Claims:
1. A system for drum brake liner replacement indicator, said system comprising:
at least one drum brake (1) with at least one brake lining (2) mounted on a table (3) and positioned against the inside surface of the drum brake (1) adapted to apply brakes to at least one moving wheel of a vehicle;
at least one mechanical sensor (5) coupled with a plurality of electrical connections;
wherein the brake lining (2) is having a predetermined thickness for gradually wearing away as the brake of the vehicle is applied; and
the mechanical sensor comprises of a sensor tip (4) which is mechanically pressurized against the brake lining (2) at preset hole depth as per useful thickness of the brake lining (2) and pressure on point of the sensor tip (4) is released as the brake lining (2) is worn out resulting in movement of the sensor tip (4) of the mechanical sensor (5) connected to the plurality of electrical connections, adapted to send signal for indication for replacement need of the brake lining (2) of the drum brake (1).

2. The system as claimed in claim 1, wherein the preset depth for the sensor tip (4) pressurization is based on the useful thickness on the brake lining (2) and additional buffer thickness

3. The system as claimed in claim 1, wherein the system is linked to a data management or fleet management system adapted to ensure the indications/ alerts on time for replacement of the brake linings (2) of the drum brake (1).

4. The system as claimed in claim 1, wherein the system can be employed to multiple points at the brake lining (2) of the drum brake or at multiple brake lining (2) of the drum brake (1).

5. The system as claimed in claim 1, wherein the sensor tip (4) move down with pressure on said sensor tip (4) due to a linear wear at a pre-determined height.

6. The system as claimed in claim 1, wherein the sensor tip (4) may comprise an additional quick break tip (6) adapted to support considerable movement of the pressurized sensor tip (4) when the lining (2) of the drum brake (1) above the preset hole depth is worn out.

7. The system as claimed in claim 1, wherein the plurality of electrical connections is an electrical circuit or a wiring connection to a bulb indictor or to a IOT platform or to a Vehicle system for related alerts.
, Description:

TECHNICAL FIELD OF THE INVENTION
The present invention relates to the field of automotive engineering and more particularly to the liner replacement sensing systems for the brake linings of vehicle drum brake or indication system for the liner replacement requirement.

BACKGROUND OF THE INVENTION
Most motor vehicles include a Drum brake system having a set of brake shoe assemblies for retarding the rotation of the Drum which is mounted to the wheels of the vehicle when the brakes are applied. Typically, each brake shoe assembly includes a brake lining made of a friction material which gradually wears away during brake applications. After numerous brake applications, the brake lining wears below a critical material thickness and, therefore, must be replaced. As a result, the brake lining must be periodically inspected for excessive wear. To eliminate time-consuming and costly visual inspections of the brake lining, the prior art has taught several types of brake lining replacement sensing for indicating when the brake lining must be replaced.

Document US4250978 A discloses a brake lining wear sensor produces an audible signal when it engages a rotating brake drum upon a predetermined amount of lining wear. The sensor is disposed within a groove between a friction lining and a brake shoe rim. Portions of the sensor project away from a body portion and engage the rotating brake drum to produce the warning signal. The projecting portions also cooperate with surfaces of the brake shoe rim or the friction lining to retain the sensor within the groove.

Document US5559286 A discloses a sensor which responds to both changes in working length and temperature is embedded in a friction lining to provide a signal indicative of both wear and temperature to an electronic control unit which interprets long term averaged change in the sensor resistance measured when the vehicle is stationary as lining wear and short term changes in sensor resistance as representative of lining temperature.

Document US5848672 A discloses a wear sensing system for the brake linings of a vehicle. Since the sensors are mounted within the brake mechanism, the reduction in the disc thickness must be taken into account to supply an accurate reading. A non-volatile memory stores the position of the brake before replacement and is compared to the position after replacement. However, the latter reading is established only after a predetermined number of brake applications to take up any starting clearances.

Document US6250429 B1 discloses a brake shoe assembly which includes a brake lining and a brake lining wear sensor. The brake lining has a predetermined thickness which gradually wears away as the brake shoe assembly is used to brake a vehicle. The brake lining wear sensor has a pair of spaced electrical conductors and an electrical resistance located across the pair of spaced conductors for indicating the thickness of the brake lining. The brake lining wear sensor is positioned to wear away concurrently with the brake lining, thereby continuously changing the electrical resistance across the pair of spaced conductors. In this manner, the electrical resistance across the pair of spaced conductors is used to determine the thickness of the brake lining.

Although the above mentioned prior arts discloses wearing system for detecting the wearing of brake lining in vehicles but still the existing systems are very complex and less user friendly. Moreover, the existing brake lining wear sensing systems are very expensive. Further, in India at present no such mechanism exists on the drum brake liners resulting in the physical verification needs. At present no such commercialized system of Liner replacement alert is available in the industry for the Drum brakes on commercial vehicles in India. Even though there are pad wear sensors available in the industry for the disc brakes and not application to the brake drum liner replacement requirements. Majority of the physical verifications are done only post the concern of less braking is observed or any abnormality is being reported by the drivers.

The above described prior art system suffers from many disadvantages, which the instant invention effectively eliminates. For this reason, there is a dire need to provide an improved system for drum brake liner replacement indicator to overcome the problems of the prior art.

SUMMARY OF THE INVENTION
The following disclosure presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.

An object of the present invention is to overcome the problems of prior art.

An object of the present invention is to provide an improved system for drum brake liner replacement indicator.

An object of the present invention is to provide a cost effective system for drum brake liner replacement indicator.

Yet another object of the present invention is to provide a system for drum brake liner replacement indicator which alerts the drivers or the fleet operator upfront and improves the safety of the driver and the vehicles.

One aspect of the present disclosure is to provide an improved system for drum brake liner replacement indicator. The invention discloses a mechanical sensor couple with the electrical connections indicates as soon as the liner reaches closer to the usable liner thickness alerting the driver/fleet data management for the replacement need.

The sensor tip in this invention is pressurized against the liner at preset depth as per the useful thickness or alert need area and connected other side with the electrical wiring. The pressure on the point of the sensor tip will get released as the liner is worn out resulting in the movement of the tip connecting the electrical signal for indication.

In one implementation, the present invention provides a system for drum brake liner replacement indicator comprising at least one drum brake with at least one brake lining mounted on a table and positioned against the inside surface of the drum brake adapted to apply brakes to at least one moving wheel of a vehicle, at least one mechanical sensor coupled with a plurality of electrical connections.

In one implementation of the present invention, the brake lining is having a predetermined thickness for gradually wearing away as the brake of the vehicle is applied and the mechanical sensor comprises of a sensor tip which is mechanically pressurized against the brake lining at preset depth as per useful thickness of the brake lining and pressure on point of the sensor tip is released as the brake lining is worn out resulting movement of the sensor tip of the mechanical sensor connected to the electrical connections adapted to send signal for indication for replacement need of the brake lining of the drum brake.

Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
The above and other aspects, features and advantages of the embodiments of the present disclosure will be more apparent in the following description taken in conjunction with the accompanying drawings, in which:

Figure 1 Illustrates the schematic view of the system for drum brake liner replacement with an additional quick break tip, according to one of the embodiments of the present invention.

Figure 2 Illustrates the magnified view of the system for drum brake liner replacement with an additional quick break tip, according to one of the embodiments of the present invention.

Figure 3 Illustrates the schematic view of the system for drum brake liner replacement, according to one of the embodiments of the present invention.

Figure 4 Illustrates the magnified view of the system for drum brake liner replacement, according to one of the embodiments of the present invention.

Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may not have been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION OF THE PRESENT INVENTION
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding, but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustration purpose only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.

It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, a reference to "a component surface" includes a reference to one or more of such surfaces.

All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which various embodiments belong. Further, the meaning of terms or words used in the specification and the claims should not be limited to the literal or commonly employed sense, but should be construed in accordance with the spirit of the disclosure to most properly describe the present disclosure.

The terminology used herein is for the purpose of describing particular various embodiments only and is not intended to be limiting of various embodiments. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising" used herein specify the presence of stated features, integers, steps, operations, members, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, members, components, and/or groups thereof. Also, Expressions such as "at least one of," when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

The present invention provides an improved system for drum brake liner replacement indicator. The invention discloses a mechanical sensor (5) coupled with the electrical connections indicates as soon as the liner reaches closer to the usable liner thickness alerting the driver/fleet data management for the replacement need. The sensor tip (4) in this invention is pressurized against the liner at preset depth as per the useful thickness or alert need area and connected other side with the electrical wiring. The pressure on the point of the sensor tip (4) will get released as the liner is worn out resulting in the movement of the tip (4) connecting the electrical signal for indication.

Reference is made to figure 1. The technical components as shown in the figure are:

4 – Tip of the Sensor (Pressurised by the mechanical spring)
1- Drum of the Wheel
2- Liner of the Drum Brake
3- is the table on which the Liner is mounted
5- Sensor mounted for detecting the wear of liner till pre-set length on Liner.
6.-Additional quick break tip

Being the mechanically pressurized sensor tip (4) there is no impact of the temperatures on the liner and would also be based on the predefined thickness at which the sensor tip (4) is pressurized against the liner. The hole depth for the sensor tip (4) pressurization can be based on the useful liner thickness on the liner plus addition buffer thickness to ensure the brake usage as per the guidelines till the replacement is carried out at the desired locations. The pressurised tip (4) can also be designed with additional quick break tip (6) to support the considerable movement of the pressurised tip (4) when the liner above the hole is worn out resulting for the additional and quick indication of the liner replacement requirement as mentioned in Figure 1 and figure 2.

In another implementation, as shown in the figure 3 and figure 4 the Tip (4) moves down with the pressure on the tip (4) due to the liner wear at the pre-determined height & provides the electrical signal by moving down in the vertical axis upon the liner wear and provides the indication of the liner replacement required.

The system disclosed in the present invention will help is alerting the drivers upfront and improves the safety of the driver and the vehicles. The system can also be linked to various data management or fleet management systems to ensure the indications/ alerts on time for the replacement liners resulting the better on road brake functioning and safety.

In one implementation, the present invention provides a system for drum brake liner replacement indicator comprising at least one drum brake (1) with at least one brake lining (2) mounted on a table (3) and positioned against the inside surface of the drum brake (1) adapted to apply brakes to at least one moving wheel of a vehicle, at least one mechanical sensor (5) coupled with a plurality of electrical connections.

In one implementation of the present invention, the brake lining (2) is having a predetermined thickness for gradually wearing away as the brake of the vehicle is applied and the mechanical sensor (5) comprises of a sensor tip (4) which is mechanically pressurized against the brake lining (2) at preset depth as per useful thickness of the brake lining (2) and pressure on point of the sensor tip (4) is released as the brake lining (2) is worn out resulting movement of the sensor tip (4) of the mechanical sensor (5) connected to the electrical connections adapted to send signal for indication for replacement need of the brake lining (2) of the drum brake (1).

In one implementation of the present invention, the preset depth for the sensor tip (4) pressurization is based on the useful thickness on the brake lining (2) and additional thickness between the range of 0.5mm to 1 mm.

In one implementation of the present invention, the system can be employed to multiple points at the brake lining (2) of the drum brake (1) or at multiple brake lining (2) of the drum brake (1).

Stages of development:
-Concept developed using the available parts and trails are done on the test benches at the facility in India.
-The customized sensor development based on the concept and findings for mass production are being taken up for industrialization.
-The Customization will be to have quick assembly and linkage to electrical ensuring the quicker assembly in plant and field.

Some of the non-limiting advantages of the present invention are as follows:
1. The system is more economical and user friendly as compared to the existing wear monitoring systems.
2. It alerts the drivers upfront and improves the safety of the driver and the vehicles.
3. The system can be easily linked to various data management or fleet management systems to ensure the indications/alerts on time for the replacement liners resulting in the better on road brake functioning and safety.
4. The system can be employed to multiple points at the brake lining of the drum brake or at multiple brake lining of the drum brake.

Those skilled in the art will recognize other use cases, improvements, and modification to the embodiments of the present disclosure. All such improvements and other use-cases are considered within the scope of the concepts disclosed herein.