DESC:FIELD OF THE INVENTION
This invention is related to combined brake arrangement in an automotive vehicle. This invention is particularly related to a combined brake arrangement in a two or three wheeled vehicle.
BACKGROUND OF INVENTION
The known brake systems for automotive vehicle for example motorcycle comprise; a front brake actuation lever mounted on a handle bar of motorcycle preferably at right side and the front brake is actuated by a rider through a front brake cable by a pressing front brake actuation lever by hand; a rear brake actuation pedal mounted on the frame of motorcycle and rear brake is actuated by a rider through a rear brake rod by pressing pedal by a foot.
Interlock or combined- brake system is well-known in two wheelers. It is the brake system where both front wheel brake and rear wheel brake are applied simultaneously by operating a single actuator like hand brake lever or foot brake pedal of a two wheeler.
The known combined brake system for motorcycle comprises; a front brake system actuated through cable; a rear brake system actuated through a rod; an equalizer link mounted on the rear brake pedal; a rear brake pedal mounted on frame of motorcycle. One end of equalizer link is connected to the front brake cable; other end of equalizer link is connected to the rear brake rod; a rear brake pedal is hinged on the frame of motorcycle; one end of pedal is connected to the equalizer link between the two ends of equalizer link. When the rider of motorcycle applies a force on pedal by foot, the pedal actuates the equalizer link which further actuates both the front brake and rear brake simultaneously through front brake cable and rear brake rod respectively. The force applied on pedal is distributed by equalizer link to front brake system and rear brake system and transmitted to front brake through cable and read brake through rod.
The main disadvantage of such type of combined brake system is that combined front brake cable is routed through a equalizer link which is located at the rear side of the vehicle and goes to front brake panel which is located at front side of the vehicle. Hence length of the cable is long and has multiple bends through the route. This results in less cable efficiency for stroke transmission to the front brake (For example approximately 50-60%). On the other hand, rear brake is actuated by brake rod which is located at rear side of the vehicle and in the vicinity of equalizer link, hence it has a smaller length. Therefore stroke transmission efficiency of rear brake rod is more (For example approximately 90-95%). Hence force and stroke transmitted and applied on front brake is less and on rear brake is higher. Due to this, when a brake is operated; rear brake contribution is much higher than front brake contribution for stopping or slowing down the vehicle. This results in rear wheel locking earlier or at less input brake force which is unsafe to rider. The problem may aggravate in low road friction surface. Also a stopping distance of vehicle after brake application is more due to less combined braking efficiency of this system. In this system as the force transmitted to front brake is less, the full capacity of front brake is not used which result is poor overall braking efficiency of vehicle.
OBJECTS OF THE INVENTION
Hence the object of the invention is to provide a combined brake system for a vehicle in which the brake operation is safe and more efficient.
Another object of the invention is to provide a combined brake system for a vehicle in which the front brake actuation force increases.
Another object of the invention is to provide a combined brake system for a vehicle in which the stroke efficiency of the rear brake reduced to desired level.
Another object of the invention is to provide a combined brake system for a vehicle in which the contributions of front brake and rear brake are optimized in stopping or slowing down the vehicle.
Another object of the invention is to provide a combined brake system for a vehicle in which the full capacity of front brake system is utilized to increase the overall braking efficiency of vehicle.
Another object of the invention is to provide a combined brake system for a vehicle which is cost effective and robust.
SUMMARY OF THE INVENTION
With above objects in view, the present invention provides a combined brake system for a vehicle comprising;
a front brake system;
a rear brake system;
a combined brake actuating system mounted on the vehicle;
a combined brake actuating system comprising at least an equalizer link;
the front brake is connected to one end of equalizer link;
the rear brake is connected to other end of equalizer link;
the said combined brake actuating system is connected to the equalizer link between its two end points to actuate front brake and rear brake simultaneously;
Wherein;
a force regulating system is provided which regulates the actuating force on front and rear brakes during operation of said combined brake system.
According to one of the embodiment of the invention, a combined brake actuating system regulates the actuation force to increase front brake force contribution.
Preferably the force regulating system of a combined brake system comprises at least one resilient element mounted on rear brake system.
The rear brake system of the combined brake system comprising a brake pedal, a brake rod, brake lever, adjuster nut, rear brake cam lever, lock nut and the said resilient element is mounted on brake rod between the rear brake cam lever and the adjuster nut.
A rear brake system comprising a spring guide; wherein the resilient element is mounted between the spring guide and the adjuster nut.
According to another embodiment of the invention; combined brake system comprising both the front brake and rear brake are drum type brakes or at least one brake is of disc type brake and both the brakes are of mechanical type brakes or at least one brake is of hydraulic type brake.
According to another embodiment of the invention; a combined brake actuating system comprising a primary equalizer link and secondary equalizer link; the primary and the secondary equalizer links are hingably connected to each other and the primary equalizer link is connected to rear brake through rear brake rod and the secondary equalizer link is connected to front brake through front brake cable; the said secondary equalizer link is pivoted on; the said combined brake actuating system is connected to the primary equalizer link between its two end points to actuate front brake and rear brake simultaneously;
Wherein;
a force regulating system is provided which regulates the actuating force on front and rear brakes during operation of said combined brake system.
Preferably the force regulating system of a combined brake system comprises at least one resilient element mounted on rear brake system.
Preferably a rear brake system of the combined brake system comprising a brake pedal, a brake rod, brake lever, spacer, rear brake cam lever, lock nut and the said resilient element is mounted/ positioned/ placed between the rear brake cam lever and the adjuster nut.
A rear brake system comprising a spring guide; wherein the resilient element is mounted between the spring guide and the adjuster nut.
Preferably the resilient element is a spring.
The spring may have variable spring rate.
The spring may have predefined pre compression.
According to another embodiment of the invention; a combined brake system is provided with a stopper system on rear brake rod to limit the stroke of spring of brake force regulating system.
Preferably the stopper system comprises a spring guide and adjuster nut; wherein the said spring guide provided with a flange and adjuster nut provided with flange to limits the stroke of spring of brake force regulating system.
According to another embodiment of the invention; a combined brake system is provided with the force regulation system which is mounted on the rear brake rod ahead of the rear brake cam lever 25.
According to another embodiment of the invention; the force regulating system of a combined brake system comprises spring, spring guide and adjuster nut b wherein; lugs of adjuster nut are engaged in the corresponding slots of the spring guide which prevents the unnecessary rotation of adjuster nut due to vibrations.
According to another embodiment of the invention; rear brake rod is of the combined brake system may be in the form of flexible brake cable. Due to the flexibility of the rear brake cable, the stroke of the rear brake reduces resulting in the increase the contribution of front brake in the combined brake system.
According to another embodiment of the invention; a combined brake system comprising spring guide inner and spring guide outer wherein; drain holes are provided on spring guide outer at space apart and a boot of flexible material is provided over spring guide to prevent unwanted entry of foreign material inside and allow to drain the water to outside through drain holes.
DETAILED DESCRIPTION OF FIGURES

Numeral Description
10 Motorcycle
11 Front Brake
12 Rear Brake
15 Combined front Brake Cable
21 Rear Brake Pedal
22 Rear Brake Rod
23 Equalizer link
24 Pivot point
25 Rear Brake Cam Lever
30 Force regulating system
30a Force regulating system as per another embodiment
30b Force regulating system as per yet another embodiment
31 Spring
32 Spring Guide
32a Spring Guide as per another embodiment
32b Spring Guide as per yet another embodiment
33 Adjuster Nut
33b Adjuster Nut as per another embodiment
34 Lock Nut
35 End point of inner flange of adjuster nut 33
36 End point of inner flange of spring guide 32
37 Inner flange of adjuster nut 33
38 Inner flange of spring guide 32
39 Stopper system
40 Motorcycle having front disc type brake
41 Primary Equalizer Link
42 Secondary Equalizer Link
43 Pivot point
44 Connecting Link
45 Pivot Point
46 Pivot Point
47 One end of rear brake pedal 21
48 Front disc type brake
50 Motorcycle having two equalizer links
51 Lugs of adjuster nut 33b
52 Slots in spring guide 32b
53 Spring guide inner
54 Spring guide outer
55 Water drain holes
56 Boot
57 Lip on boot

Figures 1a, 1b and 1c are pictorial right view, left view and top view of the motorcycle with combined brake system respectively according to one of the embodiment of the invention.
Figure 2 is a close-up view of combined brake system showing the pedal and equalizer link arrangements.
Figure 3a is a close-up view of combined brake system showing rear brake arrangement and force regulation system.
Figure 3b is a cross section view of figure 3a.
Figure 4 is a pictorial view of the motorcycle with front disc brake system of a combined brake system according to another embodiment of the invention.
Figure 5 is a pictorial right view of the motorcycle of a combined brake system with primary and secondary equalizer links according to yet another embodiment of the invention.
Figure 6 is a pictorial left view of figure 5.
Figure 7a is a close-up view of combined brake system with primary and secondary equalizer links showing the pedal and equalizer link arrangements.
Figure 7b is a isometric view of figure 7a.
Figure 8a, 8b and 8c are close up views of force regulation system of combined brake system in 3 positions of brake actuation namely initial position, intermediate position and final position respectively.
Figure 9a, 9b and 9c are close-up views of pedal and equalizer link of combined brake system in corresponding 3 positions of figure 8a, 8b and 8c respectively.
Figure 10 is a pictorial view of rear brake arrangement where a force regulation system 30a is mounted on the rod ahead of the rear brake cam lever as per another embodiment of the invention.
Figure 11a and 11b are pictorial views of rear brake arrangement where a force regulation system 30b comprises lugs and slot arrangement to lock the adjuster nut as per yet another embodiment of the invention.
Figure 12a and 112 are pictorial views of rear brake arrangement wherein a force regulation system comprises spring guide inner, spring guide outer and boot of flexible material as per yet another embodiment of the invention.
DESCRIPTION OF PREFERRED EMBODIMENT
Now the one of the embodiment of the present invention is explained in details with help of the figures 1 to 8.
A motorcycle 10 provided with combined brake system comprises a front brake 11, a rear brake 12, combined front brake cable 15, rear brake pedal 21, rear brake rod 22, equalizer link 23. A rear brake pedal 21 is pivotally mounted on frame 27 of motorcycle 10 at pivot 24. One end of rear brake pedal is connected to the equalizer link 23 at pivot 26 between two end point 28 and 29 of equalizer link 23. One end 28 of equalizer link 23 is pivotally connected to the rear brake rod 22 and another end 29 of equalizer link 23 is pivotally connected to the combined front brake cable 15. When the rider of motorcycle 10 applies a force on pedal 21 by foot, the pedal 21 actuates the equalizer link 23 which further actuates both the front brake 11 and rear brake 12 simultaneously through front brake cable 15 and rear brake rod 22 respectively. The force applied on pedal 21 is distributed by equalizer link 23 to front brake system and rear brake system and transmitted to front brake 11 through front brake cable 15 and read brake 12 through rod 22.
The combined front brake cable 15 is routed through a equalizer link 23 which is located at the rear side of the motorcycle 10 and goes to front brake 11 which is located at front side of the motorcycle. Hence length of the cable 15 is long and has multiple bends through the route. This results in less cable efficiency for stroke transmission to the front brake 11 (For example 50-60%). On the other hand, rear brake 12 is actuated by rear brake rod 22 which is located at rear side of the motorcycle and in the vicinity of equalizer link 23, hence it has a smaller length. Therefore stroke transmission efficiency of rear brake rod 22 is more (For example 90-95%). Hence force transmitted and applied on front brake 11 is less and on rear brake 12 is higher. Due to this, when a combined brake is operated; rear brake 12 contribution is much higher than front brake 11 contribution for stopping or slowing down the motorcycle. This results in rear wheel locking earlier or at less input brake force which is unsafe to rider. The problem may aggravate in low road friction surface. Also a stopping distance of motorcycle after brake application is more due to less combined braking efficiency of this system. In this system as the force transmitted to front brake 11 is less, the full capacity of front brake 11 is not used which result is poor overall braking efficiency of motorcycle.
To avoid this situation, a force regulating system 30 is provided in the combined brake system of motorcycle according to this invention. The force regulation system 30 comprises compression spring 31, spring guide 32, adjuster nut 33 and lock nut 34. This force regulation system 30 is mounted on rear brake rod 22 at its rear end side and after the rear brake cam lever 25. The rear brake force is transmitted from rear brake rod 22 to the rear brake 12 through adjuster nut 33, spring 31, spring guide 32 and rear brake cam lever 25. Lock nut 34 prevents the unnecessary rotation of adjuster nut 33 during vibrations.
Referring to the figures 8a, 8b, 8c, 9a, 9b and 9 c, a horizontal line B-B is a reference line of initial position of rear brake pedal 21 and vertical line A-A is a reference line of initial position of rear brake rod 22 when no force is applied on the rear brake pedal 21.
In the intermediate position, the brake pedal 21 is pressed by ‘X1’ stroke and the rear brake rod 22 is pulled by ‘Y1’ stroke. Some part of this stroke is utilized for compression of spring 31 and remaining part of stroke is transmitted to the rear brake cam lever 25. Hence a cam lever 25 is pulled by a less stroke. To compensate this less stroke of rear brake cam lever 25, a rear brake pedal 21 has to be pressed for more stroke. This results in the actuation of rear brake cam lever by correct stroke. But as the same time, as the rear brake pedal is pressed for more stroke, a front brake cable will also pulled for more stroke. Hence for the same rear brake force, the front brake force increases. This results in utilizing more capacity of front brake 11 and further reducing the stopping distance of motorcycle after combined brake application and increasing the overall braking efficiency of motorcycle.
In the final position, the brake pedal 21 is pressed by ‘X2’ distance and the rear brake cam lever 25 is pulled by ‘Y2’ distance. Here a spring 31 is fully compressed and force applied through rear brake rod 22 is fully transmitted to the rear brake 12 through cam lever 25.
Referring to figure 3b, in the initial position when there is no force applied on rear brake pedal 21, a gap ‘P’ exists between the end point 35 of inner flange of adjuster nut 33 and the end point 36 of inner flange of spring guide 32. As the force is applied on rear brake pedal 21, the force is transmitted to rear brake 12 through equalizer link 23, rear brake rod 22, adjuster nut 33, compression spring 31, spring guide 32 and the rear brake cam lever 25. As the spring 31 get compressed the gap ‘P’ reduces and becomes zero when the end point 35 of inner flange 37 of adjuster nut 33 and the end point 36 of inner flange 38 of spring guide 32 touched to each other. Further force applied on rear brake rod 22 will be fully transmitted to cam lever 25 and rear brake 12.
Figure 4 illustrates an embodiment of the invention where a force regulating system 30 is provided in the combined brake system of motorcycle 40 having front disc type brake 48.
Referring to the figures 1a, 1b, 1c and 2, the combined brake system having only one equalizer link 23 requires routing combined front brake 15 cable from vehicle back side. This further drops front brake cable stroke efficiency due to more bends and more cable length. Packaging is also one of the concerns to route this cable.
Therefore to solve the above problem, a secondary equalizer link 24 is additionally provided by which pulling direction of the front brake cable 15 is changed and routed with minimum bends and comparatively shorter length. With this packaging is also simplified.
Figure 5, 6, 7a & 7b illustrates an embodiment of the invention where a force regulating system 30 is provided in the combined brake system of motorcycle 50 having two equalizer links. This comprises rear brake pedal 21, primary equalizer link 41, secondary equalizer link 42, connecting link 44, front brake cable 15 and rear brake rod 22. The rear brake pedal 21 is pivotally mounted on frame of motorcycle 50 at pivot point 24. One end 47 of rear brake pedal 21 is connected to the primary equalizer link 41 through connecting link 44 at pivot point 43. One end of primary equalizer link 41 is pivotally connected to the rear brake rod 22 at pivot point 45. Other end of primary equalizer link 41 is pivotally connected to the one end of secondary equalizer link 42 at pivot point 46. Other end of secondary equalizer link 42 is connected to the front brake cable 15. Secondary equalizer link 42 is mounted on the frame of motorcycle 50 ay pivot point 24 which is also a pivot point of rear brake pedal 21.
When a force is applied on rear brake pedal 21, part of force is transmitted to the rear brake rod 22 through connecting link 44 and primary equalizer link 41. The remaining force is transmitted to front brake cable 15 through connecting link 44, primary equalizer link 41 and secondary equalizer link 42.
Figure 10 illustrates another embodiment of the invention where a force regulation system 30a is mounted on the rod 22 ahead of the rear brake cam lever 25. Here the rear brake force applied is transmitted through rod 22a, spring guide 32a, spring 31a and rod 22b to the rear brake cam lever 25.
Figure 11a and 11b illustrates another embodiment of the invention where a force regulation system 30 b comprises spring 31b, spring guide 32b and adjuster nut 33b. The lugs 51 of adjuster nut 33b are engaged in the corresponding slots 52 of the spring guide 32b which prevents the unnecessary rotation of adjuster nut 33b due to vibrations. This eliminates the requirement of lock nut 34 illustrated in figure 3a & 3b.
Figure 12a and 12b illustrates another embodiment of the invention comprises spring guide inner 53 and spring guide outer 54 and boot 56 where spring guide outer 54 is provided with drain holes 55 which are180 degree apart and a boot 56 is provided over spring guide inner 53 and outer 54 which prevents any unwanted entry of foreign material inside through drain holes 55 of spring guide outer 54, but at the same time water will drain out through holes 55. Lips 57 are provided on boot 56 from inner side which rests on spring guide 32 from outer side to prevent the boot 56 from falling which may create more space for entry of foreign material through bottom drain hole 55.
According to another embodiment of the invention, the force regulating system may be used in combined brake system for vehicles having combined brake actuating lever mounted on any part of vehicle for example handle bar or frame etc.
Modifications and variations to the combine brake system in this specification may be apparent to skilled readers. Such modifications and variations are deemed within the scope of the present invention. The applicant intends to rely on the provisional specification and drawings annexed to the provisional specification.
,CLAIMS:1. A combined brake system for a saddle type vehicle comprising;
a front brake system (11);
a rear brake system (12);
a combined brake actuating system mounted on the vehicle;
a combined brake actuating system comprising at least an equalizer link
(23);
the front brake (11) is connected to one end of equalizer link (23);
rear brake (12) is connected to other end of equalizer link (23);
the said combined brake actuating system is connected to the equalizer link (23) between its two end points to actuate front brake (11) and rear brake (12) simultaneously;
Wherein;
a force regulating system (30) is provided which regulates the actuating force on front and rear brakes during operation of said combined brake system.

2. A combined brake system as claimed in claim 1; wherein the said force regulating system (30) regulates the actuation force to increase front brake (11) contribution.

3. A combined brake system as claimed in claim 1; wherein the said force regulating system (30) comprises at least one resilient element (31) mounted on rear brake system.

4. A combined brake system as claimed in claim 3; wherein the said rear brake system comprising a rear brake pedal (21), a rear brake rod (22), rear brake cam lever (25), adjuster nut (33), lock nut (34) and the said resilient element (31) is mounted on brake rod (22) between the rear brake cam lever (25) and the adjuster nut (33).
5. A rear brake system as claimed in claim 4 comprise a spring guide (32) wherein; the resilient element (31) is mounted between the spring guide (32) and the adjuster nut (33).

6. A combined brake actuating system as claimed in claim 3 , comprising a primary equalizer link (41) and secondary equalizer link (42); the primary and the secondary equalizer links are hingably connected to each other and the primary equalizer link (41) is connected to rear brake (12) through rear brake rod (22) and the secondary equalizer link (42) is connected to front brake (11) through front brake cable (15); the said secondary equalizer link (42) is pivoted on vehicle; the said combined brake actuating system is connected to the primary equalizer link (41) between its two end points to actuate front brake and rear brake simultaneously;
Wherein;
a force regulating system (30) is provided which regulates the actuating force on front and rear brakes during operation of said combined brake system.

7. A combined brake system as claimed in claim 6; wherein the force regulating system (30) comprises at least one resilient element (31) mounted on rear brake system.

8. A combined brake system as claimed in claim 7; wherein the said rear brake system comprising a rear brake pedal (21), a rear brake rod (22), rear brake cam lever (25), adjuster nut (33), lock nut (34) and the said resilient element (31) is mounted on rear brake rod (22) between the rear brake cam lever (25) and the adjuster nut (33).
9. A rear brake system as claimed in claim 8 comprise a spring guide (32) wherein; the resilient element (31) is mounted between the spring guide (32) and the adjuster nut (33).
10. A combined brake system as claimed in any of the above claims; wherein the resilient element (31) is a spring.

11. A combined brake system as claimed in claim 10; wherein the said spring (31) has a variable spring rate.

12. A combined brake system as claimed in claim 11; wherein the said spring (31) has a predefined pre compression.

13. A combined brake system as claimed in claim 5; wherein a stopper system (39) is provided on rear brake rod (22) to limit the stroke of spring of brake force regulating system

14. A combined brake system as claimed in claim 10; wherein the stopper system (39) comprises a spring guide (32) and adjuster nut (33); wherein the said spring guide (32) provided with a flange (38) and adjuster nut (33) provided with a flange (37) to limits the stroke of spring of brake force regulating system.

15. A combined brake system as claimed in claim 5; wherein the force regulation system (30) is mounted on the rear brake rod (22) ahead of the rear brake cam lever (25).

16. A combined brake system as claimed in claim 5; wherein the force regulating system (30b) comprises spring (31), spring guide (32b) and adjuster nut (33b) wherein; lugs (51) of adjuster nut (33b) are engaged in the corresponding slots (52) of the spring guide (32b) which prevents the unnecessary rotation of adjuster nut (33b) due to vibrations.

17. A combined brake system as claimed in claim 5; comprising spring guide wherein; drain holes (55) are provided on spring guide at space apart and a boot (56) having lip (57) is provided over spring guide to prevent unwanted entry of foreign material inside and allow to drain the water to outside through drain holes (55).

18. A combined brake system as claimed in any of the above claims; wherein both the front brake and rear brake are drum type brakes or at least one brake is of disc type brake and both the brakes are of mechanical type brakes or at least one brake is of hydraulic type brake.

19. A combined brake system as claimed in claim 5; wherein the said rear brake rod (22) is in the form of flexible brake cable.

20. A combined brake system as claimed in claim 1; wherein the force regulating system used for vehicles having combined brake actuating lever mounted on any part of vehicle.