Interlink Brake System

Field of the Invention:

This invention relates to "Interlink Brake System". In particular this invention relates

to front and rear interlink brake system for two-wheeled vehicle.

Background of the Invention:

In most of the present two wheeler braking systems, both front and rear brakes are independently operated i.e. application of front brake force will activate only front wheel brake and rear brake force will activate only rear wheel brake. Rear brake force application is limited, because of dynamics of vehicle during braking. Due to load transfer to front wheel during braking, further increase in rear brake force will result in skidding rather than stopping the vehicle. Vehicle controlling becomes difficult and stopping distance will be more, thereby resulting in poor braking perfonnance due to wheel skidding. So typically in a combined or interlink brake system the available braking force is completely utilised by distributing it to front and rear brake, thereby the stopping distance is minimized in two wheelers. As disclosed in JP2004352181 the interlocking brake device ( or combined braking system), has an interlocking brake manipulating cable which is connected to an intermediate portion of an equalizer lever, which forms a front wheel brake manipulating end portion at one end portion thereof and a rear wheel brake manipulating end portion at another end portion thereof, either one of the front brake cable and the rear brake cable is formed as one independent brake manipulating cable which is connected to an independent brake manipulating member, an engaging member which is capable of being engaged with and being disengaged from the equalizer lever is mounted on the independent brake manipulating cable. In this brake system arrangement, the equalizer lever can tilt towards the wall and hit the spring placed around it. This tilting can lead to mechanism lockage. And during this lockage the front brake application is not possible. Since one spring is used to retain the equalizer in its original position, much brake force is wasted to move the equalizer against the spring. The provision of engaging member resting on equalizer lever slot which is an integral part of the brake cable for sliding and relative rotation is subject to wear and tear for continuous rubbing and sliding inside the slot. To replace the said engaging member the entire cable has to be changed.

In another patent JP9058434 which discloses a longitudinal interlocking brake (or combined brake) practicable through a structure by applying a mechanism, which generates only rear wheel brake force in an early time of brake operating input, but as the brake operating input exceeds a prescribed value, it can generate braking force even at the front wheel. In the above said mechanism there is one input and two output for which the independent lever mechanism is placed longitudinally opposite to the combined lever mechanism, thereby during rear brake application, front brake activation line length is more. The problem associated with this is that it is incapable of providing good brake feel. Since there is only one input, the equalizer lever is not supported and guided during brake operation. At the end of rear brake application, application of the front brake will result in tilting of equalizer lever thereby hitting the wall.

In another patent JP2000309294 which discloses a interlocking brake system (or combined brake system) having an equalizer lever accommodated inside an equalizer case disposed near a head pipe, where a first input cable is connected to an interlocking brake lever which is axially supported at one end of a steering handle and is connected to a mid portion of the equalizer lever. Further a first output cable and a second output cable connected to a rear wheel brake and a front wheel brake are connected to a first end and a second end of the equalizer lever. In this kind of arrangement there is no support /guiding system for front brake circuit (i.e. is not guided). During rear brake operation, the resultant thrust coming on pin joint of intermediate arm can make front brake circuit to deflect in lateral direction of the cable. This results in mechanism lockage and rubbing of front brake wire with casing walls. The other disadvantage is front brake input cable end is free to slide in the slot due to improper guiding of the joint member the front brake input cable end may bend. For which more rear brake activation force is required during interlocking braking. Even the brake cable wire endpin rotation is not allowed inside that slot. Unnecessary work is also done against the spring which is used in the front brake circuit for initiation for interlocking brake.

In fact in all the known combined brake system arrangement principally the front and rear output are in the same direction or same side thereby rendering restrictions and problems for cable routing Hence the objective of the present invention is to overcome the above problems associated with the prior arts.

Summarv of the Invention:

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

An object of the present invention is to provide an interlink brake system for two wheeled vehicle which provides better dynamics and safety.

Another object of the present invention is to provide an interlink system for two wheeled vehicle where the brake circuits are guided properly thereby improving the braking feel.

Another object of the present invention is to provide an interlink braking system for two wheeled vehicle where the brake cable wire bending is avoided.

Another object of the present invention is to provide an interlink braking system for two wheeled vehicle which will minimize the length of cable routing.

Yet another object of the present invention is to provide a cost effective arrangement for interlink brake system.

Further object of the present invention is to provide an interlink brake system with reduced part counts.

Further object of the present invention is to provide an interlink brake system which renders easy packaging for the two wheeled vehicle.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

Brief Description of the Drawings:

The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein

FIG. 1 is a conventional scooter type motorcycle.

FIG. 2 shows the interlink brake system according to the present invention.

FIG. 3 shows the interlink brake system according to one embodiment of the present invention.

FIG. 4 shows the interlink brake system according to another embodiment of the present invention.

FIG. 5 shows the interlink brake system mounted to the downtube according to one of the embodiment of the present invention.

FIG. 6 shows the interlink brake system mounted to the floor board according to one of the embodiment of the present invention.

Detailed Description of the Invention:

One or more embodiments of the invention provide an interlink brake system which can adjust brake forces of front and rear wheels in such a manner that an optimum brake characteristic can be obtained. The said interlink brake system provides a freedom of a position arrangement of the same at various location as preferred.

The present invention relates to interlinked braking system for a two wheeled vehicle. For the purpose of illustration a scooter of the general type is illustrated for the application. Referring to figure 1, a front wheel, 2 denotes a front fork, 3 denotes a front fender, 4 denotes a front cover, 5 denotes a leg shield made of resin or metal, 6 denotes a handle bar cover, 7 denotes a headlight, 8 denotes a handle bar ,17 denotes a rear fender and 18 denotes tail lamp.

The center of the body forms a low floor board 9 for functioning as a part for putting feet and a under cowl 10 which is located below the rider's seat and covers at least a part of the engine. The under cowl is made up of metal or resin. The under cowl is hinged to the seat 11. A utility box 12 opens from the rear end to hinged portion. The utility box 12 is provided under the seat extending longitudinally of a vehicle body and the inside of the utility box has a large capacity so that a large article can be housed. A main frame 14 extended along the center of the body before and behind and made of a metallic pipe and is provided under the floor board 9. A swing type power unit 13 is coupled to the rear end of the main frame 14.

A rear wheel 15 is supported on one side of the rear end of the swing type power unit 13. The swing type power unit 13 is suspended in the rear of a body frame.

The side covers 16 both on left and right sides, covers the utility box 12 and other parts of the vehicle, thereby providing a good appearance to the vehicle.

According to a first aspect of the invention and referring to figure 2 and figure 3, an interlink brake system 201 for a two wheeler is provided with a segmented equalizer lever 202 to distribute the input force from an interlinked brake lever 203 to front 205 and rear 206 wheel. The said interlink brake system 201 is housed within a casing. The said segmented equalizer 202 is constructed with three pieces namely two extreme pieces 202a, 202b and one middle piece 202c. The said three piece of the said segmented equalizer lever 202 is arranged in such a fashion that the said middle piece 202c moves in between the two extreme pieces 202a, 202b to provide rotational movement to the two said extreme piece 202a, 202b. The said two extreme pieces 202a, 202b are arranged in a manner, such that edge 202a', 202b' of the said two extreme piece 202a, 202b which faces the middle piece 202c are kept at a inclined position to each other, the edges forming a inverted V shape passage between them. In the said inverted V shaped passage a middle piece 202c (preferably wedge shaped) moves up and down.

The said two extreme pieces 202a, 202b is fixed to the casing wall 301 with one pin joint 302, 303 for each. An interlinked connecting cable 304 from the interlinked brake lever 203 is connected to the said middle piece 202c. A spring 305 is provided over the interlinked connecting cable 304, whose one end is connected to the casing wall 301 and the other end to the said middle piece 202c. The said spring 305 provides a smooth travel for the middle piece 202c without hitting the casing wall 301 of interlinked brake system 201. The said spring 305 is preferably a compression spring.

According to the first aspect, in one preferred embodiment of the present invention, two output cables 306,307 of said interlink brake system 201 are provided in same direction. The said output cables 306,307 are connected to the said two extreme pieces 202a, 202b of the segmented equalizer lever towards its end. For this particular arrangement where the said output cables 306, 307 are provided in same direction, the said two extreme pieces 202a, 202b respective pin joints 302, 303 to the casing wall positions are made aligned to each other. A delay spring 308 is provided to one of the extreme piece 202b to which one output cable 306 is fixed and thereby it is intended to provide a delay in response for that same output cable relative to the other output cable 307. The delay spring 308 can be a compression spring or tension spring.

Whenever a force is applied through the interlinked connecting cable 306, the said middle piece 202c is pulled and the said middle piece 202c travels within the inverted V shaped passage created by the edges of said two extreme pieces. Guiding means for the middle path can be provided on the casing wall or on the edges of the said extreme pieces which makes the passage. While the middle piece 202c travels from the broad edge of the passage towards the narrower or tapering edge of the passage, it exerts lateral force on the two extreme pieces 202a, 202b, and thereby induces a rotational movement to both extreme pieces. The rotational movement of the said two extreme pieces 202a, 202b about the respective pin joints 302, 303 are in same direction. The respective pin joints 302, 303 are aligned to provide rotational movement in same direction. The rotational movement of the extreme piece 202a without delay spring is more than the rotational movement of the other extreme piece 202b provided with delay spring 308, accordingly the output cable 307 which is connected to the extreme piece 202a not having delay spring is pulled first and further application of pulling force of interlink connecting cable 304 actuates the other output cable 306 which is connected to the extreme piece having delay spring 308.

Preferably the output cable 306 which actuates the front brake is connected to the extreme piece 202b which has delay spring 308 attached to it and the output cable 307 which actuates the rear brake is connected to the extreme piece 202a which does not have delay spring.

Whenever the interlink brake 203 is released the middle piece 202c slowly descends to its original position in the said inverted V passage from tapered end towards the broad end, with the help of said spring 305 connecting the middle piece'202c and casing wall 301 and accordingly the extreme pieces 202a, 202b comes back to its original position.

In another preferred embodiment of the present invention and referring to figure 4, two output cables 306, 307 of said interlink brake system 201 are provided in opposing direction. The said output cables 306, 307 are connected to the said two extreme pieces 202a, 202b of the segmented equalizer lever towards its end. For this particular arrangement where the said output cables 306, 307 are provided in opposing direction, the said two extreme pieces 202a, 202b respective pin joints 302, 303 to the casing wall 301 positions are made nonaligned to each other. A delay spring 308 is provided to one of the extreme piece 202b to which one output cable 307 is fixed and thereby it is intended to provide a delay in response for that same output cable relative to the other output cable 306. The delay spring 308 can be a compression spring or tension spring.

Whenever a force is applied through the interlinked connecting cable 304, the said middle piece 202c is pulled and the said middle piece travels within the inverted V shaped passage created by the edges 202a', 202b' of said two extreme pieces 202a, 202b. Guiding means for the middle path can be provided on the casing wall 301 or on the edges of the said extreme pieces which makes the passage. While the middle piece 202c travels from the broad edge of the passage towards the narrower or tapering edge of the passage, it exerts lateral force on the two extreme pieces 202, 202b, and thereby induces a rotational movement to both extreme pieces. The rotational movement of the said two extreme pieces 202a, 202b about the respective pin joints 302, 303 are in different direction. The respective pin joints 302, 303 are nonaligned to provide rotational movement in different or opposing direction. The rotational movement of the extreme piece 202a without delay spring is more than the rotational movement of the other extreme piece 202b provided with delay spring 308, accordingly the output cable 306 which is connected to the extreme piece 202a not having delay spring is pulled first and further application of pulling force of interlink connecting cable 304 actuates the other output cable 307 vyhich is connected to the extreme piece having delay spring 308.

Preferably the output cable 307 which actuates the front brake is connected to the extreme piece 202b which has delay spring 308 attached to it and the output cable 306 which actuates the rear brake is connected to the extreme piece 202a which does not have delay spring.

Whenever the interlink brake 203 is released the middle piece 202c slowly descends to its original position in the said inverted V passage from tapered end towards the broad end, with the help of said spring 304 connecting the middle piece 202c and casing wall 301 and accordingly the extreme pieces 202a,202b comes back to its original position.

Another aspect of the present invention and referring to figure 5 is to provide the said interlink brake system 201 for a motorcycle, where the casing of the said interlink brake system is mounted in the vicinity of downtube of the motorcycle. The said downtube extends downward rearwardly from the head pipe of the motorcycle.

In one more aspect of the present invention and referring to figure 6, the said interlink brake system 201 having output cables 306, 307 in opposing direction,

housed within a casing is mounted in the vicinity of the floorboard of a step thru vehicle.

The invention being thus 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 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 claims.

We Claim:

1. An interlink brake system for two wheelers comprising:

a segmented equalizer lever to distribute force;

at least a pair output cables connected towards end of the segmented equalizer lever; and

at least one interlink connecting cable connected to a middle piece of the segmented equalizer lever. wherein the interlink brake system is provided within a casing.

2. An interlink brake system as claimed in claim 1, wherein the segmented equalizer lever comprises:

at least two extreme piece;

at least one middle piece placed between the two extreme piece wherein the middle piece moves in between the other two extreme pieces to provide rotation to the said two extreme pieces.

3. An interlink brake system as claimed in claim 1 and claim 2, wherein the said segmented equalizer extreme piece is provided with at least one pin joint fixed to the casing wall.

4. An interlink brake system as claimed in claim 1 and claim 2,wherein the said interlink connecting cable is provided with a spring over it connecting the casing wall and the middle piece of segmented equalizer lever thereby providing smooth return path for middle piece.

5. An interlink brake system as claimed in claim 1 and claim 2, wherein the said one segmented equalizer extreme piece among the two is fixed to a delay spring which is further fixed to the casing to provide a delay in rotational movement of the same extreme piece relative to other extreme piece of segmented equalizer lever.

6. An interlink brake system as claimed in claim 1 and claim 2; wherein the said segmented equalizer lever is connected to two output cables in opposing direction.

7. An interlink brake system as claimed in claim 6, wherein the said segmented equalizer lever extreme pieces pin joints fixed to the casing wall is placed nonaligned to each other.

8. An interlink brake system as claimed in claim 1 and claim 2, wherein the said segmented equalizer lever is connected to two output cables in same direction.

9. An interlink brake system as claimed in claim 8, wherein the said segmented equalizer lever extreme pieces pin joints fixed to the casing wall is placed aligned to each other.

10. An interlink brake system as claimed in claim 5, wherein the said delay spring is preferably a compression type.

11. An interlink brake system as claimed in claim 5, wherein the said spring is preferably a tension type.

12. An interlink brake system as claimed in claim 1, claim 2 and claim 6, wherein the said interlink brake system housed within a casing is mounted in the vicinity of floor board area for a step thru vehicle.

13. An interlink brake system as claimed in claim 1, claim 2 and claim 8, wherein the said interlink brake system housed within a casing is mounted in the vicinity of downtube(s) extending from head pipe of the vehicle.

14.An interlink brake system comprising:

a segmented equalizer lever to distribute force;

at least a pair output cables connected towards end of the segmented equalizer lever; and

at least one interlink connecting cable connected to a middle piece of the segmented equalizer lever;

wherein the interlink brake system is provided within a casing.

15. An interlink brake system as claimed in claim 14, wherein the segmented equalizer lever comprises: at least two extreme piece;

at least one middle piece placed between the two extreme piece wherein the middle piece moves in between the other two extreme pieces to provide rotation to the said two extreme pieces.