Claims:We Claim:

1. A master cylinder assembly (1000) for braking system of a vehicle comprising of
? a master cylinder housing (100),
? brake actuating levers (300 and 402),
? an arm (402BA) of a rear brake lever (402),
? a pivoting pin (500),
? tension springs (30 and 40),
? actuating cables (700 and 800), and
? a brake fluid reservoir (900),
wherein, the master cylinder housing (100) is configured to have
- hollow chamber (10) carved therein, said hollow chamber (10) accommodate movable piston (10A) and return spring (10B);
- projecting filler union (10C), said filler union open into the hollow chambers (10);
- outlet port (10D), said outlet ports open into the hollow chamber (10) and connect the hollow chamber (10) to a hydraulic brake (2000) via hydraulic line (2000A);
- projections (200A, 200B and 200C) with openings (600A, 600B and 600C) for receiving a pivot pin (500), said pivot pin forming a common pivoting axis (P1) for a front brake actuating lever (300) between the projection (200A) and the projection (200B), and for a lever (402) between the projection (200B) and the projection (200C);
- an arm (200BA) integral with projection (200B), said arm receives the front brake actuating cable (700) and connects it with the front brake actuating lever (300) at it one end (300A);
- an arm (200BB) integral with projection (200B), said arm receives the rear brake actuating cable (800) and connects it with the lever (402) at it one end (402A);
- the rear brake actuating cable (800) connected to the one end (402A) of the lever (402) proceeds further to connect with a slotted connection portion (410A) of a mechanical brake actuating arm (410) of a mechanical brake (2002); and
- a spring (420) is positioned between the slotted connection portion (410A) and a cable receiving end (430), the cable receiving end (430) receives and supports the rear brake actuating cable (800) on the mechanical brake (2002).

2. The master cylinder assembly (1000) as claimed in claim 1, wherein the return spring (10B) is positioned between one end of the hollow chamber (10) and the movable piston (10A).

3. The master cylinder assembly (1000) as claimed in claim 2, wherein the lever (402) has an arm (402BA), the said arm extends to be positioned above the front brake actuating lever (300) at an optimized position between the other end (300B) and the pivoting pin (500) on the front brake actuating lever (300) within the clearance (C).

4. The master cylinder assembly (1000) as claimed in claim 3, wherein the front brake actuating cable (700) is received in a slot (300AA) provided on the one end (300A) of the front brake actuating lever (300).

5. The master cylinder assembly (1000) as claimed in claim 4, wherein the end (300B) of the front brake actuating lever (300) is positioned above the movable piston (10A).

6. The master cylinder assembly (1000) as claimed in claim 5, wherein the tensioner spring (30) is positioned between the arm (200BA) of the projection (200B) and the end (300A) of the front brake actuating lever (300); and the tensioner spring (40) is positioned between the arms (200BB) of the projection (200B) and the end (402A) of the lever (402).

7. The master cylinder assembly (1000) as claimed in claim 6, wherein the master cylinder housing (100) is provided with a flange (110) below the projections (200A, 200B and 200C) for mounting the master cylinder assembly (1000) to the motor vehicle frame.

8. The master cylinder assembly (1000) as claimed in claim 3, wherein the clearance (C) between the arm (402BA) and the front brake actuating lever (300) is in the range of 0.5 to 7.0 mm.

Dated this 1st day of June 2021

Sahastrarashmi Pund
Head – IPR
Endurance Technologies Ltd.

To,
The Controller of Patents,
The Patent Office, at Mumbai. , Description:FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2005

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

TITLE OF THE INVENTION
“MASTER CYLINDER ASSEMBLY FOR BRAKING SYSTEM OF VEHICLES”

Endurance Technologies Limited
E-92, M.I.D.C. Industrial Area, Waluj,
Aurangabad – 431136, Maharashtra, India

The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed.
This application is patent of addition of Indian Patent Application No. 202021039766 filed on 15th Sept. 2020 and the entire contents of which are specifically incorporated herein by reference.

Field of Invention

[001] The present invention is related to a braking system for vehicles. More particularly, the present invention is related to the master cylinder assembly for braking system of two wheeled motor vehicles wherein the master cylinder assembly is capable of being utilized in a combined braking system of motor vehicles deriving the benefits of compactness, better space management, reduction in number of parts and ease of manufacturing, assembly and maintenance.

Background of the Invention

[002] A conventional two wheeler combined braking system with front and rear combination of hydraulic and mechanical brake normally employs use of actuation levers, equalizers, cables, master cylinders, hydraulically operated front wheel brake and mechanically operated rear wheel brake. These features are essentially provided for achieving combined braking function with required time delay in application of front wheel brake when rear wheel brake is applied. The implementation of these systems presuppose existence of sufficient manufacturing and assembly expertise to reliably provide them on any given two wheeler. It also presupposes existence of adequate space on the two wheeler which may not always be the case.

[003] Systems and devices available in public domain have been implemented with varying level of success. Document No. JP4458791B2 discloses an interlocking braking device capable of accepting two cable based inputs from operating levers and provide one cable output for operating a mechanical rear wheel brake and a hydraulic output for operating a hydraulic front wheel brake. The master cylinder assembly disclosed accommodates in its vicinity multiple levers with complicated profiles which ensures the device’s operability. Another document No. 5138/CHE/2014 describes an interlocking braking system comprising of a distribution device with said distribution device being capable of receiving input from two brake actuators and provide two braking outputs one of which is hydraulic output which operates the front wheel hydraulic brake and the other is mechanical output which operates a cable operated rear wheel mechanical brake. It is known that these prior art systems and devices have a very complicated construction having multiple sub-components that need precise and accurate manufacturing for ensuring reliable combined braking operation. The state of the art is thus replete with systems and devices that need high number of skilled workers for reliably implementing them on any given two wheeled vehicle.

[004] The prior art Combined Braking Systems (CBS) and devices therefore essentially require high level of expertise in their manufacturing and assembly. Their regular maintenance is also very complicated and hard to perform. Thus there exists a need for a master cylinder assembly for a combined braking system that can accept different cable inputs and provide a cable and a hydraulic output with the required time differential while occupying lesser space and also having fewer moving sub-components with complicated construction.

Objectives of the Invention

[005] The main objective of the invention is to provide a master cylinder assembly for braking system of two wheeled vehicles.

[006] Another object of the present invention is to provide master cylinder assembly for combine braking system of two wheeled vehicle that accepts at least two cable inputs from handlebar mounted actuating levers and provide at least one cable output and a hydraulic output.

[007] Yet, the another object of the present invention is to provide master cylinder assembly for combined braking system of a vehicle that has less number of sub-components and is compact in construction.

[008] Still the objective of the present invention is to provide master cylinder assembly for combined braking system of a vehicle that has less number of sub-components with complicated construction needing precise and accurate manufacturing.

[009] It is yet another objective of the present invention to provide master cylinder assembly for combined braking system that is efficient and easy to maintain with reduced maintenance requirements.

Summary of the Invention

[0010] With above objectives in view, the current invention provides a master cylinder assembly (1000) for braking system of a vehicle comprising of a master cylinder housing (100), brake actuating levers (300 and 402), an arm (402BA) of a lever (402), a pivoting pin (500), tension springs (30 and 40), actuating cables (700 and 800), and a brake fluid reservoir (900), wherein, the master cylinder housing (100) is configured to have hollow chamber (10) carved therein, said hollow chamber (10) accommodate movable piston (10A) and return spring (10B), projecting filler union (10C), said filler union open into the hollow chambers (10), outlet port (10D), said outlet ports open into the hollow chamber (10) and connect the hollow chamber (10) to a hydraulic brake (2000) via hydraulic line (2000A), projections (200A, 200B and 200C) with openings (600A, 600B and 600C) for receiving a pivot pin (500), said pivot pin forming a common pivoting axis (P1) for a front brake actuating lever (300) between the projection (200A) and the projection (200B); and for a lever (402) between the projection (200B) and the projection (200C), an arm (200BA) integral with projection (200B), said arm receives the front brake actuating cable (700) and connects it with the front brake actuating lever (300) at it one end (300A), an arm (200BB) integral with projection (200B), said arm receives the rear brake actuating cable (800) and connects it with the lever (402) at it one end (402A), the rear brake actuating cable (800) connected to the one end (402A) of the lever (402) proceeds further to connect with a slotted connection portion (410A) of a mechanical brake actuating arm (410) of a mechanical brake (2002), a spring (420) is positioned between the slotted connection portion (410A) and a cable receiving end (430), the cable receiving end (430) receives and supports the rear brake actuating cable (800) on the mechanical brake (2002).

[0011] Typically, the return spring (10B) is positioned between one end of the hollow chamber (10) and the movable piston (10A). The lever (402) has an arm (402BA), the said arm extends to be positioned above the front brake actuating lever (300) at an optimized position between the other end (300B) and the pivoting pin (500) on the front brake actuating lever (300) within the clearance (C). The front brake actuating cable (700) is received in a slot (300AA) provided on the one end (300A) of the front brake actuating lever (300). The end (300B) of the front brake actuating lever (300) is positioned above the movable piston (10A).

[0012] Typically, the tensioner spring (30) is positioned between the arm (200BA) of the projection (200B) and the end (300A) of the front brake actuating lever (300); and the tensioner spring (40) is positioned between the arms (200BB) of the projection (200B) and the end (402A) of the lever (402). The master cylinder housing (100) is provided with a flange (110) below the projections (200A, 200B and 200C) for mounting the master cylinder assembly (1000) to the motor vehicle frame. The clearance (C) between the arm (402BA) and the front brake actuating lever (300) is in the range of 0.5 to 7.0 mm.

Brief Description of the Drawings

[0013] This invention is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein and advantages thereof will be better understood from the following description when read with reference to the following drawings, wherein

[0014] Figure 1 discloses a schematic diagram of a braking system with Master Cylinder Assembly in accordance with an embodiment of the present invention.

[0015] Figure 2 discloses a front view of the Master Cylinder Assembly in accordance with an embodiment of the present invention.

[0016] Figure 3 discloses a side view of the Master Cylinder Assembly in accordance with an embodiment of the present invention.

[0017] Figure 4 shows a perspective view of the Master Cylinder Assembly in accordance with an embodiment of the present invention.

[0018] Figure 5 shows another perspective view of the Master Cylinder Assembly in accordance with an embodiment of the present invention.

[0019] Figure 6a shows a perspective view of the Master Cylinder Assembly in accordance with an embodiment of the present invention in its normal position.

[0020] Figure 6b shows a perspective view of the Master Cylinder Assembly in accordance with an embodiment of the present invention in its partially operating condition.

Detailed Description of the Present Invention

[0021] The invention will now be described in detail with reference to the accompanying drawings which must not be viewed as restricting the scope and ambit of the invention.

[0022] Referring to Fig. 1, disclosing the schematic diagram of a combined braking system with the master cylinder assembly (1000) in accordance with the preferred embodiment of the invention, the master cylinder assembly (1000) receives at least two cable inputs via a front brake actuating cable (700) and a rear brake actuating cable (800). The front brake actuating cable (700) and the rear brake actuating cable (800) are connected to the brake levers mounted on handlebar of the vehicle as shown in Fig. 1 or a handlebar mounted brake lever and a brake pedal or any workable combination thereof.

[0023] The master cylinder assembly (1000) provides two outputs via a hydraulic line (2000A) and a cable (800) to a hydraulic brake (2000) and a mechanical brake (2002), respectively. The hydraulic output of the master cylinder assembly (1000) is time delayed with respect to the output transmitted by the cable (800). This allows the hydraulic brake (2000) provided at the front of the motor vehicle to be operated with a time delay after the mechanical brake (2002) provided at the rear of the motor vehicle is actuated by operation of a braking lever or a pedal by the rider of the motor vehicle. It may be noted that the hydraulic output coming out of the hydraulic line (2000A) and the cable (800) can be routed to one or more than one front wheel hydraulic brakes and to one or more than one rear wheel mechanical brakes, respectively using known means of distributing hydraulic and mechanical outputs (i.e. cable based output).

[0024] Referring to Figs. 2, 3, 4 and 5, which disclose the invention, the master cylinder assembly (1000) for braking system of a vehicle in accordance with the invention comprises of a master cylinder housing (100), brake actuating levers (300 and 402), an arm (402BA) of a rear brake lever (402), a pivoting pin (500), tension springs (30 and 40), actuating cables (700 and 800), and a brake fluid reservoir (900).

[0025] The master cylinder housing (100) of the master cylinder assembly (1000) is configured to have a hollow chamber (10) carved therein, with the hollow chamber (10) accommodating a movable piston (10A) and a return spring (10B); the return spring (10B) positioned between one end of the hollow chamber (10) and the movable piston (10A); a projecting filler union (10C), with said filler union opening into the hollow chambers (10) and an outlet port (10D), with said outlet ports opening into the hollow chamber (10) and connecting the hollow chamber (10) to a hydraulic brake (2000) via hydraulic line (2000A).

[0026] The master cylinder housing (100) of the master cylinder assembly (1000) is further configured to have projections (200A, 200B and 200C) with openings (600A, 600B and 600C) for receiving a pivot pin (500), said pivot pin forming a common pivoting axis (P1) for a front brake actuating lever (300) between the projection (200A) and the projection (200B), and for a rear brake actuating lever (402) between the projection (200B) and the projection (200C); an arm (200BA) integral with projection (200B), said arm receives the front brake actuating cable (700) and connects it with the front brake actuating lever (300) at it one end (300A); an arm (200BB) integral with projection (200B), said arm receives the rear brake actuating cable (800) and connects it with the lever (402) at it one end (402A); the rear brake actuating cable (800) connected to the one end (402A) of the lever (402) proceeds further to connect with a slotted connection portion (410A) of a mechanical brake actuating arm (410) of a mechanical brake (2002) and a spring (420) is positioned between the slotted connection portion (410A) and a cable receiving end (430), the cable receiving end (430) receives and supports the rear brake actuating cable (800) on the mechanical brake (2002).

[0027] The lever (402) of the master cylinder assembly (1000) has an arm (402BA), the arm (402BA) extends to be positioned above the front brake actuating lever (300) at an optimized position between the other end (300B) and the pivoting pin (500) on the front brake actuating lever (300) within the clearance (C). This clearance (C) between the arm (402BA) and the front brake actuating lever (300) is in the range of 0.5 to 7.0 mm. The end (300B) of the front brake actuating lever (300) is positioned above the movable piston (10A). The front brake actuating cable (700) is received in a slot (300AA) provided on the one end (300A) of the front brake actuating lever (300). The end (402A) of the lever (402) and the master cylinder housing (100) is provided with a flange (110) below the projections (200A, 200B and 200C) for mounting the master cylinder assembly (1000) to the motor vehicle frame.

[0028] The tensioner spring (30) provided in the master cylinder assembly (1000) is positioned between the arm (200BA) of the projection (200B) and the end (300A) of the front brake actuating lever (300), while the tensioner spring (40) is positioned between the arms (200BB) of the projection (200B).

[0029] When the rider actuates the front brake lever, the cable (700) pulls on the end (300A) of the front brake actuating lever (300). As the front brake actuating lever (300) is pivoted along the pivoting pin (500), operation of the front brake lever causes the end (300B) to apply a force upon the movable piston (10A) via end (300A) of the front brake actuating lever (300). At this moment the tension spring (30) is also compressed which sets up a restoring force on the lever (300) that acts against the force applied by the rider and tries to restore the front brake actuating lever (300) to its original position. As the movable piston (10A) is displaced within the master cylinder housing (100) by end (300A) of the front brake actuation lever (300), the return spring (10B) is compressed which sets up a restoring force on the movable piston (10A). The displacement of movable piston (10A) into the hollow chamber (10) within the master cylinder housing (100) displaces the braking fluid present therein into the hydraulic line (2000A) via the outlet port (10D). This causes the application of the hydraulic brake (2000).

[0030] When the rider stops operating the front brake lever the return spring (10B) restores the movable piston (10A) to its original position. The brake fluid that was displaced by the movable piston (10A) therefore return to the hollow chamber (10). The filler union (10C) that is connected to a brake fluid reservoir via a hydraulic line prevents creation of extreme vacuum inside the hollow chamber (10) at this time by allowing some braking fluid to flow in via an opening given for the same inside the hollow chamber (10). The restoring force set up by the compression of tension spring (30) causes the front brake actuating lever (300) to return to its original position at the same time.

[0031] When the rider operates the rear brake lever, the cable (800) pulls on the end (402A) of the lever (402). As the lever (402) is pivoted along the pivoting pin (500), operation of the rear brake lever causes the arm (402BA) to cover the clearance (C) and then apply a force over the end (300B) of the front brake actuating lever (300) (refer Figs. 6a and 6b). The clearance (C) thus works to provide a time delay between beginning of the rotational movement of the lever (402) and the contact between the arm (402BA) with the end (300B) of the front brake actuating lever (300). At this moment the tension spring (40) is also compressed which sets up a restoring force on the lever (402) that acts against the force applied by the rider and tries to restore the lever (402) to its original position. When the end (300B) moves to displace the movable piston (10A) into the hollow chamber (10), the cable (700) that is received within the slot (300AA) stays in its position by freely moving within the slot (300AA) given in the front brake actuating lever (300). As the tension spring (30) is compressed, a restoring force on the lever (300) is set up that acts against the force acting via the arm (402BA) and tries to restore the front brake actuating lever (300) to its original position.

[0032] The displacement of the movable piston (10A) into the hollow chamber (10) applies the hydraulic brake (2000) in the same manner as if the front brake lever has been operated by the rider (except for the fact that the displacement of the movable piston (10A) is reduced by the magnitude of the clearance (C) that is given between the arm (402BA) and the end (300B)). The cable (800) that is received and linked at the end (402A) of the lever (402) and then continues further. Thence the cable (800) is received and supported at the receiving end (430) of the mechanical brake (2002) as shown in Fig. 1. Therefore, rider’s operation of the rear brake lever causes mechanical brake actuating arm (410) (linked to the cable (800) at the slotted connection portion (410A)) to move and apply the mechanical brake (2002) without any time delay. When the rider ceases to operate the rear brake lever, the restoring force set up by the tension spring (40) and the tension spring (30) on the lever (402) and the front brake actuating lever (300) respectively, causes them to return to their original position. This leads to cessation of the application mechanical brake (2002) and the hydraulic brake (2000).

[0033] The technical advancements and advantages derived from the novel features of the master cylinder assembly of the present disclosure are as follows:
- The master cylinder assembly receives two cable inputs and provides two outputs, one hydraulic and other mechanical, with a time differential required for safe combined braking operation.
- It has fewer sub-components and a compact construction in comparison to the existing master cylinder assemblies for combined braking application leading to easiness for its maintenance.
- It is configured to be manufactured, assembled and provided on any two wheeled motor vehicle easily without requiring skilled man power in all of these stages.
- The master cylinder assembly has less moving parts than any comparable prior art master cylinder assembly performing the same combined braking function, leading to compact system and weight reduction.
- The master cylinder assembly of the invention requires less space as compared to any of the prior art combined braking systems, thus addressing the issue of space management.
- The assembly makes the user to reduce the length of actuation cable, thus leading to effective braking in the vehicle and improvement in the safety of the rider / end user
- The master cylinder assembly of the invention effectively facilitates the use of single piston caliper in the combined braking system in place of two or three piston calipers at the wheel hub level.

[0034] The disclosed invention therefore achieves the objective of providing a master cylinder assembly for combined braking application that can receive two cable inputs and provide one cable output and one hydraulic output. The simpler design of the master cylinder assembly (1000) makes it easier to manufacture, assemble and provide in any two wheeled motor vehicle. The master cylinder assembly of the invention thus overcomes the shortcomings of the prior art master cylinder assemblies making the assembly of the invention compact, safer, reliable, more resilient, easily maintainable and cost effective.

[0035] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.