The present disclosure relates to a transverse member for a drive belt for a continuously variable transmission with two pulleys for accommodating the drive belt between the, at least partly conical pulley sheaves thereof. The known drive belt comprises an endless, i.e. ring-shaped carrier that is composed of at least one, but typically of a set of nested, flexible rings and a number of these transverse members that together form an essentially contiguous row along the circumference of the endless carrier. Typically both the said flexible rings and the transverse members of the drive belt are made of metal, in particular steel.

The transverse members each include a predominantly width- wise, i.e. axially relative to the drive belt's circumfe ^¬ rence direction, extending base part with an, at least effectively, trapezoidal outline and two pillar parts that extend from a respective axial side of the base part in a direction essentially perpendicular to the aforementioned axial and circumference directions of the drive belt, i.e. in radial direction. Each transverse member thus defines a centrally located opening between the pillar parts and the base part thereof, wherein a small circumferential section of the endless carrier is accommodated. The base part and the pillar parts are integral parts of the known transverse member. Such a drive belt with effectively V-shaped trans ^¬ verse members is known from, for example, the international patent publication No. WO2015/177372-A, in particular figure 5 thereof.

According to WO2015/177372-A, one pillar part of each transverse member is provided with a hook part that extends in axial direction over the endless carrier, such that the latter is contained in the central opening of the transverse members in radial direction during operation. Two types of transverse member are included in the known drive belt, which types are differentiated by the said hook part thereof being associated with different pillar parts. In the base part of the transverse members, on a front main face thereof, a so-called tilting zone is provided. The tilting zone is an axially extending transition between a radially outer section of the transverse member of essentially constant thickness, i.e. dimension in the said circumferential direction, and a radially inner section thereof that, at least effectively, tapers in radial inward direction. Such tilting zone and tapered inner section of the transverse member allow adjacent transverse members to mutually tilt in a curved trajectory part of the drive belt in the transmission, while these adjacent transverse members remain in physical contact through, at least, an axially oriented line of contact located in the tilting zone. It is noted that a ratio between respective radial positions of the tilting edge at the two transmission pulleys determines the (rotational) speed ratio between the pulleys and (thus) of the transmission.

Further, in the pillar parts of the transverse members, studs are provided that protrude from the front main face essentially in the said circumferential direction. In the drive belt, each stud is inserted in a recess provided in an opposite, i.e. rear main face of an adjacent transverse member. Such projection and recess serve to at least limit, a relative movement between adjacent transverse members in the row of transverse members of the drive belt, at least in radial direction, but typically also in axial direction.

On either axial side of the base part thereof, the transverse member is provided with contact surfaces for frictionally engaging a pulley sheave of the transmission pulleys. These pulley contact surfaces are mutually oriented at an angle, denoted the belt angle, that matches, at least by approxima- tion, an angle defined by and between the conical pulley sheaves of the pulleys, which latter angle is denoted the pulley angle. Furthermore, these pulley contact surfaces are either corrugated or provided with a substantial surface roughness, such that only the peaks of the corrugation profile or surface roughness arrive in contact with the pulley sheave. This particular feature provides that cooling oil that is applied in the known transmission can be accommodated in the valleys of the said corrugation profile or surface roughness, thus improving the friction between the drive belt and the transmission pulleys.

During operation in the transmission, the transverse members of the drive belt that are located between the pulley sheaves of a driving pulley of the transmission are driven in the direction of rotation thereof by friction forces being exerted by these pulley sheaves on the pulley contact surfaces of these transverse members. These latter, driven transverse members push preceding transverse members along the circumference of the endless carrier of the drive belt and, ultimately, rotationally drive the driven pulley of the transmission, again by friction. In order to generate such friction (force) between the transverse members and the pulley sheaves of the transmission pulleys to build up, the pulley sheaves of a pulley are forced towards one another in axial direction, whereby these exert mutually opposed pinching force on the transverse members in the axial direction thereof.

It is an object of the present disclosure to improve on the known design of the drive belt, in particular in view of the design of the transverse members thereof, while retaining the ease of assembly of the known belt.

The drive belt according to the present disclosure is defined in the set of claims that is attached hereto. Furthermore, the subject matter of the present disclosure is explained hereinafter by way of example on the basis of the description below with reference to the drawing, in which:

- figure 1 is a simplified and schematic side elevation of a transmission with two pulleys and a drive belt;

- figure 2 illustrates the known drive belt with generally V-shaped transverse members in a cross-section thereof facing in its circumference direction and also includes a separate side elevation of only the transverse member thereof; and

- figure 3 schematically illustrates the novel transverse members according to the present disclosure.

Figure 1 schematically shows the central parts of a continuously variable transmission for use in a driveline of, for example, passenger motor vehicles. This transmission is well-known per se and comprises at least a first variable pulley 101 and a second variable pulley 102. In the driveline, the first pulley 101 is coupled to and driven by an engine and the second pulley 102 is typically coupled to driven wheels of the motor vehicle.

Both transmission pulleys 101, 102 comprise a first conical pulley sheave that is fixed to a pulley shaft 103, 104 of the respective pulley 101, 102 and a second conical pulley sheave that is axially displaceable relative to the respective pulley shaft 103, 104 and that is fixed thereto only in rotational direction. A drive belt 50 of the transmission is wrapped around the pulleys 101, 102, while being accommodated between the pulley sheaves thereof. As appears from figure 1, the trajectory of the drive belt 50 in the transmission includes two straight sections ST and two curved sections CT where the drive belt 50 is curved around a respective one of the two transmission pulleys 101, 102. During operation of the transmission, the drive belt 50 is pinched by and between the pulley sheaves of both pulleys 101, 102 and thus provides a rotational connection there between by means of friction. To this end, electronically controllable and hydraulically acting movement means that act on the respective moveable pulley sheave of each pulley 101, 102 are provided in the transmission (not shown) . In addition to exerting a pinching force on the drive belt 50, these movement means also control respective radial positions Rl and R2 of the drive belt at the pulleys 101, 102 and, hence, the speed ratio that is provided by the transmission between the pulley shafts 103, 104 thereof.

The known drive belt 50 is composed of an endless carrier 8 and a plurality of transverse members 1 that are mounted on the endless carrier 8 along the circumference thereof in an, at least essentially, contiguous row. In the drive belt 50 the transverse members 1 are movable along the circumference of the endless carrier 8, which endless carrier 8 is typically composed of a number of flexible metal rings or bands, which metal bands are stacked one around one another, i.e. are mutually nested.

In figure 2 the known drive belt 50 is illustrated in more detail. On the right side of figure 2 the drive belt 50 is shown in a cross-section facing in the belt's circumference direction and on the left side of figure 2 a cross-section of only the transverse member 1 is shown. From figure 2 it appears that the transverse members 1 of the drive belt 50 are generally shaped similar to the letter "V", i.e. are generally V-shaped, whereby an angle between the sides of the transverse members 1 is designed to closely match an angle present between the conical pulley sheaves of the transmission pulleys 101, 102.

The transverse member 1 comprises a base parts 10 and two pillar parts 11, whereof the base part 10 extends in the axial direction of the drive belt 50 and whereof the pillar parts 11 extend in the radial direction of the drive belt 50, each from a respective axial side of the base part 10. In its thickness direction, the transverse member 1 extends between a front main face 3 and a rear main face 4 thereof that are both oriented, at least generally, in the circumference direction of the drive belt 50. Between the pillar parts 11 and the base part 10 of the transverse member an opening 5 is defined, wherein a circumference section of the endless carrier 8 is accommodated.

The transverse member 1 is provided with a so-called tilting zone 4 in its front main face 3. This tilting zone 4 represents an axially extending transition between a radially outer section of the transverse member of essentially constant thickness and a radially inner section thereof that is tapered in radial inward direction. Typically, the tilting zone 4 is smoothly, convexly curved. When adjacent transverse members 1 are tilted relative to one another in the curved section CT of the drive belt 50, these (can) remain in contact at the location of the tilting zone 4. In each pillar part 11 of the transverse member 1 a stud 6 is provided that protrudes from the front main face 3 in, essentially, the said circumference direction. In the drive belt 50, the stud 6 is inserted in a recess 7 provided in the opposite, i.e. rear main face 3 of an adjacent transverse member 1 to limit a relative movement between the adjacent transverse members 1.

On the axial sides thereof, the transverse member 1 is provided with contact surfaces 12 for contacting (the pulley sheaves of) the transmission pulleys 101, 102.

In order to prevent that the transverse members 1 of the known drive belt 50 can separate from the endless carrier 8 thereof, in particular in a straight section ST thereof, one pillar part 11 of each transverse members 1 is provided with a hook part 13 that in axial direction hangs over a part of the opening 5. The drive belt includes both transverse members 1 of a first type I whereof the hook part is provided to the right-side pillar part 11-r, as well as transverse members 1 of a first type II whereof the hook part is provided to the left-side pillar part 11-1. Thus in the drive belt 50, the endless carrier 8 is contained in the central openings 5 thereof by the hook parts 13 of the two types I, II of the transverse members 1 in the drive belt 50 to either axial side thereof. These hook parts 13 engage the axial sides of the endless carrier 8 to prevent the separation of the transverse member 1 in radial inward direction relative to the endless carrier 8.

Since each individual transverse member 1 includes only one hook part 13, it can be mounted on the endless carrier 8 relatively easily when the drive belt 50 is assembled, provided that the axial or width dimension of the central opening 5 thereof exceeds the width of the endless carrier 8 by a sufficient amount. According to the present disclosure, the design of the known drive belt 50, in particular that of the transverse members 1 thereof, can be optimised in terms of the shape and size, in particular an axial width, of the central opening 5 thereof, to favourably increase the width of the endless carrier 8 that can be fitted therein.

As illustrated in figure 3, to assemble the drive belt 50, firstly each transverse member 1 is moved towards the endless carrier 8 with the pillar part 11 thereof that is without the hook part 13 (i.e. the right-side pillar part 11-r in figure 3) being located on the radial inside of the endless carrier 8, until one axial side of the endless carrier 8 (i.e. its left side in figure 3) is located between the body part 10 and the hook part 13 of the other pillar part 11 of the transverse member 1 (i.e. the left-side pillar part 11-r in figure 3) . The said axial side of the endless carrier 8 is thereby inserted in between such body part 10 and hook part 13 of the transverse member 1 as far as is possible without any substantial deformation of the endless carrier 8. Then, secondly, the transverse member 1 is rotated relative to the endless carrier 8 so as to align the body part 10 thereof endless carrier 8.

In figure 3 it is illustrated that a favourably wide endless carrier 8 can be applied, while avoiding contact between the endless carrier 9 and the respective, i.e. right-side pillar part 11-r, by inclining at least at part of a side face 20 thereof facing the opening 5 in radial inward direction away from the other, i.e. left-side pillar part 11-1 of the transverse member 1. Hereby, such inclined part of the pillar side face 20 can be incorporated as a flat surface, but it can also be concavely curved, which latter embodiment is illustrated in figure 3. In the latter case, a radius of concave curvature of the inclined part of the pillar side face 20 can be chosen to correspond to a width, i.e. axial dimension of the opening 5.

In particular, the inclined part of the pillar side face 20 is located radially inward of a position halfway a radial extend of the stud 6 (indicated in figure 3 by the dash-dot line intersecting the stud 6) . More in particular it is located radially inward of the complete radial extend of the stud 6. By either one of these latter alternative design features, the respective pillar part 11-r is optimally suited for accommodating the stud 6 therein, since an axial dimension or width of a radially outer extend of the respective pillar part 11-r remains unaffected by the said inclined part of the pillar side face 20. More in particular in this respect, the starting point and the amount of inclination of the inclined part of the pillar side face 20 is chosen such that it lies on or outside a virtual circle VC drawn around the stud 6 and touching the edges of the pillar part 11-r at two or more locations L. This particular design feature is optimal for forming the stud 6 in the process of cutting and shaping the transverse member 1 from strip-shaped base material as is customary in the art.

Furthermore, the inclined part of the pillar side face 20 is preferably located at some distance D radially outward of the base part 10 of the transverse member 1. A further, radially inner part of the pillar side face 20, located between said inclined part thereof and the base part 10, is then preferably oriented perpendicular to that base part 10 and/or in parallel with a side face facing the opening 5 of the opposite pillar part 11 (i.e. the left-side pillar part 11-1 in figure 3) . Hereby, said radially inner part of the pillar side face 20 provides a parallel abutment surface to a corresponding axial side face of the endless carrier 8, as is preferred and is customary in the art. In this respect, the said distance D corresponds to at least a dimension in radial direction or thickness of the endless carrier 8 and/or to a distance between the hook part 13 of the opposite pillar part 11-1 and the base part 10.

The present disclosure, in addition to the entirety of the preceding description and all details of the accompanying figures, also concerns and includes all the features of the appended set of claims. Bracketed references in the claims do not limit the scope thereof, but are merely provided as non- binding examples of the respective features. The claimed features can be applied separately in a given product or a given process, as the case may be, but it is also possible to apply any combination of two or more of such features therein.

The invention (s) represented by the present disclosure is (are) not limited to the embodiments and/or the examples that are explicitly mentioned herein, but also encompasses amendments, modifications and practical applications thereof, in particular those that lie within reach of the person skilled in the relevant art.