Patent Description:
Generally, a braking system is provided in vehicles, be it a mono-cycle or a multi-wheeled vehicle, and the braking system is used for slowing down the vehicle and / or for bringing the vehicle to a complete halt. Typically, multi-wheeled vehicles, especially, vehicles having a plurality of wheel incorporate various electronics based braking systems like anti-lock braking system (ABS), electronic brake-force distribution (EBD) etc., which operate based on sophisticated electronics and are powered by a battery or from power generated by a power unit of the vehicle. Such sophisticated braking systems are expensive and are primarily used in cars. Typically, small capacity vehicles like two-wheeled or three-wheeled vehicles, which are catering to commuter applications, incorporate a braking system that allows simultaneous application of a front wheel brake and a rear wheel brake by actuation of a single brake lever. The front wheel brake and the rear wheel brake can be a drum brake or a disc brake depending on cost and stopping distance requirements of the vehicle. The prior art <CIT> relates to a linked braking system which includes a first brake operation module, a second brake operation module, a first brake generator, a second brake generator and a connecting member to achieve the effect of providing an interlocking brake. The connecting member connect the first rocker arm and the second rocker arm to transmit the urging force between the first rocker arm to the second rocker arm. The operation of the first brake lever by the rider actuates a first plunger which pushes hydraulic oil engaging the first brake. A continued applied pressure on the first brake lever synchronously transmits the force from the first rocker arm to the second rocker arm through a first connecting piece. However, such a linked braking system comprises additional elements such as additional rocker arms which eventually increases the number of part thereby affecting the weight, and complexity of manufacturing.

The detailed description is described with reference to an embodiment of a two-wheeled vehicle along with the accompanying figures. Similar numbers are used throughout the drawings to reference like features and components.

Conventionally, vehicle with two- or three-wheels are considered to be less stable when compared to vehicles having four or more wheels. Hence, braking system plays a crucial role in slowing down or in bringing the vehicle to an eventual halt. Generally, in the two-wheeled or three-wheeled vehicles, a disc brake or a drum brake is provided to operate as a front wheel brake and as a rear wheel brake. Pre-dominantly, a disc brake is provided as front wheel brake in vehicles. However, in in order to achieve a shorter stopping distance and for effective braking, a disc brake is used for both the front wheel brake and the rear wheel brake. Conventionally, a hand-operated lever or a foot-operated lever is used for actuation of the brake(s) either independently or combinedly.

Generally, in order to combinedly operate both the front wheel brake and the rear wheel brake, a brake force distribution member like an equalizer is typically used in some braking system known in the art. The equalizer and corresponding cables or hose connections cannot be accommodated near a handle bar, where a hand-operated brake lever is disposed, or near a rider-foot peg / foot-rest, where a foot-operated brake lever is disposed. The equalizer-based system may require a separate space/ casing on the vehicle away from the handle bar or away from the rider-footrest. Therefore, either the equalizer setup is disposed away from the lever or else a large space is dedicated for accommodating the equalizer and other parts. Moreover, equalizer-based systems work on principle of brake force distribution. The user may have to apply more braking force at the lever to realize the effect on both the front wheel brake and the rear wheel brake. The equalizer based braking system and other braking system known in the art become even more challenging, when both the front wheel brake and the rear wheel brake are both hydraulic-disc brakes.

Generally, the known systems use two hydraulic master cylinders for achieving independent brake operation and for combined brake operation involving actuation of just the front wheel brake on actuation of rear wheel brake. Accordingly, a larger caliper member (two or more pots) is required on the front wheel. Out of the two master cylinders, one master cylinder is used to actuate one or more pots of the caliper member of the front wheel brake when one brake lever is actuated. Other master cylinder is also used to actuate other pots of the caliper member (other than the pots earlier mentioned) of the front wheel brake when the other brake lever is actuated. Thus, for operating the front wheel brake itself, two master cylinders are required in some cases. Additionally, a third master cylinder is required for actuating the rear wheel brake. Hence, the number of master cylinders and the corresponding hydraulic connections are larger making it a complex system.

Further, some braking systems use a pressure control valve and a hydraulic delay member. The braking systems with more than two master cylinders or with pressure control valves and hydraulic delay members have multiple joints therebetween and multiple hoses. The braking system with multiple joints/ hoses becomes complex and moreover, space has to be created on the vehicle for mounting the components and for routing of hoses. The master cylinder that operates in conjunction with hydraulic hoses requires hydraulic fluid in large quantities adding to the cost, potential pressure drop owing to long hose length and complexity of oil filling during assembly and maintenance. Moreover, these systems are expensive due to multiple components and their need for multiple mechanical or hydraulic connections between them adding to the weight of the vehicle. Few other systems known in the art incorporate a hydraulic connection between a valve of the rear wheel brake and a front wheel brake to achieve a combined braking, which is even more complex due to the hose length that may lead to pressure drop and due to interdependency between the systems.

Some other braking systems known in the art have a master cylinder assembly with multiple levers disposed away from the brake lever. The brake lever is connected to these multiple levers to actuate the master cylinder assembly. Hence, longer cables are required in such systems and for actuating the master cylinder assembly, the cables have to be again connected to the levers to actuate the piston of the master cylinder thereby increasing the number of components and joints. Moreover, as the multiple master cylinder could not be placed in a place that is visible to the user making it a challenge for the user to observe and act when an oil level in the hydraulic system goes down below a low-level. Accessing the master cylinder for maintenance and oil filling is also cumbersome. In the aforementioned and other systems known in the art, typically, the master cylinder is fixedly mounted to the vehicle. Further, in certain vehicles which are typically referred to as scooters, a headlamp assembly is also mounted on the handlebar assembly and accommodating more than two master cylinders is a challenge in the vicinity of the handlebar due to crowding of various components thereat leading to a compromise of size of the handlebar assembly and its covers making it look bulky with undesirable aesthetics. Also, addition of excess mass on the steering axis leads to poor steering performance of the vehicle arising out of the inertia effects.

Hence, there exists a challenge to provide a compact braking system that is capable of actuating first wheel brake and second wheel brake simultaneously. It should be capable of being accommodated in a compact vehicle like two-wheeled or three-wheeled vehicles without occupying more space and by utilising a smaller number of components without any compromise on braking effectiveness and safety. Thus, the present subject matter provides a brake system according to claim <NUM> that addresses the aforementioned and other problems in the prior arts.

The present subject matter provides a brake system for a vehicle. The vehicle comprises one or more first wheel brake(s) connected to one or more first wheel(s). The one or more first wheel brake(s) being capable of applying braking forces to the one or more first wheel(s). One or more second wheel brake(s) connected to the one or more second wheel(s). The one or more second wheel brake(s) capable of applying braking forces to the one or more second wheel(s) of the vehicle. The first wheel brake(s) can be front wheel brake(s) corresponding to front wheel(s) and the second wheel brake(s) can be rear wheel brake(s) corresponding to rear wheel(s) or vice-versa.

The brake system comprises a first brake lever functionally coupled to the one or more first wheel brake(s) through a first actuating member. The first actuating member can be a hydraulic master cylinder or a mechanical brake cable. A second brake lever, which is capable of actuating both the one or more first wheel brake(s) and the one or more second wheel brake(s) synchronously is provided.

A second actuating member of the brake system is rotatably pivoted. The second actuating member is capable of actuating the one or more second wheel brake(s). The second brake lever is configured to directly actuate the second actuating member. The first actuating member is synchronously actuated by a reaction force generated in the second actuating member and due to the second actuating member being rotatably pivoted.

The brake system is provided with the second actuating member, which is rotatably pivoted to a structural member of the vehicle, to actuate the second wheel brake(s) upon application of the second brake lever; and the reaction force from the second actuating member is configured to actuate the first actuating member. By using a single effort at the second brake lever, both the first wheel brake(s) and the second wheel brake(s) are actuated. As there is no brake force distribution and due to the utilization of the reaction force, the effort required for synchronously actuating both wheel brakes are less when compared to prior arts systems.

In one embodiment, the second actuating member is rotatably pivoted through a second pivot mounting. The second pivot mounting is provided in proximity to a piston-actuation portion of a piston of the second actuating member. For example, if the piston and the corresponding piston-actuation portion are provided on one side, the second pivot mounting is disposed in proximity to the mentioned one side. In one implementation, a fluid output of the second actuating member is disposed on a side opposite to the side at the which the piston-actuation portion is provided.

In one embodiment, the (brake) system comprises an additional transmission member functionally engaging with the second actuating member and the first actuating member. The additional transmission member comprises a first end rotatably pivoted and a second end configured to actuate first actuating member. In a first embodiment, the first actuating member and the second actuating member are mounted to a handlebar assembly of the vehicle and the additional transmission member has a short length that extends between the first actuating member and the second actuating member. The length of cable required is minimal, thereby additionally keeping any transmission loss to a minimal.

In one embodiment, the additional transmission member is a brake cable having an outer cable and an inner cable slidable about the outer cable. A first end of the inner cable is rotatably pivoted near to the second actuating member.

In one embodiment, the second actuating member comprises an engaging arm. The engaging arm is provided with a passage portion. The outer cable has one end i.e. the first end that abuts the engaging arm and the inner cable passes through the passage portion to be rotatably pivoted thereafter. In one implementation, the engaging arm is integrally formed with a body of the second actuating member.

In one implementation, the second end of the additional transmission member is configured to actuate the first actuating member, which is being a hydraulic master cylinder through a secondary lever assembly. The secondary lever assembly is configured to actuate a piston of the first actuating member and the second end of the additional transmission member is configured to actuate the second lever assembly due to a reaction of the second actuating member.

In one another embodiment, the second end of said additional transmission member is configured to actuate a first actuating member, which is a first brake-cam lever. The first brake-cam lever is part of a drum brake and actuation of the first brake-cam lever actuates brake shoes of the drum brake.

In one embodiment, the second brake lever and the first end of the additional transmission member are each rotatably pivoted to a first support. The first support is supported by a structural member of the vehicle. The structural member can be a handlebar assembly, in one implementation. In another implementation, the structural member can be a frame assembly of the vehicle.

In one embodiment, the second actuating member is rotatably pivoted to a structural member of the vehicle. In one implementation, the second actuating member is rotatably pivoted to a handlebar assembly through a mounting arm of the second actuating member.

In another embodiment, the second brake lever and the second actuating member are each rotatably pivoted to a first support. The first support is supported by a structural member of the vehicle.

In one embodiment, the first end of the additional transmission member is connected to a second support. The first support, which supports the second brake lever and the second actuating member, and the second support are securely supported by a structural member of the vehicle. The structural member includes at least one of a handlebar assembly and a frame assembly of the vehicle.

In one embodiment, the second actuating member is rotatably pivoted through a first pivot mounting. The second actuating member is configured to rotate in a clockwise direction when the first pivot mounting is disposed between a piston axis of the second actuating member and a structural member. In one implementation, the second actuating member is rotatably pivoted to the handlebar assembly through the mounting arm and the engaging arm is disposed on a side opposite to the side of the mounting arm.

In one embodiment, the second actuating member is rotatably pivoted through a first pivot mounting. The second actuating member is configured to rotate in an anti-clockwise direction when the first pivot mounting is disposed away from a region formed between a piston axis of the second actuating member and a structural member. Depending on the space requirements on the vehicle, the second actuating member can be adapted to be rotated in the clockwise direction and the anti-clockwise direction such that interference with other ancillary parts is avoided.

In one embodiment, the braking system comprises a stopper provided on the structural member. The stopper is configured to restrict the rotation of the second actuating member beyond a certain degree of rotation whereby excessive braking force to the first wheel brake(s) is avoided.

In one embodiment, the stopper engages with a body of the second actuating member to restrict the rotation thereof. In another embodiment, the stopper engages with the engaging arm of the second actuating member to restrict thereof.

The present invention provides a corresponding method of method of operation of the brake system. The comprising the steps of actuating a second actuating member disposed in a rotatably pivoted mounting. Causing a rotary movement of the second actuating member due a reaction force (say a third reaction force) generated in the second actuating member. Actuating the first actuating member through the additional transmission member, which is functionally engaging with the second actuating member, due to the rotational movement of the second actuating member. The functional engagement can be abutment or the like. Thereby actuating the first wheel brake through the first actuating member and a second wheel brake through the second actuating member synchronously.

Further, the method comprises performing a stopping of the rotational movement of the second actuating member by a stopper thereby restricting the rotational movement beyond a predetermined angle during failure of the additional transmission member. The predetermined angle is specific to a configuration of the second actuating member and dimensional parameters of the vehicle. The predetermined angle can be an angle beyond which if the second actuating member rotates, it affects operation of the second actuating member.

For example, in one embodiment, the stopper acts as a fail-safe member to enable actuation of the second wheel brake when there is a breakage of the additional transmission member. Arrows wherever shown in the drawings represents a front direction.

These and other advantages of the present subject matter would be described in greater detail in conjunction with, the figures in the following description. The present subject matter is further described with reference to accompanying figures. It should be noted that the description and figures merely illustrate principles of the present subject matter. Various arrangements may be devised that, although not explicitly described or shown herein, encompass the principles of the present subject matter. Moreover, all statements herein reciting principles, aspects, and examples of the present subject matter, as well as specific examples thereof, are intended to encompass equivalents thereof.

<FIG> illustrates a schematic layout of a brake system for a vehicle, in accordance with an embodiment of the present subject matter. The vehicle comprises one or more front wheel(s) and one or more rear wheel(s) (not shown). A power unit (not shown) is provided on the vehicle. The power unit is either fixedly or swingably mounted to the vehicle. The power unit can be at least one of an internal combustion engine and an electric motor. The power unit is configured to drive one or more wheel(s) of the vehicle. The brake system (hereinafter also referred to as 'system') <NUM> comprises one or more first wheel brake(s) <NUM> and one or more second wheel brake(s) <NUM> corresponding to the one or more front wheel(s) and the one or more rear wheel(s), respectively. Hereinafter, the terms `first wheel brake' and 'second wheel brake' are referred to in singular form, for brevity and ease of explanation but not by way of limitation. In one implementation, the second wheel brake <NUM> is a disc brake. The disc brake is at least partially supported on the rear wheel i.e. a disc member of the disc brake is mounted to the rear wheel and a caliper member that operates with the disc member is mounted to a swingarm of the vehicle. In the depicted embodiment, the front wheel brake <NUM> is also a disc brake. In another implementation, the front wheel brake <NUM> can be a drum brake.

Further, in accordance with one embodiment, a first switch assembly <NUM> and a second switch assembly <NUM> are mounted to a structural member <NUM> like a handlebar assembly. Herein, the terms 'structural member' and `handlebar assembly' are interchangeably used. The first switch assembly <NUM> and the second switch assembly <NUM> are disposed adjacent to a corresponding handle grips (not marked). A first brake lever <NUM> is mounted to a handlebar assembly <NUM> of the vehicle. Similarly, a second brake lever <NUM> is mounted to the handlebar assembly <NUM> of the vehicle. In the depicted implementation, the first brake lever <NUM> is mounted on a right-hand side and the second brake lever <NUM> is mounted on a left-hand side of the handlebar assembly <NUM>. In another implementation, the second brake lever <NUM> is a foot-operated brake lever, and the foot-operated brake lever is disposed near a rider-footrest on the right-hand side of the vehicle. The first brake lever <NUM> is functionally coupled to the first wheel brake and is configured to actuate the first wheel brake <NUM>. The second brake lever <NUM> is capable of actuating both the first wheel brake <NUM> and the second wheel brake <NUM> in a synchronous manner. The first wheel brake can be one a front wheel brake and a rear wheel brake. The second wheel brake can be other of the front wheel brake and the rear wheel brake. In a preferred implementation, the first wheel brake is the front wheel brake and the second wheel brake is the rear wheel brake.

A first actuating member <NUM> is functionally coupled to the first brake lever <NUM>. The first actuating member <NUM> is a hydraulic master cylinder, in accordance with one implementation. The first actuating member <NUM> comprises a piston (not shown). The first actuating member <NUM>, which is rotatably pivoted on the handlebar assembly <NUM>, is capable of actuating the piston thereof. When the rider operates the first brake lever <NUM>, the first brake lever <NUM> undergoes pivotal rotation thereby exerting force on the piston of the first actuating member <NUM>. The piston of the first actuating member <NUM> exerts pressure, which gets transmitted to the first wheel brake <NUM> through a first transmission member <NUM>. In one embodiment, the first transmission member <NUM> is a brake hose capable of transmitting hydraulic fluid.

The second brake lever <NUM> is rotatably pivoted on the handlebar assembly, in accordance with one embodiment. The second brake lever <NUM> may be rotatably pivoted on the handlebar assembly <NUM>, in accordance with an implementation. Application of the second brake lever <NUM> actuates a second actuating member. The second actuating member <NUM> is configured to actuate the second wheel brake <NUM> upon actuation thereof. In one implementation, the second actuating member <NUM> is a hydraulic master cylinder. The second actuating member <NUM> comprises a piston (not shown). Exertion of force on the piston, causes the piston to move/slide whereby a change in pressure is created. The second actuating member <NUM> is connected to the second wheel brake <NUM> through a second transmission member <NUM>. The change in pressure due to the movement of the piston is transmitted through the second transmission member <NUM> and to the second wheel brake <NUM>. In an implementation, the second brake lever <NUM> is supported by the second actuating member <NUM>.

An additional transmission member <NUM> is operatively coupled to the second actuating member <NUM>. In other words, the second brake lever <NUM> is configured to actuate the first wheel brake <NUM> through the second actuating member <NUM> and the additional transmission member <NUM>. In one embodiment, the additional transmission member <NUM> is a brake cable. In another embodiment, the additional transmission member <NUM> can be a brake hose or a combination of brake cable and brake hose. In one implementation, the first wheel brake <NUM> is a drum brake and the additional transmission member <NUM> functionally connects the second brake lever <NUM> to a front brake-cam lever. The front brake - cam lever is a lever of the drum brake that is capable of actuating the drum brake upon rotation. A secondary lever assembly (not shown) is rotatably pivoted near the first actuating member <NUM> and is capable of independently actuating the piston of the first actuating member <NUM> without any interference with the first brake lever <NUM>. The actuation of the first wheel brake <NUM> and the second wheel brake <NUM> by actuation of the second brake lever <NUM> is explained through the subsequent figures.

<FIG> illustrates a schematic view of a portion of the brake system, in accordance with an embodiment of the present subject matter. The brake system <NUM> comprises a second brake lever <NUM>, which is rotatably pivoted to a first support <NUM>. The second brake lever <NUM> comprises of a holding portion <NUM>, an engaging portion <NUM>, a first pivot mounting <NUM>. Through the first pivot mounting <NUM>, the second brake lever <NUM> is rotatably pivoted to the first support <NUM>. In one embodiment, the first support <NUM> is a rigid support member mounted to the handlebar assembly <NUM>. As the pivot point is fixed, and not dynamic, it is herein referred to using the terms "rotatably pivoted". The holding portion <NUM> is the portion of the second brake lever <NUM> where the user exerts force for application of brake synchronously. In the depicted implementation, the second brake lever <NUM> is an L-shaped member having a longer arm and a shorter arm. The longer arm, as can be perceived from <FIG>, acts as the holding portion <NUM>. The shorter arm forms the engaging portion <NUM>. The second actuating member <NUM> is rotatably pivoted to the handlebar assembly <NUM>, in accordance with one embodiment, through a second pivot mounting <NUM>. The second mounting member <NUM> is rotatably pivoted through a mounting arm <NUM>.

Further, the second actuating member <NUM> comprises a piston <NUM>, which is slidable within a cylinder section <NUM>. The second actuating member <NUM> comprises a fluid output <NUM>. At the fluid output <NUM>, the second transmission member <NUM> (shown in <FIG>) is connected. The engaging portion <NUM> of the second brake lever <NUM> is configured to actuate the piston <NUM> at a piston-actuation portion <NUM> to actuate the second wheel brake <NUM>. In one embodiment, the second pivot mounting <NUM> is at an offset from a first centre, which is taken in a long axis direction of a body <NUM>. In other words, the second pivot mounting <NUM> is away from the first centre, which is taken in the long axis direction of the body <NUM>. Further, a second centre, which is taken in a direction orthogonal to the long axis of the body <NUM>. As part of one implementation, the second pivot mounting <NUM> is supported on at least one side of the body <NUM> but away from the centre of the corresponding side.

In one embodiment, the second actuating member <NUM> comprises a long axis disposed substantially along the handlebar assembly <NUM>. The piston <NUM> is slidable within the cylinder section <NUM> along a piston axis P-P'. The piston <NUM> has the piston-actuation portion <NUM> extending out from one side, along the long axis and the fluid output <NUM> is disposed on other side. The second pivot mounting <NUM> is disposed in proximity to a portion at which the piston <NUM> receives force from the second brake lever <NUM>. For example, in the depicted implementation showing a plan schematic view, the piston <NUM> protrudes out from a cylinder body (not marked) at a left-hand side. The fluid output <NUM> is on the right-hand side, and both the fluid output <NUM> and the piston <NUM> (input) are along the long axis of the body <NUM>. The second pivot mounting <NUM> is provided on a side of the cylinder body facing the handlebar assembly <NUM> in order to be rotatably pivoted thereto.

The second actuating member <NUM> comprises an engaging arm <NUM>. The engaging arm <NUM> is disposed on a side opposite to a side at which the second actuating member <NUM> is rotatably pivoted. In one implementation, the mounting arm <NUM> is disposed on one side of the piston axis P-P' and the engaging arm <NUM> is disposed on other side of the piston axis P-P'. The engaging arm <NUM> is integrally formed with the body <NUM> or is connected to the body <NUM> by any knowns means including fastening. In one embodiment, the engaging arm <NUM> comprises a passage portion <NUM>. The passage portion <NUM> is a path with minimal friction. Further, the additional transmission member <NUM> comprises an outer cable <NUM> and an inner cable 225I slidable therein. At the first end <NUM>, the outer cable <NUM> abuts the engaging arm <NUM> and the inner cable 225I passes through the passage portion <NUM>. The inner cable 225I that passes through the passage portion <NUM> is rotatably pivoted to the first support <NUM>. A second end (not shown) of the additional transmission member <NUM> is functionally coupled to the first actuating member.

<FIG> illustrates another schematic view of a portion of the brake system, in accordance with an embodiment of the present subject matter. <FIG> illustrates another schematic view of a portion of the brake system in an actuated condition, in accordance with an embodiment of the present subject matter. <FIG> illustrates another schematic view of a portion of the brake system in a further actuated condition, in accordance with an embodiment of the present subject matter. As shown in <FIG>, the second brake lever <NUM> is rotatably pivoted to a first bracket <NUM>. The second actuating member <NUM> is rotatably pivoted to a second bracket <NUM>. The first end <NUM> of the additional transmission member <NUM> is rotatably pivoted to a third bracket <NUM> and through a third pivot mounting <NUM>. In the current embodiment, the first bracket <NUM> and the third bracket <NUM> are supported by the first support <NUM>. For synchronously actuating the first wheel brake <NUM> and the second wheel brake <NUM> (shown in <FIG>), the rider actuates the second brake lever <NUM> that causes it to rotate about the first pivot mounting <NUM>.

When the rider exerts an input force F1, an enhanced force F11 due a lever ratio of second brake lever <NUM> is applied to the second actuating member <NUM> through the engaging portion <NUM>. In one embodiment, the second brake lever <NUM> is a first order lever and the enhanced force F11 is a product of input force F1 with a ratio of a lever length L1 to an arm length L11. The lever length L1 is distance between a point of the input force F1 and the first pivot mounting <NUM>. Since the input force is applied at various points, an average of the various distances is considered for calculating the lever length L1. The arm length L11 is distance between the first pivot mounting <NUM> and a point of contact of the engaging portion <NUM> with the piston <NUM>. The enhanced force F11 is acting on the piston <NUM>. The piston <NUM> is preloaded with an elastic member (not shown) like a spring member. Due to the preloading on the piston and due to hydraulic fluid in the cylinder section <NUM>, a second reaction force F2 is generated by the second actuating member <NUM>. The enhanced force F11 and the second reaction force F2 are shown as arrows. When the user increases the input force F1, the piston <NUM> creates hydraulic pressure in the cylinder section due to the movement of the piston <NUM>. The movement of the piston <NUM> creates a second force F21 acting on the piston <NUM>. Due to the second force F21, a third reaction force F3 is created in the cylinder section <NUM>. The third reaction force F3 acts on the body <NUM> of the second actuating member <NUM>. The enhanced force F11 causes the piston <NUM> to slide and actuate the second wheel brake <NUM> (shown in <FIG>) through the fluid output. The second reaction force F2 and the corresponding third reaction force F3, due to the second pivot mounting <NUM> (rotatably pivoted) of the second actuating member <NUM> causes it to rotate about the second pivot mounting <NUM>. In effect, work done i.e. the movement of piston <NUM> translates into actuation of the second wheel brake <NUM> by hydraulic fluid and into pivotal movement of the second actuating member <NUM>. Once a force equilibrium is achieved, the pivotal movement of the second actuating member <NUM> stops.

In one embodiment, the second actuating member <NUM> acts as a third order lever. Therefore, a third force F31, due to the lever ratio offered by the second actuating member <NUM>, acts at end of the engaging arm <NUM>. For example, the third force F31, which is the product of the third reaction force F31 and a ratio of an offset distance L3 to an engaging arm length L4. The offset distance L3 is a distance between the second pivot mounting <NUM> and a point at which the third reaction force F31 acts on the body <NUM>. Even in the present scenario, an average is considered to calculate the offset distance L3 as the force acts at various points on the cylinder section <NUM>. The engaging arm length L4 is the distance between the second pivot mounting <NUM> and a portion at which the engaging arm <NUM> abuts the additional transmission member <NUM>. The effort/force acting on the second actuating member <NUM> is closer to the second pivot mounting <NUM> when compared to a load, which is due to a force exerted by the additional transmission member <NUM> on the engaging arm <NUM>. The third force F3 due to the second reaction force F2 causes the second actuating member <NUM> to rotate in a clockwise direction, when viewed in a plan view. In a fixed-type of body, the entire force is used to actuate the second wheel brake. Whereas, in the current invention, the work done due to the motion of the piston <NUM> is used to actuate the second wheel brake <NUM> and a third reaction force F3 is used to rotate the second actuating member <NUM> thereby actuating the first wheel brake <NUM>.

Further, due to the motion of the second actuating member <NUM> is dependent on the force-balancing, the system operates in a reliable manner. Even if there is a free play between first wheel brake and the second wheel brake due to wear or usage, the system exerts the desired braking force as the motion is controlled when a force equilibrium is achieved. Moreover, by using the lever ratio of the second brake lever <NUM>, the effort required for actuating of the both the first wheel brake and the second wheel brake is minimal, as the same effort is used to operate both wheel brakes by making use of the third reaction force.

Further, the outer cable 225O is also preloaded. In one implementation, the outer cable 225O is preloaded at the second end by using an elastic member that includes a spring or the like. The rotational motion of the second actuating member <NUM> exerts a force F21 on the outer cable 225O, which abuts the engaging arm <NUM> of the second actuating member <NUM>. The engaging arm <NUM> slides along the inner cable 225I and pushes the outer cable 225O. The second actuating member <NUM>, which acts a third order lever, provides larger displacement of the engaging arm <NUM> even with smaller angular change. For example, as the load (additional transmission member) is away from the second pivot mounting <NUM>, as shown in <FIG> & <FIG>, the smaller angular rotation of the second actuating member <NUM> provides larger displacement of the outer cable 225O. The push effect of the outer cable 225O creates a pull effect on the inner cable 225I. As the second end of the additional transmission member <NUM> is coupled to the first actuating member <NUM>, the first actuating member <NUM> is actuated by the pull of the inner cable 225I. The outer cable 225O, which is preloaded, also exerts a third reaction force F3 acting on the engaging arm <NUM>. This fourth reaction force F4 acting on the engaging arm <NUM> of the second actuating member <NUM> that leads to resultant sliding actuation of the piston <NUM> by the application of the second brake lever <NUM>.

Further, as shown in <FIG>, beyond a certain angle, the rotation of the second actuating member <NUM> is restricted. The braking system <NUM> is provided with a stopper <NUM>, which is configured to restrict a rotation of the second actuating member <NUM> beyond a certain angle. This helps in restricting excessive braking force to the first actuating member <NUM> and to the corresponding first wheel brake <NUM>. When the rider further exerts braking force on the second brake lever <NUM>, only the second actuating member <NUM> is actuated. Further, the stopper <NUM> acts as a fail-safe. Whenever, there is a failure like breakage of additional transmission member <NUM>, the second actuating member <NUM> rotates and abuts the stopper <NUM> since there is no reaction force from the additional transmission member <NUM>. Thus, during such breakage, the application of the second brake lever <NUM> actuates the second wheel brake <NUM> thereby providing an independent operation of the second wheel brake <NUM> and achieving a fail-safe working.

In the depicted embodiment, as shown in <FIG>, the second brake lever <NUM> and the second actuating member <NUM> are in proximity to the handlebar assembly <NUM>. The current embodiment, is preferably applicable to brake system <NUM>, which is having the second brake lever <NUM> as a hand-operated brake lever. In the hand-operated brake lever, the user rests his hands on the handlebar assembly <NUM> and applies force to the second brake lever <NUM> during need for application of brake. It is preferred that the distance between the second brake lever <NUM> and the handlebar assembly <NUM> is small for ease of use.

<FIG> a schematic view of a portion of the brake system <NUM>, in accordance with a second embodiment of the present subject matter. The brake system <NUM> comprises a second brake lever <NUM> rotatably pivoted through a first pivot mounting <NUM> to a first support <NUM>. A second actuating member <NUM> rotatably pivoted through a second pivot mounting <NUM> to a second support <NUM>. An additional transmission member <NUM> rotatably pivoted to a second support <NUM> through a third pivot mounting <NUM>. In one implementation, the first support <NUM> and the second support <NUM> are supported by a structural member <NUM>. In one implementation, the structural member <NUM> is a handlebar assembly. In another implementation, the structural member is a frame assembly (not shown).

The second actuating member <NUM> comprises a piston <NUM>, which is slidable along a piston axis P-P'. Further, the second actuating member <NUM> comprises an engaging arm <NUM> disposed on one side of the piston axis P-P' and a mounting arm <NUM> disposed on other side of the piston axis P-P'. The mounting arm <NUM> is configured for fixedly pivoting the second actuating member <NUM>. In the depicted embodiment, the second pivot mounting <NUM> is disposed on a side away from the structural member <NUM>. The second actuating member <NUM> in the present embodiment rotates in an anti-clock wise direction, as shown in <FIG> and <FIG>. In other words, the second actuating member <NUM> rotates in a clockwise direction when the second pivot mounting is disposed between the structural member and the piston axis P-P'. It rotates in anti-clock wise direction when the second pivot mounting <NUM> is disposed outside of a region formed between the piston axis P-P' and the structural member <NUM>. <FIG> illustrates a schematic view of the brake system <NUM> in an actuated condition, in accordance with the second embodiment of the present subject matter. <FIG> illustrates a schematic view of the brake system <NUM> in a further actuated condition, in accordance with the second embodiment of the present subject matter.

A first end <NUM> of the additional transmission member <NUM> is connected to the second support <NUM> and a second end (not shown) thereof is connected to a first actuating member (not shown). A stopper <NUM> is provided on the structural member <NUM>. The stopper <NUM> restricts the rotation of the second actuating member <NUM>. In one implementation, the engaging arm <NUM> of the second actuating member <NUM> engages with the stopper <NUM> thereby restricting further rotation. Further, the stopper acts a fail-safe during any failure of the additional transmission member <NUM>.

Upon actuation of the second brake lever <NUM> with an input force, the second brake lever <NUM> exerts an enhanced force on the piston <NUM> of the second actuating member <NUM>. The second actuating member <NUM> generates a second reaction force due to the enhanced force exerted thereon. When the user increases the input force, it causes a corresponding increase in the enhanced force thereby moving the piston <NUM>. The piston <NUM> moves till a force equilibrium/balance is achieved between the enhanced force and the second reaction force. The motion of the piston <NUM> causes an increase in pressure in a cylinder section <NUM> of the second actuating member <NUM> creating a corresponding second force F21. The second force F21 further creates a third reaction force F3. The third reaction force acting on the second actuating member <NUM> causes it to rotate in the anti-clockwise direction with respect to the second pivot mounting <NUM>. In the present embodiment, the engaging arm <NUM> extends towards the structural member <NUM> and the additional transmission member <NUM>. The additional transmission member <NUM>, at least partially disposed between the second actuating member <NUM> and the structural member <NUM>, is actuated due to the rotation of the second actuating member <NUM>. The first actuating member <NUM> (as shown in <FIG>) that is coupled to the additional transmission member <NUM> is actuated. The inner cable 325I experiences a pull effect due to a pushing of the outer cable 325O by the engaging arm <NUM>. The outer cable 325O also generates a reaction force.

At equilibrium condition, the force actuating the second actuating member <NUM> and the reaction of second actuating member <NUM> acting on the additional transmission member are balanced by each other. Hence, the force-balancing for this configuration is more reliable to achieve variable free play between first wheel brake and the second wheel brake. The effort required for actuating of the both the first wheel brake and the second wheel brake is minimal.

Although the subject matter has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible. It is to be understood that the appended claims are not necessarily limited to the features described herein. Rather, the features are disclosed as embodiments of the braking system of the present subject matter.

Claim 1:
A brake system (<NUM>, <NUM>) for a vehicle, said vehicle comprising:
one or more first wheel brake(s) (<NUM>), said one or more first wheel brake(s) (<NUM>) being connected to the one or more first wheel(s) and, said one or more first wheel brake(s) (<NUM>) being capable of applying a braking force to said one or more first wheel(s) of said vehicle;
one or more second wheel brake(s) (<NUM>), said one or more second wheel brake(s) (<NUM>) being connected to one or more second wheel (s), and said one or more second wheel brake(s) (<NUM>) being capable of applying braking forces to said one or more second wheel(s) of said vehicle;
a first brake lever (<NUM>), said first brake lever (<NUM>) being functionally coupled to said one or more first wheel brake(s) (<NUM>) through a first actuating member (<NUM>);
a second brake lever (<NUM>, <NUM>), said second brake lever (<NUM>, <NUM>) being capable of actuating both said one or more first wheel brake(s) (<NUM>) and said one or more second wheel brake(s) (<NUM>) synchronously; and
a second actuating member (<NUM>, <NUM>) capable of actuating said one or more second wheel brake(s) (<NUM>), wherein
said second brake lever (<NUM>, <NUM>) is configured to directly actuate said second actuating member (<NUM>, <NUM>), and wherein
said first actuating member (<NUM>) is synchronously actuated by a reaction force of said second actuating member (<NUM>), characterised in that said second actuating member (<NUM>) is rotatably pivoted to a structural member (<NUM>) of said vehicle.