TECHNICAL FIELD
[0001] The present subject matter relates to braking system for motor vehicles and more particularly to an adjustable braking system for the motor vehicles.
BACKGROUND
[0002] Generally, two major types of brake systems are used on vehicles, viz. the disc brake system and the drum brake system. The drum brake systems are being used for a long time because of its reliability and its cost-effectiveness. Generally, the drum brake systems are used .in vehicles with low speed applications. For example, drum brake system is used in two-wheeled and three-wheeled vehicles, which run at low speeds, especially commuter vehicles. The drum brake system comprises a brake drum and at least one brake shoe provided with frictional liner that engages with an inner surface of the brake drum. Either mechanical or hydraulic mechanism is used for actuating the brake for making the liner of the brake shoe to come in contact with the brake drum. Upon actuation, the liners of the brake shoe come in contact with the drum and the frictional contact between the brake shoe and the inner wall of brake drum reduces the rotational speed of the wheel.
BRIEF DESCRIPTION OP THE DRAWINGS
' [0003] The detailed description of the present subject matter is described with reference to the accompanying figures. Same numbers are used throughout the drawings to reference like features and components.
[0004] Fig. 1 (a) illustrates a left side view of an exemplary two-wheeled motor vehicle, in accordance with an embodiment of the present subject matter. [0005] '" Fig. I (b) illustrates a right side view of a portion of the vehicle 100, depicted in accordance with the embodiment of Fig. 1 (a).
[0006] Fig. 2 (a) illustrates a perspective view of the wheel brake assembly, in accordance with the embodiment of Fig. 1 (b).

[0007] Fig. 2 (b) depicts an enlarged view of the wheel brake assembly in accordance with the embodiment as depicted in Fig. 2 (a).
[0008] Fig. 2 (c) depicts a side view of the lever arm, in accordance with the embodiment as depicted in Fig. 2 (b).
[0009] Fig. 2 (d) depicts a rear view of the lever arm, in accordance with the embodiment as depicted in Fig. 2 (c).
[00010] Fig. 2 (e) depicts a perspective view of the lever arm, in accordance with the present embodiment.
[00011] Fig. 2 (f) depicts an adjustment mechanism of the wheel brake
assembly, in accordance with the embodiment as depicted in Fig. 2 (a).
[00012] Fig. 2 (g) depicts another side view of the lever arm with the slidable
pin engaged at the second slot, in accordance with the embodiment of Fig. 2 (f).
-■ DETAILED DESCRIPTION
[00013] Generally, in vehicles a brake system is used either to slow down or to stop the moving vehicle. In two-wheeled or three-wheeled vehicles, a drum brake system is used as at least one of the braking systems. The drum brake system is installed on either a front wheel or a rear wheel or on all the wheels of the vehicle. Conventionally, the rear wheel is installed with a drum brake.
[00014] Generally, the braking system is to be adjustable depending on the user requirements like varying road conditions or varying riding conditions. Further, depending on the load, which includes number of riders seated on the vehicle or the additional payload being carried by user, the braking force required for stopping the vehicle is also varied. Conventionally, drum brake systems includes a cam lever that is installed on the brake drum assembly. The braking force in such vehicles is predominantly governed by the lever ratio of the system. Conventionally, the lever ratio of the system is set to a pre-determined value at the design stage. The braking system includes an adjustment mechanism including a threaded screw for adjusting the connecting point of the brake cable to the lever. However, such an adjustment is generally performed to compensate any increase in free play of the brake lever or cam lever due to wear of the brake

liners or due to expansion of the brake cable. Such adjustments are generally done during the regular service of the vehicle. The user can also adjust the connection by either tightening or loosening the screw. Nonetheless, for varying the lever ratio or for providing desired torque for actuation of the brake, generally, different cam levers may be used according to the force or torque requirements provided by the cam levers. Such, adjustment requires removal of the cam lever and attaching another cam lever according to the user requirement, which is not user friendly and requires experts or service personnel,- Also, this requires additional cam levers according to the braking requirement, which results multiple parts to be carried by the user for replacement. Such use of multiple parts, for example various cam levers with different lever ratios, affects the cost of the system. Also, such replacement process is time consuming.
[00015] . Thus, there arises a need for a braking system with user adjustable lever ratio setting so that the user can change the lever ratio depending on the riding and road conditions as desired.
[00016] Hence, the present subject matter is aimed at addressing the aforementioned and other problems in the prior art. Thus, the present subject matter provides a wheel brake assembly for "a motor vehicle including a lever arm that enables adjustment of the lever ratio of the lever arm without the need for dismantling the lever arm from the vehicle or any other component from the assembly.
[00017] It is an aspect of the present subject matter that the brake assembly provided with a lever arm enables adjustment of the effective lever length depending on user requirement without the need for dismantling any components of the wheel brake assembly.
[00018] ^ It is yet another aspect of the present subject matter that the brake assembly enables easy and quick adjustment by the user itself without the need of an expert.

[00019] Further, brake can be adjusted without the need for any additional tool. Thus, it is an advantage that the user-can change the brake setting with ease.
[00020] It is an aspect of the present subject matter that the lever arm of the wheel brake assembly extending outward from pivot point provides ease of access of the user and does not require any tool for accessing any compact location on the vehicle.
[00021] It is another aspect of the present subject matter that the single lever arm enables provisions of different brake settings thereby eliminating the need for the user to carry along multiple levers.
' [00022] It is an additional feature that the manufacturer can provide the preset, settings regarding the adjustment whereby the user can choose the desired setting depending on the load, road, or riding requirements.
[00023] -■ The brake assembly is applicable to a front wheel or a rear wheel of a two wheeled vehicle or a three wheeled vehicle that is employed with a drum brake system or the like that operates based on lever ratio, wherein the transmission member is either a flexible member or a rigid member.
[00024] It is a feature of the present subject matter that the brake assembly enables user lo adjust brake lever arm depending on the payload of the vehicle, which varies based on the number of riders seated on the vehicle. For example, the user can operate the vehicle with a particular setting of the lever arm when a single rider is seated and adjust the lever arm to another setting when more than one rider is seated on the vehicle. This enables the user to adjust the brake assembly depending on number of riders and corresponding braking requirements.
[00025] It is an additional feature that the lever arm of the wheel brake assembly,;, is retrofittable. on the motor vehicle and provides ease of implementation.
[00026] In one embodiment, the present subject matter is employed on a motor vehicle. The wheel brake assembly is mounted to at least one wheel of the

motor vehicle. The wheel brake assembly is cable of applying braking forces to the wheel. The wheel brake assembly includes a cam member pivotable about a pivot point and the cam member enables application of braking forces upon, rotation. In one embodiment, the cam member enables engagement of the brake shoes about a brake drum.
[00027] In one embodiment, a brake actuation member is cable of transmitting brake actuating forces to the wheel brake assembly through a transmission member. The. transmission member can be rigid or flexible. For ■ example, a rigid transmission member is a brake rod and a flexible transmission member is a brake cable.
[00028] The wheel brake assembly provides a lever arm functionally connected to the cam member. The lever arm is cable of rotating the cam member upon rotation thereof. In other words, rotation of the lever arm rotated the cam member. The lever arm includes plurality of mounting points disposed at varying distance from the pivot point at which the lever arm is connected to the cam member. The lever, arm enables the transmission member to be selectively conneclable to one mounting point of plurality of mounting points on the cam lever.
[00029] In one embodiment, the lever arm includes a body portion with one end portion connected to the cam member at the pivot point and other end portion of the lever arm includes the plurality of mounting points. In one embodiment, the mounting points include plurality of engaging slots.
[00030] Further, the transmission member includes one end portion that supports a slider pin and other end portion is functionally connected to the brake actuation member. The slider pin is cable of engaging with one engaging slot of the plurality of engaging slots.
[00031] In an embodiment, the engaging slots are elongated type that enables the slidable pin to slide therein. The engaging slots include an abutting portion for the slidable pin to be engaged thereat.

[00032] The motor vehicle as claimed in claim , wherein said engaging
slots are elongated in a direction substantially orthogonal to an imaginary' line
passing through the pivot point P and said slidable pin .
[00033] In one embodiment, the engaging slots are separated by a partial
wall that separates adjacently disposed engaging slots at least partially. The
partial wall forms a common slot portion'to enable movement of the slider pin
between the plurality of engaging slots. The common slot portion is preferably
disposed away from the abutting portion.
[00034] In an embodiment, the abutting portion of the plurality of engaging
slots is disposed in line.
[00035] In another embodiment, the abutting portion of the plurality of
engaging slots are at an offset from one another to compensate free play variation
of brake actuation member when connected to different engaging slots.
[00036] The motor vehicle includes at least two wheels and the wheel brake
assembly, is hub mounted thereof. The wheel can be a casted wheel or a
spoke-type having a hub portion to accommodate the wheel brake assembly.
[00037] The brake actuation member includes at least one of a hand operated
lever or a leg operated foot pedal.
[00038] Various other features, aspects, and advantages of the present subject
matter will be would be described in greater detail in conjunction with the figures
in the following description. In the ensuing exemplary embodiments, the vehicle
is a two wheeled vehicle. However it is contemplated that .the disclosure in the
present invention may be applied to any two wheeled or three wheeled vehicle or
the like that incorporates similar wheel brake assembly. The detailed explanation
of the constitution of parts other than the present invention which constitutes an
essential part has been omitted at suitable places.
[00039] The directions front, rear, left, and right are referred with respect to the vehicle direction. A longitudinal axis F-R.of the vehicle 100 extends from front F to rear R and a lateral axis of the vehicle 100 is perpendicular to the

longitudinal axis F-R of the vehiclelOO. The arrow marked as Up indicates upward direction and the arrow marked as Dw indicated downward direction.
[00040] Fig. I (a) illustrates a left side view of a two-wheeled motor vehicle, in accordance with an embodiment of the present subject matter. The niotor vehicle 100 (hereinafter referred to as 'vehicle') comprises a frame assembly 105 extending from a front portion towards a rear portion of the vehicle 100. A power unit 110 is mounted on the frame assembly 105 of the vehicle 100. The power unit 110 includes at least one of an internal combustion engine or a traction motor. In an embodiment, the power unit 110 is a four-stroke single cylinder type IC engine. The traction motor is preferably a brushless direct niotor current motor type. The power unit 110 includes a starter system. Particularly, the starter system includes an electric start systenvor a mechanical kick-start system or both that are . employed with _power unit 110 provided with the IC engine. Through a transmission system 115, a wheel 120, which is specifically a rear wheel 120, is functionally coupled to the power unit 110; The transmission system 115 may include a fixed gear chain drive or continuously variable transmission (CVT) or an automatic" manual transmission (AMT) or a multi-speed manual control . . gearbox system: A rear fender 125 covers at least a portion of the rear wheel 120. Further, one or more rear suspension spring and damper system(s) 130 functionally connect the rear wheel 120 to the frame assembly 105.
[00041] A head tube 105A of the frame assembly 105 is rotatably supported by a steering shaft (not shown). A handle bar assembly 135 is connected to the steering shaft. One or more front suspension spring and damper system(s) 140 rotatably support a front wheel. 145 and connect the front wheel 145 to the steering shaft. A front fender 150 covers at least a portion of the front wheel 145. A seat assembly 155 is supported by a portion of the frame assembly 105. The fuel tank 160 is disposed in'anterior portion of the seat assembly 155 and upwardly of the power, unit 110.
[00042] " The vehicle. 100 comprises a front drum brake assembly (not shown) disposed at the front wheel 145 and an actuating lever 170 is provided on the ■ICF ' f H F MM AT R^/G\Q/-~>cii7 1 1 . ^ Q

handle bar assembly 135. The rear wheel 120 is provided with another drum
wheel brake assembly 200 that is actuated by either a hand-operated lever or a leg
operated lever. ,
[00043] The vehicle 100 includes a transmission cover 165 covering at least a portion of the transmission 115. Plurality of panels I75A and 175B are disposed longitudinally and downwardly from the seat assembly 155. The infernal combustion engine of the power unit 110 will be supplied with air fuel mixture supplied by a fuel tank (not shown) and an air induction system (not shown) that are coupled through a carburetor or a fuel injection system (not shown). The vehicle 100 comprises an auxiliary power source (not shown) that includes a battery or a hydrogen cell or a fuel cell or the like. Further, the traction motor of the power unit 110 is powered by the auxiliary power source mounted on the vehicle 100.
[00044] Further, the vehicle 100 includes various electronic, electrical, and mechanical systems such as a vehicle control unit, an anti-lock braking system, or a synchronous braking system. Also, an electrical starter system, a headlamp 180, and a tail lamp 185 are provided on said vehicle.
[00045] Fig. 1 (b) illustrates a right side view of a portion of the vehicle 100, as depicted in accordance with the embodiment of Fig. I (a). The rear wheel 120 is swingably connected to the frame assembly 105 through a swing arm 190 that is having one end pivoted to the frame assembly 105. In the present embodiment, the rear wheel 120 is a casted wheel assembly having a hub portion mounted with a wheel brake assembly 200.'The wheel 120 includes a hub portion (not shown) that is capable of accommodating the wheel brake assembly 200. The wheel 120 includes a rim portion 120B connected to the hub through plurality of arms 120C, wherein the entire wheel is casted as single piece. The rim portion 120B supports a tyre 120A.
[00046] The vehicle 100 includes a brake actuation member 195, which is a foot operated pedal 195 or hand operated lever that is connected to the wheel brake assembly 200. In the present embodiment, the brake actuation member 195

is a leg operated type that is disposed adjacent to a foot rest (not shown) of user. The brake actuation member 195 is pivoted to the frame 105 and the application of braking force on the brake actuation member 195 tends to pivot thereof whereby the wheel brake assembly 200 is actuated. The brake actuation lever 195, which is a brake actuation member 195, is connected to the wheel brake assembly 200 through a transmission member 210, wherein the transmission member 210 connects the brake actuation lever 195 to the wheel brake assembly 200. The wheel brake assembly 200 includes an axle portion 225 that extends laterally along the wheel brake assembly 200 about which an axle of the wheel passes through for supporting the wheel 120 and the wheel brake assembly 200.
[00047] Fig. 2 (a) illustrates a perspective" view of the drum wheel brake assembly 200. The drum wheel brake assembly 200 comprises of anchor plate member 205 that supports plurality of brake shoes 215. The brake shoes 215 are preferably arc shaped and each of said brake shoes 215 are provided with a frictional liner (not shown) on an outer surface. One end of the brake shoes 215 are mounted on a pin (not shown) that is connected to the anchor plate member 205. Other end of the brake shoes 215 are functionally connected to a cam member 220 that is rotalably supported by the anchor plate member 205. The cam member 220 is rotatable and is connected to a lever arm 300, wherein rotation of the lever arm 300 enables rotation of the cam member 220. In one embodiment, a brake drum (not shown) is en-casted or affixed to a hub portion of the wheel. Therefore, the anchor plate member 205 is a stationary part that is mounted about the brake drum of the wheel 120, while the brake drum rotates along with .the wheel. The wheel brake assembly 200 is secured to the hub of the wheel 120 through the plate member 205.
[00048] In normal state, which is brake disengages condition, the brake shoes 215 are in disengaged state. Actuation of brake actuation lever 105 will enable rotation of the lever arm 300 that will in turn rotate the cam member 220, which will push the brake shoes 215 radially outward thereby moving the brake shoes 215 towards the inner circumferential surface of the brake drum. The lever arm

300 is spring loaded so as lo retract to an unengaged condition upon release of the application of brake. The frictional liners provided on the brake shoes 215 come in contact with the inner circumferential surface of the brake drum thereby creating 'friction between the frictional liners and brake drum, resulting in reducing (he speed of the rotation of the wheel. The lever arm 300 according to the present subject matter enables adjustment of the lever ratio of the lever arm 300 thereby enabling user to vary the braking depending on user requirement.
[00049] Fig. 2 (b) depicts an enlarged view of the wheel brake assembly 200 in accordance with the embodiment as depicted in Fig. 2 (a). The lever arm 300 is pivotally connected to the cam at pivot point P through the cover member 230. The transmission member 210 in the present embodiment is a rigid rod member that is having one end connected to the brake actuation lever 195 and other end of the transmission member 210 is connected to the lever arm 300 of the present subject matter. The transmission member 210 includes the rear end portion 235 being provided with a threaded portion 235, hereafter terms threaded portion and rear end portion are interchangeably used. The rear end portion 235 is provided is a slidable pin 240, wherein the slidable pin 240 is slidable about the rear end portion 235. A stopper 245 is secured to the threaded portion 235 whereby the stopper 245 restricts the slidable pin from coming off the rear end portion 235. Further, a spring 250 is disposed between the slidable pin 240 and restricting disc provided at a front portion of the rear end portion 235. The spring 250 provides tension on the slidable pin 240 whereby the slidable pin 240 abuts against the stopper member 245.
[00050] The lever arm 300 of the present subject member is provided with plurality of mounting points SI, S2, which are engaging slots SI, S2 in the present implementation, at which the slidable pin 240 is engaged. The mounting points are disposed at varying distance from the pivot point P. The stopper member 245 includes a head portion that is capable of being engaged with any conventional tool lo enable adjustment of lever arm 300 position on the rear end portion 235. The slidable pin 240 engages with one.of the engaging slots SI, S2

of the lever arm 300. In the present-implementation as depicted in Fig. 2 (b), the slidable pin 240 is engages with a first slot SI of the plurality of slots of the cam member 225.
[00051] u Upon application of the brake by the user, the brake actuation lever 195 pulls the transmission member 210, that is substantially movable in a direct BA, whereby the slidable pin 240 is engaged at an abutting portion AP of the first slot SI, pulls the lever arm 300. The pulling of the lever arm 300 results in angular or pivotal rotation of the lever arm 300 whereby the cam is rotated thereby engaging the rear wheel brake. In the present implementation as depicted in Fig. 2 (b), the first slot SI is at a distance of LI from the pivot point P of the lever arm 300. Therefore, the force applied on the cam is substantially equal to the force that reaches the transmission member 210 multiplied by the effective length of the lever, which is LI in the present implementation.
[00052] Fig. 2 (c) depicts a side view of the lever arm 300, in accordance with the embodiment as depicted in Fig. 2 (b). Fig. 2 (d) depicts a rear view of the lever arm 300, in accordance with the embodiment as depicted in Fig. 2 (c). Fig. 2 (e) depicts a perspective view of the lever arm 300, in accordance with the present embodiment. The lever 300 is made of a rigid material including any known metal. The lever arm 300 is having a body portion 305 with one. end portion 310 that is having an aperture portion for mounting at the pivot point P. Other end portion 315 of the body portion 305 is provided with plurality of slots SI, S2. The slots SI, S2 are disposed adjacent to each other and at selective distance from the pivot point P. In the present implementation, the first slot SI is disposed on the other end portion 315 of the body 305 at a first distance LI and the second slot S2 is disposed adjacent to the first slot SI and the second slot S2 is at a second distance L2 from the pivot point P. Therefore, engaging the slidable pin 240 at one of the slots provides an effective arm length. The effective arm length provides the force or torque acting on the cam. In the present embodiment, slots S1, S2 are elongated type to enable movement of the slidable pin 240 about the slidable pin 240 therein. In one embodiment, the engaging slots SI, S2are

elongated in a direction substantially orthogonal to an imaginary line LI passing
through the pivot point P and the slidable pin 240. In the depicted embodiments,
the lines LI, L2 are considered as the imaginary lines that pass through the pivot
point P and the slidable pin 240. Further, the slot SI, S2 are having a common
slot portion SC that merges one end portion of each the slots SI, S2 to enables
adjustment without dismantling the assembly. Preferably, the slots SI and S2 are
having common slot portion SC provided at the end portion ,of the slot SI, S2,
wherein the end portion of the slots is the end portion that is away from the
abutting portion of the slots SI, S2. The slots SI and S2 are separated a partial
wall PW that forms the common slot portion SC. The other end portion 315 of
the body portion 305 includes two sub-arms 3I5A, 3I5B that are spaced apart
from each other at a distance, wherein the distance is less than the width of the
pin 240. The lever arm of the present subject matter enables ease of adjustment of
the lever ratio.
i [00053] Fig. 2 (f) depicts an adjustment mechanism of the brake assembly, in
accordance with the embodiment as depicted in Fig. 2 (a). For adjustment of the
effective lever length, user is required to press the lever arm 300 in a direction of
engagement of the brake. The slidable pin 240 is retained at the same position on
the end portion 235 of the transmission member 210. The lever arm 300 is
pivoted till the slidable pin 240 reaches the common slot portion from the
abutting portion in slot SI,.during first step ST1. Once the slidable pin 240
reaches the common slot portion SC, the slider is movable to any one of the slots.
During the subsequent step ST2, user can position the slidable pin 240 at the
desired slot, say S2 and release the lever arm 300, whereby the slider pin engages
■ with the second slot S2. The lever arm 300 reaches the non-engaging position due
to spring loading or the tension of the spring acting thereon. Fig. 2 (g) depicts
another side view of the lever arm 300 with the slidable pin 240 engaged at the
second slot S2. The second length L2 is further away from the slot SI whereby
the effective lever length for application of braking force has increased by the

difference of Ihe first length LI and the second length L2 multiplied by the force acting on the lever arm 300.
[00054] In one implementation, the slots are provided with varying elongations or varying abutting points, wherein the slots disposed away from the closest slot are disposed ahead of the abutting portion the slider pin whereby the free play and the engagement position of the brake actuation lever is not affected.
[00055] It is to be understood that the aspects of the embodiments are not necessarily limited to the features described herein. Many modifications and variations of the present subject matter are possible in the light of above disclosure. The present invention is thus briefly described. It will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the present invention.

We claim:
1. A motor vehicle (100) comprising:
a wheel brake assembly (200) mounted to a wheel (120) of said motor vehicle (100) and said wheel brake assembly (200) capable of applying, braking forces to said wheel (120), said wheel brake assembly (200) includes a cam member (220) pivotable about a pivot point (P) and said cam member (220) enables application of braking forces upon rotation thereof; and
a brake actuation member (195) capable of transmitting brake actuating forces to said wheel brake assembly (200) through a transmission member (210),
wherein said wheel brake assembly (200) includes a lever arm (300) functionally connected to said cam member (220) and said lever arm (300) capable of rotating said cam member (220), said lever arm (300) includes plurality of mounting points (SI, S2) disposed at -varying distance (LI, L2) from said pivot point (P), and said transmission member (210) being selectively connectable to one mounting point of said plurality of mounting point (SI, S2).
2: The motor vehicle (100) as claimed in claim I, wherein said lever arm (300) includes a body portion (305) with one end portion (310) connected to said cam member (220) at said pivot point (P) and other end portion (315) of the lever arm (300) includes said mounting points (SI, S2) wherein said mounting points (SI, S2) includes plurality of engaging slots (SI, S2).
3. The motor vehicle (100) as claimed in claim 1 or 2, wherein said transmission member (210) includes a rear end portion (235) that supports a slider pin (240) and other end portion functionally connected to said brake actuation member (195), said slider pin (240) capable of engaging with one engaging slot of said plurality of engaging slots (SI, S2).

4. The motor vehicle (100) as claimed in claim 3, wherein said engaging slots
(SI, S2) are elongated to enable the slidable pin (240) to slide therein, and
each of said engaging slots (SI, S2) includes an abutting portion (AP) for the
slidable pin (240) to be engaged.
5. The motor vehicle (100) as claimed in claim 2, wherein said engaging slots
(SI, S2) are elongated in a direction substantially orthogonal to an imaginary
line (Ll, L2) passing through the pivot point (P) and said slidable pin (240).
6. The motor vehicle (100) as claimed in claim 4, wherein said engaging slots
(SI, S2) are separated by a partial wall (PW) that separates adjacently
disposed engaging slots (SI, S2) at least partially and said partial wall forms a
common slot portion (SC) to enable movement of said slider pin (240)
between said plurality of engaging slots (SI, S2), and said common slot
portion (SC) is disposed away from the abutting portion (AP).
• 7.' The motor vehicle (100) as claimed in claim 4, wherein said abutting portion (AP) of said plurality of engaging slots (SI, S2) are disposed in line.
8. The motor vehicle (100) as claimed in claim 4, wherein said abutting portion (AP) of said plurality of engaging slots (SI, S2) are at an offset from one another to compensate free play variation of brake actuation member (195).
9. The motor vehicle (100) as claimed in claim I, wherein said motor vehicle (100) includes at least two wheels (120, 145) and said wheel brake assembly (200) is hub mounted thereof.
10. The motor vehicle (100) as claimed in claim 1, wherein said brake actuation member (195) includes at least one of a hand operated lever or a leg operated foot pedal (195).