _j , 2 l _j -i-21 j- ₄ - More specifically, any lateral motion of the elongate member 30 towards outside of the space between the projections 62 _1; 62 ₂ will be counteracted when the wheel-facing face 63 of one of the projections 62 ₁₅ 62 ₂ comes into contact with one of the wheels 18 _j , 19 _j , 2I _j-1 ^I _j-4 , thus guiding the elongate member 30 back towards a center region of the space between the projections 62 _\ , 62 ₂ . Through these components, the track 12j can thus remain laterally centered between the projections 62 _1? 62 ₂ and so remain on its endless path.

While in this embodiment the projections 62 _ls 62 ₂ are configured as right-angled triangles, in other embodiments, the projections 62 _1? 62 ₂ may have various other shapes. For example, in some embodiments, the projections 62 _l5 62 ₂ may be configured as non- right-angled triangles (e.g., isosceles or equilateral triangles). Also, in some embodiments, the wheel-facing face 63 may define an arc that approximates a profile of the wheels 18,-, 19,-, 21 _j .i-21 _H .

In this embodiment, the projections 62 _l9 62 ₂ are made of metallic material, in this case 4140 high-strength steel, and are secured to the elongate member 30 by welding them to the belt-engaging face 33. In other embodiments, the projections 62 _l5 62 ₂ may be made of various other materials and/or may be secured to the elongate member 30 in various other ways, such as via nut and bolt fasteners. In yet other embodiments, the projections 62^ 62 ₂ may be integrally formed with the elongate member 30.

With continued reference to Figures IA to 19, the sole 40 can be mounted to the elongate member 30 when the tracked vehicle 10 is to travel on a hard surface (e.g., a paved surface) in order to minimize an impact of the cross-link 14; on that surface. More particularly, the sole 40 comprises an inner side 42 for facing the elongate member 30 to mount the sole 40 to the elongate member 30 and an outer side 44 opposite the inner side 42 for engaging the ground surface on which the tracked vehicle 10 moves. In this embodiment, the sole 40 is mounted to the elongate member 30 via a plurality of fasteners 41 _! -4I ₆ extending from the inner side 42 to the elongate member 30.

The sole 40 comprises a base portion 46 that is mountable within the channel 35 of the elongate member 30 and a ground-engaging portion 48 for engaging the ground surface on which the tracked vehicle 10 travels. In this case, certain sections of the ground- engaging portion 48 (e.g., extremities corresponding to the first end 3I ₁ and the second end 3I ₂ of the elongate member 30) may not always engage the ground surface, but may rather only come into contact with the ground surface in situations where the tracked vehicle 10 is resting on an incline and/or a soft surface (such as mud) where the elongate member 30 and/or the sole 40 are partially submerged.

More particularly, in this embodiment, the base portion 46 of the sole 40 comprises a pair of sidewall-engaging surfaces 47 _ls 47 ₂ for engaging the sidewalls 36 _l5 36 ₂ of the elongate member 30 when the sole 40 is mounted in the channel 35. Thus, in this case, the sidewall-engaging surfaces 47i, 47 ₂ are generally parallel to one another and separated by a distance corresponding to the substantially constant width W ₀ of the channel 35 to allow the base portion 46 of the sole 40 to fit within the channel 35. When the base portion 46 is mounted within the channel 35, the sidewall-engaging surfaces 47 _\ , Al ₂ contact the sidewalls 36 _l5 36 ₂ (and in this case the sole-engaging surface 37) of the elongate member 30, which helps retains the sole 40 in the channel 35 when the crosslink 14; is subjected to forces as the tracked vehicle 10 moves on the ground surface.

Also, in this embodiment, the ground-engaging portion 48 comprises elastomeric material for engaging the ground surface on which the tracked vehicle 10 moves. More specifically, in this embodiment, the elastomeric material of the ground-engaging portion 48 is rubber, which can be any natural, synthetic, or modified high polymer with elastic properties, such as acrylate rubber, acrylic rubber, acrylonitrile rubber, acrylonitrile- butadiene rubber or butadiene rubber. In other embodiments, any other suitable elastomeric material may be used.

When the ground surface is hard (e.g., a paved road), the rubber of the ground-engaging portion 48 helps minimize effects of the cross-link 14i as it comes into repeated contact with the hard ground surface, while providing traction for the tracked vehicle 10 to travel along such a surface. In fact, the rubber of the ground-engaging portion 48 enhances traction of the sole 40 by "gripping" the ground surface on which the tracked vehicle 10 travels, in particular when the ground surface includes one or more inclined surfaces that may need to be traversed, such as steep paths that run up hills or down gullies.

In this case, the ground-engaging portion 48 comprises a tread pattern 71 which may assist in improving traction of the tracked vehicle 10 on a variety of ground surfaces. The tread pattern 71 may also allow channeling of water or other liquids away from that section of the ground-engaging portion 48 that is in contact with a wet ground surface, which may improve handling of the tracked vehicle 10 under wet or adverse weather conditions. Also, the tread pattern 71 is configured such that it lacks spaces in which rocks or other hard objects could become trapped in when it contacts the ground surface.

For its part, in this embodiment, the base portion 46 of the sole 40 is also made of the same elastomeric material (in this case, rubber) as that of the ground-engaging portion 48. In fact, in this embodiment, the base portion 46 and ground-engaging portion 48 of the sole 40 constitute a single rubber component. The rubber of the base portion 46 helps in retaining the sole 40 in the channel 35.

In other embodiments, the base portion 46 may be a component distinct from but connected to the ground-engaging portion 48 and may be made of a material different than that of the ground-engaging portion 48. For example, the base portion 46 may contain a rigid material, such as ultra-high molecular weight (UHMW) plastic or another rigid plastic, while the ground-engaging portion 48 may contain the elastomeric material and be secured to the base portion 46 through one or more fasteners (e.g., screws or nuts/bolts) or some bonding technique (e.g., glue or epoxy).

When the sole 40 is used as part of the cross-link 14;, it is mounted to the elongate member 30 via the fasteners 41 ^4I ₆ that extend from its inner side 42. In this embodiment, the fasteners 41i-41 ₆ are integrated with the sole 40. More particularly, in this case, the sole 40 comprises a frame member 49 which acts as an armature on which the rubber of the sole 40 is supported. The frame member 49, which may be made of any suitable rigid material (e.g., steel), also supports the fasteners 41 _! -4I ₆ , which, for instance, can be threaded into or welded to the frame member 49.

The frame member 49, which may be made of any suitable rigid material (e.g., steel), supports the fasteners 41 i-41 ₆ . For example, the fasteners 4I ₁ ^l ₆ may be attached to the frame member 49 by screwing one of their ends into the frame member 49 or by welding one of their ends directly to the frame member 49. Alternatively, the fasteners 41 r41 ₆ may be integrally formed with the frame member 49. In any event, the fasteners 41 _! -4I ₆ and the frame member 49 are combined in a way that allows their integration with other components of the sole 40.

The fasteners 41!-4I ₆ are arranged on the frame member 49 in such a way that each fastener may be aligned with one of the holes 73i-73 ₆ of the elongate member 30. More particularly, in this case, the fasteners 411-4I ₆ are divided equally between two (2) sets that are located in respective lateral portions of the sole 40 to match the two (2) sets of holes 73i-733 and 73 ₄ -73 ₆ of the elongate member 30. In this way, the fasteners 41 _! -4I ₆ may be used to mount the sole 40 to the elongate member 30 and thus mount the crosslink 14i to the belts 2O ₁ , 2O ₂ .

In this embodiment, the rubber used to form the base portion 46 and the ground-engaging portion 48 of the sole 40 is molded around the frame member 49 and the fasteners 4I ₁ - 4I ₆ . In addition to facilitating manufacturing of the sole 40, this integration of the frame member 49 and the fasteners 41 _! -4I ₆ with a remainder of the sole 40 (i.e.., the base portion 46 and the ground-engaging portion 48) help simplify and speed up mounting and dismounting of the sole 40 to and from the elongate member 30..

Also, in this embodiment, the outer side 44 of the sole 40 lacks holes through which the fasteners 41 _! -4I ₆ are exposed when the sole 40 is mounted to the elongate member 30. This lack of holes on the outer side 44 of the sole 40 prevents rocks and other objects from being trapped in the outer side 44 of the sole 40, which could otherwise contribute to damaging a hard ground surface (e.g., a paved road) on which the tracked vehicle 10 travels under the vehicle's weight.

More specifically, in this case, since a first end of each of the fasteners 41 _! -4I ₆ is attached to the frame member 49, around which the rubber of the sole 40 is molded, only a second end of each fastener is exposed. In other words, the sole 40 can be viewed as defining a plurality of blind holes that extend from the inner side 42 without reaching the outer side 44, in which are received the fasteners 41 r41 ₆ . As a result, when the sole 40 is mounted to the elongate member 30, the outer side 44 of the sole 40 lacks holes through which the first end of the fasteners 41i-41 ₆ would otherwise be exposed. This seamless nature of the outer side 44 prevents rocks and other small objects from becoming trapped within such holes and also protects the fasteners 41 _! -4I ₆ from damage from such debris, which may extend their operational life.

While in this embodiment the fasteners 41i-41 ₆ are integrated with the sole 40, in other embodiments, separate fasteners may be used to mount the sole 40 to the elongate member 30 (e.g., by screwing them into the base portion 46 of the sole 40 from its inner side 24). Also, when the sole 40 is not used as part of the cross-link 14i, the elongate

member 30 may be mounted to the belts 20i, 2O ₂ via separate fasteners or a frame member similar to the frame member 49 supporting a plurality of fasteners.

With continued reference to Figures IA to 19, the backing parts 5O ₁ , 5O ₂ are configured to be mounted to the belts 2O ₁ , 2O ₂ to assist the elongate member 30 in interconnecting the belts 2O ₁ , 2O ₂ . Each of the backing parts 5O ₁ , 5O ₂ has a belt-engaging face 51 that contacts a respective one of the belts 2O ₁ , 2O ₂ on its inner side 24 when the backing part is mounted to that belt. Thus, when the cross-link 14 _j is mounted to the belts 2O ₁ , 2O ₂ , the belts 2O ₁ , 2O ₂ are sandwiched between the belt-engaging face 33 of the elongate member 30 and the belt-engaging face 51 of each of backing parts 5O ₁ , 5O ₂ .

In this embodiment, the backing parts 5O ₁ , 5O ₂ are metallic plates that may be formed from any suitably rigid metallic material, such as steel. Each of the parts 5O ₁ , 5O ₂ is pierced with a plurality of holes 8O ₁ -SO ₃ to receive fasteners, such as the fasteners 41]-41 ₆ of the sole 40 or separate fasteners when the sole 40 is not used. In this way, the backing parts 5O ₁ , 5O ₂ may be used to interconnect the elongate member 30 (and the sole 40, when used) to the belts 2O ₁ , 2O ₂ .

It will thus be appreciated that the cross-link 14 _f (and other ones of the cross-links H ₁ - 14 _N ) can conveniently be mounted to the belts 2O ₁ , 2O ₂ to interconnect them. A portion of each of the belts 2O ₁ , 2O ₂ is designed to lie between the belt-engaging face 33 of the elongate member 30 on one side (i.e., the ground-facing side 25) and the belt-engaging face 51 of one of the backing parts 5O ₁ , 5O ₂ on the other side (i.e., the inner side 24).

Holes in the belts 2O ₁ , 2O ₂ allow alignment of the holes 73i-73 ₆ of the elongate member 30 and the holes 8O ₁ -SO ₃ of the backing parts 5O ₁ , 5O ₂ that sandwich the belts. When suitably aligned, a fastener (e.g., 4I ₁ ) inserted through one of the holes 73^73 ₆ of the elongate member 30 emerges through the belt-engaging face 33, passes through the corresponding hole in the belt (2O ₁ or 2O ₂ ), and then emerges through the corresponding hole (e.g., 8O ₁ ) in the belt-engaging face 51.

When the holes 73i-73 ₆ of the elongate member 30 are so aligned with the holes in the belts 2O ₁ , 2O ₂ , the elongate member 30 lies transversely across the ground-facing side 25 of each of the belts. Each of the backing parts 5O ₁ , 5O ₂ lies transversely across the inner side 24 of one of the belts 2O ₁ , 2O ₂ . In this configuration, the elongate member 30 and the backing parts 5O ₁ , 5O ₂ are appropriately aligned with the belts 2O ₁ , 2O ₂ . The fasteners 4I ₁ - 4I ₆ are used to attach these components together and thus form the cross-link 14; with the sole 40 mounted thereon.

The base portion 46 of the sole 40 fits within the channel 35 of the elongate member 30 to allow mounting of the sole 40 to the elongate member 30. Thus, when the sole 40 is mounted to the member 30: the sidewall-engaging surfaces 47 _1; 47 ₂ of the sole 40 engage the sidewalls 3O ₁ , 36 ₂ of the elongate member 30; the inner side 42 of the sole 40 comes into contact with the flat sole-engaging surface 37 of the elongate member 30; and each of the fasteners 41 r41g attached to the frame member 49 enclosed within the sole 40 may penetrate its corresponding one of the holes 73i-73 ₆ of the elongate member 30.

In particular, when the sole 40 is mounted, the exposed end of each of the fasteners 4I ₁ - 4I ₆ passes through a corresponding one of the holes 73i-73 ₆ of the elongate member 30, then passes through one or the holes of the belts 2O ₁ , 2O ₂ and finally passes through a corresponding one of the holes 8O ₁ -SO ₃ in one of the backing parts 5O ₁ , 5O ₂ . Tightening the fasteners 41i-41 ₆ (e.g., through the use of a threaded nut) to a suitable amount sandwiches the belts 2O ₁ , 2O ₂ between the backing parts 5O ₁ , 5O ₂ and the elongate member 30 to which the sole 40 is mounted, thereby securing the cross-link 14; to the belts 2O ₁ , 2O ₂ .

While this example included the sole 40 as part of the cross-link 14;, there may be some situations where the sole 40 may be purposely excluded. For example, the sole 40 may be excluded from the cross-link 14; in a situation where enhanced traction is required, such as when the tracked vehicle 10 must traverse a very soft ground surface, such as travelling through sand or mud.

In such situations, the sole 40 may be removed from the cross-link 14i (or not mounted thereon to begin with) to provide the enhanced traction needed to move across such surfaces. To remove the sole 40, the fasteners 41^4I ₆ that are integrated with the sole 40 (via the frame member 49) are first loosened to the point where they allow movement, such as by loosing and/or removing a nut from each fastener.

With the fasteners 41 _! -4I ₆ having been loosened, the sole 40 may remain mounted to the elongate member 30 in the channel 35 due to engagement between the sidewall-engaging surfaces 47 _1} 47 ₂ of the sole 40 and the sidewalls 36 _1; 36 ₂ of the elongate member 30. By pulling on the sole 40 (on the ground-engaging portion 48) in a perpendicularly opposite direction to the belts 2O ₁ , 2O ₂ , the engagement between the base portion 46 of the sole 40 and the channel 35 of the elongate member 30 may be removed to allow removal of the sole 40. As the sole 40 is removed, the fasteners 41 _! -4I ₆ pass through the holes 80i-80 ₃ in the backing parts 5O ₁ , 5O ₂ , then through the holes in the belts 2O ₁ , 2O ₂ , and finally through the holes 73 _! -73 ₆ of the elongate member 30.

Once the sole 40 is removed, the fasteners 41i-41 ₆ must be replaced with a second set of fasteners to keep the cross-link 14; mounted to the belts 2O ₁ , 2O ₂ . This second set of fasteners may be provided individually or via a frame member that is similar to the frame member 49, as mentioned previously. If fasteners in the second set of the fasteners are provided individually, one end of each fastener is fed through a corresponding one of the holes 73 _\ - 73 ₆ of the elongate member 30, then through a corresponding one of the holes in the belts 2O ₁ , 2O ₂ , and then through a corresponding one of the holes 8O ₁ -8O ₃ in the backing parts 5O ₁ , 5O ₂ , while its other end is secured within the channel 35 (e.g., via a suitable nut). Alternatively, if the second set of fasteners is provided via a frame member that is similar to the frame member 49, the exposed ends of these fasteners are first aligned with the holes 731 - 73 ₆ in the bottom portion 34 of the elongate member 30. Upon insertion of the frame member into the channel 35 of the elongate member 30, the fasteners linked to this frame member pass through the components of the cross-link 14; and the belts 2O ₁ , 2O ₂ in a manner similar to that described above and are suitably tightened (e.g., through threaded nuts) to keep the belts 2O ₁ , 2O ₂ sandwiched between the

backing parts 5O ₁ , 5O ₂ and the elongate member 30, which keeps the cross-link 14 _f mounted to the belts 2O ₁ , 2O ₂ without the use of the sole 40.

It will thus be appreciated that this ability to mount and dismount the sole 40 from elongate member 30 allows the tracked vehicle 10 to traverse a wide variety of ground surfaces with improved traction while minimizing impact on the traversed surface.

Although various embodiments and examples have been presented, this was for the purpose of describing, but not limiting, the invention. Various modifications and enhancements will become apparent to those of ordinary skill in the art and are within the scope of the invention, which is defined by the appended claims.