DESC:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2005
COMPLETE SPECIFICATION
(See section 10, rule 13)
1. TITLE OF THE INVENTION:
SYSTEM FOR DETECTING SPRING BRAKE FAILURE IN A BRAKING ASSEMBLY OF A VEHICLE
2. APPLICANTS
(a) Name (b) Nationality (c) Address
Knorr-Bremse Systems for Commercials Vehicles India Pvt. Ltd. An Indian Company Survey No.276, Village Mann,
Hinjawadi, Phase II, Taluka Mulshi, Pune -411057 Maharashtra, India.
3. PREAMBLE TO THE DESCRIPTION
PROVISIONAL SPECIFICATION
The following specification describes the invention. COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD
[001] The present invention relates to system for detecting of spring brake failure in a braking assembly of a vehicle and more particularly, the present invention relates to a positive sensing system for early detecting of spring brake failure in a vehicle for avoiding abnormal wear, heating, bursting and potential fire hazards on tyre in commercial vehicles.

BACKGROUND
[002] In commercial vehicles, an actuator also known as pneumatic cylinder or brake chamber is used to meet high brake force requirements to slow down the vehicle, to stop the vehicle and to hold the vehicle in traffic on the slope. The actuator is operated by compressed air. Specifically, for higher braking force requirement, larger diameter brake chambers are used. The driver derives required braking force by controlling the air pressure being applied to the brake chamber through a foot brake valve connected to a brake pedal.
[003] However, for parking the vehicle while driver is away from the vehicle or hold the vehicle for longer duration on road, especially on the slope, it is mandatory to apply the parking brake through mechanical means as per the regulations. This is important step to ensure the vehicle safety. While the vehicle is in parked condition and if the vehicle system has any air leak, the vehicle is still is in hold condition, a spring keeps vehicle in the same hold condition as the spring force application is not influenced by the compressed air pressure. To meet this requirement optimally and with least complications, the brake chambers gets integrated with high force spring. This brake chamber integrated with high force spring is called as spring brake actuator (SBA).
[004] The commercial vehicle is often equipped with the pair of few brake chambers and a pair of few spring brake actuators depending on vehicle application and regulation requirement and usually every vehicle has at least one pair of the spring brake actuator.
[005] As the parking force is applied by the high force spring integrated in spring brake actuator (SBA) to drive off the vehicle, it is important to release the parking force. To release the parking force and to drive off the vehicle, the compressed air pressure is applied against the spring force. The compressed air pressure to release the parking brake by applying pressure or to apply the parking brake by releasing the compressed air pressure is managed by the driver by operating the parking brake valve or hand brake valve.
[006] Due to certain failure in the vehicle while driving, if the pressure applied by the driver to release the parking brake is dropped slowly or partially, then partial spring force gets applied to the wheel and this causes moderate to high risk failures in the vehicle such as brake damage, abnormal tyre wear, tyre heating, tyre catching fire and the like.
[007] Certain prior art systems may detect such failures but those are mostly ineffective in actual field condition as those are as such not mainly meant for detecting such slow or partial parking brake application detection.
[008] Further, a pressure switch is provided in the vehicle to detect parking brake valve position set by the driver and accordingly show the parking brake status on instrument cluster so that driver would know the status and release the parking brake while driving off.
[009] Accordingly, there exists a need to provide a system for detecting of spring brake failure in a braking assembly of a vehicle, which overcomes the abovementioned drawbacks.

OBJECTS OF THE PRESENT INVENTION
[0010] An object of the present invention is to provide safety system to protect vehicle in such situations of slow air leakage from the spring brake actuator or partial parking brake application situations.
[0011] Another object of the present invention is to detect start of spring brake application regardless of mode of failure in the spring brake actuator or in the vehicle system.
[0012] Yet another object of the present invention is to warn a driver about failure in spring brake actuator or even intervene actively or passively to avoid potential damage.

SUMMARY
[0013] In an implementation a system (100) to detect spring brake failure in a braking assembly of a vehicle is disclosed. The system (100) comprises a spring brake actuator (10). The spring brake actuator (10) further comprises two-part devices a service chambers and parking chambers. Further an inlet port (11) may be provided within the spring brake actuator (10) and configured to receive the air pressure in the service chamber. The system (100) may further comprise a second port (12) provided within the spring brake actuator (10)configured to supply compressed air from a parking brake valve to release the parking brake.
[0014] In an implementation a system (100) for detecting a spring brake failure in a braking assembly of a vehicle is disclosed. The system (100) may be configured to protect the vehicle in situations of slow air leakage from the spring brake actuator or partial parking brake application situations. The system (100) comprises, a spring brake actuator (10) configured to receive the air pressure applied through a foot brake valve by a driver to decelerate or stop the vehicle while driving, wherein the spring brake actuator has ports to supply compressed air from a parking brake valve to release the parking brake, a piston (14) for receiving compressed air supplied from the second port (12), and a spring (16) responsive to the piston (14). The system (100) further comprises a sensor (20) configured on the rear of the spring brake actuator (10) to sense piston movements thereby any unintended movements of the piston and give a signal to a module configured on a vehicle dashboard.

BRIEF DESCRIPTION OF DRAWINGS
[0015] The embodiments can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, the emphasis instead being placed upon illustrating the principles of the embodiments. Moreover, the figures, like reference numerals designate corresponding parts throughout the different views.
[0016] Reference will be made to embodiments of the invention, examples of which may be illustrated in the accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
[0017] The above and other objects, features, and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
[0018] Figure 1 illustrates a prior art system for releasing parking brake in accordance with the exemplary embodiment.
[0019] Figure 2 illustrates exemplary embodiment of spring brake actuator in accordance with the present disclosure.

DETAILED DESCRIPTION
[0020] The foregoing objects of the invention are accomplished, and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiments.
[0021] In the following description, for the purpose of explanation, specific details are set forth in order to provide an understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these details. One skilled in the art will recognize that embodiments of the present invention, some of which are described below, may be incorporated into a number of systems.
[0022] Furthermore, connections between components and/or modules within the figures are not intended to be limited to direct connections. Rather, these components and modules may be modified, re-formatted or otherwise changed by intermediary components and modules.
[0023] The systems/device and methods described herein are explained using examples with specific details for better understanding. However, the disclosed embodiments can be worked on by a person skilled in the art without the use of these specific details.
[0024] Throughout this application, with respect to all reasonable derivatives of such terms, and unless otherwise specified (and/or unless the particular context clearly dictates otherwise), each usage of:
“a” or “an” is meant to read as “at least one.”
“the” is meant to be read as “the at least one.”
[0025] References in the present invention to “one embodiment” or “an embodiment” mean that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
[0026] If the specification states a component or feature "may' can", "could", or "might" be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0027] As used in the description herein and throughout the claims that follow, the meaning of "a, an," and "the" includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of "in" includes "in" and "on" unless the context clearly dictates otherwise.
[0028] Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this invention will be thorough and complete and will fully convey the scope of the invention to those of ordinary skill in the art. Moreover, all statements herein reciting embodiments of the invention, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure).
[0029] Hereinafter, embodiments will be described in detail. For clarity of the description, known constructions and functions will be omitted. Parts of the description may be presented in terms of operations performed by an.
[0030] While embodiments of the present invention have been illustrated and described, it will be clear that the invention is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents will be apparent to those skilled in the art, without departing from the spirit and scope of the invention, as described in the claim.
[0031] Figure 1 shows a prior art system for releasing parking brake. The system as shown in figure 1 includes a vehicle engine (1) which drives an air compressor (2) to pump the compressed air which can be further used for the brake application. The air compressed by the compressor (2) goes to a pressure regulator (3) which limits the maximum and minimum pressure level in certain operating range for the consistence in the brake system functioning. Further, the compressed air passes to an air dryer (4) to remove the moisture from compressed air and dried compressed air passes to an air distribution and protection valve (5). Further, the compressed air gets distributed in several partially isolated pneumatic circuits and get stored in the air reservoir (6) for front brake applications, in the air reservoir (7) for rear brake application and in the air reservoir (8) for the parking brake application. In an embodiment, the air reservoir (8) is only effective based on volume of an air pipe.
[0032] When the air reservoir (8) is empty, in absence of air pressure in the circuit from air reservoir (8) to the parking brake valve (10) to the spring side of the SBA (13,14), the high force spring in SBA exerts force on brake and the vehicle cannot move.
[0033] Specifically, the following condition needs to be met to make the vehicle moveable by releasing the parking brake:
1. Pressure in the air reservoir should be sufficient to compress the high force spring in the SBA.
2. The parking brake valve (10) should be turned to OFF position by the driver so that the air from parking brake reservoir should pass through & reach in the SBA (13,14) in the parking circuit.
[0034] When this condition is met, the pressure switch (15) gives signal to the instrument cluster to turn off the parking lamp and the driver can drive off the vehicle.
[0035] In certain vehicles, the additional relay valve (16) is used to increase the parking brake application and release the speed. If the vehicle is rolling and if the pressure in the delivery of the parking brake valve (16) drops below certain limit then the switch (15) detects such pressure drop and can give signal to the driver through the lamp on instrument cluster.
[0036] Further The existing prior art for has following limitation:
1. The switch (15) is located on the parking brake valve (10) which is far away from the SBA (13, 14). Hence, minor air leakage at the SBA (13, 14) from their parking side is not detected by the switch (15) as it is closer to the air reservoir (8). And hence, the pressure at the SBA (13,14) doesn’t drop. This leads to non-detection of the partial spring force application while the vehicle is rolling and can cause hot brake, tyre wear, tyre burning and the like. This is even worst in case of circuits with relay valve (16) since the switch (15) remain in control circuit in such cases where air is not consumed from this circuit directly.
2. The pressure switch itself has large operating band, hysteresis and may detect leakage much later after start of brake application due to pressure drop in the parking circuit.
3. The pressure switches are not very reliable due to low profile design, materials and also not maintained in many vehicles as those or not treated as safety devices, but only used as for indication of parking brake position which otherwise the driver can also see from hand brake valve lever position marked as ON & OFF.
4. If the SBA (13, 14) piston starts applying brake force due to some mechanical failure within SBA (13, 14) then the SBA (13,14) may not cause air leakage and such brake applications cannot be detected by the pressure switch.
[0037] Referring to Figure 2, illustrates an exemplary system to detect spring brake failure in accordance with the present disclosure. The present system (100) may be configured to provide a positive detection of spring brake application (A), detection of vehicle moving (B) and also detects if the driver has not applied parking brake (C). In case, when A and B, or A, B & C are true then the system (100) generates signal which can be further utilized for warning or other means of interventions like derating an engine and the like.
[0038] Referring now to figure 2, there is shown a system (100) for detecting of spring brake failure in a braking assembly of a vehicle. The system (100) is described in conjunction with various vehicle parts known to person skilled in the art.
[0039] The system (100) may be configured to comprise at least one spring brake actuator (10). The spring brake actuator (10)in accordance with the exemplary embodiment may be configured to receive or detect air pressure applied through a foot brake valve (not shown) by a driver to decelerate or stop the vehicle while driving. The spring brake actuator (10) are two-part devices consisting of service and parking chambers, with air pressure applied into the service chamber converted into a mechanical output. The mechanical braking force holds the vehicle in the parked position via the parking chamber.
[0040] Additionally, the spring brake actuator (10) may comprise a physical release mechanism to free the parking brake in the event of a brake failure. Further the spring brake actuator (10) serves as a parking brake when the vehicle is turned off.
[0041] The spring brake actuator (10) is further provided with an inlet port (11). The inlet port (11) may be configured to receive the air pressure applied through the foot brake valve by the driver to decelerate or stop the vehicle while driving. In accordance with an exemplary aspect the inlet port (11) may be referred to as service brake port.
[0042] The spring brake actuator (10) further comprises a second port (12) to supply compressed air from a parking brake valve to release the parking brake. The spring brake actuator (10) is further configured to comprise a piston (14). The piston (14) may be configured to receive compressed air supplied from the second port (12). The compressed air received may be configured to reciprocate the piston (14).
[0043] The spring brake actuator (10) further includes a spring (16). The spring (16) may be capable of getting compressed by the force of piston (14) thereby releasing its force on a pusher a through a diaphragm (18).
[0044] The system (100) may be further characterized by comprising a sensor (20). The sensor (20) may be further provided on rear of the spring brake actuator (10) to detect the movement of the piston (14). The sensor (20) is configured to detect the unintended movement of the piston and give signal to a module configured on a dashboard of the vehicle through a PLC.
[0045] In a preferred embodiment, the sensor (20) is a pressure sensor. In another embodiment, the sensor (20) may be a limit switch, or magnetic switch, and/or Hall Effect sensor with optical sensing.
[0046] In the event of any failure in the spring brake actuator (10) or in vehicle system while the vehicle is moving, if the piston (14) movement starts unintentionally in the forward direction, the spring brake actuator (10) will immediately start pushing the piston (14) through the diaphragm (18) and start unintended brake application while the vehicle is rolling. The sensor (20) integrated on the rear body of the spring brake actuator (10) detects the movement of the piston (14).
[0047] In an embodiment, one or more than one spring brake actuator (10) on the vehicle can be integrated with the sensors (20) connected to provide piston (14) movement signal as a warning signal of the dash board of the vehicle. In a preferred, embodiment, the sensor (20) is connected to the dashboard system controller through a PLC system.
[0048] In an embodiment, the sensor (20) is coupled to the indicating means of the dash board via wireless connection, for example, Bluetooth and the like.
[0049] In another situation, if the piston (14) moves even when the vehicle is parked and parking brake is applied through the high force spring F in the spring brake actuator (10), it is important to generate warning signal only when the piston movement starts while the vehicle is rolling. Specifically, such signal is available from the vehicle speed meter or odometer. Alternatively, such signal can also be acquired from other sources like anti-lock brake system sensors installed on the wheel or also through GPS sensors. More specifically, it is important is to detect that the vehicle is not stationary by any means to avoid false warning.
[0050] To avoid a false warning, two additional interlocks are configured with the SBA, such that when sensor on the SBA rear body gives warning signal about piston (14) movement, the controller also check parking brake is not applied by the driver and vehicle is stationary through Odometer sensor reading.
[0051] In some specific situations, the driver may apply the parking brake while vehicle is rolling. Such situations are usually very remote and emergency situations where driver applies the parking brake to decelerate or stop the vehicle instead of applying the fullservice brake. This may happen during failure of service brake or if suddenly driver has some physical difficulty in his leg to operate service brake.
[0052] In an embodiment, the SBA is also configured with additional interlocks like parking brake signal and vehicle not moving signal interlocks to meet the situations when the driver is unable to operate service brake.
[0053] Advantages of the invention:
[0054] The system (100) protect vehicle in situations of slow air leakage from the spring brake actuator or partial parking brake application situations.
[0055] The system (100) detects start of spring brake application regardless of mode of failure in the spring brake actuator or in the vehicle system.
[0056] The system (100) warn the driver about failure in spring brake actuator or even intervene actively or passively to avoid potential damage.
[0057] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the scope of the present invention.
,CLAIMS:We claim:

1. A system (100) to detect spring brake failure in a braking assembly of a vehicle, the system (100) comprises:
a spring brake actuator (10), wherein the spring brake actuator (10) comprises two-part devices, a service chamber and a parking chamber;
an inlet port (11) provided within the spring brake actuator (10)and configured to receive the air pressure in the service chamber; and
a second port (12) provided within the spring brake actuator (10) configured to supply compressed air from a parking brake valve to release the parking brake.

2. The system as claimed in claim 1, wherein air pressure applied into the service chamber converted into a mechanical output, further the mechanical output is configured to hold the vehicle in the parked position via the parking chamber.
3. The system as claimed in claim 1, wherein a piston (14) is provided in the spring brake actuator (10), and is configured to receive compressed air supplied from the second port (12).
4. The system as claimed in claim 3, further includes a spring (16), wherein the spring (16) is capable of being compressed by the force of piston (14) thereby releasing its force on a pusher through a diaphragm (18).
5. The system as claimed in claim 3, further includes a spring (16), wherein a sensor (20) is provided within the spring brake actuator (10) to detect the movement of the piston (14).
6. The system as claimed in claim 5, wherein the sensor (20) is configured to give signal to a module on a dashboard of the vehicle through a PLC upon detecting the unintended movement of the piston (14).
7. The system as claimed in claim 5, wherein if the piston (14) movement starts unintentionally in the forward direction, the spring brake actuator (10) will immediately start pushing the piston (14) through the diaphragm (18) and start unintended brake application while the vehicle is rolling.
8. The system as claimed in claim 5, wherein to avoid a false warning, two additional interlocks are configured with spring brake actuator (10), such that when the sensor (20) on the spring brake actuator rear body gives warning signal about piston (14) movement, a controller checks if the parking brake is applied by the driver and vehicle is stationary through the sensor (20) reading.
9. A system (100) for detecting a spring brake failure in a braking assembly of a vehicle comprises:
a spring brake actuator (10) configured to receive the air pressure applied through a foot brake valve by a driver to decelerate or stop the vehicle while driving, wherein the spring brake actuator (10) has ports to supply compressed air from a parking brake valve to release the parking brake;
a piston (14) for receiving compressed air supplied from the second port (12), and a spring (16) responsive to the piston (14); and
a sensor (20) configured on the rear of the spring brake actuator (10) to sense piston movements thereby any unintended movements of the piston and give a signal to a module configured on a vehicle dashboard.

Dated this on 14th day of February, 2024