FIELD OF THE INVENTION
The present invention relates to a contact switch module, more particularly to a contact switch module having butt contacts for removal of the oxide layer at contact area of switch module.
BACKGROUND OF THE INVENTION
Generally, vehicles are provided with a start switch module to initiate the combustion of engine. The switch module comprises a fixed and a movable contact that triggers the starter motor of the vehicle when the contacts engage with each other. The starter motor provides the initial torque required for starting the engine of the vehicle. The switch module activates the starter relay and activates the starter control circuit that cranks the engine. The starter relay works at very low amperage current for actuation and due to this low amperage the area of contact made by the fixed and the movable contacts should be void of any contamination consisting of dust, sand particles, grease, water or mixture of more than one contamination or oxide layer formation at the contact area. However, contaminating particles from switch arcing or ingress accumulates on the contact surface thereby diminishing the electrical conduction between the contacts. It is therefore desirable to impart wiping action between the contacts during switch operation to scrape off any impurities collecting on the contact surface, thereby providing clean surface for maximum conduction between the contacts.
Conventional switch modules are constructed such that the moving contact and fixed contact have sliding contact and due to the sliding more friction occurs and therefore the contaminations and oxide layer formed on the contact are not removed. This type of sliding contact does not help in removing the contaminations present on the contacts and therefore diminish the conduction between the contacts. Hence there arises a need to provide a mechanism which helps in removing the contaminations and oxide layer in order to avoid the malfunctioning of the switch.
OBJECT OF THE INVENTION
The main object of the present invention is to provide a contact switch assembly which prevents accumulation of dust, water, oxide layer formation and other contaminating particles.

Another object of the present invention is to provide enhanced life span and reliability of the switch assembly.
SUMMARY OF THE INVENTION
Accordingly the present invention comprises a contact switch assembly comprising: a switch cover accommodating a fixed contact means; a switch button; and a traversing member mounted on the said switch button, the said traversing member comprising: a bracket attached with said switch button; and a movable contact means disposed on the said metallic insert; said fixed and the movable contact means have curved surfaces so as to form an arc of a circle; said traversing member is pivoted, under the force of a spring, to a pin attached to the switch cover.
In one embodiment of the present invention, the fixed contact and the movable contact means are disposed such that axis of the fixed contact means is offset with the axis of the movable contact means.
In one embodiment of the present invention, said bracket is insert molded with said switch button. In one embodiment of the present invention, the surfaces of the fixed and the movable contact means are formed so as to make a point contact when the switch button is pressed.
In one embodiment of the present invention, the said traversing member is pivoted under the force of a torsion spring when the switch button is pressed. In one embodiment of the present invention, the switch button is a push button.
In one embodiment of the present invention, the pin and the bracket are provided with a predetermined clearance disposed there between. In one embodiment, the bracket is made up of metal. In another embodiment of the present invention, the clearance between the pin and the metallic bracket is predetermined to 0.05mm per side.
In one embodiment of the present invention, said traversing member is pivoted to the pin with a terminal attached to the pin. In one embodiment, said terminal is conductively coupled with the said movable contact means.
In one embodiment of the present invention, said offset is the distance between the axis of the fixed and the movable contact means.

In one embodiment of the present invention, the surface of the movable contact means is formed so as to wipe over the surface of the fixed contact means due to the clearance when the switch button is released.
In another embodiment of the present invention, the position of movable contact and fixed contact means is raised with respect to switch button.
In one embodiment of the present invention, the material of movable and fixed contact is same.
BRIEF DESCRIPTION OF THE DRAWINGS
The features of the present invention are set forth with particularity in the appended claims. The invention itself, together with further features and attended advantages, will become apparent from consideration of the following detailed description, taken in conjunction with the accompanying drawings. One or more embodiments of the present invention are now described, by way of example only, with reference to the accompanied drawings wherein like reference numerals represent like elements and in which:
Figure 1 illustrates an exemplary sectional view of right hand side (RH) handle bar switch assembly in accordance with an embodiment of the present invention.
Figure 2 illustrates an exemplary sectional view of contact switch module in accordance with an embodiment of the present invention.
Figure 3 illustrates a detail view of curvature provided over movable contact and fixed contact means in accordance with an embodiment of the present invention.
Figure 4 illustrates an exemplary view showing clearance between pin and metallic bracket in accordance with an embodiment of the present invention.
Figure 5 illustrates an exemplary side view of the RH handle bar switch assembly in accordance with another embodiment of the present invention.

Figure 6 illustrates an exemplary front view of the RH handle bar switch assembly in accordance "with another embodiment of the present invention.
Figure 7 illustrates an exemplary sectional view (along axis BB) of the RH handle bar switch assembly in accordance with another embodiment of the present invention.
Figure 8 illustrates an exemplary sectional view of the contact switch module in accordance with another embodiment of the present invention.
Figure 9 illustrates an exemplary bottom view of the contact switch module in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION OF THE DRAWINGS
The present invention relates to contact switch module in a handle bar switch assembly of two or three wheeled vehicles and more particularly, the present invention relates to contact switch having butt type moving and fixed contacts fixed offset with each other. The switch module comprises a bracket such as a metallic bracket insert molded with the switch button. An intentional clearance is provided between the metallic bracket and a pin.
When the switch button is pressed manually, the butt type contacts come into contact with each other provide wiping or rubbing action desirable to remove the oxide layer at contact area due to the intentional clearance. The wiping action causes the contact surface clean of any foreign matter, dust, grease, oxide layer formation and other contamination, thereby enhancing the life of the switch module.
Figure 1 illustrates an exemplary sectional view of right hand side (RH) handle bar switch assembly 100 of a vehicle in accordance with an embodiment of the present invention.
The RH handle bar switch assembly 100 comprises a switch console upper 102 and a switch console lower 104. In one embodiment, the switch console lower 104 comprises a contact switch module covered by a protective cover 106. The protective cover is made up of material, for example metal or plastic. The switch module houses one or more components such as a
switch cover, a switch button 108, and a traversing member attached to the said switch button.

The switch cover accommodates a fixed contact means as shown in Fig.l. When the switch button is pressed, the fixed contact means engages with a movable contact means mounted on the traversing member. One or more drain holes 110 are provided at the bottom of the switch console lower 104 to prevent accumulation of water, grease and other contaminating particles. The contact switch module is protected by an outer cover 112 and is fastened to the switch console lower 104 by a fastening means 114 such as screw.
Figure 2 illustrates an exemplary sectional view of contact switch module in accordance with an embodiment of the present invention.
According to an embodiment of the present invention, the contact switch module comprises a switch cover 202 accommodating a fixed contact means 204, the switch button 108, and the traversing member attached to the switch button. The switch button 108 is a push type button and can be any other types of button. The switch button 108 is made up of material such as plastic and can be made of any suitable material.
The traversing member comprises a metallic bracket 208 attached to the switch button 108. The bracket can be made of any material such as plastic or polymer composite material or any other suitable material. In an embodiment, the metallic bracket 208 is insert molded to the switch button 108 and a movable contact means 210 is disposed on the metallic bracket 208. Both the fixed and movable contact means (204, 210) are made of same material. For example, both the fixed and movable contact means are made of material such as metal, for example copper without any plating over them. The metallic contacts reduce the effect of galvanic corrosion at contact area when load is applied in a corrosive environment. The effect of galvanic corrosion reduces when the fixed and movable contact means made from same material or metal engage with each other.
The traversing member attached to the switch cover 202 is pivoted, under the force of a spring, to a pin 212. In one embodiment, the spring is a torsion spring 214. In addition to the traversing member, a terminal 216 is also attached to the pin 212. One end of the fixed contact means 204 is connected to ground wherein the terminal 216 is connected to the positive end of the power supply or vice versa. A predetermined intentional clearance or allowance is provided between the pin 212 and the metallic bracket 208 on each side.

Both the fixed and the movable contact means (204, 210) are provided with a curvature on the exposed surfaces. In an embodiment, the surfaces of the contact means (204, 210) are curved so as to make a point contact when both the contact means (204, 210) contact with each other. Further, the contact means (204, 210) are disposed such that the axis of the fixed contact means 204 is offset with the axis of the movable contact means 210 as shown in the Figl. In one embodiment, the offset is predetermined at the time of manufacture.
When the switch button 108 is pressed manually, the traversing member attached to the switch button 108 is also pressed. The movable contact means 210 attached to the traversing member moves towards the fixed contact means 204 and makes point contact with the fixed contact means 204. When the point contact is made between the fixed and the movable contact means (204, 210), a closed circuit is formed thereby allowing the current to flow from the terminal 216 to the pin 212, then to the movable contact means 210 via the metallic bracket 208 and finally to the fixed contact means 204.
Due to the intentional clearance provided between the pin 212 and the metallic bracket 208 and the curvature provided on the surfaces of the contact means (204, 210), the surface of the movable contact means 210 wipes over the surface of the fixed contact means 204. The wiping action removes the oxide layer formation over the surfaces of the fixed and movable contact means (204, 210) every time when the contact is made and also facilitates flow of current through the contact means. The wiping action also removes grease, dust, water and other contaminating particles accumulating on the surfaces of both the contact means (204, 210).
Figure 3 illustrates a detail view of curvature provided over movable contact and fixed contact means in accordance with an embodiment of the present invention.
Both the fixed and the movable contact means (204, 210) are provided with a curvature (302, 304) on the exposed surfaces. In an embodiment, the surfaces of the contact means (204, 210) are formed so as to make point contact when both the fixed and movable contact means (204, 210) engage with each other. In another embodiment, the surfaces of the contact means (204, 210) are convex shaped surfaces. Further, the contact means are disposed such that the axis of the fixed contact means is offset with the axis of the movable contact means as shown in the Figl. The offset is defined as radial or angular distance between the axis of the fixed and

movable contact means. In one embodiment, the offset is predetermined at the time of "manufacture.
When the fixed and the movable contact means contact each other to make the point contact, the curvature (302, 304) on the surfaces of both contact means (204, 210) form an arc of circle. This arc formation removes the oxide layer or any other contaminating particles accumulating on the surfaces of the contact means (204,210).
Figure 4 illustrates an exemplary view showing clearance between pin and metallic bracket in accordance with an embodiment of the present invention.
A predetermined intentional clearance or allowance is provided between the pin 212 and the metallic bracket 208 on each side. The clearance is the minimum difference in dimensions of the pin 212 and the metallic bracket 208. In one embodiment, dimension of the pin 212 is set as 2.95mm and that of the metallic bracket 208 is set as 3.05mm, thereby the clearance is set to 0.05 mm per side thereby providing a total 1.0 mm of clearance between the pin 212 and the metallic bracket 208.
According to an embodiment of the present invention, the clearance can also be provided between the spring and the pin so that upon releasing the switch button there is no movement in the movable contact for a predetermined retraction of the spring.
Figure 5 illustrates an exemplary side view of the RH handle bar switch assembly in accordance with another embodiment of the present invention.
According to another embodiment of the present invention, the RH handle bar switch assembly comprises a contact switch module assembled inside the handle bar switch assembly through fastening means 114 or snap fitting. The contact switch module comprises a switch button 108 mounted at the lower side of the switch console lower 104 as compared with Figure 1, in which the switch button 108 is mounted at the upper end of the switch console lower 104. The switch button 108 is mounted along with drain holes 110 as shown in Figure 5. Drain holes 110 facilitate drainage of water, oil, dust and other contaminating particles accumulating inside the switch module.

figure 6 illustrates an exemplary front view of the RH handle bar switch assembly in accordance with another embodiment of the present invention.
The front view of the handle bar switch assembly illustrates the switch button 108 mounted on the lower end of the switch console lower along with the drain holes 110 in accordance with another embodiment of the present invention.
Figure 7 illustrates an exemplary sectional view (along axis BB) of the RH handle bar switch assembly in accordance with another embodiment of the present invention.
According to another embodiment of the present invention, RH handle bar switch assembly 700 comprises a switch console upper 102 and a switch console lower 104. The switch console lower 104 comprises a contact switch module covered by a protective cover 106. The protective cover 106 is made up of material, such as metal or plastic. The switch module houses one or more components such as a switch cover, a switch button 108, and a traversing member attached to the said switch button 108. The switch button 108 is mounted on the lower end of the switch console lower 104 along with the drain holes 110 as shown in Fig 7.
The switch cover accommodates the fixed contact means 204 that engages with a movable contact means 210 disposed on the traversing member when the switch button 108 is pressed. The fixed contact means 204 is insulated with the switch cover using an insulating means such as an insulation washer 702. The traversing member is pivoted, under the force of a spring, to a pin 212. In one embodiment, the spring is a torsion spring 214. In addition to the traversing member, a terminal 216 is also attached to the pin 212. One end of the fixed contact means 204 is connected to ground wherein the terminal 216 is connected to the positive end of the power supply or vice versa.
Both the fixed and the movable contact means (204, 210) are positioned higher such that they are protected from water ingression and accumulation. The drain holes 110 are provided at the bottom of the switch console lower 104 to prevent accumulation of water, grease and other contaminating particles. The contact switch module is protected by an outer cover 112 and is fastened to the switch console lower 104 by a fastening means 114 such as screw.
Figure 8 illustrates an exemplary sectional view of the contact switch module in accordance with
another embodiment of the present invention.

According to another embodiment of the present invention, the contact switch module comprises a switch cover 202 accommodating a fixed contact means 204, the switch button 108, and the traversing member attached to the switch button 108. The switch button 108 is a push type button and can be any other types of button known in the art. The switch button 108 is mounted at the lower end of the switch console lower 104 along with drain holes 110 as shown in Fig. 8.
The traversing member comprises a metallic bracket 208 attached to the switch button 108. In an embodiment, the metallic bracket 208 is insert molded to the switch button 108 and a movable contact means 210 is disposed on the metallic bracket 208. Both the fixed and the movable contact means (204, 210) are positioned higher, with respect to the switch console lower 104, such that they are protected from water ingression and water accumulation. In particular, the pressing position of the switch button 108 is shifted upwards and the pivot point position is shifted downwards with respect to switch console lower. Both the fixed and movable contact means (204, 210) are made of same material. For example, both the fixed and movable contact means are made of material such as metals, for example copper without any plating over them. The metallic contacts reduce the effect of galvanic corrosion at contact area when load is applied in a corrosive environment. The effect of galvanic corrosion reduces when the fixed and movable contact means made from same material engage with each other.
The traversing member attached to the switch cover 202 is pivoted, under the force of a spring, to a pin 212. In one embodiment, the spring is a torsion spring 214. In addition to the traversing member, a terminal 216 is also attached to the pin 212. One end of the fixed contact means 204 is connected to ground wherein the terminal 216 is connected to the positive end of the power supply or vice versa. A predetermined intentional clearance or allowance is provided between the pin 212 and the metallic bracket 208 on each side.
Both the fixed and the movable contact means (204, 210) are provided with a curvature on the exposed surfaces. In an embodiment, the surfaces of the contact means (204, 210) are formed so as to make a point contact when both the contact means (204, 210) contact with each other. Further, the contact means (204, 210) are disposed such that the axis of the fixed contact means 204 is offset with the axis of the movable contact means 210 as shown in the Figl. In one embodiment, the offset is predetermined at the time of manufacture.

When the switch button 108 is pressed manually, the traversing member attached to the switch button 108 is also depressed. The movable contact means 210 attached to the traversing member moves towards the fixed contact means 204 and makes point contact with the fixed contact means 204. When the point contact is made between the fixed and the movable contact means (204, 210), a closed circuit is formed thereby allowing the current to flow from the terminal 216 to the pin 212, then to the movable contact means 210 via the metallic bracket 208 and finally to the fixed contact means 204.
Due to the intentional clearance between the pin 212 and the metallic bracket 208 and the curvature provided on the surfaces of the contact means (204, 210), the surface of the movable contact means 210 wipes over the surface of the fixed contact means 204. The wiping action removes the oxide layer formation over the surfaces of the fixed and movable contact means (204, 210) every time when the contact is made and also facilitates flow of current through the contact means. The wiping action also removes grease, dust, water and other contaminating particles accumulating on the surfaces of both the contact means (204,210).
Figure 9 illustrates an exemplary bottom view of the contact switch module in accordance with another embodiment of the present invention.
The bottom view of the contact switch module illustrates drain holes 110a and 110b and the fastening means 114. Drain holes 110a and 110b are provided to drain accumulating water, dust, grease and other contaminating particles. In one embodiment, the fastening means 114 is a screw.
The above description describes the present invention with respect to the right hand side (RH) handle bar switch assembly. However, the present invention can be implemented in the left hand side (LH) handle bar switch assembly or any other suitable switch assembly.
The present invention provides a butt type contacts provided with a curvature on the surfaces. Due to the intentional clearance provided between the pin and the metallic bracket and the curvature provided on the surfaces of the contact means, the surface of the movable contact means wipes over the surface of the fixed contact means. The wiping action removes the oxide layer formation over the surfaces of the fixed and movable contact means every time when the contact is made and also facilitates flow of current through the contact means. The wiping action

also removes grease, dust, water and other contaminating particles accumulating on the surfaces of both the contact means. The present invention enhances the life span of the switch assembly by removal of oxide layer and contaminating particles whenever the switch is actuated.
The present invention also results in reducing the effect of Galvanic corrosion during switch operation in a corrosive environment due to use of like metals for both fixed and movable contact means.
While the particular preferred embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the teachings of the invention. It is therefore contemplates that the present invention cover any and all modifications, variations or equivalents that fall within the scope of the basic underlying principles disclosed above and claimed herein.

We Claim:
1. A contact switch assembly comprising:
a. a switch cover accommodating a fixed contact means;
b. a switch button; and
c. a traversing member mounted on the said switch button, the said traversing
member comprising:
i. a bracket attached with said switch button; and ii. a movable contact means disposed on the said metallic insert; said fixed and the movable contact means have curved surfaces so as to form an arc of a circle; said traversing member is pivoted, under the force of a spring, to a pin attached to the switch cover.
2. The switch assembly as claimed in claim 1, wherein the fixed contact and the movable contact means are disposed such that axis of the fixed contact means is offset with the axis of the movable contact means.
3. The switch assembly as claimed in claim 1, wherein said bracket is insert molded with said switch button.
4. The switch assembly as claimed in claim 1, wherein the surfaces of the fixed and the movable contact means are formed so as to make a point contact when the switch button is pressed.
5. The switch assembly as claimed in claim 1, wherein the said traversing member is pivoted under the force of a torsion spring when the switch button is pressed.
6. The switch assembly as claimed in claim 1, wherein the pin and the bracket are provided with a predetermined clearance disposed there between.
7. The switch assembly as claimed in claim 1, wherein said bracket is made of metal.
8. The switch assembly as claimed in claim 6, wherein the clearance between the pin and the metallic bracket is predetermined to 0.05mm per side.

9. The switch assembly as claimed in claim 1, wherein the switch button is a push button.
10. The switch assembly as claimed in claim 1, wherein said traversing member is pivoted to the pin with a terminal attached to the pin.
11. The switch assembly as claimed in claim 10, wherein said terminal is conductively coupled with the said movable contact means.
12. The switch assembly as claimed in claim 2, wherein said offset is the distance between the axis of the fixed and the movable contact means.
13. The switch assembly as claimed in claim 1, wherein the surface of the movable contact means is formed so as to wipe over the surface of the fixed contact means due to the clearance when the switch button is released.
14. The switch assembly as claimed in claim 1, wherein the position of movable contact and fixed contact means is raised with respect to switch button.
15. The switch assembly as claimed in claim 1, wherein the material of movable and fixed contact is same.
16. A contact switch assembly substantially as herein described with reference to the foregoing paragraphs and the accompanying drawings.