FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10, rule 13)
“HORN PAD ASSEMBLY FOR STEERING WHEEL OF VEHICLE AND METHOD OF ACTUATING A HORN”
TATA MOTORS PASSENGER VEHICLES LIMITED, of Floor 3, 4, Plot-18, Nanavati Mahalaya, Mudhana Shetty Marg, BSE, Fort, Mumbai, Mumbai City, Maharashtra, 400001, India
The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD
[001] The present invention is, in general, related to the field of automobiles. In particular, it
relates to a horn pad assembly for a steering wheel of a vehicle and a method of
actuating a horn through the horn pad assembly.
BACKGROUND
[002] The following description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[003] Every steering wheel in vehicles primarily consist of a horn-pad assembly. Function of the horn pad assembly is to actuate horn for sending alert signals to other drivers or pedestrians present on the road so that accidents can be prevented. Conventionally, horn-pad assembly is formed with a combination of movable part and stationary part. The movable part is often associated with airbag module whereas the stationary part of the horn pad assembly is steering wheel frame. On both the moveable part and the stationary part of the horn pad assembly, copper contacts are provided, and these copper contacts are spaced apart from one another by means of metal springs. Particularly, if no force is applied to the movable part, copper contacts present on the movable part of the assembly remained spaced apart from copper contacts present on the stationary part of the horn pad assembly. However, as soon as the movable part is pressed down against the force of said metal springs the copper contacts present on the movable part come in contact with copper contacts present on the stationary part of the horn pad assembly. As a result, a relay circuit gets activation signal which leads to an actuation of the horn.
[004] However, there are many drawbacks associated with this conventional horn pad assembly. For instance, in many cases due to uneven pressing, the copper contacts present on the movable part don’t get engaged with the copper contacts present on the stationary part of the assembly and therefore, actuation of horn is either not performed or a very low sound is generated. Also, since the whole mechanism of sounding the horn depends on metal springs, if any kind of permanent deformation happens in the metal springs, then the whole Horn-pad assembly needs to be replaced. Moreover, the conventional horn pad assemblies are very bulky and lacks efficiency and durability.

Further, as stated above, due to the requirement of replacing the complete assembly in case of any anomaly or failure, this system is not cost effective as well.
Furthermore, due to the reasons stated above, the conventional system can fail to sound a horn at any emergency scenario and thus may present unpredictable operating conditions. This can prove fatal both for the driver and other people on the road and can even lead to hazardous accidents.
Therefore, there is a need for an improved horn pad assembly that overcomes the limitations of the existing horn pad assembly.
SUMMARY
The present disclosure overcomes one or more shortcomings of the prior art and provides additional advantages. Embodiments and aspects of the disclosure described in detail herein are considered a part of the claimed disclosure.
In one non-limiting embodiment of the present disclosure, a horn-pad assembly for a steering wheel of a vehicle is disclosed. The horn pad assembly comprises a pair of deflection causing elements, a plurality of strain gauges, a relay circuit, a plurality of illumination devices and an Electronic Control Unit (ECU). The pair of deflection causing elements is placed beneath a horn pad to cause a deflection in the horn pad. The plurality of strain gauges is arranged on an inner surface of the horn pad and in close proximity to the pair of deflection causing elements, where the plurality of strain gauges is configured to measure a strain caused due to the caused deflection, by the pair of deflection causing elements, in at least one of horizontal and vertical direction. Further, the ECU is operatively connected to the plurality of strain gauges and is configured to determine a change in an output voltage of the plurality of strain gauges caused due to strain. The ECU then compares the change in the output voltage with a pre-defined threshold voltage and if the change in the output voltage exceeds the pre-defined threshold voltage, the ECU is configured to activate a horn, via the relay circuit and illuminate the plurality of illumination devices.
In yet another embodiment of the present disclosure, the pair of deflection causing elements are positioned in a manner such that a first deflection causing element is placed in a horizontal direction and a second deflection causing element is placed in a vertical direction, covering a maximum area of the horn pad.

In still another embodiment of the present disclosure, the pair of deflection causing elements are arranged to form a hinge for causing the deflection in the horn pad.
In yet another embodiment of the present disclosure, at least a pair of strain gauges of the plurality of strain gauges are placed in horizontal and vertical direction, around each corner of the pair of deflection causing elements.
In yet another embodiment of the present disclosure, the pair of strain gauges is connected in half bridge Wheatstone configuration.
In yet another embodiment of the present disclosure, the horn-pad assembly for a steering wheel of a vehicle further comprises a signal amplifier. The signal amplifier is configured to amplify the change in output voltage and share the amplified output voltage with the Electronic Control Unit.
In yet another non-limiting embodiment of the present disclosure, a method for actuating a horn on a steering wheel of a vehicle is disclosed. The method comprises locating a deflection in a horn pad and measuring a strain caused due to the deflection, in at least one of horizontal and vertical direction. Further, the method comprises determining a change in an output voltage caused due to measured strain . The method further comprises comparing the change in the output voltage with a pre-defined threshold voltage and if the change in the output voltage exceeds the pre-defined threshold voltage, the method comprises activating a horn and illuminating a plurality of illumination devices.
In yet another non-limiting embodiment of the present disclosure, the method further comprises positioning the pair of deflection causing elements beneath the horn pad in such a manner that a first deflection causing element is placed in a horizontal direction and a second deflection causing element is placed in a vertical direction, covering a maximum area of the horn pad.
In yet another non-limiting embodiment of the present disclosure, the method further comprises positioning at least a pair of strain gauges in horizontal and vertical direction, around each corner of the pair of deflection causing elements.

In yet another non-limiting embodiment of the present disclosure, the method further comprises amplifying the change in output voltage prior to sharing the change in output voltage for comparing.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF DRAWINGS
The features, nature, and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout. Some embodiments of system and/or methods in accordance with embodiments of the present subject matter are now described, by way of example only, and with reference to the accompanying Figs., in which:
Figure 1 depicts a conventional horn pad assembly for a steering wheel of the vehicle.
Figure 2a depicts an exemplary block diagram 200 illustrating a horn pad assembly for a steering wheel of the vehicle, in accordance with an embodiment of the present disclosure.
Figure 2b depicts a proposed horn pad assembly for a steering wheel of the vehicle, in accordance with an embodiment of the present disclosure.
Figure 3 depicts an exemplary internal view of the horn pad assembly, in accordance with an embodiment of the present disclosure.
Figure 4 depicts an exemplary external view of the horn pad assembly, in accordance with an embodiment of the present disclosure.
Figure 5 depicts an exemplary flowchart of a method 500 for actuating the horn through the horn pad assembly, in accordance with an embodiment of the present disclosure.

[0026] It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative systems embodying the principles of the present subject matter. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be represented in a computer readable medium and executed by a computer or processor, whether or not such computer or processor is explicitly shown.
DETAILED DESCRIPTION
[0027] The foregoing has broadly outlined the features and technical advantages of the
present disclosure in order that the detailed description of the disclosure that follows may be better understood. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure.
[0028] The novel features which are believed to be characteristic of the disclosure, both
as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying Figures. It is to be expressly understood, however, that each of the Figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure.
[0029] Various embodiments of the present invention now will be described more fully
hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. The term “or” is used herein in both the alternative and conjunctive sense, unless otherwise indicated. The terms “illustrative,” “example,” and “exemplary” are used to be examples with no indication of quality level.
[0030] The phrases “in an embodiment,” “in one embodiment,” “according to one
embodiment,” and the like generally mean that the particular feature, structure, or
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characteristic following the phrase may be included in at least one embodiment of the present disclosure and may be included in more than one embodiment of the present disclosure (importantly, such phrases do not necessarily refer to the same embodiment).
[0031] The word “exemplary” is used herein to mean “serving as an example, instance,
or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations. If the specification states a component or feature “can,” “may,” “could,” “should,” “would,” “preferably,” “possibly,” “typically,” “optionally,” “for example,” “often,” or “might” (or other such language) be included or have a characteristic, that particular component or feature is not required to be included or to have the characteristic. Such component or feature may be optionally included in some embodiments, or it may be excluded.
[0032] Horn pad assembly in automobiles is very essential to provide alert to the other
drivers or pedestrians present on the road while driving the vehicle. Conventional horn pad assembly, as shown in figure 1, works on the basis of engagement of copper contacts located on movable part (101) and stationary part (102) of the assembly by means of metal springs (103). Precisely, the horn pad assembly works when a contact
(104) at the stationery part of the steering wheel (102) gets engaged with the contact
(105) on the movable part of the steering wheel (101). As long as no actuation force is applied to the movable part (101), the contacts (104, 105) are spaced part from another by means of the spring (103). If the movable part is pressed down against the force of the spring (103), the two contacts (104 and 105) come in contact with one another. Due to this mating, a signal is provided to the relay circuit (106) which leads to an actuation of the horn (107). Major drawback of this design is that the contacts can be subjected to mechanical or electrical wear. Further, the metal springs (103) if deformed may lead to non-functioning of the horn (107) and it may require complete replacement of the horn pad assembly. Further, the whole system is quite bulky and hard to press as well.
[0033] In order to overcome the above-mentioned challenges, the present disclosure
provides a novel horn pad assembly which utilizes a pair of deflection causing elements that work in conjunction with plurality of strain gauges. Whenever a pressure is exerted on the horn pad, the deflection causing elements may cause the deflection in the horn pad. Due to this deflection, the plurality of strain gauges experiences the strain and
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measures a change in output voltage. An ECU which is operatively coupled with the plurality of strain gauges when determines that change in voltage reaches above the predefined threshold, it activates the relay circuit which may lead to actuation of horn. In addition to that, to present the feedback about actuation of horn, the ECU also sends a signal to illumination devices for illumination. A detailed explanation of the proposed solution is disclosed in the forthcoming paragraphs.
[001] The present disclosure is applicable for a vehicle such as a car, van, truck etc. that includes a steering assembly associated with a horn pad assembly. The horn pad assembly is positioned at or near center of the steering wheel as discussed herein. However, horn pad assembly may be positioned at any appropriate location on the steering wheel as well. A detailed description of the proposed horn pad assembly is disclosed in the forthcoming paragraphs in accordance with Figure 2-4.
[0034] Figure 2a depicts an exemplary block diagram 200 of the horn pad assembly.
The horn pad assembly (200) comprises a horn pad (202), Electronic Control Unit (ECU 204), a horn (214) and plurality of illumination devices (216). Further, the horn pad (202) comprises a pair of deflection causing elements (204), a plurality of strain gauges (206), a signal amplifier (208). All the elements of the horn pad assembly (200) illustrated in Figure 2a are essential elements, but the horn pad assembly (200) may also include the elements other than the elements illustrated in Figure 2a, however the same are not explained for the sake of brevity.
[0035] The pair of deflection causing elements (204) are placed beneath the horn pad
(202) and are arranged in such a way that one of the deflection causing elements is positioned in vertical direction and the other one is positioned in horizontal direction. In an exemplary embodiment, the deflection causing elements (204) are ribs or bars that have the property to support the horn pad during deflection from the original position to another position (located towards inner surface) when horn pad is pressed and also helps in attaining the original position when horn pad is released. Precisely, whenever a pressure is exerted through the upper surface of horn pad, the deflection causing elements (204) may deform the specific location for that instant of time. Once the pressure is released, the deflection causing elements (204) may support the horn pad (202) to retain its original position. The pair of deflection causing elements (204) are
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positioned in the vertical and horizontal direction (as presented in figure 3 of the disclosure) so that maximum area under the horn pad is covered and any area present on the upper surface of horn pad when pressed create/cause the pressure. Accordingly, the deflection causing elements may send a signal to the plurality of strain gauges (206) present on the inner surface of the horn pad. The pair of deflection causing elements (204) form a hinge to provide forward and backward movement to the horn pad (202) and helps in locating or causing the deflection when horn pad (202) is pressed. This provides ease to the driver of the vehicle in pressing the horn pad (202) and also helps in resolving the problem of uneven pressing that is major drawback of the conventional horn pad assembly. In an exemplary scenario, present disclosure provides a comfort to the driver of the vehicle that even pressing of the horn pad through the thumb may be detected properly.
[0036] Coming back to Figure 2a, the plurality of strain gauges (206) is arranged on
an inner surface of the horn pad (202) and in close proximity to the pair of deflection causing elements (204). An exemplary embodiment depicting the positioning of the plurality of strain gauges (206) is presented in figure 3 of the disclosure and will be explained in detail in the forthcoming paragraphs of the disclosure. The plurality of strain gauges (206) is configured to measure a strain caused due to the deflection in the pair of deflection causing elements (204) in at least one of horizontal and vertical direction. In a preferred embodiment, a pair of strain gauges (206) are placed in horizontal and vertical direction around each corner of the deflection causing elements (204). In an exemplary embodiment, the pair of strain gauges are arranged in half-bridge Wheatstone configuration. For the ease of understanding, square shaped horn pad is considered for explaining the functioning of the horn pad assembly elements. However, a person skilled in the art may appreciate that there may be other shapes of the horn pad as well and the present disclosure may work in equivalent manner for those shapes of horn pad as well.
[0037] As presented in figure 3, a pair of strain gauges when mounted in horizontal and
vertical direction may help in measuring strain around locations projected as 1, 2, 3 and 4. As soon as pressure is exerted on the upper surface of the horn pad, the pair of deflection causing elements (204) helps the horn pad to deflect or deform the area under the upper surface (e.g. 1, 2, 3, 4) and accordingly the pair of strain gauges present
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in that area may experience the strain and provide the change in output voltage. A person skilled in the art may appreciate that the pair of strain gauges (206) when connected in half bridge Wheatstone configuration may present the output voltage as Zero when there is no force or pressure applied on the horn pad (202). However, as soon as the pressure is exerted on the horn pad, the pair of strain gauges (206) may provide a change in the output voltage based on the strain experienced in that particular area. In an exemplary scenario, while driving a vehicle, the driver of the car may want to actuate the horn by pressing the horn pad on upper right corner by his right thumb, then the deflection causing elements (204) may help in locating the area based on the deformation i.e., marked as 1 in figure 3 and the strain gauges present in that area i.e. 1 may experience the strain due to the pressure exerted on that area. As a result of the strain, a change in the output voltage from 0 to V volts is detected. This change in voltage is then provided to the signal amplifier (208) for amplification purpose as the detected voltage may be very low. A skilled person may appreciate that the pressure exerted in the horizontal direction may be sensed by the strain gauge present in the horizontal direction whereas the pressure exerted in the vertical direction may be sensed by the strain gauge present in the vertical direction. However, if the pressure is exerted in the middle part of any location (i.e.,1,2,3 and 4), then both the vertical and horizontal strain gauges (206) present in that area may experience some amount of strain and change in output voltage is provided based on the combined result. The above example is used to explain one of the scenarios only, however, it should not be considered as a limiting as there may be other scenarios available as well such as pressing of horn pad on the upper left, bottom left, bottom right, middle etc. but the same are not explained for the sake of brevity.
[0038] The signal amplifier (208) present on the horn pad receives the change in the
output voltage from the pair of the strain gauges (206). The signal amplification is required to amplify the change in output voltage received from the plurality of strain gauges. In an exemplary embodiment, the signal amplifier (208) is set to amplify the voltages above a threshold to filter out interference signals observed while driving on a poor road. The amplified output voltage is provided to the ECU (210).
[0039] The Electronic Control Unit (ECU, 210) receives the signal from the signal
amplifier (208). ECU determines the change in the output voltage caused due to strain
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by comparing the change in the output voltage with a pre-defined threshold voltage. If the change in the output voltage exceeds the pre-defined threshold voltage, then the ECU (210) may send a signal to relay circuit (212) to activate a horn (214). For example, the predefined threshold is 3 volts and if the change in the output voltage received by the ECU is more than 3 volts then the ECU (210) may provide a signal to the relay circuit for actuating the horn (214). In another scenario, if the change in output voltage is 0.5volt only then the ECU (210) may consider this as interference signal only and may not provide any signal to the relay circuit. In an exemplary embodiment, the pre-defined threshold voltage may be set by the manufacturer at the time of manufacturing, or it may be programmed at later stage while assembling the components of the horn pad assembly. Parallel to activation of relay circuit (212), the ECU (210) may also send another signal to a driver circuit (not shown in figure) for activation of the plurality of illumination devices (216). The illumination devices may be light emitting elements such as LEDs or laser and are configured to irradiate light toward the passenger (particularly, the driver) in the vehicle. In an exemplary embodiment, the ECU (210) may be configured to control the intensity of the plurality of illumination devices (216) through the driver circuit. In another exemplary embodiment, the ECU (210) may also be configured to control the time of blinking and frequency of blinking of the plurality of illumination devices (216) through the driver circuit.
[0040] The ECU (210) preferably includes a microcontroller with a control program
that controls the operation of horn pad assembly as discussed herein. The ECU (210) may include other conventional components such as an input interface circuit, an output interface circuit, and storage devices such as a ROM (Read Only Memory) device and a RAM (Random Access Memory) device. The ECU (210) along with other functionality of the vehicle may additionally be programmed to control the horn pad assembly in accordance with the flow chart presented in Figure 5 as discussed below. It will be apparent to those skilled in the art from this disclosure that the precise structure and algorithms for the micro controller can be any combination of hardware and software that will carry out the functions of the present invention.
[0041] Figure 2b depicts proposed horn pad assembly for a steering wheel of the
vehicle, in accordance with an embodiment of the present disclosure. The novel
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assembly disclosed in figure 2b clearly depicts that there is no copper contacts and metal springs required for the horn pad assembly 200. Further, as seen in figure 2(b), the pair of deflection causing elements (204) are placed beneath the horn pad (202) to form a hinge so as to cause deflection in the horn pad (202) when the horn pad (202) is pressed by the user or driver of the vehicle. Due to the formation of hinge, the effort of the user or driver of the vehicle gets reduced as the horn pad may deflect smoothly, and deflection may be caused easily as well. Further, on the inner surface of the horn pad (202), plurality of strain gauges (206) is arranged in close proximity to the deflection causing elements (204) to cover the maximum area under the horn pad. Particularly, in all the sections 1,2,3,4 as shown in figure 3, strain gauges (206) are placed to measure the deflection caused by the movement of the horn pad (202) in x-y plane (i.e., in horizontal and vertical directions).
[0042] The horn pad assembly 200 of the vehicle, as shown in Figure2b, also includes
an airbag assembly (218). The airbag assembly (218) includes an airbag that is deployed upon detection of rapid/sudden deceleration of vehicle such as during an accident or impact event. As explained above, the strain gauges (206) are mounted on inner surface of horn pad (202) above the airbag assembly (218). The whole airbag assembly (218) is enclosed in the steering housing (220) and is further locked with the horn pad (202) with help of any suitable means like adhesives, bolts etc. As soon as, a pressure is exerted on upper surface of the horn pad (202), the strain gauges (206) associated with the horn pad (202) measures a change in the output voltage and provides the same to the ECU (210). The ECU (210) then compares the change in output voltage with a predefined threshold and accordingly, send a signal for actuating the horn (214) and illumination devices (216).
[0043] Figure 4 depicts the external view 400 of the horn pad assembly. The steering
wheel (402) and the external surface of the horn pad assembly resembles quite similar to the conventional one. However, there are a plurality of illumination devices disposed on the outer surface of the horn pad not only enhances aesthetic appearance of the horn pad but also helps in providing an indication to the user about actuation of horn (214). This illumination of the illumination devices (216) helps the user in checking the blowing of horn at crowded and noisy places as well. In an exemplary scenario, the plurality of illumination devices (216) may be placed at each corner of the horn pad. In
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another exemplary scenario, only an illumination device is placed at the center of the horn pad. The mounting of the illumination devices (216) may be customized according to the manufacturer of the vehicle.
[0044] Figure 5 illustrates a flowchart 500 of an exemplary method for actuating a horn
on steering wheel of the vehicle through the horn pad assembly in accordance with an embodiment of the present disclosure. The method 500 may also be described in the general context of computer executable instructions. Computer executable instructions may include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform specific functions or implement specific abstract data types.
[0045] The order in which the method 500 is described is not intended to be construed
as a limitation, and any number of the described method blocks may be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the spirit and scope of the subject matter described.
[0046] At step 502, the method 500 may include locating a deflection in a horn pad
(202). In an exemplary aspect, the deflection causing elements (204) presented in Fig. 2 may be configured to carry out the process step disclosed in step 502.
[0047] At step 504, the method 500 may include measuring a strain caused due to the
deflection caused in the horn pad (202), in at least one of horizontal and vertical direction. In an exemplary aspect, the plurality of strain gauges (206) presented in Fig. 2 may be configured to carry out the process step disclosed in step 504.
[0048] At step 506, the method 500 may include determining a change in an output
voltage caused due to measured strain. In an exemplary aspect, the ECU (210) presented in Fig. 2 may be configured to carry out the process step disclosed in step 506.
[0049] At step 508, the method 500 may include comparing the change in the output
voltage with a pre-defined threshold voltage and if the change in the output voltage exceeds the pre-defined threshold voltage. In an exemplary aspect, the ECU (210)
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presented in Fig. 2 may be configured to carry out the process step disclosed in step 508.
[0050] At step 510, the method 500 may include activating a horn if the change in the
output voltage exceeds the pre-defined threshold voltage. In an exemplary aspect, the ECU (210) presented in Fig. 2 may be configured to carry out the process step disclosed in step 510.
[0051] At step 512, the method 500 may include illuminating a plurality of illumination
devices if the change in the output voltage exceeds the pre-defined threshold voltage. In an exemplary aspect, the ECU (210) presented in Fig. 2 may be configured to carry out the process step disclosed in step 512.
[0052] While the above description constitutes the preferred embodiment of the present
invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims.
Advantages of the embodiment of the present disclosure are illustrated herein-[0053] Present disclosure provides a novel horn pad assembly that uses simple structure formed with strain gauges and deflection causing elements.
[0054] Present disclosure provides feedback to the user about the actuation of the horn in the form of illumination through the illumination devices.
[0055] Present disclosure provides ease to the driver in pressing the horn pad.
[0056] Present disclosure eliminates unpredictable operating conditions and increasing the effectiveness of the horn.
[0057] Present disclosure provides a technique for eliminating the bulky conventional systems for sounding the horn in automobiles and simultaneously enhances the efficiency of the hard pad assembly by reducing the replacement costs associated with it.
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REFERENCE NUMERALS
[0058] Conventional horn pad assembly 100
[0059] Movable part of the assembly (101)
[0060] Stationary part of the assembly (102)
[0061] Metal springs (103)
[0062] Copper contacts (104, 105)
[0063] Relay (106)
[0064] Horn (107)
[0065] Proposed Horn pad assembly (200)
[0066] Horn pad (202)
[0067] Deflection causing elements (204)
[0068] Strain gauges (206)
[0069] Signal Amplifier (208)
[0070] Electronic Control unit (210)
[0071] Relay (212)
[0072] Horn (214)
[0073] Illumination devices (216)
[0074] Internal view of horn pad assembly 300
[0075] External view of horn pad assembly 400
[0076] Steering wheel (402)
[0077] Method 500
[0078] Method steps 502-510

We claim:
1. A horn pad assembly for a steering wheel of a vehicle, comprising:
a pair of deflection causing elements placed beneath a horn pad to cause a deflection in the horn pad;
a plurality of strain gauges arranged on an inner surface of the horn pad and in close proximity to the pair of deflection causing elements, the plurality of strain gauges being configured to measure a strain caused due to the deflection by the pair of deflection causing elements in at least one of horizontal and vertical direction;
an Electronic Control Unit operatively connected to the plurality of strain gauges and configured to:
determine a change in an output voltage of the plurality of strain gauges caused due to the measured strain;
compare the determined change in the output voltage with a pre-defined threshold voltage, if the determined change in the output voltage exceeds the pre-defined threshold voltage:
activate a horn, via a relay circuit; and
illuminate a plurality of illumination devices.
2. The horn pad assembly as claimed in claim 1, wherein the pair of deflection causing elements are positioned in a manner such that a first deflection causing element is placed in a horizontal direction and a second deflection causing element is placed in a vertical direction covering a maximum area of the horn pad.
3. The horn pad assembly as claimed in claim 1, wherein the pair of deflection causing elements are arranged to form a hinge for causing the deflection in the horn pad.
4. The horn pad assembly as claimed in claim 1, wherein at least a pair of strain gauges of the plurality of strain gauges are placed in horizontal and vertical direction, around each corner of the pair of deflection causing elements.
5. The horn pad assembly as claimed in claim 3, wherein the pair of strain gauges is connected in half bridge Wheatstone configuration.
6. The horn pad assembly as claimed in claim 4, further comprising:
a signal amplifier configured to amplify the change in output voltage and share the amplified output voltage with the Electronic Control Unit.
7. A method for actuating a horn on a steering wheel of a vehicle, the method comprising:

locating a deflection in a horn pad;
measuring a strain caused due to the deflection caused in the horn pad, in at least one of horizontal and vertical direction; and
determining a change in an output voltage caused due to strain;
comparing the determined change in the output voltage with a pre-defined threshold voltage, if the change in the output voltage exceeds the pre-defined threshold voltage:
activating a horn; and
illuminating a plurality of illumination devices.
8. The method as claimed in claim 7, further comprising:
positioning the pair of deflection causing elements beneath the horn pad in such a manner that a first deflection causing element is placed in a horizontal direction and a second deflection causing element is placed in a vertical direction, covering a maximum area of the horn pad.
9. The method as claimed in claim 7, further comprising:
positioning at least a pair of strain gauges in horizontal and vertical direction, around each corner of the pair of deflection causing elements.
10. The method as claimed in claim 7, further comprising:
amplifying the change in output voltage prior to sharing the change in output voltage for comparing.