TRAINS OF VEHICLES

TECHNI CAL FI ELD

The present disclosure relates generally tovehicle drive trains; and m ore specifically, tosystem s for transferring rotation motion in drive trains of vehicles.

BACKGROUND

Historically, ever since the advent of internal combustion engines, vehicles of different kinds have been used by people for com m uting between different places. Such vehicles include two-wheelers such as scooters, m otorcycles and so forth and four-wheelers such as cars, buses and the like. The vehicles em ploy the internal com bustion engine to generate torque for driving the vehicle, wherein the generated torque is transm itted to wheels of the vehicle when the vehicle is driven. Furthermore, when the vehicle is required to be m aintained in a stationary state (such as, during braking) , the transm ission of the torque is required to be tem porarily paused.

Conventionally, clutch arrangem ents have been em ployed for the transm ission of the torque generated by the engine of the vehicle to the wheels thereof. Such conventional clutch arrangem ents generally employ a pair of clutch plates, wherein a clutch plate is operatively coupled to the engine of the vehicle and another clutch plate is operatively coupled to wheels of the vehicle (such as, via a gear train of the vehicle) . Furtherm ore, during operation of the vehicle, the clutch plates are engaged by a driver of the vehicle (such as, by pressing a clutch pedal) to couple the pair of clutch plates with each other, thereby, operatively coupling the engine with the wheels of the vehicle for transm ission of the torque therebetween.

However, conventional clutch arrangem ents are associated with various drawbacks. For example, when there is no requirem ent for transm itting the torque generated by the engine of the vehicle to the wheels thereof, such as, when the vehicle is travelling downhill, the driver of the vehicle is required to m anually disengage the clutch, thereby, causing inconvenience to the driver. Consequently, the inconvenience caused to the driver may lead to the driver driving the vehicle without disengaging the clutch plates, thereby, causing the vehicle to use fuel for an operation thereof. Such a usage of fuel even when mom entum gained by the vehicle is causing the vehicle to move, without requiring usage of fuel, causes wastage of the fuel. Such a wastage of fuel incurs increased costs for the driver associated with operating the vehicle. Moreover, the wastage of fuel leads to increasing environm ental pollution (such as deterioration in air quality) caused due to operation of the vehicle and a continuous operation of the engine of the vehicle leads to increased noise pollution.

Therefore, in light of the foregoing discussion, there existsa need to overcome the aforementioned problem s associated with conventional clutch arrangem ents used in vehicles.

SUMMARY

The present disclosure seeks to provide an im provedsystem for transferring rotational motion in a drive train of a vehicle.

According to a first aspect, an em bodiment of the present disclosure provides asystem for transferring rotational motion in a drive train of a vehicle, the system com prising a driving part having a first cylindrical portion and a driven part having a second cylindrical portion, wherein :

- the first cylindrical portion is configured to be received into the second cylindrical portion for operative coupling of the driving part with the driven part; and

- the first cylindrical portion and/or the second cylindrical portion com prises a coupling m eans having :

- a casing having a plurality of partitions; - a stopper within each of the plurality of partitions; and

- a roller elem ent arranged within each of the plurality of partitions;

wherein

- the roller elements are configured to roll when the driving part is not rotated, to allow relative rotation between the driving part and the driven part; and

the roller elem ents are obstructed against corresponding stoppers within the plurality of partitions when the driving part is rotated, to inhibit the rolling of the roller elem ents and prevent the relative rotation between the driving part and the driven part.

The present disclosure seeks to providethesystem that enables convenient operative coupling between the driving part and the driven part of the vehicle, thereby, enabling to em ploy a mom entum gained by the vehicle during m ovem ent thereof to move the vehicle, and consequently, reduce a requirem ent of fuel for operation of the vehicle to reduce operating costs and pollution associated with operation of the vehicle.

I t will be appreciated that features of the present disclosure are susceptible to being com bined in various com binations without departing from the scope of the present disclosure as defined by the appended claim s.

DESCRI PTI ON OF THE DRAWI NGS

The sum m ary above, as well as the following detailed description of illustrative em bodim ents, is better understood when read in conj unction with the appended drawings. For the purpose of illustrating the present disclosure, exem plary constructions of the disclosure are shown in the drawings. However, the present disclosure is not lim ited to specific m ethods and instrum entalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.

Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:

FIG. 1 is a front-view of a system for transferring rotational motion in a drive train of a vehicle, in accordance with an embodiment of the present disclosure;

FIG. 2 is a front-view of the driving part of FIG. 1, in accordance with an embodiment of the present disclosure;

FIG.3 is a front-view of the driven part of FIG.1 , in accordance with an embodiment of the present disclosure;

FIG. 4, there are shown the driving part (shown in FIG. 2) and the driven part (shown in FIG. 3) in an operatively coupled state, in accordance with an embodiment of the present disclosure;

FIG.5 is a front-view of a system for transferring rotational motion in a drive train of a vehicle, in accordance with an embodiment of the present disclosure;

FIG.6 is a front-view of the driving part ofFIG.5, in accordance with an embodiment of the present disclosure; and

FIG.7 is a block diagram of a system (such as the system of FIG. 1 or the system of FIG.5) for transferring rotational motion in a drive train of a vehicle, in accordance with an embodiment of the present disclosure.

In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.

DESCRIPTION OF EMBODIMENTS

In overview, embodiments of the present disclosure are concerned withsystems for transferring rotational motion in drive trains of vehicles.

Referring to FIG. 1, there is shown a front-view of a system 10 for transferring rotational motion in a drive train of a vehicle, in accordance with an embodiment of the present disclosure. The system 10 is arranged as part of the driven train of the vehicle. As shown, the system 10 comprises a shaft 12 that is used for transmitting torque from a component of the vehicle that is configured to generate the torque, such as an engine (not shown) of the vehicle. The system lOcomprises a driving part 14 having a first cylindrical portion (shown in FIG.2 herein later) and a driven part 16 having a second cylindrical portion (shown in FIG.3 herein later).

In an embodiment, the driving part 14 and the driven part 16 are implemented as disks, and wherein the first cylindrical portion is provided along a centre of the driving part 14 and the second cylindrical portion is provided along a centre of the driven part 16. As shown, the driving part 14 and the driven part 16 are implemented as circular disks. The first cylindrical portion is provided along a centre of the driving part 14, such that the first cylindrical portion is a hollow cylindrical element that is integrally formed as part of the driving part 14. Furthermore, an axis of the first cylindrical portion is coaxial with an axis of the driving part 14 implemented as the circular disk. Furthermore, the second cylindrical portion is provided along a centre of the driven part 1 6 , such that the second cylindrical portion is a hollow cylindrical element that is integrally formed as part of the driven part 1 6. Moreover, an axis of the second cylindrical portion is coaxial with an axis of the driven part 1 6 im plem ented as the circular disk. Optionally, the driving part 1 4 and the driven part 1 6 im plemented as circular disks can have a substantially same diam eter (such as, to within 90% of each other) . Alternatively, as shown, the driving part 1 4 and the driven part 1 6 can have different diam eters with respect to each other.

Furthermore, the first cylindrical portion is configured to be received into the second cylindrical portion for operative coupling of the driving part 1 4with the driven parti 6. According to one embodim ent, a diam eter of the first cylindrical portion is m ore than a diameter of the second cylindrical portion. Alternatively, the diam eter of the first cylindrical portion is less than the diam eter of the second cylindrical portion. For exam ple, the first cylindrical portion and the second cylindrical portion are im plem ented such that an external diam eter of the first cylindrical portion (or the second cylindrical portion) is less than an internal diam eter of the second cylindrical portion (or the first cylindrical portion) . Consequently, the first cylindrical portion is a m ale part that is configured to be receivedinto the second cylindrical portion that is a fem ale part, to enable secure coupling of the first cylindrical portion with the second cylindrical portion. It will be appreciated that, as the first cylindrical portion is formed as an integral mem ber of the driving part 1 4and the second cylindrical portion is formed as an integral mem ber of the driven parti 6 , the coupling of the first cylindrical portion with the second cylindrical portion further enables to operatively couple of the driving part 1 4with the driven parti 6.

As shown, the driven part 1 6 is provided with a ball bearing 1 8 arranged along a centre thereof. The ball bearing 1 8 enables to reduce a friction caused due to rotation of the shaft 12, between the shaft 12 and the driven part 16. Furthermore, a brake drum 20 is provided that is configured to function as an automatic-clutch. Such a brake drum 20 enables the coupling and decoupling of the driving part 14 and the driven part 16, such as, when a brake is used (for example by pressing a brake pedal) to bring the vehicle to a halt, or when the brake is released to facilitate movement of the vehicle respectively. Moreover, the brake drum 20 is provided with a ball bearing 22 to reduce friction between the brake drum 20 and the shaft 12 due to rotation of the shaft 12. In an embodiment, the system 10 further comprises a housing (not shown), wherein the housing is configured to incorporate the driving part 14 and/or the driven part 16 therein. The housing can be implemented as a hollow cylindrical member having a diameter more than the diameter of the driving part 14 and/or the driven part 16. Such a housing is configured to therein and provide support to the driving part 14 and/or the driven part 16.

Referring to FIG.2, there is shown a front-view of the driving part 14 of FIG.1 , in accordance with an embodiment of the present disclosure. In an embodiment, the driving part 14 is operatively coupled to an engine (not shown) of the vehicle. In an embodiment, the vehicle is a motorcycle. As shown, the driving part 14 is implemented as a sprocket wheel having a plurality of teeth along a circumference thereof. In an example, the sprocket wheel can be implemented within a drive train of the motorcycle. In such an example, a drive chain (not shown) is operable to be arranged with the sprocket wheel, such that the drive chain meshes with the plurality of teeth of the sprocket wheel. Furthermore, the drive chain is rotated along the driving part 14, thereby transmitting torque generated by the engine of the motorcycle to the driving part 14. Subsequently, due to the operative coupling of the driving part 14 with the driven part 16, the torque is transmitted to the driven part 16. In an embodiment, the driven part 16 is operatively coupled to wheels of the vehicle. Moreover, the torque provided to the driven part 1 6 is transm itted as rotation to an output shaft, wherefrom the torque is further transm itted to wheels of the m otorcycle, thereby enabling m ovement of the motorcycle. The above exam ple has been explained with respect to the m otorcycle for illustration purposes. It will be appreciated that such a vehicle can comprise any other vehicle configured to be driven on two-wheels and that employs a sim ilar transm ission system as a motorcycle. I n an embodim ent, the vehicle is a scooter.

Furthermore, the driving part 1 4 comprises the first cylindrical portion 24 along the centre thereof. As shown, the first cylindrical portion 24 is implem ented as a hollow cylinder com prising a plurality of needles (or sem i-cylindrical members) along an internal surface thereof. The plurality of needles of the first cylindrical portion 24 are configured to m esh with a plurality of teeth provided on an external surface of the shaft 1 2 (shown in FI G. 1 ) , to provide secure coupling therebetween and transm ission of torque from the shaft 1 2 to the driving part 1 4.

Referring to FI G. 3, there is shown a front-view of the driven part 1 6 of FI G. 1 , in accordance with an embodiment of the present disclosure. As shown, the driven part 1 6 is im plemented as the circular disk. Furthermore, the driven part 1 6 com prises the second cylindrical portion 26 im plemented as the hollow cylinder, such that the internal diam eter of the second cylindrical portion 26 is more than the external diameter of the first cylindrical portion 24 of the driving part 1 4 (shown in FI G. 2) . Such an internal diam eter of the second cylindrical portion 26 being m ore than the external diam eter of the first cylindrical portion 24 enables the second cylindrical portion 26 to receive the first cylindrical portion 24therein.

Furthermore, the second cylindrical portion 26 comprises a coupling m eans 28 having a casing 30 having a plurality of partitions 32A- B. The casing 30 is configured to enclose other com ponents of the coupling means 28 therein . The coupling m eans 28 com prises a stopper within each pair 32A and 32 Bof the plurality of partitions 32A- B. As shown, each of the stoppers is im plemented as a spring 34. Moreover, the coupling means 28 com prises a roller elem ent 36 arranged between each pair 32A and 32 Bof the plurality of partitions 32A- B. The roller elem ent 36 is implem ented as a solid cylindrical com ponent, such as, as a roller element of a roller bearing.

Referring to FI G. 4, there are shown the driving part 1 4 (shown in FI G. 2) and the driven part 1 6 (shown in FI G. 3) in an operatively coupled state, in accordance with an em bodiment of the present disclosure. I n one em bodim ent, the system 1 0 further com prises a bush bearing 40 arranged between the first cylindrical portion 24 and the second cylindrical portion 26. As shown, the bush bearing 40 is arranged on the first cylindrical portion 24 of the driving part 1 4. Subsequently, the driving part 1 4 and the driven part 1 6 are operatively coupled by receiving the first cylindrical portion 24 with the bush bearing 40 arranged thereon , into the second cylindrical portion 26 of the driven part 1 6.

I t will be appreciated that, during m ovement of the vehicle, torque is transm itted from an engine of the vehicle to wheels of the vehicle. Consequently, the vehicle gains m om entum and moves in a required direction (such as, in a forward direction) . Such a momentum gained by the vehicle can be utilized for enabling movem ent of the vehicle for a substantial distance without providing additional torque to the wheels of the vehicle, such that the vehicle attains a “free-wheeling” state. Flowever, in vehicles employing conventional clutch arrangem ents therein, a driver of the vehicle is required to m anually disengage the clutch for enabling such free-wheeling of the vehicle and subsequently engage the clutch for enabling transm ission of the torque again to the wheels of the vehicle (towards an end of the free-wheeling state of the vehicle) , which is generally inconvenient for the driver. Thus, such a driver m ay not decouple the clutch and m ay continue to drive the vehicle in a neutral gear. Alternatively, when additional acceleration is not required by the vehicle (by com bustion of additional fuel in an internal com bustion engine of the vehicle) , such as when the vehicle is m oving due to the m omentum gained by the vehicle and/or when the vehicle is moving downhill, conventional clutch arrangements do not enable the free-wheeling of the vehicle without decoupling the clutch plates thereof from each other. I t will be appreciated that such a practice of driving the vehicle with the clutch plates in the coupled stateleads to wastage of energy utilized for generating the torque, such as, by combustion of fuel in the internal combustion engine of the vehicle.

The roller elem ents 36 are configured to roll when the driving part 1 4 is not rotated, to allow relative rotation between the driving part 1 4 and the driven part 1 6. For example, when the vehicle is m oving downhill, or when the vehicle is required to be brought to a halt, torque is not required to be provided to the wheels of the vehicle. Consequently, the rotation of the driving part 1 4 can be tem porarily stopped, such as, by stopping operation of the engine of the vehicle. Alternatively, the driving part 1 4 could be rotating at a nom inal speed, such as, when no additional acceleration is provided to the vehicle (such as, by engaging anaccelerator of the vehicle) . I n such instances, as mentioned hereinabove, a m om entum gained by the vehicle during prior m ovem ent thereof can be utilized for further m ovem ent of the vehicle for a substantial distance. Furtherm ore, as the rotation of the driving part 1 4 is stopped, the driven part 1 6 continues to rotate due to the coupling thereof with the driving part 1 4 and the m omentum gained by the driven part 1 6 during m ovem ent of the vehicle. Furtherm ore, the roller elem ents 36 are configured to roll, such as, over the bush bearing 40 arranged between the driving part 1 4 and the driven part 1 6. Moreover, as surfaces of each of the plurality of partitions 32 B facing the roller elem ents are im plem ented to have a sem i-cylindrical shape (or a sem i-circular cross-section) , the rotation of the roller elem ents 36 is allowed to be continued without facing obstruction due to contact of the roller elements 36 with the corresponding partitions 32 B. Thus, such continuance of the rotation of the roller elem ents 36 allows the relative rotation between the driving part 1 4 and the driven part 1 6 , thereby, allowing free-wheeling of the vehicle for a substantial distance. According to one em bodim ent, the driven part 1 6 is operatively coupled to a flywheel (not shown) . Such a flywheel enables to store momentum due to rotation of the driven part 1 6. Subsequently, the m omentum stored by the flywheel can be transferred to the driven part 1 6 when the rotation of the driving part 1 4 is stopped or a speed of rotation thereof is reduced, thereby enabling to continue the rotation of the driven part 1 6 and the free-wheeling of the vehicle.

The roller elem ents 36 are obstructed against corresponding stoppers within the plurality of partitions 32A- B when the driving part 1 4 is rotated, to inhibit the rolling of the roller elements 36 and prevent the relative rotation between the driving part 1 4 and the driven part 1 6. As the vehicle nears an end of the distance travelled during the free wheeling thereof, the torque generated by the engine of the vehicle is again required to be provided to the wheels, to enable movem ent of the vehicle (or to accelerate the vehicle to an increased m ovement speed thereof) . I n such an instance, the operation of the engine of the vehicle is restarted or m ore fuel is combusted therein, and the torque generated by the engine is transm itted to the driving part 1 4. Consequently, the driving part 1 4 is rotated, such as, in a clockwise direction (or an anticlockwise direction) . Such a rotation of the driving part 1 4 applies force on and moves the roller elem ents 36 away from the corresponding plurality of partitions 32 B,andtowards the corresponding plurality of partitions 32A. As shown, the stopper implem ented as the springs 34 are arranged proximate to each of the plurality of partitions 32A. Thus, as the roller elem ents 36 m ove towards the corresponding springs 34 , a force applied by each of the roller elem ents 36 due to rotation of the driving parti 4 is balanced by com pression of the corresponding springs 34. Consequently, the springs 34 support the corresponding roller elem ents 36 thereon and obstruct the rolling thereof. Therefore, the relative rotation between the driving part 1 4 and the driven part 1 6 is prevented, thereby, enabling transm ission of torque from the driving part 1 4 to the driven part 1 6 and sim ultaneous rotation thereof. Thus, providing the torque generated by the engine of the vehicle to the wheels thereof can be conveniently stopped and resum ed, without requiring substantial effort to be exerted by the driver of the vehicle (such as, simple starting and stopping of the engine enables the transm ission of torque, without the driver having to engage and disengage the clutch as with conventional clutch arrangements) . Alternatively, the driver of the vehicle is required to engage the clutch only once during com m encem ent of operation of the vehicle, such as to operatively couple the driving part 1 4 with the driven part 1 6. Subsequently, the transm ission of torque between the driving part 1 4 and the driven part 1 6 happens autom atically based on a speed of rotation of the driving part 1 4.

Referring to FI G. 5, there is shown a front-view of a system 50 for transferring rotational motion in a drive train of a vehicle, in accordance with an em bodim ent of the present disclosure. According to an embodim ent, the vehicle is a car. As shown, the system 50 com prises a driving part 52 coupled to an output-shaft 54 of a gear-train of the car. Furtherm ore, the system 50 comprises a driven part 56 operatively coupled to wheels of the car. Referring to FI G. 6, there is shown a front-view of the driving part 52 ofFI G. 5, in accordance with an embodiment of the present disclosure. As shown, the driving part 52 has a first cylindrical portion 58 , wherein the first cylindrical portion 58 comprises a coupling m eans 60. The coupling means 60 comprises a casing 62 and a star-shaped disc 64. As shown, the star-shaped disc 64 com prisesa plurality of teeth 66 , wherein the plurality of teeth 66 forms a plurality of partitions 68 within the casing 62. Moreover, each of the plurality of teeth 66 com prises a stopper 69within each of the plurality of partitions 68 of the casing 62 , wherein each stopper 69 is im plem ented as a spring. As shown, the coupling m eans 60 com prises a roller element 70 arranged within each of the plurality of partitions 68.

Furthermore, when the car is required to be m oved by transm itting torque generated by an engine of the car to the wheels of the car, a rotation of driving part 52 in an anti-clockwise direction (or a clockwise direction) causes the roller elements 70 to be obstructed against corresponding teeth 66 of the star-shaped disc 64and the springs 69 , causing the springs 69 to attain a com pressed state. It will be appreciated that such an obstruction of the roller elements 70 against the plurality of teeth 66 inhibits rolling of the roller elem ents 70 , thereby, preventing relative rotation between the driving part 52 and the driven part 56 (shown in FI G. 5) . Thus, such a prevention of the relative rotation between the driving part 52 and the driven part 56 enables sim ultaneous rotation thereof. Consequently, the torque generated by the engine of the car is transm itted to the wheels thereof.

Furthermore, when the car has gained m omentum due to m ovem ent thereof (such as due to movement of the car downhill or when the car is accelerated to an increased movem ent speed by com bustion of fuel in an internal combustion engine of the car) , the mom entum of the car can be employed to move the car a substantial distance (such as, tosave fuel used by the internal combustion engine of the car) . I n such an instance, the torque generated by the engine of the car is not required to be provided to the wheels thereof and consequently, an operation of the engine can be stopped. Suchstopping of operation of the engine stops the rotation of the driving part 52. However, due to the m omentum gained by the car, the wheels and the driven part 54 of the car continue to rotate, thus, causing the springs 69 to expand and the roller elem ents 70 to move away from the plurality of teeth 66 , towards an open area of the partitions 68 wherein the roller elements 70 are free to roll. Therefore, the roller elem ents 70 are configured to roll when the driving part 52 is not rotated, to allow relative rotation between the driving part 52 and the driven part 54.

I t will be appreciated that allowing the relative rotation between the driving part 52 and the driven part 54 enablesrotation of the wheels of the car due to the m om entum gained by the car, when the engine of the caris stopped. Alternatively, the driving part 52 could be rotating at a nom inal speed (when the engine of the car is operating at a nom inal capacity) , such as, when an accelerator of the car is not engaged (by pressing an accelerator pedal of the car) . Thus, the car is allowed to attain the free-wheeling state, as explained hereinabove. Furtherm ore, such free-wheeling enables the car to be driven a substantial distance without a requirem ent of com bustion of fuel (or with a reduced requirement of combustion of fuel, such as, when the engine of the car is operating at the nom inal capacity) within the internal com bustion engine of the car. Thus, the free-wheeling allows a user of the car to save fuel required for travelling. Furthermore, reducing the requirement of combustion of the fuel for travelling further enables to reduce environm ental pollution caused by driving the car and/or sound pollution caused by operation of the engine of the car. Referring to FI G. 7, there is shown a block diagram of a system 72 (such as the system 1 0 of FI G. 1 or the system 50 of FI G. 5) for transferring rotational motion in a drive train of a vehicle, in accordance with an em bodim ent of the present disclosure. The system 72 com prises a driving part 74 having a first cylindrical portion 76 and a driven part 78 having a second cylindrical portion 80. Furtherm ore, the second cylindrical portion 80 com prises a coupling means 82. As shown, the driving part 74 is operatively coupled to an engine 84 of the vehicle and the driven part 78 isoperativelycoupled to wheels 86 of the vehicle.

The system comprises the driving part and the driven part that are configured to be operatively coupled together using the first cylindrical portion and the second cylindrical portion respectively. Such an operatively coupling of the driving part and the driven part using the first cylindrical portion and the second cylindrical portion respectively elim inates a requirement of using friction disks and/or springs for operative coupling of clutch plates used in conventional clutch arrangem ents, thereby, overcom ing problem s associated with coupling in conventional clutch arrangements (such as, due to wear and tear of the friction disks) . Furtherm ore, the system com prises the coupling m eans in the first cylindrical portion and/or the second cylindrical portion , wherein the roller elem ents of the coupling m eans are configured to roll when the driving part is not rotated, to allow relative rotation between the driving part and the driven part. The relative rotation between the driving part and the driven part further allows rotation of the driven part to be continued (such as, due to m om entum gained by the vehicle during movem ent thereof) even when torque is not transm itted thereto by the driving part (or when a nom inal am ount of torque is transm itted thereto by the driving part) . Such a rotation of the driven part allows the vehicle to attain the free-wheeling state, wherein the vehicle continues to move without using fuel (or using a m inimal amount of fuel) . It will be appreciated that reducing a requirement of fuel for operation of the vehicle leads to a reduction in operating costs associated with driving the vehicle. Furthermore, reducing the requirement of fuel enables a reduction in carbon em issions during use of the vehicle and also a reduction in other forms of environm ental pollution (such as noise pollution) associated with using the vehicle. Therefore, the system enables to substantially overcome various problem s associated with conventional clutch arrangem ents.

Modifications to embodim ents of the invention described in the foregoing are possible without departing from the scope of the invention as defined by the accompanying claims. Expressions such as “including”, “com prising”, “incorporating”, “consisting of”, “have”, “is” used to describe and claim the present invention are intended to be construed in a non-exclusive m anner, namely allowing for item s, com ponents or elem ents not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural. Numerals included within parentheses in the accompanying claims are intended to assist understanding of the claim s and should not be construed in any way to lim it subject m atter claim ed by these claims.