The invention relates to switches for automotive applications. In particular, the invention relates to switches for use in automotive application which operate at ultra-low current with PCB.
Background of the Invention:
In automotive applications, contact based switches are extensively used, because of their low cost. However, such contact based switches generally operate at high current ratings. In some instances, automotive applications require the switch to operate at ultra-low current. In such instances, micro-switches are used. While the micro-switches provide satisfactory functioning, the cost of such switches is very high.
Thus, there exists a need to provide a contact based switch which can operate at both ultra-low currents as well as high currents it's also protect from dust & water ingress, is easy to manufacture and cost effective so that the unmet demand in the automotive industry for such a switch can be catered.
Summary of the Invention:
This summary is provided to introduce a selection of concepts in a simplified format that are further described in the detailed description of the invention. This summary is neither intended to identify key or essential inventive concepts of the invention and nor is it intended for determining the scope of the invention.
In accordance with an embodiment, the present invention provides a contact based switch for operation at both ultra-low currents as well as high currents it's also protect from dust & water ingress. The contact based switch comprises a housing defining a top open end, an inner space and an aperture on a side wall. The contact based switch further comprises cover adapted to close the top open end. The cover provided a printed circuit board having a pair of fixed contact terminals disposed thereupon, the printed circuit board being accommodated in the inner space. The carrier is provided with a plunger that protrudes via the aperture provided on the side wall of the housing. The plunger functions as element for receiving and transmitting actuating force to the carrier. The carrier being further provided with a leaf-spring type moving contact terminal that selectively provides an electrical path between the fixed contact terminals provided on the printed circuit board.

To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES:
In order that the invention may be readily understood and put into practical effect, reference
will now be made to exemplary embodiments as illustrated with reference to the
accompanying drawings, where like reference numerals refer to identical or functionally
similar elements throughout the separate views. The figures together with a detailed
description below, are incorporated in and form part of the specification, and serve to further
illustrate the embodiments and explain various principles and advantages, in accordance with
the present invention where:
Figure 1 illustrates an exploded view of the automobile contact switch in accordance with an
embodiment of the invention;
Figure 2 illustrates a sectional view of the automobile contact switch in accordance with an
embodiment of the invention;
Figure 3 illustrates a magnified view of the carrier and associated elements in accordance
with an embodiment of the invention;
Figure 4 illustrates the steps involved in making the automobile contact switch in accordance
with an embodiment of the invention;
Figure 5 illustrates a semi-transparent view of the automobile contact switch in OFF state in
accordance with an embodiment of the invention; and
Figure 6 illustrates a semi-transparent view of the automobile contact switch in ON state in
accordance with an embodiment of the invention.
Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve understanding of aspects of the present invention. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details

that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
DETAILED DESCRIPTION OF FIGURES
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
It will be understood by those skilled in the art that the foregoing general description and the following detailed description are explanatory of the invention and are not intended to be restrictive thereof.
Reference throughout this specification to "an aspect", "another aspect" or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a device that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by "comprises... a" does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skilled in the art to which this invention

belongs. The device, methods, and examples provided herein are illustrative only and not intended to be limiting.
Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
Referring to Figure 1, the present invention provides a contact based switch for operation at both ultra-low currents as well as high currents. In an embodiment of the invention, the contact based switch can operate at ultra low current in the range of 0.5 to 2.0 Milli-Amperes. In an embodiment of the invention, the contact based switch can further operate at high current in the range of 0.5 to 1.5 Amperes. In still another embodiment of the invention, the contact based switch can further operate at any current level between 0.5 milliamperes to 2 Amperes.
Referring to Figures 1 and 2, in an embodiment of the invention, the contact based switch (10) comprises a housing (12) defining a top open end, an inner space (14) and an aperture (16) on a side wall. The contact based switch further comprises a cover (18) adapted to close the top open end of housing. The switch further comprises a printed circuit board (20) having a pair of fixed contact terminals (22) (best seen in Figure 2) disposed thereupon. The printed circuit board is accommodated within the inner space (14). The contact based switch (10) further comprises a carrier (24) accommodated within the inner space (14). The carrier (24) is provided with a plunger (26) that protrudes via the aperture (16) (best seen in Figure 2) provided on the side wall of the housing (12). The plunger (26) functions as element for receiving and transmitting actuating force to the carrier (24).
The contact based switch (10) is further provided with a first spring (28) located within the housing (12) and acting to apply a restoring force on the carrier (24). The carrier is further provided with a leaf-spring type moving contact terminal (30) that selectively provides an electrical path between the fixed contact terminals (22).
In an embodiment of the invention, a grommet (32) co-operates with grommet fixing wall (34) (best seen in Figure 2) surrounding the aperture (16) and provides sealing effect. In particular, the grommet seals the aperture (16) and thereby prohibits ingress of water and dust into the switch housing.

Now referring to Figure 3, there is illustrated a magnified view of the carrier and the associated elements. The leaf-spring type moving contact terminal (30) is provided on a top surface of the carrier (24) such that the leaf-spring type moving contact terminal (30) extends towards the PCB which is located there-above.
Now referring to Figure 4, there are illustrated the steps involved in making the automobile contact switch in accordance with an embodiment of the invention. In a first step, the housing is obtained. In a second step, a carrier assembly comprising the carrier (24) loaded with the plunger (26), the first spring (28), and the moving contact (30) is obtained. In a third step, the grommet is provided so as to cover the aperture. In a fourth step, the carrier assembly is placed in the inner space (14) such that the plunger (26) protrudes out of the aperture (16). In a fifth step, the PCB is located within the cover. In sixth step, the cover having the PCB located therein is assembled with the assembly as obtained in the fourth step.
In an embodiment of the invention, the contact switch (10) in an OFF state is shown in Figure 5 and the contact switch in an ON state is shown in Figure 6.
While specific language has been used to describe the disclosure, any limitations arising on account of the same are not intended. As would be apparent to a person in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.
The drawings and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. The scope of embodiments is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. The scope of embodiments is at least as broad as given by the following claims.

WE CLAIM:

An automobile switch (10) configured for operation at ultra-low current as well as
high current, comprising:
a housing (12) defining a top open end, an inner space (14) and an aperture (16) on a
side wall;
a cover (18) adapted to close the top open end of the housing;
a printed circuit board (20) having a pair of fixed contact terminals (22) disposed
thereupon, the printed circuit board being accommodated in the inner space (14); and
a carrier (24) accommodated in the inner space (14), the carrier (24) being provided
with a plunger (26) that protrudes via the aperture (16), the plunger (26) acting as an
element for receiving and transmitting actuating force to the carrier (24), the carrier
being further provided with a leaf-spring type moving contact terminal (30) that
selectively provides an electrical path between the fixed contact terminals (22)
provided on the printed circuit board (20).
The switch as claimed in claim 1, comprising a first spring (28) located within the housing (12) and co-operating with the carrier for apply a restoring force on the carrier (24).
The switch as claimed in claim 1, comprising a grommet (32) that co-operates with grommet fixing wall (34) for providing a sealing effect, the grommet fixing wall surrounding the aperture (16).
The switch as claimed in claim 1, wherein the carrier (24) includes a top surface facing the printed circuit board, the top surface being provided with the leaf spring type moving contact terminal (30).
The switch as claimed in claim 1, wherein the cover is provided with a recess for accommodating the PCB.