DESC:FIELD OF INVENTON
This invention is related to a combined brake system in an automotive vehicle. Particularly, this invention is related to a combined brake system in a saddle type vehicle and three wheeled vehicles.
CROSS REFERENCE TO RELATED INVENTION
This invention takes priority from an earlier filed provisional patent application no. 201921029383 filed on July 22, 2019; which is incorporated herein as reference.
BACKGROUND OF THE INVENTION
The known brake systems for automotive vehicle for example motorcycle, comprise a front brake actuation lever generally mounted on a handle bar of the motorcycle preferably at right side and the front brake is actuated by rider through a front brake cable by a pressing front brake actuation lever by hand; a rear brake actuation pedal generally 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 are well-known to be used in two wheelers. It is a 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 motorcycles comprises; a front brake system actuated through cable; a rear brake system actuated through a rod; an equalizer link mounted on the brake pedal; a 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; the 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 rider of the motorcycle applies a force on pedal by foot, the pedal actuates the equalizer link which further actuates both the brakes i.e. 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 to rear brake through rod or cable.
The main disadvantage of such type of combined brake system is that if there is a slag or excessive free play exists in the rear brake system then the force applied on the brake pedal is not properly distributed by the equalizer link to front brake system and rear brake system respectively. In such case, both brakes may not operate simultaneously as intended by the combined brake system.
If free play in the rear brake system is set as per standard, system ensures simultaneous front and rear brake application.
If there is a slag or excessive free play exist in the rear brake system and the front brake free play is normal, the front brake may get applied before the rear brake and both brakes may not operate simultaneously as intended by the combined brake system. This is because of more travel required to actuate rear brake and front brake application may happen first as travel required is same as case of standard free play setting.
This problem may be attended by providing an additional link (called connecting link) in the system. However, this will increase the size of system, number of parts and looks bulky. Further, This reduces the aesthetics of the vehicle and Additional covers have to be provided to hide this linkages Which increases the overall costs. . Thus, the challenge is to install combined brake system without above problems.

OBJECT 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 more efficient even if there is an excessive free play or slag in the rear brake system.
Another object of the invention is to provide a combined brake system for a vehicle having less number of linkages and parts used.
Another object of the invention is to provide a combined brake system for a vehicle which does not affect the aesthetics of the vehicle.
Another object of the invention is to provide a combined brake system which is cost effective.
SUMMARY OF INVENTION
With above objects in view, the present invention provides a combined brake system for a vehicle comprising;
a front brake system comprising; a front brake cable, front brake lever, front brake shoes, front brake drum or disc.
a rear brake system comprising; a rear brake rod or cable, rear brake lever, rear brake shoes, rear brake drum;
at least an equalizer link;
the front brake system is connected to one end of equalizer link through front brake cable;
rear brake system is connected to other end of equalizer link through rear brake rod or cable;
the said equalizer link is pivoted between its two end points and said pivot (A) is connected to the one end of brake pedal;
the said brake pedal transmits the brake actuating force to front and rear brake system through the said equalizer link during operation of the combined brake system;
Wherein the equalizer link has a sliding means and the pivot point (A) slides in this sliding means during the combined brake operation.
In the case if there is an excessive free play or slag in the rear brake system, the equalizer link adjust itself by sliding its pivot (A) in the sliding means so that the slag in the rear brake system is compensated ensuring simultaneous front and rear brake application.
Preferably, the sliding means of the equalizer link may be an oblong slot between its end points.
Preferably, the brake pedal is pivotally mounted on a frame of the vehicle at pivot (B) with one end is connected to the equalizer link at pivot (A) and another end is a brake force application point.
Preferably, the said brake pedal is pivotally mounted on step holder which is mounted on the frame of the vehicle.
Preferably, the combined brake system comprising a secondary link wherein; one end of the secondary link is connected to the front brake cable and another end of secondary link is connected to the end 1 of equalizer link and the secondary link is pivoted between its two end points and said pivotally mounted on the frame of the vehicle at pivot (B).
Preferably, the combined brake system comprising the equalizer link having oblong slot, brake pedal having its one end as pivot (A); wherein a pin is provided at the end of brake pedal and a sleeve is provided on the pin and this sleeve is slidably connected in the oblong slot of the equalizer link.
Preferably, the sleeve is made of stainless steel or Derlin or equivalent material for friction free sliding operation of the pin in the oblong slot of equalizer link.
Preferably the front brake cable is a single joint less cable which is connected between connecting link and front brake system. This single brake cable looks aesthetically better and avoids cable hanging which can be seen from vehicle side view.
Preferably the front brake cable is routed along the frame of the vehicle near central tube, lower central tube and head pipe of the vehicle. This routine of cable close to steering axis of the vehicle will avoid pulling of inner cable while steering the vehicle, thus avoid loop formation of cable while steering the vehicle., This avoid hitting/ rubbing of cable with nearby parts like fender or brackets which will increases durability of the cable and ensures less service cost to customer.
Preferably the oblong slot axis can be parallel or at an angle to length of equalizer link or of curved shape.
The above arrangement ensures proper functioning of combined brake system and proper distribution of applied force between front and rear brake system when there is an excessive free play or slag in the rear brake system.
BRIEF DESCRIPTION OF DRAWINGS:
In order to understand the invention and to see how it can be carried out in practice, non-limiting examples and embodiments will now be described with reference to the accompanying drawings, in which:
FIG. 1 is a pictorial view of a motorcycle with combined brake system with equalizer link according to prior art;
FIG. 2 is a close-up view of the combined brake system according to prior art shown in FIG. 1;
FIG. 3 and 4 are close up views of details of equalizer links of combined brake system according to one embodiment of the present invention;
FIG. 5 is an isometric view of details of equalizer links of combined brake system according to one embodiment of the present invention;
FIG. 6 is a cross section view of details of equalizer links of combined brake system according to one embodiment of the present invention;
FIG. 7a and 7b are isometric view of details of equalizer links of combined brake system according to another embodiment of the present invention; and
FIG. 8 is pictorial view showing the front brake cable routine according to one embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT:
Embodiments of present invention will now be explained with the help of FIG.s herein below. All the aspects described herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope herein without departing from the spirit and scope thereof, and the present invention herein includes all such modifications.
The description of combi-brake arrangement according to the prior art is explained with the help of FIG.s 1 and 2. A motorcycle 10 comprise a front brake system 17 and a rear brake system 18. A combi brake actuating pedal 13 actuate an equalizer link 14 through a pivot (A) 15, which further actuate front brake cable 11 through secondary link 19 and rear brake rod or cable 12 simultaneously to actuate front brake system 17 and rear brake system 18 respectively.
FIG.s. 3 to 6 relate to a combined brake system 100 according to one of the embodiment of the present invention. A combi brake actuating pedal 113 actuates an equalizer link 114 through a pivot (A) 115, which further actuates front brake cable 111 through a secondary link 119 and a rear brake rod or cable 112 simultaneously to actuate front brake system 17 and rear brake system 18 respectively. Here, an equalizer link 114 have an oblong slot 120 instead of circular hole. In the case, if there is an excessive free play or slag in the rear brake system 18, the equalizer link 114 adjust itself by sliding its pivot (A) 115 in the oblong slot 120 so that the slag in the rear brake system 18 is compensated and ensures simultaneous front and rear brake application. This feature is explained in detail in following paragraph.
During the combined brake force application at brake force application point (121) of the rear brake pedal (113), when there is excessive play in the rear brake system 18, the equalizer link pivot A 115 slides upward with respect to the equalizer link 114 along the oblong slot 120. Due to provision of the oblong slot 120 to the equalizing mechanism, the rear brake rod 12 travels more to compensate excessive play in the rear brake system. At the same time, the front cable 111 travel does not increase till excessive slag in rear brake system 18 is consumed. The pivot A 115 comprises a pin 123 and sleeve 124 mounted on the pin 123. The sleeve 124 slides in the oblong slot 120 of the equalizer link 114.
In this embodiment, the pivot (B) 116 of the combi brake actuating pedal 113 is mounted on the frame 21 of the motorcycle 10.
According to another embodiment of the present invention (Refer FIG. 7a and 7b), the pivot (B) 116 of the combi brake actuating pedal 113 is mounted on the step holder 122. The step holder 122 is mounted on a frame 21. The pivot point (B) 116 may be outside of the step holder 112 or it may be inside of the step holder 122 for better aesthetics.
According to another embodiment of the present invention, the oblong slot 120 can be parallel or at an angle to length of the equalizer link or of a curved shape. Refer FIG. 6 for parallel axis 125 and curved axis 126 of the slot 120.
Referring to FIG. 8, the front brake cable 111 is a single jointless cable which is connected between secondary link 119 and front brake system 17. The front brake cable 111 is routed along the frame 21 of the vehicle 10 near central tube 23, lower central tube 22 and head pipe 24 of the vehicle 10.
According to another embodiment of present invention, when excessive free play is generated in the front brake system 17, simultaneous braking happens only after excessive free play on front brake system 17 consumed. In this case pivot A 115 will move downward along oblong slot 120 length. It can be done by limiting compensation of free play increase in front brake system by limiting length of oblong slot. In this case the travel of brake pedal 113 will be higher.
According to another embodiment of present invention, the movement of Pivot A 115 can be made in opposite direction with different positon of linkage pivots or by changing the rear brake rod and the front brake cable mounting location.
The above embodiments of the invention is described for solving the problem of excessive free play in the rear brake system. A similar system can also be used for solving the problem of excessive free play in the front brake system. This invention can be applied to all types of brake system viz front brake system of disc type or drum type and rear brake system of disc type or drum type.
Although the invention has been described with regard to its embodiments, specific embodiments, and various examples, which constitute the best mode presently known to the inventors, it should be understood that various changes and modifications as would be obvious to one having the ordinary skill in this art may be made without departing from the scope of the invention. The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole. All changes that come with meaning and range of equivalency of the claims are to be embraced within their scope.
,CLAIMS:1. A combined brake system (100) for a vehicle comprising;
a front brake system (17) comprising; a front brake cable (111), a front brake lever (25), front brake shoes, a front brake drum or disc;
a rear brake system (18) comprising; a rear brake rod or cable (112), a rear brake pedal (113), rear brake shoes, a rear brake drum;
at least an equalizer link (114);
the front brake system (17) is connected to one end of the equalizer link (114) through the front brake cable (111);
the rear brake system (18) is connected to other end of the equalizer link (114) through the rear brake rod or cable (112);
the equalizer link (114) is pivoted between its two end points and pivot A (115) is connected to the one end of brake pedal (113);
the brake pedal (113) transmits brake actuating force to the front (17) and the rear brake system (18) through the equalizer link (114) during operation of the combined brake system (100);
wherein the equalizer link (114) has a sliding means (120) and the pivot point A (115) slides in the sliding means (120) during the combined brake operation.
2. The combined brake system (100) as claimed in claim 1, wherein the sliding means (120) of the equalizer link (114) is an oblong slot (120) between its end points.
3. The combined brake system (100) as claimed in claim 2, wherein the brake pedal (113) is pivotally mounted on a frame (21) of the vehicle at pivot B (116) with it’s one end connected to the equalizer link (114) at the pivot A (115) and another end is a brake force application point (121).
4. The combined brake system (100) as claimed in claim 3, wherein the brake pedal (113) is pivotally mounted on step holder (122) mounted on the frame (21).
5. The combined brake system (100) as claimed in claim 4, wherein the combined brake system (100) comprising a secondary link (119), wherein one end of the secondary link (119) is connected to the front brake cable (111) and another end of the secondary link (119) is connected to the one end of equalizer link (114); and the secondary link (119) is pivoted between its two end points and pivotally mounted on the frame (21) of the vehicle at the pivot (B) (116).
6. The combined brake system (100) as claimed in claim 5, wherein a pin (123) is provided at the end of brake pedal (113) and a sleeve (124) is provided on the pin (123) and this sleeve (124) is slidably connected in the oblong slot (120) of the equalizer link (114).
7. The combined brake system (100) as claimed in claim 6, wherein the sleeve (124) is made of stainless steel or Derlin or equivalent material for friction free sliding operation of the pin (123) in the oblong slot (120) of the equalizer link (114).
8. The combined brake system (100) as claimed in claim 7, wherein the front brake cable (111) is a single jointless cable which is connected between the connecting link (119) and the front brake system (17).
9. The combined brake system (100) as claimed in claim 8, wherein the front brake cable (111) is routed along the frame (21) of the vehicle near a central tube (23),a lower central tube (22) and a head pipe (24) of the vehicle.
10. The combined brake system (100) as claimed in claim 2, wherein the oblong slot (120) axis is parallel (125) or at an angle to length of the equalizer link (114) or of a curved shape (126).