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
“DEVICE FOR PARKING BRAKE SYSTEM
OF COMMERCIAL VEHICLES”

VE Commercial Vehicle Ltd.
of VE Commercial Vehicles Ltd, 102, Industrial Area
No. 1 Pithampur-454775, Dist. Dhar, Madhya Pradesh, India
The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of Invention
[001] The invention relates to mechanical brakes provided in commercial vehicles. It more particularly relates to devices provided in parking brakes for adjusting wire slack and for indicating the extent of wear of the brake lining.
Background of the Invention
[002] Parking brakes in commercial vehicles are typically actuated using hand brake levers that are connected with drum brakes provided on each of the vehicle’s wheels by means of a connecting metallic cable. For a typical commercial vehicle, the length of cable extending from the driver cabin to the wheel drum brake can be significantly high. This leads to significant friction losses during transmission of parking brake actuation force. Ordinarily all the force required for actuating the parking brake has to be supplied by the driver through actuation of the parking brake lever mechanism provided at the driver’s end in the vehicle cabin. If the driver parks the vehicle on a high gradient and then fails to apply sufficient force on the parking brake lever, the vehicle can roll off despite of the parking brake having been applied. This is usually not a very significant problem as usually it is recommended that driver or vehicle operator put the vehicle in a gear after applying the parking brake.
[003] This solution works for IC engine driven vehicles as it is very hard to simultaneously overcome the parking brake and then induce rotations in the IC engine as well. But this option does not remain available in electric vehicles towards which the industry is set to transition in the coming years. Therefore in electric vehicles, it would be necessary that the parking brakes function perfectly as there is no IC engine and corresponding transmission to act as a safeguard. Typical, adjustments like increasing the size of drum brakes or increasing the lever size to provide greater mechanical advantage at either the wheel end or driver cabin end is significantly hard to achieve as the same space is required for providing a comfortable cabin or other necessary vehicle mounted features like additional batteries, and associated electrical components. Given the competing requirements, the parking brake system too has to be made compact and yet more effective than it was in typical IC engine powered vehicles.
[004] Another issue with existing technologies is that of cost. Even though conventional solutions capable of resolving this problems exist, none of them are as affordable as a mechanical parking brake system that is actuated via a cable. Given that cable actuated parking braking systems are also convenient to maintain with cheaper yet plentiful semi-skilled maintenance workforce, there is an additional economic incentive to keep using existing cable actuated parking brake systems because of its comparably simpler construction.
[005] Therefore, to keep the existing parking brake systems with cable based actuation mechanisms in use, the issues associated with ensuring sufficient tightening of parking brake actuation cables during vehicle assembly and also providing adequate mechanical advantage to overcome known friction loses have to be resolved satisfactorily that too without increasing the size of the drum brakes or the levers at the driver cabin end. Hence, it is an objective of the present invention, to provide a device for parking brake system of commercial vehicles that not only aids providing sufficient tensioning to the parking brake cables during vehicle assembly but also improves the mechanical advantage to facilitate better application of parking brakes during ordinary usage.
[006] It is another objective of the present invention to provide a. device for parking brake system of commercial vehicles that is easy to maintain using existing semi-skilled workforce.
[007] It is still another objective of the present invention to provide a device for parking brake system of commercial vehicles that is very economical to provide given its simple construction and ease of assembly.
[008] It is yet another objective of the present invention to provide a device for parking brake system of commercial vehicles that can easily accommodate for typical issues such as drum brake liner erosion that are typically experienced during operational lifetime of the drum brake-based parking brake system.
Summary of the Invention
[009] An embodiment of the invention that helps in overcoming the limitations of the existing drum brake-based parking brake system, that is device for parking brake system of commercial vehicles (100) as disclosed, comprises of, a base platform (10), an actuation cable (20), an actuation cable (30), and an arm (40). In the device for parking brake system of commercial vehicles (100), the base platform (10) has three receptacle arms (10R1, 10R2, 10R3) that are respectively located at its first arm (10LA), its top edge and its second arm (10RA). The first receptacle arm (10R1) in its opening receives the actuation cable (20) along with its sheathing (20WS1) as provided from the driver cabin side. The third receptacle arm (10R3) in its opening receives the actuation cable (30) along with its sheathing (30WS1) as provided from the wheel drum brake side. The second receptacle arm (10R2), provided along the top edge of the base platform (10), has downward projections with openings to receive a top portion of the arm (40). One end of the actuation cable (20) is received in the opening (40A2) provided along the lower end of the arm (40) and held in its position through its sheathing (20WS2). The actuation cable (30) is received in the opening (40A1) provided on the arm (40) above the position of the opening (40A1) but below the location where the arm (40) is received on the second receptacle arm (10R2).
Brief Description of Drawings
[0010] The present invention is illustrated in the accompanying drawings that contain references numerals for indicating its various parts. The description of the present invention would therefore be better understood with reference to accompanying diagrams, wherein
[0011] Figure 1 discloses the isometric view of the device as per the first preferred embodiment of the present invention.
[0012] Figure 2 discloses another isometric view of the preferred embodiment of the present invention.
[0013] Figure 3 discloses the front view of the device as per the preferred embodiment of the present invention.
[0014] Figure 4 discloses the back view of the preferred embodiment of the present invention.
[0015] Figure 5 discloses the side view of the preferred embodiments of the present invention.

Detailed Description of the Invention
[0016] Referring to the set of figures 1, and 2, a device for parking brake system of commercial vehicles (100), that helps in overcoming the stated issues, comprises of, a base platform (10), an actuation cable (20), an actuation cable (30), and an arm (40).
[0017] In the device for parking brake system of commercial vehicles (100) (refer figures 1 and 2), the base platform (10) has three receptacle arms (10R1, 10R2, 10R3) that are respectively located at its first arm (10LA), its top edge and its second arm (10RA). The first receptacle arm (10R1) in its opening receives the actuation cable (20) along with its sheathing (20WS1) as provided from the driver cabin side. This cable is attached to the parking brake lever at its other end. The third receptacle arm (10R3) in its opening receives the actuation cable (30) along with its sheathing (30WS1) as provided from the wheel drum brake side. The end of this cable is attached to the actuating arm of the parking brake drum. The second receptacle arm (10R2), provided along the top edge of the base platform (10), has downward projections with openings to receive a top portion of the arm (40). The arm (40) is received and held within the openings of the second receptacle arm (10R2) by means of a pin.
[0018] One end of the actuation cable (20) (refer to Figs 3, 4 and 5) is received in the opening (40A2) provided along the lower end of the arm (40) and held in its position through its sheathing (20WS2). The actuation cable (30) is received in the opening (40A1) provided on the arm (40) above the position of the opening (40A1) but below the location where the arm (40) is received on the second receptacle arm (10R2).
[0019] The base platform (10) is attached to the vehicle chassis at four points (10F) (refer to Figs 3, 4 and 5) given on the top portion of said base platform (10) by means of conventional fastening means. The conventional fastening means are nuts and bolts or any other known fasteners with matching characteristics and capacity to restrict motion and handle operational loads. The first arm (10LA) is provided with a curved surface profile to enable provision of a reinforcement rib (10LAR) between the upper portion of said base platform (10) and the first receptacle (10R1).
[0020] The arm (40), and arms (10LA and 10RA) of the base platform (10) (refer to Fig 5) are together configured to have a profile that accommodates both a vertical and horizontal offset between the positions where the actuation cables (20, 30) are received on the respective arms. The arm (40) is provided with symmetrical slots between the receiving positions (40A1, 40A2) for the cables (20, 30) where material has been removed to improve strength and reduce weight.
[0021] The sheath (20WS2) (refer to Figs 1, 2 and 3) grips an end of the cable (20) within itself and is configured to allow tightening of said cable (20) through rotation of nuts provided on the body of said sheath (20WS2). The sheath (30WS2) grips an end of the cable (30) within itself and is configures to allow tightening of said cable (30) though rotation of nuts provided on the body of said sheath (30WS2).
[0022] The second receptacle arm (10R2) (refer to figs 1, 2 and 3) as provided along the top edge of the base platform (10) is provided with a scale on its bottom outward facing surface that aligns with different possible positions of a dot marked on a top outward facing surface of the arm (40). The base platform (10) is provided with an opening (10H) in its top portion that is located between the arms (10LA, 10RA) to improve its physical characteristics. The arm (40) is received and held in the second receptacle arm (10R2) by means of a pin.
[0023] The sheath (20WS1) (refer to Figs 1, 2 and 3) of the actuation cable (20) received on the first receptacle arm (10R1) is held in its position in the opening by means of two conventional nuts. The sheath (30WS1) of the actuation cable (30) received on the third receptacle arm (10R3) is held in its position in the opening by means of two conventional nuts. The sheaths (20WS2, 30WS2) of the actuation cables (20, 30) are received in the openings (40A1, 40A2) of the arm (40) by means of cylindrical projections given on the body of said sheaths (20WS2, 30WS2).
[0024] During the assembly of the parking brake system in a commercial vehicle, the workmen assembling the driver cabin side brake cable from the parking brake lever to the point of connection with the cabling provided of the parking brake drum, can take the other end of this driver cabin side actuation cable (20) and assemble so as to allow its sheath (20WS1) to be received and held on the first receptacle arm (10R1) and the actuation cable (20) itself to be received in the opening (40A2) through its sheath (20WS2). The workmen assembling the parking brake drum side cabling, can take the other end of the brake drum side actuation cable (30) and assemble so as to allow its sheath (30WS1) to be received and held on the third receptacle arm (10R3) and the actuation cable (30) itself to be received in the opening (40A1) through its sheath (30WS2). This allows for ease of assembly on the assembly line as typically the assembly of these portions is handled at different sections by different people.
[0025] Given that tightness of both portions of actuation cables (20, 30) can be adjusted at the base platform (10) by adjusting the nuts given on the sheathings (20WS2, 30WS2), the actuation cables (20, 30) can be kept in sufficient tension to prevent excessive friction loses in the parking brake actuation force. Given that the position of the attachment point (40A1) for actuation cable (30) is closer to the point of attachment of the arm (40) with the second receptacle arm than the attachment point (40A2) for the actuation cable (20), when the parking brake is applied a mechanical advantage is made available for the driver or the vehicle operator thereby allowing the actual parking brake actuation force to be higher than that applied by the driver or the vehicle operator. When during the operational life the drum brake lining wears out the position at which the arm (40) comes to rest when both actuation cables (20, 30) are in sufficient tension changes. This allows the dot given on the arm (40) to align with a different line on the scale provided on the second receptacle arm (10R2). This gives an indication that allows the maintenance personnel to determine the extent of wear (post vehicle assembly) of the drum brake lining and adjust of change the brake shoes depending upon the extent of adjudged wear.
[0026] Technical advantages offered by the invention i.e., the device for parking brake system of commercial vehicles (100) are-
- It not only aids providing sufficient tensioning to the parking brake cables during vehicle assembly but also improves the mechanical advantage to facilitate better application of parking brakes during ordinary usage.
- It is very economical to provide given its simple construction and ease of assembly.
- It can easily indicate and therefore facilitate easy maintenance to accommodate for the drum brake lining wear during operational life of the vehicle’s drum brakes.
- Its provision facilitates better heat management in the parking brake system.
- It occupies very little space in itself and facilitates separate assembly of driver cabin side parking brake actuation cable and the drum brake side parking brake actuation cable.
[0027] The disclosed invention i.e. the device for parking brake system of commercial vehicles (100) achieves all the set-out objectives.
[0028] 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 present invention has been herein described in terms of its preferred embodiment, those skilled in the art will recognize that the preferred embodiment herein disclosed, can be practiced with modifications within the scope of the invention herein described.
, Claims:We Claim,
1. A device for parking brake system of commercial vehicles (100) comprising,
• a base platform (10),
• an actuation cable (20),
• an actuation cable (30),
• an arm (40),
wherein,
- the base platform (10) has three receptacle arms (10R1, 10R2, 10R3) that are respectively located at its first arm (10LA), its top edge and its second arm (10RA), where the first receptacle arm (10R1) in its opening receives the actuation cable (20) along with its sheathing (20WS1) as provided from the driver cabin side, the third receptacle arm (10R3) in its opening receives the actuation cable (30) along with its sheathing (30WS1) as provided from the wheel drum brake side, and where again the second receptacle arm (10R2), provided along the top edge of the base platform (10), has downward projections with openings to receive a top portion of the arm (40); and
- one end of the actuation cable (20) is received in the opening (40A2) provided along the lower end of the arm (40) and held in its position through its sheathing (20WS2), and the actuation cable (30) is received in the opening (40A1) provided on the arm (40) above the position of the opening (40A1) but below the location where the arm (40) is received on the second receptacle arm (10R2).
2. The device for parking brake system of commercial vehicles (100) as claimed in claim 1, wherein,
- the base platform (10) is attached to the vehicle chassis at four points (10F) given on the top portion of said base platform (10) by means of conventional fastening means;
- the first arm (10LA) is provided with a curved surface profile to enable provision of a reinforcement rib (10LAR) between the upper portion of said base platform (10) and the first receptacle (10R1); and
- the arm (40), and arms (10LA and 10RA) of the base platform (10) are together configured to have a profile that accommodates both a vertical and horizontal offset between the positions where the actuation cables (20, 30) are received on the respective arms.
3. The device for parking brake system of commercial vehicles (100) as claimed in claim 2, wherein
- the arm (40) is provided with symmetrical slots between the receiving positions (40A1, 40A2) for the cables (20, 30) where material has been removed to improve strength and reduce weight;
- the sheath (20WS2) grips an end of the cable (20) within itself and is configured to allow tightening of said cable (20) through rotation of nuts provided on the body of said sheath (20WS2); and
- the sheath (30WS2) grips an end of the cable (30) within itself and is configures to allow tightening of said cable (30) though rotation of nuts provided on the body of said sheath (30WS2).
4. The device for parking brake system of commercial vehicles (100) as claimed in claim 3, wherein,
- the second receptacle arm (10R2) as provided along the top edge of the base platform (10) is provided with a scale on its bottom outward facing surface that aligns with different possible positions of a dot marked on a top outward facing surface of the arm (40); and
- the base platform (10) is provided with an opening (10H) in its top portion that is located between the arms (10LA, 10RA) to improve its physical characteristics.
5. The device for parking brake system of commercial vehicles (100) as claimed in claim 4, wherein,
- the arm (40) is received and held in the second receptacle arm (10R2) by means of a pin;
- the sheath (20WS1) of the actuation cable (20) received on the first receptacle arm (10R1) is held in its position in the opening by means of two conventional nuts;
- the sheath (30WS1) of the actuation cable (30) received on the third receptacle arm (10R3) is held in its position in the opening by means of two conventional nuts; and
- the sheaths (20WS2, 30WS2) of the actuation cables (20, 30) are received in the openings (40A1, 40A2) of the arm (40) by means of cylindrical projections given on the body of said sheaths (20WS2, 30WS2).

Dated 18th day of January 2025

VIDIT CHOUBEY
(IN P/A 5566)
AGENT FOR THE APPLICANT(S)

To,
The Controller of Patents,
The Patent Office, at Mumbai