Claims:WE CLAIM:
1. An anti-lock braking (100) system for a vehicle (10), comprising:
a first rigid member (110) being connected to a brake input means, the brake input means being capable of being operated by a rider;
a second rigid member (120) extending between a top end (120A) and a bottom end (120B), the top end (120A) of the second rigid member (120) being hingedly connected to the first rigid member (110);
a third rigid member (130) extending between a first end (130A) and a second end (130B), the first end (130A) of the third rigid member (130) being hingedly connected to the bottom end (120B) of the second rigid member (120);
a fourth rigid member (140) hingedly connected to the second end (130B) of the third rigid member (130), the fourth rigid member (140) being further connected a brake cam of a drum brake of a wheel (12);
a housing (150) connected to the wheel (12) of the vehicle (10);
a spring (160) connected to an inner wall of the housing (150); and
a mechanical plug (170) having a body portion (172) and an arm portion (174) connected to the body portion (172), the body portion (172) being housed inside the housing (150) and being connected to the spring (160), and the arm portion (174) being slidable through the housing (150) and being hingedly connected to the second rigid member (120) such that the mechanical plug (170) exerts a force on the second rigid member (120) in the opposite direction of the force exerted by the first rigid member (110) on the second rigid member (120), thereby controlling the movement of the second rigid member (120), and hence the brake cam through the third rigid member (130) and the fourth rigid member (140).

2. The anti-lock braking system (100) as claimed in claim 1, wherein the vehicle (10) comprises a suspension (14) that supports the sprung part of the vehicle (10), and the housing (150) is provided on the unsprung part of the vehicle (10).

3. The anti-lock braking system (100) as claimed in claim 1, further comprising a stopper (152) extending upwardly from the housing (150), the stopper (152) being configured for restricting the movement of the top end (120A) of the second rigid member (120).

4. The anti-lock braking system (100) as claimed in claim 1, wherein, under braking condition, the direction of application of force by the first rigid member (110) on the second rigid member (120) is in the opposite direction of the movement of the vehicle (10).

5. The anti-lock braking system (100) as claimed in claim 1, wherein under braking condition, the direction of application of force by the mechanical plug (170) on the second rigid member (120) is in the direction of the movement of the vehicle (10).

6. The anti-lock braking system (100) as claimed in claim 1, wherein the hinged connection of the arm portion (174) of the mechanical plug (170) is configured to act as a fixed fulcrum if the braking force is less than a threshold braking force (B1).

7. The anti-lock braking system (100) as claimed in claim 1, wherein the hinged connection of the arm portion (174) of the mechanical plug (170) is configured to act as a moving fulcrum if the braking force is more than the threshold braking force (B1).

8. The anti-lock braking system (100) as claimed in claim 7, wherein the moving fulcrum moves in the opposite direction of the vehicle (10) movement if the braking force is more than the threshold braking force (B1).

9. The anti-lock braking system (100) as claimed in claim 1, comprising:
a rotary pendulum (200) having a top slot (202), a bottom slot (204), a left notch (206) and a right notch (208), the rotary pendulum (200) configured to rotate when the vehicle (10) is on an inclined surface;
a locking arm (210) connected to the body portion (172) of the mechanical plug (170), the locking arm (210) having a protrusion (212) configured to engage and disengage with the bottom slot (204) of the rotary pendulum (200);
a left spring (220) and a left lock (222), the left lock (222) configured to engage or disengage with the left notch (206) of the rotary pendulum (200);
a right spring (230) and a right lock (232), the right lock (232) configured to engage or disengage with the right notch (208) of the rotary pendulum (200); and
a top spring (240) and a top lock (242), the top lock (242) configured to engage or disengage with the top slot (202) of the rotary pendulum (200).

10. The anti-lock braking system (100) as claimed in claim 9, wherein when the vehicle (10) is in a stationary condition on an upward incline, the top slot (202) of the rotary pendulum (200) disengages with the top lock (242), the left notch (206) of the rotary pendulum (200) engages with the left lock (222), the right notch (208) of the rotary pendulum (200) disengages with the right lock (232), and the bottom slot (204) of the rotary pendulum (200) disengages with the protrusion (212), thereby restricting the movement of the locking arm (210), and hence the mechanical plug (170).

11. The anti-lock braking system (100) as claimed in claim 9, wherein when the vehicle (10) is moving on an upward incline and under braking condition, the top slot (202) of the rotary pendulum (200) engages with the top lock (242), the left notch (206) of the rotary pendulum (200) disengages with the left lock (222), the right notch (208) of the rotary pendulum (200) engages with the right lock (232), and the bottom slot (204) of the rotary pendulum (200) engages with the protrusion (212), thereby allowing movement of the locking arm (210), and hence the mechanical plug (170).

Dated this 17th day of February 2022

TVS MOTOR COMPANY LIMITED
By their Agent & Attorney

(Nikhil Ranjan)
of Khaitan & Co
Reg No IN/PA-1471 , Description:FIELD OF THE INVENTION
[001] The present invention generally relates to an anti-lock braking system for a vehicle.

BACKGROUND OF THE INVENTION
[002] In most vehicles, owning to increasing safety standards across the globe and domestic homologation requirements, mechanisms to prevent locking of wheels of a vehicle on actuation of brakes are effectuated. Locking of wheels occur when brake callipers or brake shoes in a brake are so tightly pressed that the wheel can no longer spin. However, the vehicle’s momentum causes the vehicle to skid forward without any control wherein, tyres of the wheels no longer roll but are dragged across. Loss of control during vehicle locking can be catastrophic to the occupants of the vehicle and any other pedestrian or vehicle nearby.
[003] Conventionally, anti-lock braking systems are used in vehicles to prevent locking up of the wheels of the vehicles. Anti-lock braking systems are primarily of two variants: mechanical and hydraulic. Most mechanical anti-lock braking systems are limited in their functionality having very limited efficacy on sloped road surfaces. Further, mechanical anti-lock braking systems are not suited for all road surfaces. On the other hand, hydraulic anti-lock braking systems are quite expensive and have complex electronic control units that increases both operational and maintenance costs.
[004] Thus, there is a need in the art for an anti-lock braking system for a vehicle which can address at least the aforementioned problems and limitations.

SUMMARY OF THE INVENTION
[005] In one aspect, the present invention is directed to an anti-lock braking system for a vehicle that includes a first rigid member, a second rigid member, a third rigid member and a fourth rigid member. The first member is connected to a brake input means and the brake input means is capable of being operated by a rider. The second rigid member extends between a top end and a bottom end. The top end of the second rigid member is hingedly connected to the first rigid member. The third rigid member extends between a first end and a second end. The first end of the third rigid member is hingedly connected to the bottom end of the second rigid member. The fourth rigid member is hingedly connected to the second end of the third rigid member and is further connected to a brake cam of a drum brake of a wheel. The anti-lock braking system further includes a housing connected to the wheel of the vehicle. A spring is connected to an inner wall of the housing. A mechanical plug has a body portion and an arm portion connected to the body portion. The body portion is housed inside the housing and is connected to the spring and the arm portion is slidable through the housing and is hingedly connected to the second rigid member such that the mechanical plug exerts a force on the second rigid member in the opposite direction of the force exerted by the first rigid member on the second rigid member thereby controlling the movement of the second rigid member and hence the brake came through the third rigid member and the fourth rigid member.
[006] In an embodiment, the vehicle includes a suspension that supports the sprung part of the vehicle. The housing is provided on the unsprung part of the vehicle.
[007] In another embodiment, a stopper extends upwardly from the housing and is configured for restricting the movement of the top end of the second rigid member.
[008] In another embodiment, under braking condition, the direction of application of force by the first rigid member on the second rigid member is in the opposite direction of the movement of the vehicle.
[009] In another embodiment, wherein under braking condition, the direction of application of force by the mechanical plug on the second rigid member is in the direction of the movement of the vehicle.
[010] In another embodiment, the hinged connection of the arm portion of the mechanical plug is configured to act as a fixed fulcrum if the braking force is less than a threshold braking force.
[011] In another embodiment, the hinged connection of the arm portion of the mechanical plug is configured to act as a moving fulcrum if the braking force is more than the threshold braking force.
[012] In another embodiment, the moving fulcrum moves in the opposite direction of the vehicle movement if the braking force is more than the threshold braking force.
[013] In another embodiment, the anti-lock braking system includes a rotary pendulum and a locking arm. The rotary pendulum has a top slot, a bottom slot, a left notch and a right notch. The rotary pendulum is configured to rotate when the vehicle is on an inclined surface. The locking arm is connected to the body portion of the mechanical plug and has a protrusion configured to engage and disengage with the bottom slot of the rotary pendulum. The anti-lock braking system further includes a left spring, a left lock, a right spring, a right lock, a top spring and a top lock. The left lock is configured to engage or disengage with the left notch of the rotary pendulum. The right lock is configured to engage or disengage with the right notch of the rotary pendulum. The top lock is configured to engage or disengage with the top slot of the rotary pendulum.
[014] In another embodiment, when the vehicle is in a stationary condition on an upward incline, the top slot of the rotary pendulum disengages with the top lock, the left notch of the rotary pendulum engages with the left lock, the right notch of the rotary pendulum disengages with the right lock, and the bottom slot of the rotary pendulum disengages with the protrusion, thereby restricting the movement of the locking arm, and hence the mechanical plug.
[015] In another embodiment, when the vehicle is moving on an upward incline and under braking condition, the top slot of the rotary pendulum engages with the top lock, the left notch of the rotary pendulum disengages with the left lock, the right notch of the rotary pendulum engages with the right lock, and the bottom slot of the rotary pendulum engages with the protrusion, thereby allowing movement of the locking arm, and hence the mechanical plug.

BRIEF DESCRIPTION OF THE DRAWINGS
[016] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 illustrates a schematic view of an anti-lock braking system, in accordance with an embodiment of the present invention.
Figure 2 illustrates a schematic view of the anti-lock braking system when braking force is less than a threshold braking force, in accordance with an embodiment of the present invention.
Figure 3 illustrates a schematic view of the anti-lock braking system when braking force is more than the threshold braking force, in accordance with an embodiment of the present invention.
Figure 4 illustrates a schematic view of the anti-lock braking system, in accordance with an embodiment of the present invention.
Figure 5 illustrates a schematic view of the anti-lock braking system when a vehicle is in a stationary condition on an upward incline, in accordance with an embodiment of the present invention.
Figure 6 illustrates a schematic view of the anti-lock braking system when a vehicle is moving on an upward incline and under braking condition, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[017] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder.
[018] The present invention generally relates to an anti-lock braking system for a vehicle.
[019] Figure 1 illustrates a schematic view of an anti-lock braking system 100 for a vehicle 10 in accordance with an embodiment of the present invention. The system 100 includes a first rigid member 110 connected to a brake input means (not shown) capable of being operated by a rider. A second rigid member 120 extends from a top end 120A and a bottom end 120B in a vehicle top-down direction. The top end 120A of the second rigid member 120 is hingedly connected to the first rigid member 110. A third rigid member 130 extends between a first end 130A and a second end 130B in a vehicle front rear direction. The first end 130A of the third rigid member 130 is hingedly connected to the bottom end 120B of the second rigid member 120. A fourth rigid member 140 is hingedly connected to the second end 130B of the third rigid member 130. The fourth rigid member 140 is hingedly connected to the second end 130B of the third rigid member 130. Further, the fourth rigid member 140 is connected to a brake cam (not shown) of a drum brake (not shown) of a wheel 12. The system 100 further includes a housing 150 connected to the wheel 12 of the vehicle 10. A spring 160 is connected to an inner wall of the housing 150. The system 100 further includes a mechanical plug 170 having a body portion 172 and an arm portion 174 connected to the body portion 172. The body portion 172 is disposed inside the housing 150 and is connected to the spring 160 and the arm portion 174 is slidable through the housing 150 and is hingedly connected to the second rigid member 120. The mechanical plug 170 exerts a force on the second rigid member 120 in the opposite direction of the force exerted by the first rigid member 110 on the second rigid member 120 and consequently, controlling the movement of the second rigid member 120 and hence, the brake cam through the third rigid member 130 and the fourth rigid member 140.
[020] As illustrated in Figure 1, the vehicle 10 includes a suspension 14 that supports a sprung part of the vehicle 10. The housing 150 is provided on the unsprung part of the vehicle 10. The system 100 includes a stopper 152 that extends upwardly from the housing 150 and the stopper 152 is configured to restrict the movement of the top end 120A of the second rigid member 120 when actuated by movement of the first rigid member 110.
[021] Figure 2 illustrates a schematic view of the anti-lock braking system 100 when braking force is less than a threshold braking force B1, in accordance with an embodiment of the present invention. The threshold braking force is a braking force beyond which the vehicle 10 begins to skid. When brake input on the brake increases, brake torque increases which causes an increase in retarding force generated due to the friction between a tyre (not shown) of the wheel 12 and road. At the threshold braking force B1, retarding force reaches wheel skidding inception and the wheel 12 begins to skid. As illustrated in Figure 2, the brake input means actuates the first rigid member 110 and the first rigid member 110 being hingedly connected to the top end 120A of the second rigid member 120, in turn, moves the top end 120A. Movement of the top end 120A of the second rigid member 120 is limited to a maximum mechanical path till the stopper 152 beyond which no further movement is possible. As braking causes retardation, inertial force in the opposite direction is generated as per the Newtonian first law of motion. Inertial force is generated in an opposite direction to movement of the top end 120A of the second rigid member 120. Inertial force acting on the mechanical plug 170 causes the mechanical plug 170 to behave as a fixed fulcrum instead of a floating fulcrum. The spring 160 disposed behind the body portion 172 of the mechanical plug 170 disallows the mechanical plug 170 to act like a floating fulcrum during initiation of braking when inertial force is absent. Thus, the arm portion 174 of the mechanical plug 170 being a fixed fulcrum, the second rigid member 120 acts as a first order lever and force actuated on the top end 120A of the second rigid member 120 is transmitted to the bottom end 120B of the second rigid member 120. The bottom end 120B of the second rigid member 120 is connected to the third rigid member 130 at first end 130B that causes movement in the third rigid member 130 opposite in direction to movement in the first rigid member 110. The fourth rigid member 140 being in connection with the second end 130B of the third rigid member 130, moves consequently and causes the brake shoes in the brake drum to be actuated.
[022] Figure 3 illustrates a schematic view of the anti-lock braking system 100 when braking force is more than the threshold braking force B1, in accordance with an embodiment of the present invention. The threshold braking force B1 exceeds in event of hard braking, excessive braking and sudden braking. When threshold braking force B1 is exceeded, the first rigid member 110 actuated by the brake input means moves upto the stopper 152. Force of movement of the top end 120A of the second rigid member 120 exceeds any inertial force generated in the opposite direction due to deceleration. The force causes the mechanical plug 170 to move within the housing 150 in the direction of the first rigid member 110. The mechanical plug 170 is unable to act as a fixed fulcrum and behaves as a moving / floating fulcrum. Thus, the second rigid member 120 cannot function as a first order lever and proportional force is not transmitted from the first end 120A to the bottom end 120B of the second rigid member 120. Consequently, the third rigid member 130 and the fourth rigid member 140 are not actuated and the brake shoes are not actuated resultantly. The wheel 12 of the vehicle 10 does not skid due to absence of retarding force that cannot generate in absence of brake torque. The system 100 is functional of any road surface and any environment as the threshold braking force B1 is a function of the retarding force between the tyre and road.
[023] Figure 4 illustrates a schematic view of the anti-lock braking system 100, in accordance with an embodiment of the present invention. The system 100 includes a rotary pendulum 200 and locking arm 210. The rotary pendulum 200 has a top slot 202, a bottom slot 204, a left notch 206 and a right notch 208. The rotary pendulum 200 is configured to rotate when the vehicle 10 is on an inclined surface. The locking arm 210 is connected to the body portion 172 of the mechanical plug 170 and has a protrusion 212 configured to engage and disengage with the bottom slot 204 of the rotary pendulum 200. The system 100 further includes a left spring 220 and a left lock 222. The left lock 222 is configured to engage and disengage with the left notch 206 of the rotary pendulum 200. The system 100 further includes a right spring 230 and a right lock 232. The right lock 232 is configured to engage and disengage with the right notch 208 of the rotary pendulum 200. The system 100 further includes a top spring 240 and a top lock 242. The top lock 242 is configured to engage or disengage with the top slot 202 of the rotary pendulum.
[024] Figure 5 illustrates a schematic view of the anti-lock braking system 100 when the vehicle 10 is in a stationary condition on an upward incline, in accordance with an embodiment of the present invention. The rotary pendulum 200 having eccentric mass and being rotatable, rotates due to gravitational force in a manner that the top slot 202 of the rotary pendulum 200 disengages with the top lock 242. Further, the left notch 206 of the rotary pendulum 200 engages with the left lock 222. Further, the right notch 208 of the rotary pendulum 200 disengages with the right lock 232. Further, the bottom slot 204 of the rotary pendulum 200 disengages with the protrusion 212. In the present disposition, the locking arm 210 cannot move freely and as a consequence, movement of the mechanical plug 170 is restricted. In this instance, the mechanical plug 170 acts like a fixed fulcrum. When the rider actuates brake input means, the first rigid member 110 is caused to move and further causes to move the top end 120A of the second rigid member 120. The arm portion 174 of the mechanical plug 170 acting as fixed fulcrum, the second rigid member 120 behaves as a first order lever and the bottom end 120B of the second rigid member 120 is caused to move. As a consequence, the third rigid member 130 and the fourth rigid member 140 are actuated and the fourth rigid member 140 actuates the brake shoes. The instant embodiment of the system 100 is generally implemented for parking brake operation on an upward slope.
[025] Figure 6 illustrates a schematic view of the anti-lock braking system 100 when the vehicle 10 is moving on an upward incline and under braking condition, in accordance with an embodiment of the present invention. The top slot 202 of the rotary pendulum 200 engages with the top lock 242. Further, the left notch 206 of the rotary pendulum 200 disengages with the left lock 222. Further, the right notch 208 of the rotary pendulum 200 engages with the right lock 232. Furthermore, the bottom slot 204 of the rotary pendulum 200 engages with the protrusion 212, thereby allowing movement of the locking arm 210, and causes the mechanical plug 170 to move when braking force is less than a threshold braking force B1.
[026] Advantageously, the anti-lock braking system in the present invention is fully functional on sloped road surfaces and is indifferent to road surface conditions.
[027] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.