WO2015124709A1

WO2015124709A1 - Vehicle having two or three wheels

Info

Publication number: WO2015124709A1
Application number: PCT/EP2015/053572
Authority: WO
Inventors: Alexander Hohenegger
Original assignee: Alter Ego S.A.S.
Priority date: 2014-02-21
Filing date: 2015-02-20
Publication date: 2015-08-27

Abstract

A vehicle having two or three wheels comprises an engine adapted to supply a drive torque by means of a drive shaft with a transverse axis of rotation with respect to a direction of advance of the vehicle, a variable speed ratio transmission which comprises a secondary shaft which receives the drive torque from the drive shaft, an auxiliary transmission shaft which receives driving torque from the secondary transmission shaft through an intermediate transmission element, the intermediate transmission element defining a movement path which delimits a closed region, and a final transmission member which transmits the drive torque from the auxiliary transmission shaft to a drive wheel of the vehicle. The secondary shaft, the drive shaft and the auxiliary transmission shaft are positioned in such a way that the axis of rotation of the secondary shaft is in a forward position, the axis of rotation of the drive shaft is in an intermediate position and the axis of rotation of the auxiliary transmission shaft is in a rearward position in relation to the direction of advance of the vehicle, and the axis of rotation of the drive shaft defines a centre of rotation located within the closed region bounded by the movement path of the intermediate transmission element.

Description

VEHICLE HAVING TWO OR THREE WHEELS

DESCRIPTION

The present invention relates to a vehicle having two or three wheels, of the type comprising an engine with a transverse axis of rotation with respect to the direction of advance of the vehicle.

A typical configuration of propulsion systems used in two-wheeled vehicles provides for the use of an internal combustion engine with a transverse axis of rotation, with the two shafts of the gearbox, namely the primary and secondary shafts, mounted downstream of the drive shaft.

Motion is transmitted from the drive shaft to the primary shaft of the gearbox by a pair of gears, or alternatively by a chain transmission, and is then transmitted from the secondary gearbox shaft to the drive wheel.

These components form the main moving masses of a propulsion system for motor vehicles, and their positioning therefore has a significant effect on the behaviour of the vehicle.

However, their distribution is not only dependent on the requirements of manoeuvrability and optimization of behaviour on the road, but must also be such that the overall dimensions of the vehicle are suitably limited.

Because of the need to meet these different requirements, most motor vehicle manufacturers use a configuration in which the gearbox shafts are placed in a position at the rear of the drive shaft, relative to the direction of advance of the vehicle.

However, this configuration, especially when a two-cylinder or multiple-cylinder V-shaped engine is used, requires a relatively long extension of the vehicle's propulsion system in the longitudinal direction of the vehicle. This feature gives rise to problems, or at least limitations in the handling characteristics of the vehicle, since large longitudinal dimensions generally make it difficult to achieve optimal balance in handling. Moreover, in some solutions the distribution of the masses is not suitably distributed between the front and rear wheels, since the weights are mainly concentrated in the rear area.

In addition, this configuration restricts the positioning of the rear fork pivot pin, the location of which is necessarily dependent on the overall dimensions of the engine and transmission. Therefore, in order to limit the wheelbase of the vehicle, there is a tendency to use relatively short forks, even though, in this case, this has an adverse effect on the balance in handling.

Although alternative configurations have been proposed in the search for more favourable, or at least different, solutions for the handling of the vehicle, none of these has been of practical use in the manufacture of series production vehicles or competition vehicles.

In particular, the proposed solutions require a rearrangement of the bank, or banks, of cylinders, which, although allowing a repositioning of the masses, causes a substantial change in the driving behaviour of the vehicle, as a result of which this solution is unpopular with users.

The fundamental technical problem of the present invention is therefore that of providing a two-wheeled vehicle whose structural and functional design is such that all the aforementioned drawbacks of the cited prior art can be overcome. This problem is resolved by means of a two-wheeled vehicle according to Claim 1.

Preferred characteristics of the invention are defined in the dependent claims. The discovery according to the present invention makes it possible to produce a two-wheeled vehicle in which there is an overall improvement in the handling characteristics of the vehicle, or an optimization of these characteristics. Furthermore, in the vehicle according to the present invention, the masses are displaced forward by comparison with known configurations, thereby providing, in the first place, a more suitable distribution of the weights on the two wheels, particularly where, in solutions using V-shaped engines with two cylinders or multiple cylinders, the overall dimensions of the front cylinder or cylinders requires non-optimal rearward positioning.

Additionally, in the present two-wheeled vehicle the clutch is located at a distance from the point of attachment of the fork, thus enabling a more compact, robust and rigid fork attachment system to be provided in particular fork attachment arrangements.

The characteristics and further advantages of the invention will be more clearly apparent from the following detailed description of a preferred, but non- exclusive, example of embodiment of the invention, illustrated, for guidance and in a non-limiting way, with reference to the attached drawings, in which:

Figure 1 is a side view showing in a schematic way a two-wheeled vehicle according to the present invention;

Figure 2 is a sectional plan view showing the essential elements of an engine and its transmission belonging to the vehicle of Figure 1 ;

Figures 3A and 3B are a left-hand side view and a right-hand side view, respectively, of the engine and transmission of Figure 2;

Figures 4 and 5 are, respectively, a sectional plan view and a left- hand side view showing the essential elements of an engine and its transmission belonging to a vehicle according to the present invention, in a first variant embodiment;

Figures 6 and 7 are, respectively, a sectional plan view and a left- hand side view showing the essential elements of an engine and its transmission belonging to a vehicle according to the present invention, in a second variant embodiment; and

Figures 8 and 9 are, respectively, a sectional plan view and a left- hand side view showing the essential elements of an engine and its transmission belonging to a vehicle according to the present invention, in a third variant embodiment.

With initial reference to Figure 1 , a two-wheeled vehicle is indicated as a whole by the reference numeral 100. As will be more fully apparent from the following text, the present invention may also be applied to vehicles having three wheels, such as that described in European Patent EP 1 484 239. The vehicle 100 comprises a frame structure 101 , shown only schematically in the drawing, which supports an engine 1 and incorporates a transmission 2 which transmits the torque generated by the engine 1 to a drive wheel 4, located in the rear part of the vehicle 100.

The drive wheel 4 is supported by means of a fork 5, connected rotatably to the frame structure 101 or directly to the engine 1 , according to procedures described more fully below.

The frame 101 also supports a front fork 102, to which the front wheel 103 is rotatably fixed, and which is connected to the handlebar, not shown in the Figures. Alternatively, the engine 1 may conveniently directly support a front fork, in the case of an indirect steering system.

A saddle, not shown in the drawing, on which the driver can sit to drive the vehicle 100, is also supported on the frame structure 101 , in an intermediate position between the front wheel and the rear drive wheel.

Clearly, the vehicle 100 and the frame structure 101 described above define in a unique way a front part and a rear part, which identify a direction of advance A, shown by an arrow in the Figures. Similarly, a right-hand side and a left-hand side of the vehicle are defined in the following with reference to the direction of advance A.

According to a preferred embodiment, the engine 1 is of the internal combustion type, being for example a two-cylinder engine with the cylinders in a V arrangement. As will be more fully apparent from the following text, the present invention is particularly advantageous in the case of applications with two-cylinder or multiple-cylinder V-shaped engines with banks of cylinders inclined at an angle of 45° to 90° to one another.

With reference to Figure 2, the engine 1 and the transmission 2 will now be described in greater detail.

The engine 1 and the transmission 2 are supported within a housing 5, preferably made in two parts 5 A and 5B separated along a plane passing along a longitudinal and vertical axis of the vehicle. Alternatively, the parts 5A and 5B may be separated along a horizontal plane.

The engine 1 comprises a pair of thermal systems 10A, 10B, each constituting an assembly of a cylinder head, cylinder and piston, which extend in a V- shape defined by the two cylinders, as illustrated above.

The cylinders transmit motion to the drive shaft 11 , at a crankshaft portion which converts the linear motion of the cylinders to a rotary motion about an axis of rotation X which is transverse to the direction of advance A of the vehicle.

The drive shaft 11 is connected, preferably at its left-hand end, to the free wheel 13 for starting the vehicle, and to the generator unit 14 for producing electrical current.

At its opposite end, the drive shaft is connected to a pair of gears 12, 24 which transmit the motion and the drive torque generated by the engine 1 to a primary shaft 21 of the transmission 2. Clearly, however, the drive torque may be transmitted from the drive shaft to the primary shaft 21 by other transmission means, such as a belt or chain system.

Preferably, also, the primary shaft 21 is located in a forward and lower position, in conditions in which the vehicle is at rest, relative to the drive shaft 11 , as will be more fully apparent from Figure 3B. This configuration enables the overall dimensions to be optimized, particularly in the case where a multiple-cylinder V engine is used, in which case it is convenient to have the parts of the housing cut along a horizontal plane.

With further reference to Figure 2, the primary shaft 21 is connected to the secondary shaft 22 of the transmission by a series of gears which are selectively engageable with one another and have different transmission ratios, thus providing, in other words, a gearbox with discrete ratios. To allow gear changing, the primary shaft 21 is also connected to a clutch unit 25, preferably located on the right-hand side and operating in known ways.

As is more fully apparent from Figure 3A, the secondary shaft 22 is preferably located in a forward and higher position relative to the primary shaft 21. Additionally, according to a preferred embodiment, in conditions in which the vehicle 100 is at rest, the secondary shaft 22 and the drive shaft 11 are placed in the same plane which is substantially horizontal or, more generally, parallel to the surface on which the vehicle 100 is supported.

It should also be noted that the primary and secondary transmission shafts 21 , 22 have respective axes of rotation Z, Y parallel to the axis of rotation X of the drive shaft 11.

The vehicle according to the present invention further comprises an auxiliary transmission shaft 3 which receives the drive torque from the secondary transmission shaft 22 through an intermediate transmission element 31 , preferably with a fixed transmission ratio.

The auxiliary transmission shaft 3 also has an axis of rotation W parallel to the axis X of the drive shaft 11 , and transmits motion to a final pulley/sprocket 34, engaged by a chain 32 which transmits the drive torque to the drive wheel 4.

As an alternative to the chain, it is possible to provide final transmission members 32 of a different type, such as a toothed belt or a shaft parallel to the extension of the fork 5.

Additionally, according to a preferred embodiment, the fork 5 may advantageously be fastened rotatably relative to the engine 1 at the axis of rotation W, being, in other words, pivoted on this axis W. This is not a constraint if it is desired to use a fork pivot not coinciding with the axis Y for the purpose of controlling the chain pull.

As may be seen, in particular, in Figure 3A, the auxiliary transmission shaft 3 is positioned in such a way that the centres of the axis of rotation Y of the secondary shaft 22, the axis of rotation X of the drive shaft 1 1 , and the axis of rotation W of the auxiliary transmission shaft 3 are substantially in line with each other, preferably on a straight line, with the axis X of the drive shaft 1 1 interposed between the other two axes Y and W.

More precisely, with reference to the direction of advance A of the vehicle 100, the axis of rotation Y of the secondary shaft 22 is in a more forward position, the axis of rotation X of the drive shaft 11 is in an intermediate position, and the axis of rotation W of the auxiliary transmission shaft 3 is in the most rearward position.

This arrangement enables the transmission 2 to be located in a front position, that is to say a more forward position, relative to the drive shaft 11 , thereby providing an efficient redistribution of the masses and containment of the overall dimensions.

Furthermore, by aligning the three axes of rotation X, Y and W, and using a

V engine if appropriate, it is possible to contain the vertical overall dimension of the assembly formed by the engine 1 and the transmission 2, positioning the shafts 22 and 3 immediately under the thermal system 10A and the thermal system 10B respectively.

According to a preferred embodiment, a particularly advantageous configuration in terms of mass distribution is obtained by positioning the axes of rotation X,

Y and W, in conditions in which the vehicle is at rest, within a plane substantially parallel to the surface on which the vehicle is supported.

With further reference to Figure 3A, the intermediate transmission element 31 transmits motion from a sprocket 23 keyed onto the secondary shaft 22 to a sprocket 33 keyed onto the auxiliary transmission shaft 3.

Preferably, the transmission member has a transmission ratio below 1 , thus demultiplying the motion output by the transmission 2. Because of this characteristic, it is possible to improve the efficiency of the final transmission, which has a transmission ratio closer to 1 : 1 , and to provide a wider choice of final ratios, especially for small cylinder capacities.

Additionally, if a toothed belt is used, this characteristic is also advantageous because it is unnecessary to use a final pulley 34 with an excessively small diameter.

Furthermore, preferably, the sprocket 33 is keyed onto the auxiliary transmission shaft 3 so as to be located on the opposite side of the housing 5 from the pulley 34, thereby optimizing the overall dimensions and mass distribution. In particular, in the present embodiment, the final pulley 34 is positioned on the same side of the clutch unit 25, thus further improving the compactness of the solution.

According to the present embodiment, the transmission element 31 is formed by a chain 311 , preferably a Morse chain, extending between the aforesaid sprockets 23 and 33. By way of example, the roller chain may be of the duplex or triplex or Morse type, running in an oil bath if appropriate.

As may be seen in Figure 3A, a length under tension 31 1A and a length not under tension 311 B are defined on the chain, and the axis of rotation X of the drive shaft 11 is located so as to be vertically interposed between the length under tension 311A and the length not under tension 311 B. More precisely, in the present embodiment, the length of the chain under tension is positioned above the axis X, while the length not under tension is positioned below it. More generally, in the vehicle according to the present invention, the intermediate transmission element 31 , in this case represented by the chain 311 , defines a movement path which bounds a closed region a. The arrangement of the transmission element 31 and of the drive shaft 11 is therefore such that the axis of rotation X of the shaft defines a centre of rotation positioned inside the aforesaid closed region a.

The applicant has observed that this arrangement enables the overall dimensions and the arrangement of the masses to be balanced in an optimal manner, with considerable benefits for the handling of the vehicle.

Additionally, the chain 311 , when positioned in the aforesaid way, has no negative effect on the positioning of the free wheel 13 and of the generator unit 14, which can in any case receive the motion from the drive shaft 11 , without any need for repositioning the components, apart from any lateral translation that may be required.

In other words, the generator unit 14 and/or the free wheel 13 may be connected to the drive shaft 11 and positioned externally with respect to the transmission element 31 , given that the drive shaft 11 passes between the length of the chain under tension and the length not under tension. Clearly, however, the portion of drive shaft 11 that supports the generator unit 14 and/or the free wheel 13 may also not pass beyond the plane of the bearing which supports it, but remains the reference of the axis X.

As an alternative to the chain, a toothed belt may be used, operating in a dry state or in an oil bath and being suitably guided and provided with suitable manual and/or automatic tensioning devices, not shown in the drawing.

With reference to Figures 4 and 5, according to an alternative embodiment, the intermediate transmission element 31 comprises an idle sprocket 31 2 which engages respectively with the sprocket 23, keyed onto the secondary shaft 22, and transmits the drive torque to the sprocket 33, so that it can then be transferred to the drive wheel 4, through the auxiliary transmission shaft 3 and the chain 32.

To achieve efficient reduction of the overall dimensions, the idle sprocket 31 2 is preferably positioned coaxially with the axis of rotation X of the drive shaft 11.

Additionally, in order to provide greater freedom of choice in the transmission ratios, and containment of the dimensions of the sprockets of the intermediate transmission element, according to a preferred embodiment a further idle sprocket 313 is also provided coaxially with the other idle sprocket 31 2.

The sprockets 312 and 313 are fixed with respect to rotation, preferably by providing a flexible coupling element 314 interposed between the two wheels. By way of example, the flexible coupling may be of the axial or radial type, and may be a metal spring or may be made of polymers. It should also be noted that the flexible coupling element may also be present in the chain/belt transmission described with reference to the preceding embodiment, and may conveniently be inserted between the sprocket/pulley and the corresponding shafts. Furthermore, in all the embodiments of the present invention, a further flexible coupling of the front cam type, may be inserted on the shaft 3.

Additionally, according to a preferred embodiment, the further sprocket 313 has a smaller number of teeth than the other idle sprocket 31 2, thus providing demultiplication, with the same advantages as those outlined with reference to the chain transmission.

It should be noted that, in this case also, the intermediate transmission element 31 defines a movement path, determined by the portion covered by the sprockets 312 and 313, which bounds a closed region, also identified by the letter a in this case, within which the centre defines by the axis X of the drive shaft 1 1 lies.

A further variant embodiment is described in Figures 6 and 7, in which the sprocket 33, which receives the motion from the intermediate transmission element 31 , in the form of a chain 311 for example, and the sprocket 34, which transmits the motion to the drive wheel through the final transmission member 32, are located on the same side of the housing 5.

In this case, the auxiliary shaft 3 may have smaller dimensions and may be made so as to project on one side, preferably the left-hand side, of the housing 5. Thus it is possible to reduce the overall dimensions further, avoid the use of a shaft passing between the two sides of the housing 5, and position the final transmission member 32 on the left-hand side, in a solution similar to those typically adopted by leading motor vehicle manufacturers.

A further variant embodiment is described in Figures 8 and 9, in which the auxiliary shaft 3 is positioned on the frame at a predetermined fixed distance from the axis Y, in a position which is preferably coaxial with the fork pivot. As another alternative, Figure 10 shows a variant embodiment in which a continuously variable transmission member is used, that is to say a member not having a fixed transmission ratio. In this case, as may be seen in the drawing, the two shafts of the transmission 2 are not present, and the drive shaft 11 is directly coupled to the secondary shaft 22.

The ratios are varied in this case by means of a transmission with a trapezoidal belt 311 ' and corresponding tapered pulleys 23', 33', coaxial with the axis Y for the driving pair and with the axis W for the driven pair. This solution is particularly advantageous in the case of application to scooters. Thus the invention resolves the problem which was proposed, while providing a number of advantages. In particular, the vehicle according to the present invention enables the masses to be displaced forward, thereby providing a more suitable distribution of the weights on the two wheels. Moreover, this advantage is enhanced if use is made of two-cylinder or multiple-cylinder engines positioned in a typical longitudinal V configuration. This is in particular achieved by providing that the axis of rotation X, Y and W lie within a plane which is substantially parallel to a surface supporting the vehicle in conditions in which the vehicle is at rest.

Additionally, the configuration of the engine and of the transmission in the vehicle according to the present invention makes it possible to eliminate the overall dimensions of the clutch unit in the fork attachment area, thereby providing a more rigid and compact fork attachment system. Furthermore, the possibility of positioning the fork pivot in a coaxial position with respect to the axis of the sprocket or pulley of the final transmission is found to be particularly advantageous. The fork may conveniently be attached directly to the engine by means of special supports.

Additionally, if a transmission member of the sprocket type is used, it is possible to fit at least one flexible coupling in replacement of, or in addition to, the flexible coupling system normally fitted in the rear wheel.

The vehicle according to the present invention also enables the transmission ratio to be reduced towards the ideal final ratio of 1 : 1 , owing to the inclusion of the demultiplication provided by the intermediate transmission element.

Bringing the axis of rotation of the final transmission nearer to the axis of the drive shaft also proves to be particularly advantageous, since it allows the fork to be elongated for the same vehicle wheelbase, or allows equivalent repositioning of the thermal system of the engine by rotation.

Finally, the proposed solution does not require any particular redesign of the existing engines, as it allows the same distribution of the right- and left-hand sides of the main components of the engine and transmission as that used in the solutions most commonly adopted in the motorcycling field.

Claims

A vehicle having two or three wheels (100), comprising:

• an engine ( 1 ) capable of providing a drive torque through a drive shaft (11) having an axis of rotation (X) which is transverse with respect to a direction of advance (A) of the vehicle;

• a variable speed ratio transmission ( 2 ) which comprises a secondary shaft (22) receiving the drive torque from the drive shaft (11), the secondary transmission shaft (22) having an axis of rotation (Y) which is parallel to the axis of the drive shaft (X);

• an auxiliary transmission shaft ( 3 ) which receives the drive torque from the secondary transmission shaft (22) through an intermediate transmission element (31), the auxiliary transmission shaft (3) having an axis of rotation (W) parallel to the axis of the drive shaft (X), the intermediate transmission element (31) defining a movement path delimiting a closed region (a); and

• a final transmission member (32) which transmits the drive torque from the auxiliary transmission shaft ( 3 ) to a drive wheel ( 4 ) of the vehicle (100);

characterized in that the secondary shaft (22), the drive shaft (11) and the auxiliary transmission shaft ( 3 ) are positioned in such a way that the axis of rotation (Y) of the secondary shaft (22) is in a forward position, the axis of rotation (X) of the drive shaft (11) is in an intermediate position and the axis of rotation (W) of the auxiliary transmission shaft ( 3 ) is in a rearward position in relation to the direction of advance (A) of the vehicle, and in that the axis of rotation (X) of the drive shaft (11) defines a centre of rotation located within the closed region (a) bounded by the movement path of the intermediate transmission element (31).

2. A vehicle having two or three wheels (100) according to Claim 1, wherein the axis of rotation (Y) of the secondary shaft (22) and the axis of rotation (W) of the auxiliary transmission shaft (3) define corresponding centres in line with the axis of rotation (X) of the drive shaft (11).

3. A vehicle having two or three wheels (100) according to Claim 1 or 2, wherein the transmission (2) is of the variable speed ratio type and further comprises a primary shaft (21) which receives the drive torque from the drive shaft (11), the secondary shaft (22) receiving the drive torque from the primary shaft (21) with a variable transmission ratio, the primary transmission shaft (21) having an axis of rotation ( Z ) parallel to the axis of the drive shaft ( X ) .

4. A vehicle having two or three wheels (100) according to any one of Claims 1 to 3, wherein the axis of rotation (Y) of the secondary shaft (22), the axis of rotation (X) of the drive shaft (11), and the axis of rotation (W) of the auxiliary transmission shaft (3) lie within a plane which is substantially parallel to a surface supporting the vehicle in conditions in which the vehicle is at rest.

5. A vehicle having two or three wheels (100) according to any one of Claims 1 to 4, wherein the intermediate transmission element (31) transmits motion from a sprocket (23) keyed onto the secondary shaft (22) and a sprocket (33) keyed onto the auxiliary transmission shaft (3).

6. A vehicle having two or three wheels (100) according to Claim 5, wherein the intermediate transmission element (31) comprises a chain (311) which extends from the sprocket (23) keyed onto the secondary shaft (22) and the sprocket (33) keyed onto the auxiliary transmission shaft ( 3 ) , and on which there is defined a length under tension ( 311 A ) and a length not under tension (311B), the axis of rotation (X) of the drive shaft (11) being located between the length under tension ( 311 A ) and the length not under tension (311B).

7. A vehicle having two or three wheels (100) according to Claim 5, wherein the intermediate transmission element (31) comprises an idle sprocket (312) which engages respectively with the sprocket (23) keyed onto the secondary shaft (22) and transmits drive torque to the sprocket (33) keyed onto the auxiliary transmission shaft (3).

8. A vehicle having two or three wheels (100) according to Claim 7, wherein the idle sprocket (312) is coaxial with the axis of rotation (X) of the drive shaft (11).

9. A vehicle having two or three wheels (100) according to Claim 7 or 8, comprising a further idle sprocket (313) which is coaxial with the other idle sprocket (312), from which it derives motion, and has a number of teeth which is less than that of the other idle sprocket (312).

10. A vehicle having two or three wheels (100) according to Claim 9, wherein the idle sprockets (312, 313) are connected together through an intermediate flexible coupling device (314).

11. A vehicle having two or three wheels (100) according to any one of the preceding claims, wherein the transmission member is of the type having a transmission ratio of less than 1.

12. A vehicle having two or three wheels (100) according to any one of the preceding claims, further comprising a housing ( 5 ) in which the engine and the variable speed ratio transmission ( 2 ) are housed, the final transmission member (32) comprising a pulley (34) keyed onto the auxiliary rotation shaft (3), the pulley (34) being located on the opposite side of the housing (5) from the sprocket (33) keyed onto the auxiliary transmission shaft ( 3 ) .

13. A vehicle having two or three wheels (100) according to any one of the preceding claims, further comprising a frame structure (101) which supports the engine ( 1 ) and the transmission ( 2 ) , and which comprises a fork (6) for supporting the drive wheel (4), the fork

( 6 ) being hinged about an axis which coincides with the axis of rotation (W) of the auxiliary rotation shaft (3).

14. A vehicle having two or three wheels (100) according to any one of the preceding claims, wherein the engine ( 1 ) is a multiple-cylinder engine positioned in a longitudinal V configuration.

15. A vehicle having two or three wheels (100) according to claim 14, wherein the banks of cylinders are inclined at an angle comprised between 45° and 90° to one another.

16. A vehicle having two or three wheels (100) according to claim 14 or 15, wherein the axis of rotation (Y) of the secondary shaft (22) is positioned below a bank of cylinder/s and the axis of rotation ( W ) of the auxiliary transmission shaft ( 3 ) is positioned below the other bank of cylinder/s.