FIELD OF INVENTION

The present invention generally relates to a control switch assembly for a vehicle and more particularly to a control switch assembly with a touch sensitive surface for a vehicle.

BACKGROUND OF THE INVENTION

Generally conventional switches are known to be convenient means of operating electrical loads present in a typical automobile. Apart from the ease of operation these switches also are prone to getting short circuited at certain conditions causing sparking during operation of the switch. During opening or closing of the switch circuit high current passes through the metal contacts causing heat generation which affects life of the switch. Further, due to water and dust entry in the exposed switch, leakage of current adds to the poor durability of said switch. Recent improvements in switches to avoid problem of spark and heating at contacts include lighting control modules. Said lighting control module houses a controJJer that takes inputs from micro switches and-controller controls the switching loads requiring different current depending upon the power rating of each of them. Said micro switch carry very low current in the range of micro amperes through them at a rated voltage system of the automobile. But presence of such systems hardly solve the problem of short-circuit at the contacts due" to water or dust entry.

To solve above mentioned issue there is a need for switch systems with different configurations. In order to solve similar issues, US 2007/0103451A1 discloses a capacitive touch switch which contains two conductive plates connected by a conductive spring acting as a capacitive sensor element. This switch structure provides an appearance of conventional switch operation to the operator with an embedded LED light source in the centre of the lower conductive plate. This embedded LED light switch facilitates visibility of the status of activation of the switch. Further, US 2008/0099322A1 discloses a similar method of sensing touch as described above with a modification in the structure of the conductive spring which acts as a sensing element and hence taking care of the sensitivity of touch under different ambient conditions. The above mentioned prior art documents are based on capacitive touch sensing. Said method uses a capacitive sensor element working based upon the skin touch of the user passing through a touch panel. Said touch passes through the touch panel in dielectric forms such as capacitance which changes according to the actuation of the touch switch. The touch panel is associated with- the capacitive sensor element being touched or not being touched decides the change in said capacitance. This change is then detected by the detection circuitry upon which the desired operation is performed. In this design springs play a crucial role in sensing the switch operation. Any degradation of springs due toageing or entry of foreign particles such as dust or water entry can result in non-functioning of the switch and thereby affecting the sensing performance characteristics.. In view of the above mentioned problems, there is a need to have a control switch assembly whose functionality is not affected by ingress of foreign particles as well as provides ease of use.

SUMMARY OF THE INVENTION

The present invention is related to a control switch assembly which has a touch sensitive surface for user interface. This arrangement overcomes the problems caused due to water and dust entry which is present in the conventional switches. Said control switch assembly has a movable unit pivotally fixed with an immovable unit. A touch sensing surface is embedded to the movable unit such that touch sensing surface isconnected to a touch sensor circuitry. Said touch sensor circuitry is activated by human interface with said touch sensing surface. Said touch sensor circuitry is configured to activate a load control circuitry managing flow of predefined amount of current to a predefined load. Activation of touch sensor circuitry depends on a predefined * pressure on the touch sensing surface by human interface andTnaximum limit of the predefined pressure is defined by a non conductive contact mechanism. This non conductive mechanism has an upper part and a base part in which upper part touches the base part at the maximum pressure over the touch sensing surface. Said upper part is fixed with the movable unit and the base part is fixed with the immovable unit. Summary provided above explains the basic features of the invention and does not limit the scope of the invention. Additional detailed information related to the enablement of the invention will be provided in the detailed description and accompanying claims. Scope of the invention shall be based on the claims provided.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING

The present invention will become more fully understood from the detailed description given herein below and the accompanying drawing which is incorporated in and .constitute embodiments of the invention, illustrate several aspects of the invention and together with a description of the embodiments serve to explain the principles of the invention and thus, are not limited of the present invention and a brief description- of the drawing is as follows:

Figure 1 is showing a motorcycle capable of incorporating the claimed invention.

Figure 2 is depicting the existing technology for the conventional control switch of the vehicle.*"' —"' _. .. — - .

Figure 3 is showing the essential embodiments of the claimed invention.

Figure 4 is depicting the enabling mechanism of the claimed invention.

DETAILED DESCRIPTION OF THE INVENTION

The embodiments disclosed below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings. The invention may have application to all types of vehicles. As shown in Figure 1, a motorcycle M is shown as an example of the vehicle capable of incorporating the claimed invention. As shown a control switch 101 is provided with the handle bar assembly 01 in general. Said switch or switch assembly 101 is located such that while driving the vehicle rider can operate said control switches 101 in order to operate different electrical function of the motorcycle M. However this invention can be incorporated on any vehicle like step through motorcycle, our wheeler, three wheelers or any other application suitable for switch operation. This conventional switch assembly, as shown in Figure 1 and Figure 2, is used for several functionalities such as electric start, horn, headlamp actuation, turn indicators actuation etc.

In order to address the previously discussed problems related to conventional'switches, there"is a'ne'ed for a'switch unit which does not get affected even in the presence of water and dust and which takes very less current for its actuation, and still retains the same mechanical movement type design for easy operation. For this purpose, a touch based switch is proposed as shown in Figure 3. A touch sensitive surface 204 is over-layed on the movable unit 201 of the conventional switch 200. The other parts. of the switch remain unchanged except the internal structure of the contact points e.g. points to pass activation signal in order to activate required load. Since the actual actuation part of the switch 200 here is taken care by the touch sensitive surface 204 and the corresponding circuitry, there is no need of the metal • contacts (102/105) inside the conventional-switch 101/200, rather a spring 210 is required which can either be conductive or insulating in order to maintain usage similarity for the user. As mentioned above metal contacts and the spring does not have any functionality in-terms of activation of switch circuit thus even in case-of water and dust entry inside said contacts and spring area functionality of the switch does not get affected.

Referring back to Figure 2, a conventional switch is shown which is widely being used in most of the automobiles. To describe briefly the principle of operation, the tip of the switch 101 which is nothing but the contact surface 102 is internally connected to one end of the circuit 103 through a spring 104, and the other end of the circuit is 105. Whenever the user tries to operate the switch by pressing using his finger on the tip of switch 101, the spring 104 connected to the contact surface gets compressed/stressed hence facilitating the contact surface 102 to come in contact with 105 hence forming a conductive path for the current to flow. Further referring to Figure 3 and Figure 4, a touch based conventional type switch unit 200 is shown which solves problems related to conventional switches 101 which were discussed earlier. To describe the principle of operation of the disclosed invention, the movable unit 201 has a touch sensitive surface 204. This touch sensitive surface 204 is internally connected to a touch -sensing circuitry 202 which can detect the pressure caused due to-human -interface with the touch sensitive surface 204. Touch sensing circuitry 202 signals to the load control circuitry 203, which is operating the activation of electrical loads 208.

Maximum amount of pressure over the touch sensor surface 204 can; be controlled by a non conductive contact mechanism 209. This contact mechanism 209 has an upper part 207 and a base part 205. Upper part 207 is connected with the movable unit 201 of the switch 200. The base part 205 of the contact mechanism 209 is fixed with the immovable part 206 of the control switch assembly 200. Upper part 207 moves downwards at the time of human interface with the touch sensitive surface 204 and touches the base part 205 of the contact mechanism 209 indicating the allowed maximum limit of pressure on the touch sensitive surface 204. Further the contact mechanism is fixed with a spring mechanism 210 such that the working mechanism of non conductive contact mechanism 209 and spring mechanism 210 together facilitates working movement of the switch 200 in the same manner as done in existing technology. This provides a familiar operation to the user as well as takes care of the above issues mentioned. In preferred embodiment for enablement of the invention a capacitive touch based layer or a resistive touch based layer 204 is overlaid on the switch movable part 201 which is internally connected to a common touch sensing circuit 202: This touch sensing circuit-202 continuously check -for-, the changes in the capacitance on the touch-surface 204 surrounding. Whenever the user touches the switch 200, due to conductive nature of human interface there will be a change in the resultant capacitance which will-be detected.-by the touch sensory circuit hence activating the corresponding load. Similarly, inductive and resistive touch based switch can also be used to suffice the desired switching operation. While the preferred embodiment has been explained for illustration purpose, other modifications are possible without departing from the spirit and scope of the invention.

WHAT IS CLAIMED IS

1) A control switch assembly 200 comprising; a movable unit 201 pivotally fixed with an immovable unit 206, a touch sensing surface 204 embedded to the movable unit 201 suchthat touch sensing surface 204 is connected to a touch sensor circuitry 202 activated by human interface with said touch sensing surface 204 and configured to activate a load control circuitry 203 configured to manage flow of predefined amount of current to a predefined load 208:

2) The control switch assembly, as claimed in claim 1, wherein activation of touch sensor circuitry 202 depends on a predefined pressure-on the touch sensing surface 204 by human interface.

3) The control switch assembly, as claimed in claim 1, wherein maximum limit of the predefined pressure is defined by a npn conductive contact mechanism 209 having an upper part 207 and a base part 205.

4) The control switch assembly, as claimed in claim"3, wherein the upper part 207 is fixed with the movable unit 201 and the base part 205 is fixed with the immovable unit 206.