DESC:CROSS REFERENCE TO RELATED APPLICATION
This application is based on and derives the benefit of Indian Provisional Application 201821002570, the contents of which are incorporated herein by reference.

TECHNICAL FIELD
[001] The embodiments herein generally relate tobraking systems in vehicles, more particularly to a brake adjusting mechanism for avehicle, which enables automatic brake pre-setting.
BACKGROUND
[002] Brakesystemsin vehicles are pre-set by original equipment manufacturers (OEM) during pre-delivery inspection (PDI) stage.Once in use, with increase in vehicle running, brake lining friction material wears off due to repetitive application of the brake systems, thus resulting in increase of a distance between the brake linings and a brake drum. This increase in distance results in the requirement for a greater travel of the wheel cylinder pistons in order to actuate the brake. This requires additional fluid displacement, leading to additional brake pedal travel before the brakes are applied.When the brake pedal travel exceeds a limit of threshold value, which corresponds to a desired comfort limit of the driver, this higher pedal travel leads to driver’s fatigue. Therefore, the brake setting needs to be done afresh to bring the brake pedal travel within the driver’s comfort zone.
[003] However, if the brake setting is not done on time, this may lead to accidental damage that may be fatal to the driver.Further, adjusting the brake setting manually increases vehicle brake down time thereby reducing the productivity.Anew operator without proper instructions may not be able to adjust the desired brake setting as specified by the OEM.
[004] Furthermore, numerous devices are available in market for automatically adjusting the space between the brake drum and the brake liner to compensate for the wear, but they are not completely satisfactory for many reasons. Most of them are intricate and expensive and have to be custom-made for each particular installation. Others require that the existing shoes or drums be replaced with specially designed ones.
[005] Therefore, there exists a need forabrake adjusting mechanism for a vehicle, which obviates the aforementioned drawbacks.

OBJECTS

[006] The principal object of embodiments herein is toprovidea brake adjusting mechanism for avehicle, which enables automatic brake pre-setting.
[007] Another object of embodiments hereinis to providea brake adjusting mechanism for a vehicle, which restricts free play of the brake pedal.
[008] Yet another object of embodiments hereinis to providea brake adjusting mechanism for a vehicle, which is adapted to compensate for wear of the friction lining.
[009] These and other objects of the embodiments 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 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 of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.
BRIEF DESCRIPTION OF DRAWINGS
[0010] The embodiments herein are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures.The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0011] FIG. 1 depicts a perspective view ofa brake adjusting mechanism for a vehicle, according to embodiments as disclosed herein;
[0012] FIG. 2 depicts a side view of a portion of the brake adjusting mechanism, according to embodimentsas disclosed herein;
[0013] FIG. 3 depicts another side view of the portion of the brake adjusting mechanism, according to embodiments as disclosed herein;
[0014] FIG. 4 depicts a side view of another portion of the brake adjusting mechanism, where an actuating linkage is at non-actuated position, according to embodimentsas disclosed herein;
[0015] FIG. 5 depicts the side view of another portion of the brake adjusting mechanism, where the actuating linkage is at actuated position, according to embodimentsas disclosed herein;
[0016] FIG. 6 depicts a cross-sectional view of the portion of the brake adjusting mechanism, where a hydraulic mechanism is at non-actuated position, according to embodimentsas disclosed herein;
[0017] FIG. 7 depicts the cross-sectional view of the portion of the brake adjusting mechanism, where the hydraulic mechanism is at actuated position, according to embodimentsas disclosed herein;
[0018] FIG.8 depicts a perspective view of a brake adjusting mechanism for a vehicle, according to embodiments as disclosed herein;
[0019] FIG. 9 depicts a side view of a primary ratchet mechanism of the brake adjusting mechanism,where the primary ratchet mechanism is at non-actuated position, according to embodiments as disclosed herein;
[0020] FIG. 10 depicts the side view of the primary ratchet mechanism of the brake adjusting mechanism, where the primary ratchet mechanism is at actuated position, according to embodimentsas disclosed herein; and
[0021] FIG. 11 depicts a cross-sectional view of a secondary ratchet mechanism of the brake adjusting mechanism, according to embodiments as disclosed herein.

DETAILED DESCRIPTION
[0022] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description.Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein.The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein.Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0023] The embodiments herein achievea brake adjusting mechanism fora vehicle, which enables automatic brake pre-setting.Further, the embodiments herein achieve a brake adjusting mechanism for a vehicle, which restricts the free play of the brake pedal.Referring now to the drawings, and more particularly to Figs. 1 through 11, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0024] FIG. 1 depicts a perspective view of a brake adjusting mechanism for a vehicle, according to embodiments as disclosed herein.In an embodiment, the brake adjusting mechanism(100) includes a hydraulic mechanism (102), a link (104), a first connecting member (106), a plunger assembly(108), a movable brake actuator (110), a clevis (112) and at least oneactuating link member (120).
[0025] The brake adjusting mechanism(100) includes a hydraulic mechanism (102).The hydraulic mechanism (102)helps to ensure calculated backward motion of the first connecting member(106)and hence the plunger assembly(108).The hydraulic mechanism (102) is mounted on the link(104) which is coupled between the first connecting member(106)(also referred to as L-plate in this description) and the clevis (112)of the movable brake actuator (110) (also referred to as brake pedal in this description).The hydraulic mechanism (102) further includes at least one hydraulic cylinder(114), at least one vacuum chamber(116), a lever (118),the actuating link member (120), a first non-return valve (124), a second non-return valve (128)and the actuating link member (120) having an engaging portion (120a), as shown in FIG. 2,and FIG 3.The actuating link member(120) includes a first end (120f) and a second end (120s).The engaging portion (120a) of the actuating link member (120) includes an oval shaped opening ”O” which is adapted to engage with a pivot point head “P” of the L-plate (106) on the second end (120s).The first end (120f) of the actuating link member (120) is connected to the lever (118).
[0026] In normal braking condition, when a friction plate (not shown) isnot considerably worn-out, the engaging portion (120a)remains in a non-actuated condition, as shown in FIG. 4.At this condition, theactuating link member (120)remains at position 1 (not shown) which is free from tension.With usage of the vehicle, the friction plate (not shown) wearsout considerably.Based on the worn-out condition, the actuating link member (120)moves in a downward direction, and finally the actuating link member (120) reaches position 2 (not shown) as shown in FIG. 5.At this condition, the engaging portion (120a)gets locked at the pivot point head “P” of the L-plate(106).The actuating link member (120) is held under tension at the position 2.
[0027] Further, continuous usage of the brake, leads to additional brake pedal travel for applying the brake.At this condition, the hydraulic cylinder(114) of the hydraulic mechanism (102) is adapted to move downwards which rotates the lever (118)about its pivot point “P1”.Thehydraulic cylinder(114) is configured to store oil at atmospheric pressure.In an embodiment, the hydraulic cylinder(114)is a double acting cylinder. The hydraulic cylinder(114) is further connected to the vacuum chamber (116)through the first non-return valve (124)at upper side of the hydraulic cylinder (114)as shown in FIG. 6.Once the first non-return valve (124) is actuated, the oil from the hydraulic cylinder(114)flows into the vacuum chamber(116),due to vacuum pressure in the vacuum chamber (116).The oil from the oil chamber (114) is displaced by a piston (126) which is assembled within the hydraulic cylinder(114).The oil continuous to flow into the vacuum chamber until there is pressure difference. Due to this pressure difference, the pressure in the hydraulic cylinder (114)reaches atmospheric pressure.
[0028] Further, when the brake pedal is released, due to low atmospheric pressure in the hydraulic cylinder (114), the piston (126) is configured to travel in an upward direction. The movement of the piston (126) in the upward direction causes the oil to flow below the piston (126) through the second non-return valve (128) at lower side of the hydraulic cylinder (114). The displacement of the oil from the vacuum chamber (116) through the second non-return valve (128) to the lower side of the hydraulic cylinder (114) locks the piston (126) at the same position “PL”. The locking “PL” does not allow the piston (126) to move down further which eliminates free play in brake pedal travel created due to friction plate wear. When the brake is applied next time (i.e. after the piston is locked by the locking “PL”), the brake pedal travel would be the same as when there is no friction liner wear. In this way, with the help of hydraulic mechanism (102), the brake is set automatically as shown in FIG. 7.
[0029] FIG. 8 depicts a perspective view of a brake adjusting mechanism for a vehicle, according to an embodiment as disclosed herein. The brake adjusting mechanism (100) further includes a primary ratchet mechanism (200) and a secondary ratchet mechanism (300). The primary ratchet mechanism (200) facilitates a calculated backward motion of the L-plate (106) and hence the pull-rod (108). As shown in FIG. 9, the primary ratchet mechanism (200) includes a ratchet wheel A, a ratchet wheel B and a stopper pin (202). The ratchet wheel A is coupled to the first connecting member (106) at a predetermined position. Further, the ratchet wheel A includes a plurality of outer teeth. The ratchet wheel B is engaged with the ratchet wheel A. The ratchet wheel B includes a predetermined number of outer teeth which can engage with the teeth of ratchet wheel A. When brake is at non-actuated position, the ratchet wheel B rests on the stopper pin (202). A tension is given to the ratchet wheel B in clockwise direction with help of a spiral spring (204) (not shown), so that the ratchet wheel B is always in contact with the ratchet wheel A. As shown in FIG. 10, when the brake is applied, the ratchet wheel A rotates in a clockwise direction along with the L-plate (106) moving in downward direction. The rotation of ratchet wheel A in the clockwise direction, forces the ratchet wheel B to rotate in anticlockwise direction. After certain degrees of rotation, the ratchet wheel B starts to slip over the ratchet wheel A, which allows the ratchet wheel A to rotate in an indefinite degree’s of rotation. The rotations of the ratchet wheel A and the ratchet wheel B may vary from 5 degrees to 10.5 degrees. The rotations of the ratchet wheel A and the ratchet wheel B is explained herein. For example: At condition-1(no wear in friction plate lining), for complete brake application the brake pedal110 needs to expandabout 1.3mm, and theplunger assembly (108) need to travel about 3.25mm. The L-plate (106) along with ratchet wheel A rotates about 5.2 degrees, and the ratchet wheel B engaged with ratchet wheel A rotates about 10.4 degrees which is its maximum permissible degrees due to its design. There is no slippage occurring between the ratchet wheel A and the ratchet wheel B as there is no wear in Friction lining. At Condition-2 (friction plate worn out), for example: when the friction plate lining wears off by 0.5 mm,the brake pedal (110) needs to expand about 1.8 mm, and the plunger assembly (108) needs to travel about 4.5 mm. The L-plate (106) along with the ratchet wheel A rotatesabout 7.2 Degrees, the ratchet wheel B engaged with ratchet wheel A rotates about 10.4 after which the ratchet wheel B starts slipping over the ratchet wheel A.). When the brake pedal is released, the ratchet wheel A starts to rotate in anticlockwise direction. Due to the spring tension given to the ratchet wheel B, the teeth of the ratchet wheel B engage with teeth of the ratchet wheel A and the ratchet wheel B starts rotating in a clockwise direction till the ratchet wheel B rests on the stopper pin (202). In this way, the reverse motion of brake pull rod is controlled which eventually controls a gap in between the friction plates.
[0030] The brake adjusting mechanism (100) further includes the secondary ratchet mechanism (300). The secondary ratchet mechanism (300) helps to ensure that the travel length of the brake pedal required to apply the brakes remains the same as normal braking condition. Due to friction plate wear, the primary ratchet mechanism (200) locks the L-plate (106) some degrees early, whereby the free play in brake pedal travel increases. The primary ratchet mechanism (200) may lock the L-plate 106 at about 1 degree to 4 degrees early. The secondary ratchet mechanism (300) in the brake adjusting mechanism (100) can absorb this free play in the brake pedal (110).The rotation of the primary ratchet mechanism (200) is explained herein. For example, at the time of brake release, the ratchet wheel B rotates clockwise through 10.4 degrees and the rotation is stopped at the stopper pin (202), thereby the ratchet wheel A stops to rotate in anticlockwise direction. For the rotation of the ratchet wheel B for about 10.4degrees, the ratchet wheel A rotates in anticlockwise for about 5.2 degrees. For achieving thisthe L-plate (106) stops 2 degrees earlier from the no wear condition for maintaining the brake pedal required clearance. Further, to facilitate the change in rotation of the 2 degrees, the secondary ratchet mechanism (300) is used in the brake adjusting mechanism 100.
[0031] The secondary ratchet mechanism (300) includes a first rod member 302, a second rod member (304) and a locking pin (306). The first rod member 302 includes a first end (not shown) and a second end (not shown). The first end of the first rod member 302 is coupled to the first connecting member (106). Further, the second rod member (304) includes a first end (not shown) and a second end (not shown). The first end of the second rod member (304) is coupled to the movable brake actuator (110). The second end of the second rod member (304) is adapted to be received by the second end of the first rod member (302). The locking pin (306) is disposed in the first rod member (302). In an embodiment, the first rod member (302) is an eye bolt C. The eye bolt C is coupled at a predetermined position i.e. the position of the eye bolt C is fixed in the brake adjusting mechanism (100). In an embodiment, the second rod member (304) is an eye bolt D. The eye bolt D is allowed to travel in upward direction within the eye bolt C. The eye bolt C is provided with a hollow portion (306), as shown in FIG. 11 to receive an engraved portion (308) of the eye bolt D. In an embodiment, the engraved portion (308) has a plurality of circular grooves. The eye bolt D travels in upward direction in the eye bolt C with the help of brake pedal spring tension. The eye bolt D is adapted to travel in the upward direction till the brake pedal reaches the stopper (130). The relative position of the eye bolt C and the eye bolt D is locked by a locking pin (306) which allows the eye bolt D to travel in upward direction only. The locking pin (306) is configured to restrict the movement of the eye bolt D in downward direction i.e. the eye bolt C remains stationery while the eye bolt D, due to spring tension provided to brake pedal 110 tends to move inside the eye bolt C. The locking pin ((306)) is provided on the eye bolt C allows the eyebolt D to move upward and restricts downward movement of the eye bolt D.)
[0032] Embodiments herein eliminate manual intervention for brake setting, minimize the risk of accidents, and improve the safety of the operator. Embodiments herein achieve a high accuracy in accommodating the gap in brake friction plates. Embodiments herein avoid free play in the brake pedal travel due to friction plate wear.
[0033] 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 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.
,CLAIMS:We claim:
1. A brake adjusting mechanism (100) for a vehicle, the brake adjusting mechanism (100) comprising:
a movable brake actuator (110);
a link (104) disposed between themovable brake actuator (110)and a first connecting member(106);
a plunger assembly(108)operatively connected to the first connecting member (106);
at least oneactuating link member (120) connected between the first connecting member (106) and the link (104);and
a hydraulic mechanism (102)mounted on the link (104) and connected to the actuating link member (120) through a lever (118).
2. The brake adjusting mechanism (100)as claimed in claim 1, wherein a first end (120f) of the at least one actuating link member (120) is connected to the lever (118) and a second end (120s)of the at least one actuating link member (120)is connected to a pivot point head “P” of thefirst connecting member (106).
3. The brake adjusting mechanism (100)as claimed in claim 1, whereinthe hydraulic mechanism (102) includes:
at least onehydraulic cylinder (114) having a piston (126) adapted to move in one of an upward direction and a downward direction; and
at least one vacuum chamber (116) connected to thehydraulic cylinder (114) through a first non-return valve (124)atan upper side of the hydraulic cylinder (114) and a second non-return valve (128) at a lower side of the hydraulic cylinder (114).
4. The brake adjusting mechanism (100)as claimed in claim 1, wherein the movement of the piston (126) in the upward direction causes oil to flow from the vacuum chamber (116) to the hydraulic chamber (114)below the piston (126) through the second non-return valve (128).
5. The brake adjusting mechanism (100)as claimed in claim 1, wherein the flow of oil from the vacuum chamber (116) to the hydraulic chamber (114)locks the piston (126) at a position “PL”.
6. The brake adjusting mechanism (100)as claimed in claim 1, wherein the hydraulic cylinder (114) is adapted to move downwards which rotates the lever (118) about a pivot point “P1” of the lever (118).
7. The brake adjusting mechanism (100)as claimed in claim 1, wherein the hydraulic cylinder (114)is a double acting cylinder.
8. The brake adjusting mechanism (100)as claimed in claim 1, wherein the hydraulic mechanism (102) is mounted on the link (104) which is coupled between the first connecting member(106)and a clevis (112) of the movable brake actuator (110).
9. The brake adjusting mechanism (100)as claimed in claim 1, wherein the actuating link member (120) includes an opening “O”in an engaging portion (120a),wherein the opening “O” is adapted to engage with a pivot point head “P” of the first connecting member (106).
10. The brake adjusting mechanism (100) for the vehicle, the brake adjusting mechanism (100),further comprising:
the movable brake actuator (110);
the first connecting member(106) connected to themovable brake actuator (110) through a secondary ratchet mechanism (300);and
a primary ratchet mechanism (200)coupled to the first connecting member (106).
11. The brake adjusting mechanism (100) as claimed in claim 10, wherein the primary ratchet mechanism (200) includes:
a ratchet wheel A coupled to the first connecting member (106), wherein the ratchet wheel A includes a plurality of first outer teeth;
a ratchet wheel B, wherein the ratchet wheel Bincludes a plurality of second outer teethconfigured to engage with theplurality of first outer teeth of the ratchet wheel A; and
a stopper pin (202).
12. The brake adjusting mechanism (100) as claimed in claim 10, wherein the ratchet wheel B is in contact with the ratchet wheel A by a spiral spring (204).
13. The brake adjusting mechanism (100) as claimed in claim 10, wherein the secondary ratchet mechanism (200) includes:
a first rod member (302) having a first end coupled to the first connecting member (106);
a second rod member (304) having a first end coupled to the movable brake actuator (110) and a second end adapted to be received by a second end of the first rod member (302); and
a locking pin (306)configured to restrict movement of the second rod member (304) in a downward direction.