DESC:FIELD OF INVENTON
[0001] The invention relates to a brake system in an automotive vehicle and more particularly, it relates to a combined brake system in vehicle.

CROSS-REFERENCE TO RELATED APPLICATIONS
[0002] This invention takes priority from an earlier filed provisional patent application no. 202221044473 filed on August 03, 2022; which is incorporated herein as reference.

BACKGROUND OF THE INVENTION
[0003] In a conventional independent brake system for vehicles, a front brake and a rear brake are operated independent of each other. The front brake is actuated by rider through an actuation lever generally mounted on a handlebar of a vehicle, while the rear brake is actuated by rider through a foot pedal generally mounted on the frame or actuated by pressing the rear brake actuation lever by hand similar to front brake system.
[0004] This braking system has certain disadvantages linked to it. Generally, when the rider applies either front or rear brakes, the braked wheel tends to lock up faster than in case of braking both wheels together through application of both brakes together. Further, a need is felt for reducing the braking distance of the vehicle, which is not possible for independent braking mechanism as individual operation of brake tends to lock the wheel of the vehicle after a considerable distance travel. Also, there remains a high probability that the driver accidentally operates only front or rear brake alone during panic, causing skidding of the respective wheel. During aggressive braking the front brake is used more than the rear brake, which leads to sudden shift of weight on front side, on the other hand only rear braking increases stopping distance for vehicle. Hence, a need is felt to have more control over the vehicle.
[0005] In view of the above encumbrances, a Combined Braking system (CBS) has been developed which caters to the better distribution of the brake forces between both the wheels, to achieve better deceleration. Hence, it enhances safety of the rider as the body inertia is well balanced due to the symbiotic action of both the wheels.
[0006] A rear brake with combined braking system/ mechanism (CBS) is preferable for the rider to experience better braking over that of only rear brakes application or only front brake application. This is due to the fact that the load transfer during braking event leads to an increase in front axle reaction and decrease in rear axle reaction. As a result, it is recommended that the CBS engage the rear wheel brake first for all road conditions. The available wheel reaction at the rear brake is more before braking event starts and after a certain delay the front wheel brake is engaged when the available wheel reaction starts increasing.
[0007] Although for the aforementioned advantages the known combined brake system for vehicle has some limitations.
[0008] For braking force allocation, most of the current CBS systems are constructed with a fixed leverage ratio generally with larger allocation on rear over front (called simple CBS). Simple CBS provides the benefits of minimal costs and ease of implementation.
[0009] However, simple CBS is typically designed with a fixed leverage ratio with small front brake force allocation making the conventional CBS system inefficient to quickly stop the vehicle with better braking experience.
[0010] For the simple CBS with fixed leverage ratio and small front brake force allocation, the front braking is not very effective and over this the rear wheel might get locked during excessive braking efforts. Due to less front braking force there is not adequate deceleration to stop the vehicle in the least possible stopping distance. To achieve significant deceleration while maintaining the motorcycle's stability during emergency braking, a varying front braking force and rear braking force distribution ratio is required.
[0011] This unsatisfactory braking operation causes premature brake degradation and only allows the braking system to function for a short period of time. This is extremely unreliable and necessitates frequent repair of the apparatus, resulting in increased braking system operating costs. Further there may be wear & tear, degeneration of the tires due to unsatisfactory braking operation.
[0012] It has been observed that there is an abrupt increase of braking force on the front wheels in the conventional combined brake systems that have been designed with excessive front bias with fixed brake force distribution which leads to untoward incidents of accident. Due to continuous usage in such brake systems, there has been uneven wear and tear of the rear and front brake shoe, most prominent is the wearing of the rear brake shoe wear due to comparatively higher usage of the rear brake system. Hence, the rider/user while operating in these circumstances do not get any indication or feeling of the malfunction of the brakes, leading to locking of the front wheel first against the rear wheel, which is controlling the drive wheel especially during panic condition. This can lead to serious accidents which can be life threatening. Also, this results in frequent replacement of brake shoes or adjustments of brake shoe wear.
[0013] Even if the above-mentioned factor is mitigated to some extent, by providing a brake nut adjustment at the front brake still a problem lies that due to comparatively excess bias distribution there may be more wearing of the front brake shoe in that case. This may lead to fatal accidents.
[0014] The conventional braking systems have greater number of linkages involved, leading to a complex braking system which not only needs troublesome servicing in case of repair, but also this ultimately leads to a certain lag for the rear brake operation. Further, there is space constraint especially for two wheeled vehicles to accommodate greater number of brake linkages.
[0015] In addition to that, the cost of the vehicle vis a vis the brake system increases due to employment of more linkages required to provide a variable ratio compact braking system.
[0016] Further, some vehicles comprise of a single link to actuate the braking system. Although it provides a compact system but the objective of achieving variability in the front and rear braking system of the vehicle cannot be achieved with that.

OBJECT OF THE INVENTION
[0017] An object of the invention is to provide a Brake System that produces appropriate braking force distribution (BFD) ratio to generate adequate braking force under most driving conditions.
[0018] Yet, another objective of the invention is to optimally design a braking system, which has improved manufacturability, is of low cost and is less complex.
[0019] A further object of the invention is to provide brake linkage systems with varying brake distribution ratio to front & rear brakes.
[0020] Another object of the invention is to provide a brake system for a vehicle which is compact, lightweight and provides better aesthetics of the vehicle.
[0021] Another object of the invention is to reduce the number of linkages of the braking system.
[0022] Another object of the invention is to provide enhanced deceleration and reduced stopping distance of the vehicle.
[0023] Another objective of the invention is to avoid kinematic lock of the mechanism during full operation.
[0024] A further object of the invention is to aid rider safety & avoid front wheel lock during braking.
[0025] Still another object of the invention is to overcome lacunas of existing system explained herein above.

SUMMARY OF THE INVENTION
[0026] With the above objectives in view, the present invention provides a brake system for a vehicle comprising:
[0027] a front brake system including:
[0028] at least a front brake actuator, and a front brake panel connected to the front wheel of the vehicle;
[0029] a rear brake system including:
[0030] at least a rear brake actuator, and a rear brake panel connected to the rear wheel of the vehicle;
[0031] at least a brake operating means comprising of a brake pedal for actuating at least the front brake actuator or a rear brake actuator;
[0032] force distribution mechanism comprising of brake linkages connected to the brake operating means for force distribution comprising:
[0033] at least a first link and a second link connected to at least a front brake actuator or rear brake actuator; wherein the first link provided with a first pivot enabling sliding movement of the first pivot within the first link to vary ratio of braking force distribution for the front brake system and the rear brake system.
[0034] According to an embodiment of the invention, the first link is mounted on the second link through a second pivot; wherein the second pivot is connected to the first pivot.
[0035] According to an embodiment of the invention, the first pivot on the first link is connected to the second pivot by means of an elastic or flexible or recoil arrangement. According to an exemplary embodiment, the arrangement is a recoil spring.
[0036] According to an embodiment of the invention, a force distribution mechanism comprising plurality of brake linkages mounted on the front brake actuator and rear brake actuator provided on front brake panel and rear brake panel respectively.
[0037] According to an embodiment of the invention, the rear brake actuator comprises of a lever, which may be a brake lever. The front brake actuator comprises of a front brake cable and a lever in case of a drum-drum configuration for front & rear applications, comprises of a front brake cable and a secondary lever in front master cylinder in case of a disc-drum configuration for front & rear applications. According to an embodiment of the invention, the first pivot may be the cam end of the brake lever.
[0038] According to an embodiment of the invention, the brake operating means comprises a brake pedal or hand brake lever connected to the second link preferably by a brake rod or hose or wire.
[0039] According to an embodiment of the invention, the second link is connected to the rear brake actuator through a third pivot and operates the rear brake actuator to actuate the rear brake system.
[0040] According to an embodiment of the invention, the first link is pivotally connected to the front brake actuator and is operated by the second link vis a vis the brake pedal or hand brake lever to actuate the front brake.
[0041] According to an embodiment of the invention, upon actuating brake operating means; the first link and second link collinearly moves to generate a fixed ratio combined braking force on front and rear brake system till the rear brake actuator free play is consumed.
[0042] According to an embodiment of the invention, upon consumption of free play of rear brake actuator; the second link is rotated on the third pivot provided on the brake lever, leading to the rotation of the first link on the second pivot to generate a higher front braking force, while keeping fixed rear braking force thereby forming a variable ratio combined brake system.
[0043] According to an embodiment of the invention, the brake system may be enclosed in a hub cover at the rear brake panel.
[0044] According to an embodiment of the invention, the slot helps to avoid kinematic locking of the mechanism during braking operation. This slot also helps to achieve variability in brake force distribution. This leads to a controlled progressive braking force at the front wheel and restraining the front wheel braking force to a certain threshold level.
[0045] According to another embodiment of the invention, the brake operating means connected to the first link through first pivot and the first link is enabling sliding movement of the first pivot to vary ratio of braking force distribution for the front brake system and the rear brake system.
[0046] According to another embodiment of the invention, the brake operating means comprises of at least one brake pedal.
[0047] According to another embodiment of the invention, the brake operating means is pivotally connected to the first link through at least one connecting link and at least one primary link.
[0048] According to another embodiment of the invention, the rear brake actuator is pivotally connected to the first link by the bolt placed on the first link and is operated by the first link vis a vis the brake pedal to actuate the rear brake system.
[0049] According to another embodiment of the invention, the front brake actuator is pivotally connected to the one second link and another end of the second link is pivotally connected to an end of the first link. The second link is operated by the first link vis a vis the brake pedal to actuate the front brake.
[0050] According to another embodiment of the invention, the front brake actuator and rear brake actuator means comprises of a front brake cable/ rod and rear brake cable/ rod respectively.
[0051] According to another embodiment of the invention, at least a first link connected to the rear brake actuators and a second link connected to the front brake actuator.
[0052] According to another embodiment of the invention, a force distribution mechanism comprising plurality of brake linkages mounted on brake pedal region.
[0053] According to another embodiment of the invention, the first pivot enabled in the slot connected to the bolt by means of a central recoil arrangement.
[0054] According to an embodiment of the invention, the sliding movement of the first pivot is enabled by sliding means, preferably provided in form of a slot inside the first link. The slot preferably of an oblong shape, though other suitably shapes are also possible.
[0055] According to an embodiment of the invention, the brake system wherein at least one brake is a drum type brake.
[0056] According to an embodiment, the front brake actuator or rear brake actuator is connected to a cam lever placed at a front wheel hub or rear wheel hub to actuate a drum brake system.
[0057] According to an embodiment of the invention, wherein at least one brake is a disc type brake comprising hose to supply hydraulic fluids for brake actuation and a valve or hydraulic actuator configured to control supply of hydraulic fluid to the disc type brake for controlling braking force.
[0058] According to an embodiment of the invention, the valve or hydraulic actuator may be further connected to a master cylinder assembly by the hose. The brake system wherein a master hose connected from the master cylinder assembly to a brake caliper placed at the wheel hub to actuate the brake system.
[0059] The brake caliper may be a two-pod or a three-pod caliper.
[0060] The brake system may be employed, preferably in a two wheeled vehicle.

BRIEF DESCRIPTION OF DRAWINGS:
[0061] The above and other objects, features, and advantages of the present disclosure will be more apparent from the detailed description taken in conjunction with the accompanying drawings. One or more embodiments of the present invention are now described, by way of example only with reference to the accompanied drawings wherein like reference numerals represent like elements.
[0062] FIG. 1 is a side view of a motorcycle with a front disc and rear drum brake system according to the present embodiment.
[0063] FIG. 2 is a top view of a motorcycle with a front disc and rear drum brake system according to the present embodiment.
[0064] FIG. 3 is a magnified view of a variable ratio combined brake system in an unoperated condition according to a present embodiment.
[0065] FIG.4A, 4B, 4C depicts a brake system in three conditions initial condition, when rear free play is consumed & a front Application according to the present embodiment.
[0066] FIG.5 depicts a force action diagram with arrow marks depicting the action of linkages for the brake system according to the present embodiment.
[0067] FIG.6 represents graphical representation illustrating the front brake distribution on application of brake force in the current brake system compared to conventional brake system according to the present embodiment.
[0068] FIG. 7 is a pictorial right view of the motorcycle of a variable ratio combined brake system with first and second links according to another embodiment;
[0069] FIG. 8 is a magnified view of a variable ratio combined brake system in an unoperated condition according to a another embodiment;
[0070] FIG. 9 is an isometric view of the variable ratio combined brake system in an unoperated condition according to another embodiment;
[0071] FIG. 10 is a front view of the variable ratio combined brake system in an operated condition according to another embodiment;
[0072] FIG. 11 is an isometric view of the variable ratio combined brake system in an operated condition according to another embodiment;
[0073] FIG. 12 is a graphical representation illustrating the brake ratio versus the brake pedal load highlighting the utility of VCBS as compared to fixed ratio Combined Brake System; according to another embodiment of the present invention;
[0074] FIG. 13 is a graphical representation of analysis of a variable ratio combined brake system depicting brake ratio versus deceleration when pressure is applied on pedal; according to another embodiment of the present invention.

DETAILED DESCRIPTION:
[0075] The invention along with preferred embodiments will now be described in detail with reference to the accompanying drawings. The preferred embodiment does not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
[0076] It will be readily understood that components of the present invention, as generally described and illustrated in figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the invention as represented in the figures is not intended to limit the scope of the invention but is merely representative of certain examples of presently contemplated embodiments in accordance with the invention. The presently described embodiments will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout.
[0077] According to FIG. 1 which illustrates a side view of a two wheeled motorcycle and FIG.2 depicts the top view of a two wheeled motorcycle comprising of a variable ratio combined braking system. There is a front brake system which may comprise of a front brake actuator (20), and a front brake panel (510) connected to the front wheel of the vehicle. There is a rear brake system including a rear brake actuator (30), connected to the rear wheel of the vehicle.
[0078] The brake actuators comprise of cables, rods or a hose and multiple valves. In the present embodiment the front brake actuator (20) comprises a cable or rod and the rear brake actuator (30) comprises a brake lever (160) (best seen in FIG. 4C). According to the present embodiment there is a brake pedal (90) coupled with the rear brake rod (150) which forms part of the brake operating means to actuate the rear & front wheel. In another embodiment, there may be a hand brake lever (160) connected to a second link (120) by a rear brake cable or rod (150). There is force distribution mechanism comprising a plurality of brake linkages connected to the brake operating means comprising at least a first link (40) (best seen in FIG. 3) and a second link (120) which is connected to a front brake actuator (20) and a rear brake actuator (30) respectively.
[0079] FIG. 3 depicts a magnified view of a variable ratio combined brake system (10) with in an unoperated condition according to a present embodiment. The first link (40) is provided with a first pivot (60) enabling sliding movement of the first pivot (60) to vary ratio of braking force distribution for the front brake system and the rear brake system. The first link (40) is mounted on the second link (120) through a second pivot (530). The second pivot (530) is connected to the first pivot (60) by means of a tension spring allowing sliding movement of the first pivot (60) to progressively vary ratio of braking force distribution for the front brake system and the rear brake system. Any other elastic or flexible or recoil arrangement may also be suitably used for connecting the first pivot (60) & the second pivot (530). The tension spring helps in effective and required distribution of braking force to front brake system without complete transmission of the complete braking force which happens at the rear brake system.
[0080] According to the present embodiment the rear brake system employed is a drum type brake wherein the brake lever (160) forms part of the rear brake actuator (30). The brake lever (160) is mounted and rotated on a second link (120) by a third pivot (540) whenever the rear brake rod (150) actuates the second link (120). The front brake actuator (20) comprises of a front brake cable which originates from the first link (40) and terminates to a master cylinder (210) which may be positioned at a brake handle. Further a hose is connected from the master cylinder (210) to a caliper positioned at the rim of the front wheel. The caliper may be a two pod or three pod calipers depending on the suitable need. The flow of the fluid through the hose actuates the caliper at the wheel to actuate the frontal disc braking operation. According to another embodiment there may be a drum brake at the front side of the vehicle, hence a cable originating from the first link (40) can be directly connected to a brake lever of the front brake.
[0081] FIG.4A, 4B, 4C depicts a brake system (10) in three conditions initial condition, when rear free play is consumed & a further front application. According to an embodiment of the invention, upon actuating brake operating means; the first link (40) and second link (120) collinearly moves to generate a fixed ratio combined braking force on front and rear brake system till the rear brake actuator (30) free play is consumed. Initially the rear brake rod (150) pulls the second link (120), and a combined braking system operation takes place. The braking regulation states that rear braking operation should be initiated prior and more compared to the frontal braking operation. So, adhering to the regulatory requirement & safety concerns the rear wheel braking force is kept more than the front braking force during initial operation.
[0082] FIG.5 depicts a force action diagram with arrow marks depicting the action of linkages and in conjunction with FIG. 4C on further application of the braking force. There is a consumption of the rear brake lever (160) free play, the rear wheel gets locked with minimal increase of force at the rear brake. The second link (120) is rotated on the third pivot (540) provided on the brake lever (160), leading to the rotation of the first link (40) on the second pivot (530) to generate a higher front braking force, while keeping fixed rear braking force thereby forming a variable ratio combined brake system (10).
[0083] The invention has manifold advantages, which have been described below. There is a slot (70) which houses the first pivot (60) which helps to avoid kinematic locking of the mechanism during full braking operation. Kinematic locking of the brakes, also known as "brake lock-up," refers to a situation where the wheels of a vehicle lock and stop rotating while the brakes are applied. This condition typically occurs when the braking force exceeds the tire's maximum traction or when the braking system malfunctions. When the brakes lock up, the wheels lose their ability to roll freely, resulting in skidding and a loss of steering control. This happens due to uneven brake force distribution. If there is an imbalance in the brake force applied to each wheel, it can lead to one or more wheels locking, while others continue to rotate.
[0084] Due to this uneven brake force distribution rear wheel brake shoe will undergo more frequent braking force application, the wear and tear will be prominent compared to the front wheel brake shoe. Hence in conventional brake system there might be a possibility that on application of brake force by operator, there is a sudden abrupt increase in the front brake operation which can lead to accidents. Further the operator may also face some inconvenience during braking operation as more force may be required to stall the vehicle. Hence the conventional systems require frequent nut adjustments.
[0085] In order to solve the aforementioned problems, the present brake system (10) has been invented which eliminates frequent nut adjustment of the front and rear wheel braking system and also protects the operator from any untoward accidents by applying the rear brake first and then the front brake.
[0086] The oblong shape slot (70) helps to achieve variability in brake force distribution. This leads to a controlled progressive braking force at the front wheel and restraining the front wheel braking force to a certain threshold level. The slot (70) preferably of an oblong shape, though other suitably shapes are also possible.
[0087] FIG. 6 depicts a graphical comparison between the conventional braking system (CBS) and the variable ratio compact braking system (VCBS) of the present invention. The graph shows an analysis of percent (%) front distribution v/s pedal travel. It can be observed that front braking force percent distribution is more for the VCBS (present invention) compared to the conventional brake system. There is a 25% higher deceleration achieved through progressive increase of braking force at the front wheel with increased pedal travel in the present invention. The first pivot (60) is a rear brake cam end in the present embodiment although a separate pivot may be employed to actuate the brake system (10) in another embodiment. Hence, progressive front brake application through brake cam end is performed through this invention.
[0088] According to the present embodiment the first lever is a secondary lever, and the second lever is an equalizer link.
[0089] According to another embodiment, FIG. 7 is a pictorial side view of a two wheeled vehicle comprising of a variable ratio compact combined brake system (10).
[0090] It is a brake force control device for front and rear wheels that can interlock the front and rear wheel brakes and vary the front and rear wheel brake forces ratio automatically and constantly. The technology described here provides a wide range of braking force distribution (BFD) ratios between the front and rear wheels. The variable ratio combined brake system (10) can simultaneously achieve high braking effort and driving comfort performances.
[0091] According to another embodiment, a front brake rod (140) and a rear brake rod (150) is connected at two ends of the brake system (10). The front brake rod (140) and the rear brake rod (150) is further connected to the master cylinder assembly (210) and the rear cam lever (160) respectively. There may be a master hose (280) connected from the master cylinder assembly (210) to a two-pod brake caliper (290) (although a three pod or a single pod caliper may also be used) placed at the front wheel hub (270) to actuate the front wheel brake system. According to another embodiment, there may be a valve or hydraulic actuator placed in the braking line of both or anyone of the front or rear brake hose (not shown). The master cylinder assembly (210) may be located anywhere along the path of the rear brake rods (150).
[0092] According to another embodiment of the combined brake system, a front brake rod originating from the second link (120) is connected to a front cam lever placed at a front wheel hub to actuate a front wheel drum brake system.
[0093] According to another embodiment of the combined brake system, a rear brake rod (150) originating from the first link (40) operates a valve or hydraulic actuator to control supply of hydraulic fluids through a hose connected to a caliper at a rear wheel hub to actuate a rear wheel disc brake system.
[0094] According to another embodiment of the invention, a rear brake rod (150) originating from one end of the first link (40) is connected to rear cam lever (160), mounted at the rear wheel hub (220) for actuation of a drum brake system. There may be a hose in place of a brake rod connected to the caliper of the wheel hub (220) of the rear wheel when a disc brake is used which is actuated using hydraulic fluids. The rear brake rod (150) is suspended from the swing arm (320) by the help of rear recoil (190) arrangement.
[0095] The Variable Ratio Combined Brake system (10) is connected to a brake operating means. The brake operating means comprises of a brake pedal (90), brake rod (230) and a primary link (100) wherein the parts are attached with each other to form an assembly. The brake pedal (90) and the brake rod (230) may be integrated to form a single assembly. The brake is actuated by a rider through a brake rod (230) by pressing brake pedal (90) with the help of a foot. Further, the brake operating means is mounted on the frame (130) structure by a primary hinge joint (240) arrangement.
[0096] The Variable Ratio Combined Brake system (10) according to an embodiment of the present disclosure is described herein below as illustrated in FIG.8. The present invention provides a two wheeled vehicle that includes a variable ratio combined brake system (10) controlled by a brake operating means comprising of a pedal (90) for restraining vehicle motion, a brake rod (230) attached to the brake pedal (90) and a primary link (100) further attached to the brake rod (230). There may be an elastic or front recoil (180) arrangement preferably a tension spring suspended on a bolt, placed on the vehicle frame (130) structure, and connected to the brake rod (230). The front recoil (180) arrangement facilitates the brake rod (230) to attain the default position as and when force is removed from brake pedal (90). Further, the brake rod (230) is connected to a primary link (100) preferably by a primary hinge joint (240) although other joints (for eg. Pin joints or knuckle joints) may be used. The primary link (100) is connected to a connecting link (110) by connecting hinge joint (250). The connecting link (110) is attached to the first link (40) by a pivot (60).
[0097] A second link (120) is further attached to the bottom end of the first link (40) by another joint preferably a hinge joint (200), (although any other joints may be employed) which enables the second link (120) to move about a hinge joint (200). Further, the second link (120) is connected to the frame structure (130) by a secondary pivot (330). A front brake rod (140) or a hose originates at bottom end of the secondary link (120) for actuating the front brake system of the vehicle. There may be a pair of brake pedal stoppers (170) attached with the frame (130) which helps to retain the first link (40) and second link (120) achieve default position as and when force is removed from brake pedal. According to another embodiment of the invention, the front brake rod (140) or hose may be directly connected to the master cylinder positioned at the handle of the two wheeled vehicle. The front brake rod (140) is suspended from the frame (130) by the help of front recoil (180) arrangement.
[0098] The first link (40) comprises of an oblong slot (70) houses the pivot (60) arrangement. The pivot (60) is connected to a bolt (260) by an elastic or recoil arrangement preferably a central recoil arrangement (80) comprising a delay spring. The bolt (260) in the first link (40) is further connected to a rear brake rod (150) or hose for actuating the rear brake.
[0099] FIG. 8 and FIG. 9 depict a front view and an isometric view respectively of the variable ratio brake system (10) at unoperated condition. When no brake force is applied on the brake pedal (90) the pivot (60) is held at the topmost position of the oblong slot (70), the central recoil arrangement (80) preferably a delay spring attached to the bolt (260) holds the pivot (60) at its default top position. At this position, no braking force is imparted on both the wheels.
[0100] According to another embodiment in FIG. 10 and FIG. 11, a front view and an isometric view respectively of the variable ratio brake system (10) during operated condition. When force is imparted on brake pedal (90) by foot operation, the pivot (60) inside the oblong slot (70) is pulled down towards the second link (120). The oblong slot (70) is being in the form of an ellipse has a major axis along the first link (40), due to which on operation of the brake pedal the pivot has to move along the major axis. This movement of the pivot (60) along the major axis provides the requisite distribution of braking force to the front and rear braking system. The pivot (60) moves along the major axis of the oblong slot (70), proportional to the brake force applied on the brake pedal (90). On an initial application of the force on the brake pedal (90) the pivot (60) moves a small distance from the default position. The pull generated at the rear brake rod (150) is more than the front brake rod (140) due to the proximity of the pivot (60) near the rear brake rod (150). Hence, rear brake actuation force is more than front brake actuation force.
[0101] Further, on increased application of force on brake pedal (90), the pivot (60) is pulled down gradually towards the second link (120). The pull generated at the front brake rod (140) becomes more than the rear brake rod (150) due to the proximity of the pivot (60) near the front brake rod (140). Hence, front brake actuation force is more than rear brake force. This provides a high degree of variation ratio range for brake systems.
[0102] According to another embodiment in FIG. 12, is a graphical representation illustrating the brake ratio versus the brake pedal (90) load highlighting the utility of VCBS as compared to fixed ratio Combined Brake system (10). It can be inferred from the provided figure that with increased brake load, the brake ratio (brake ratio = rear deceleration/ (front deceleration + rear deceleration)) remains constant for a combined brake system (10) (as indicated by line 300). The curve for the Combined Brake system (10) represents braking, wherein the front and rear wheels are locked at the same time to obtain the maximum deceleration and keep the body stable. On the contrary, it is observed that brake ratio subsequently decreases for the variable ratio combined brake system (10) according to the present invention (as indicated by line 310). This decrease in the brake ratio is the resultant of decrease in rear deceleration and subsequent increase of front deceleration. According to another embodiment there may be a constant rear deceleration, but subsequent increase of front deceleration on application of increased braking force. This may provide a similar effect in subsequent decrease in the brake ratio.
[0103] The invention facilitates that when small input force in the early stage of the braking is provided, the braking force applied to the rear wheel is greater than that applied to the front wheel. In the middle and later stages of the braking process, the front wheel braking force is greater than the rear wheel braking force. This is required as in the case of large braking force; the vertical load of the front wheel is increased due to the inertial force of the vehicle. At this time, it is better that the front wheel braking force is greater than the rear wheel braking force, and the vehicle can have sufficient and rapid deceleration to quickly stop the vehicle body. This achieves significant deceleration while maintaining the vehicle’s stability during emergency braking, where an adequate front braking force distribution ratio is required. Also, a severe skid on the rear tyre may be averted as the rear wheel will not get locked, avoiding poor deceleration and stability performance in the present invention. Hence, possible accidents of the pedestrians and rider safety can be enhanced by implementing this braking system in vehicles.
[0104] According to a preferred embodiment, FIG. 13 is a graphical representation of analysis of a variable ratio combined brake system (10) depicting brake ratio versus deceleration of the vehicle, when force is applied on pedal. The ideal curve illustrates the gradual linear decrease of the proportion of rear braking force and increase of front braking force. This characteristic enhances the braking efficiency, reduces the braking distance as gradual increase of deceleration of the vehicle is observed and thus improves the vehicle body stability and enhances rider comfortability. When the two wheels are locked at the same time, maximum deceleration can be obtained which is evident from the graphical representation at (0.8 m/s^2).
[0105] There is an automatic and continuous variation of the brake ratio in the vehicle with the amount of force applied on the brake pedal (90). The initial brake ratio corresponds to a small braking force, and the braking force of the rear wheel is much larger than that of the front wheel. When the pressure applied on the brake pedal (90) is continuously increased, the pivot (60) moves down inside the oblong slot (70) and the front wheel braking force gradually increases to a high ratio value. The second link (120) placed at one end of the first link (40) becomes proximal to the pivot (60). Hence force imparted on the second link (120) is imparted more resulting in increased tension or pull on the front brake rod (140), which is attached to another end of the second link (120) thereby increasing front braking force.
[0106] According to another embodiment, the VCBS linkage mechanism can be placed at handlebar or any portion of the frame (130) structure of the vehicle. The force with which the driver presses the brake handle, the front and rear brake ratios can be automatically and constantly allocated. In another embodiment the invention may be applied to front and rear drum brakes, front disc-rear drum brakes, front drum- rear disc brakes, front and rear disc brakes and other brake systems. In a further embodiment mounting position of front and rear brake rods can be interchanged by mounting them on the first link (40) and second link (120) respectively.
[0107] According to another embodiment of the present invention, the oblong slot (70) can be parallel or at any angle to length of the first link (40) or of a curved shape including any other shape not defined herein but giving similar technical effect may be utilized.
[0108] According to another embodiment of present invention, the movement of pivot (60) can be made in opposite direction with different position of linkage pivots or by changing the rear brake rod (150) or cable and the front brake rod (140) or cable mounting location.
[0109] The present invention may be implemented in a variety of applications and preferably to any types of vehicles, (such as a two-wheeled, three-wheeled, four wheeled vehicle).
[0110] The present invention caters to a series response of proposed CBS (pedal to rear brake and then rear brake to front brake) to aid rider safety & avoid front wheel lock during panic braking as against that of parallel response with existing CBS (pedal to rear brake & front brake) in case of uneven brake shoe wear at both wheels. Further, unequal brake shoe wear can be compensated without compromising on the performance. Alongside safety consideration this brake system (10) provides robust control of the vehicle by providing enhanced deceleration and the operator can stop the vehicle at much less distance than the conventional brake system (10). Further the brake system (10) comprises of only three links positioned conveniently on the brake panel of rear wheel which not only increases mechanical efficiency of the brake system (10), but also reduces substantial cost. The brake system (10) may be enclosed in a hub cover at the rear brake panel (520) or at any position convenient for operation of the brake system (10). Also, the present invention is much more compact and suitably positioned at the rear hub (220) of the wheel, which is aesthetically appealing.
[0111] According to the present embodiment, the ratio of braking force between the front and rear brakes can vary depending on factors such as vehicle speed, weight distribution, and the intensity of the brake input. The variable ratio combined braking system offers several benefits, such as
[0112] Enhanced stability: By automatically distributing braking force between the front and rear wheels, the system helps to prevent the front or rear wheel from locking up, reducing the risk of loss of control and skidding.
[0113] Shorter stopping distances: The system optimizes the distribution of braking force, allowing the vehicle to stop more quickly and efficiently by utilizing the available traction of both the front and rear wheels.
[0114] Improved control: The combined braking system simplifies the braking process for the rider or driver by reducing the need to modulate and coordinate separate controls for the front and rear brakes. This can enhance overall braking control and make it easier to apply the brakes smoothly.
[0115] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in respects as illustrative and not restrictive.
[0116] Although the exemplary forms of the present disclosure have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the present disclosure.
List of Reference Numerals: -
[0117] brake system (10)
[0118] first link (40)
[0119] second link/ secondary link (120)
[0120] front brake panel (510)
[0121] rear brake panel (520)
[0122] front brake actuator/ brake cable or hose (20)
[0123] rear brake actuator/ brake lever (30)/ (160)
[0124] first pivot or cam end (60)
[0125] second pivot (530)
[0126] third pivot (540)
[0127] slot (70)
[0128] central recoil arrangement (80)
[0129] brake pedal (90)
[0130] primary link (100)
[0131] connecting link (110)
[0132] frame (130)
[0133] front brake cable/ rod (140)
[0134] rear brake rod (150)
[0135] stopper (170)
[0136] front recoil (180)
[0137] rear recoil (190)
[0138] hinge joint (200)
[0139] master cylinder (210)
[0140] rear wheel hub (220)
[0141] brake rod (230)
[0142] primary hinge joint (240)
[0143] connecting hinge joint (250)
[0144] bolt (260)
[0145] front wheel hub (270)
[0146] master hose (280)
[0147] two pod caliper (290)
[0148] yellow line (300)
[0149] blue line (310)
[0150] swing arm (320)
[0151] secondary pivot (330)
,CLAIMS:1. A brake system (10) for a vehicle, comprising:
a front brake system including at least a front brake actuator (20), and a front brake panel (510) connected to the front wheel of the vehicle;
a rear brake system including at least a rear brake actuator (30), and a rear brake panel (520) connected to the rear wheel of the vehicle;
at least a brake operating means comprising of a brake pedal (90) for actuating at least the front brake actuator (20) or a rear brake actuator (30);
a force distribution mechanism comprising of brake linkages connected to the brake operating means for force distribution, the force distribution mechanism comprising:
at least a first link (40) and a second link (120) connected to at least the front brake actuator (20) or the rear brake actuator (30);
wherein the first link (40) is provided with a first pivot (60) for enabling sliding movement of the first pivot (60) within the first link (40) to vary a ratio of braking force distribution for the front brake system and the rear brake system.
2. The brake system (10) for a vehicle as claimed in Claim 1, wherein the first link (40) is mounted on the second link (120) through a second pivot (530); and wherein the second pivot (530) is connected to the first pivot (60).

3. The brake system (10) for a vehicle as claimed in Claim 2, wherein the first pivot (60) on the first link (40) is connected to the second pivot (530) by means of a recoil arrangement (80).

4. The brake system (10) for a vehicle as claimed in Claim 1, wherein the front brake actuator (20) and the rear brake actuator (30) are connected to the plurality of brake linkages.

5. The brake system (10) for a vehicle as claimed in Claim 2, wherein the second link (120) is connected to the rear brake actuator (30) through a third pivot (540) and operates the rear brake actuator (30) to actuate the rear brake system (10).

6. The brake system (10) for a vehicle as claimed in Claim 1, wherein the front brake actuator (20) comprises of a brake hose or cable (20) configured to operate the front brake system (10).

7. The brake system (10) for a vehicle as claimed in Claim 1, wherein the brake operating means is connected to the second link (120) by a rear brake rod (150).

8. The brake system (10) for a vehicle as claimed in Claim 5, wherein the rear brake actuator (30) comprises of a brake lever (160) mounted on the rear brake panel (520) configured to operate the rear brake system (10).

9. The brake system (10) for a vehicle as claimed in Claim 1, wherein the first link (40) and second link (120) collinearly move to generate a fixed ratio combined braking force on the front and rear brake system (10) till the rear brake actuator (30) free play is consumed.

10. The brake system (10) for a vehicle as claimed in Claim 1, wherein the first link (40) is pivotally connected to the front brake actuator (20) and is operated by the second link (120) to actuate the front brake system.

11. The brake system (10) for a vehicle as claimed in Claim 5, wherein the second link (120) rotates on the third pivot (540), leading to the rotation of the first link (40) on the second pivot (530) to generate a higher front braking force.

12. The brake system (10) for a vehicle as claimed in Claim 1, wherein the brake system (10) is enclosed in a hub cover at the rear brake panel (520).

13. The brake system (10) for a vehicle as claimed in Claim 1, wherein the brake operating means connected to the first link (40) through first pivot (60) and the first link (40) is enabling sliding movement of the first pivot (60) to vary ratio of braking force distribution for the front brake system and the rear brake system.

14. The brake system (10) for a vehicle as claimed in Claim 13, wherein the brake operating means comprises of the brake pedal (90) pivotally connected to the first link (40) through at least one connecting link (110) and at least one primary link (100).

15. The brake system (10) for a vehicle as claimed in Claim 13, wherein the rear brake actuator (30) comprises of a brake rod (150) pivotally connected to the first link (40) by a bolt (260) placed on the first link (40) and operated by the first link (40) to actuate the rear brake system.

16. The brake system (10) for a vehicle as claimed in Claim 13, wherein the front brake actuator (20) comprises of a brake rod (140) pivotally connected to the second link (120) to actuate the front brake and the second link (120) is pivotally connected to the first link (40).

17. The brake system (10) for a vehicle as claimed in Claim 1, wherein the rear brake actuator (30) comprises of a rear brake rod or hose, or a cable (150) configured to operate the rear brake system.

18. The brake system (10) for a vehicle as claimed in Claim 13, wherein the force distribution mechanism comprises of brake linkages connected to the brake operating means for force distribution and is mounted on brake pedal (90) region.

19. The brake system (10) for a vehicle as claimed in Claim 13, wherein the first pivot (60) is connected to the bolt (260) by means of a central recoil arrangement (80).

20. The brake system (10) for a vehicle as claimed in Claim 1, wherein the first pivot (60) is enabled in a slot (70) provided on the first link (40).

21. The brake system (10) for a vehicle as claimed in Claim 20, wherein the slot (70) is having an oblong shape.

22. The brake system (10) for a vehicle as claimed in Claims 1; wherein the front brake actuator (20) or rear brake actuator (30) comprises of a brake lever (160) placed at a front wheel hub (270) and a rear wheel hub (220) respectively to actuate the drum brake system (10).

23. The brake system (10) for a vehicle as claimed in Claim 1; wherein at least one front or rear brake system is a drum type brake or a disc type brake comprising hose to supply hydraulic fluids for brake actuation and a valve or hydraulic actuator configured to control supply of hydraulic fluid to the disc type brake for controlling braking force.

24. The brake system (10) for a vehicle as claimed in Claim 23, wherein the valve or hydraulic actuator is connected to a master cylinder (210) assembly and the master cylinder (210) is connected to brake caliper mounted on the wheel hubs (270, 220) by a master hose (280).

25. The brake system (10) for a vehicle as claimed in Claim 24; wherein the brake caliper is a two-pod or a three-pod caliper.

26. The brake system (10) for a vehicle as claimed in Claim 1; wherein the brake system (10) is employed, in a two wheeled vehicle