The following specification particularly describes the nature of the invention and the manner in which it is to be performed.
TECHNICAL FIELD
Present disclosure generally relates to the field of electro-mechanical engineering. Particularly, but not exclusively, the present disclosure relates to a switch assembly. Further, embodiments of the present disclosure disclose a switch assembly configured with an arrangement to prevent entry of water and dust into the switch assembly.
BACKGROUND OF THE DISCLOSURE
Switching circuits are extensively used across several sectors such as automobile equipment’s, home appliances, industrial equipment’s, machine tools and so on. They are generally known to make and break the contacts either to allow flow of current, or interrupt the flow of current. A number of switching elements have been designed and developed for achieving various switching functions. Commonly used types of switching arrangements include but not limited to sliding type switching mechanism, rotary knob type switches, push button switches, toggle switches, touch capacitive switch and other similar switching elements. Each of these involves different actuating mechanism to make and break electrical contacts to open and close the circuits. For example, a sliding type switch employs sliding contacts for making and breaking the circuits, push button switches use extending and retracting movements inside a casing to make and break contacts, and so on.

In automotive sectors, sliding type switching mechanisms are widely used for operating and controlling various systems such as head-lamps, operating indicators, regulating resolution of head-lamps, etc, and for applications such as controlling duty cycle functions of air-conditioning systems, temperature control systems and related systems in four wheeled and heavy duty vehicles. Apart from these, the switches are used to provide different types of indication to user such as engine ignition ON or OFF condition, A/C system ON or OFF condition, Head-lamps ON or OFF condition and the like. These types of switching mechanisms generally make use of one or more movable members that are actuated by operators for operating the switch assembly, and one or more fixed elements that remain stationary relative to movable members.

In typical switch assemblies such as but not limited to push button type or touch capacitive switch assemblies, are used in the automobiles for performing operations including but not limiting to start and stop of the automobile. In such switches, there are problems of entry of water and dust from various gaps, recesses and grooves. The water and dust entering into the assembly might accumulate in critical regions such as PCBs, terminals and the like. The contact of these critical and delicate components with dust and water may adversely affect the functioning of associated circuits and circuit elements, and might disrupt the flow of electric current leading to circuit breakdown. Also, contact between water and metallic components inside the switch assembly in presence of air may result in rusting of the metallic components, which is undesirable.

FIGS. 1 and 2 illustrate Prior Art switch assembly which may be prone to ingress of foreign particles such as water and dust seepage through various passages, gaps and recesses, particularly where gaps are formed intermittently during movement of movable member with respect to fixed members. As it can be seen in FIGS. 1 and 2, water and dust can leak into an annular gap between actuating knob of the switch assembly and the casing which holds the knob within it. Also, the absence of sealing members at appropriate locations inside the switch assembly causes water ingress towards critical components of switch assembly. In addition, in some prior art switches, certain protection arrangements comprising of elements in the form of outer hoods and/or internal accessories, such as membranes, are employed to provide protection against water and dust. These elements are usually made of elastomeric materials, which have limited operating life and resistance to failure. Therefore, these elements need to be supplemented with additional elements which need to have certain shapes and means of attachment, which involve production expense, installation time, and labor.

In light of the foregoing discussion, there is a need to develop an improved switch assembly to overcome one or more limitations stated above.

SUMMARY OF THE DISCLOSURE

The shortcomings of the prior art are overcome and additional advantages are provided through the provision of the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the disclosure.

In a non-limiting embodiment of the present disclosure, there is provided a switch assembly in an automobile. The switch assembly comprises a casing to house a knob and printed circuit board (PCB) of the switch assembly, where the casing comprises at least one tapered projection on its outer periphery. There is a connector configured to accommodate the casing and it comprises at least one slot to accommodate the at least one tapered projection. Further, the switch assembly has a polymeric sealing interposed between the knob and the connector. The provision of the polymeric between the knob and the connector and assembly of the at least one tapered projection with the at least one slot prevents ingress of foreign particles into the switch assembly.

In an embodiment of the disclosure, the switch assembly comprises an illumination ring insert molded in an annular gap between the knob and the casing. The illumination ring is configured to prevent ingress of the foreign particles to the switch assembly.

In an embodiment of the disclosure, the switch assembly comprises a locking mechanism provided on a peripheral surface of the casing. The locking mechanism comprises a channel including an inlet and an outlet. The channel is adapted to receive the foreign particles entering the switch assembly and guides the foreign particles away from the switch assembly.

In an embodiment of the disclosure, the switch assembly comprises a plurality of terminals where one end each of the plurality of terminals is soldered to the PCB. The connector comprises a plurality of terminal slots for insert molding the plurality of terminals.

In an embodiment of the disclosure, the switch assembly is a capacitive touch type switch operable between start and stop operating conditions.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.

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 THE ACCOMPANYING DRAWINGS

The novel features and characteristics of the disclosure are set forth in the description. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein like reference numerals represent like elements and in which:

FIGS. 1 and 2 illustrate switch assemblies of prior arts.

FIG. 3 illustrates exploded perspective view of the switch assembly with arrangements for preventing ingress of water and dust, according to an embodiment of the present disclosure.

FIG. 4 illustrates assembled perspective view of the switch assembly of FIG. 3.

FIG. 5 illustrates sectional view of the switch assembly of FIG. 4.

FIGS. 6A and 6B illustrate front and side views of the switch assembly of FIG. 4.

FIG. 7 illustrates sectional view of receiving annular recess of the connector accommodated with at least a portion of casing, according to an embodiment of the present disclosure.

FIG. 8 illustrates sectional view of the switch assembly configured with exaggerated view of a locking mechanism, according to an embodiment of the present disclosure.

FIG. 9 illustrates exploded perspective view of the switch assembly with polymeric sealing for preventing ingress of water and dust, according to an embodiment of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the assemblies, structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

In the following description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the description and drawings are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.

In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the disclosure.

The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device, assembly or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or an assembly or an apparatus proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.

In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

Present disclosure discloses a switch assembly with arrangements to prevent water and dust ingress with critical components constituting the circuitry of the switch assembly. The switch assembly comprises at least one movable knob accommodated in a casing, the knob is configured to actuate between a first position and a second position inside the casing. A gap is configured between outer peripheral surface of the at least one knob and inner peripheral surface of the casing. The gap is provided to facilitate actuation of the at least one knob between the first and second positions. One or more illumination rings are removably accommodated in the gap between the at least one knob and casing, and is configured to prevent entry or ingress of any foreign particles such as but not limited to water or dust from external environment into the casing from top of the knob. In an embodiment, the illumination ring is placed in the casing by process including but not limited to insert molding techniques. The insert molded illumination ring ensures fluid tight connectivity between the knob and the gap in casing. The presence of illumination ring in the gap fluidly isolates the inside portion of casing from external environment, thereby prevents leakage or seepage or ingress of water and other foreign particles such as dust into the casing. In an embodiment, the switch assembly is a capacitive touch type switch assembly.

Further, the assembly comprises a connector to accommodate the casing comprising the illumination ring. The connector comprises a plurality of slots to accommodate a plurality of terminals, which are intended to provide electrical interfaces with respect to circuits incorporated therein. In an embodiment, the terminals are soldered to the Printed Circuit Board and to the Connector, and are insert molded with the connector to prevent entry of water into the connector. At least one Printed Circuit Board (PCB) is interposed between the casing and the connector. It comprises at least one pair of conducting discs, where one of conducting discs of the pair of conducting discs has an electrical contact with the plurality of terminals. In an embodiment, the pair of discs is positioned such that their peripheral surfaces are parallel to each other and are perpendicular to the longitudinal axis of the switch assembly. Further, one or more tapered projections are configured at substantially lower end of the casing on its outer periphery, so that the tapered projection can lock the casing with the connector. To accomplish this, the periphery of connector is provisioned with a slot such that the tapered projection resides in the slot. The presence of tapered projection inside the connector slot prevents entry of water from bottom of the connector. In an embodiment of the present disclosure, a portion of casing which resides inside the connector and is provided with at least one draft to provide fluid tight connectivity between the portion of the casing and the connector.

In another embodiment of the present disclosure, the connector is provided with a receiving annular recess to receive a portion of the casing, for example, the wall of casing. In still another embodiment of the present disclosure, the receiving annular recess is configured with a draft angle to provide interference fit between the at least a portion of the casing and the annular gap of the connector. The interference fit between the at least a portion of the casing and the annular gap of the connector prevents water from entering into the connector.

Furthermore, there is provided a locking mechanism to facilitate locking of the switch assembly described in above paragraphs with at least one supporting member of the vehicle. The locking mechanism comprises at least one locking member removably configured on peripheral surface of the switch assembly. The locking mechanism comprises a channel configured along its longitudinal axis to allow flow of water. The channel comprises an inlet which is provided proximal to the knob of the switch assembly, and an outlet provided proximal to bottom of the connector. Water entering from inlet of the channel flows towards the outlet, and then out of the casing, thereby preventing its entry inside connector. In one embodiment, the channel is a through hole configured along the longitudinal axis of the at least one locking member which fluidly communicates between the inlet and the outlet to discharge water entering from the inlet side towards outlet side. In an embodiment of the present disclosure, a first predetermined gap is formed between the casing and a first end of the locking member, and a second predetermined gap is formed between the connector and a second end of the locking member. In an embodiment, the first predetermined gap forms the inlet of the channel, and the second predetermined gap forms the outlet of the channel.

In an exemplary embodiment of the present disclosure, there is provided at least one polymeric sealing interposed between the casing and the connector. The material used to manufacture the polymeric sealing is selected from a group of polymeric materials, so that there is required flexibility and adaptability to meet assembly requirements, as well as to ensure leak proof joint between the assembly elements. In an embodiment, the at least one polymeric sealing can deform over a range of 0.3 millimeter and 0.5 millimeter.

Reference will now be made to the exemplary embodiments of the disclosure, as illustrated in the accompanying drawings. Where ever possible same numerals will be used to refer to the same or like parts.

FIGS. 3 and 4 are exemplary embodiments of the present disclosure which illustrate exploded perspective view and assembled perspective view of a switch assembly (100) with arrangements to prevent foreign particles such as water and dust ingress into critical components constituting the circuitry of the switch assembly (100). A switch assembly (100), as is well known allows contact to be made to allow flow of electric current, or to be broken to interrupt flow of electric current. In embodiments of the present disclosure, a push button switch of capacitive touch contact type is illustrated for sake of understanding and simplicity, and should not be considered as limitation on present disclosure. The switch assembly (100) comprises one or more movable knobs (112) accommodated in a casing (110). The knob (112) may be adapted to actuate or move between a first position and a second position [not shown] inside the casing (110). A gap (114) may be defined between outer peripheral surface of the knob (112) and inner peripheral surface of the casing (110). The gap (114) facilitates actuation of the knob (112) between the first and second positions. In an embodiment of the present disclosure, the gap (114) is an annular space or recess between the knob (112) and the casing (110) periphery.

Further, one or more illumination rings (116) may be placed in the gap (114) between the knob (112) and casing (110), and is configured to prevent entry or ingress of foreign particles water, dust particles, or any other fluid particles like oil and the like from external environment or from vehicle into the casing (110) from top of knob (112). In an embodiment, the illumination ring (116) may be inserted into the gap (114) by processes including but not limited to insert molding techniques. The insert molded illumination ring (116) ensures fluid tight connectivity between the knob (112) and the gap (114) in casing (110). The presence of illumination ring (116) in the gap (114) fluidly isolates the inside portion of casing (114) from external environment, thereby prevents leakage or seepage or ingress of water and other foreign particles such as dust into the inner region of casing (110).

Further, as shown in FIG. 3, the assembly (100) comprises a connector (140) to hold the casing (110) comprising the illumination ring (116). The connector (140) comprises a plurality of slots (142) to accommodate a plurality of terminals (130), which are intended to provide electrical interfaces with respect to circuits incorporated therein. The terminals (130) may also be incorporated integral with the circuitry of switch assembly (100). The assembly (100) is provided with a Printed Circuit Board (120) [hereafter referred to as PCB] which constitutes main circuit board of the switch assembly (100). The PCB comprises chipsets that take part in flow of electric current within the switch assembly (100). In one embodiment of the present disclosure, one end of the terminals (130) are soldered to the Printed Circuit Board (120) and to the connector (140), and are insert molded with the connector (140) to prevent undesired entry of water into the connector (140), which can be clearly seen in FIG. 5. The Printed Circuit Board (120) may be interposed between the casing (110) and the connector (140). It comprises at least one pair of conducting discs (122 and 124), where one of conducting discs (124) of the pair of conducting discs (122 and 124) has an electrical contact with the plurality of terminals (130). In an embodiment, the pair of discs (122 and 124) is positioned such that their peripheral surfaces are parallel to each other and are perpendicular to the longitudinal axis of the switch assembly (100).

Further, the assembly (100) comprises at least one tapered projections (118) which are provided at a lower end of the casing (110) on its outer periphery. The tapered projection (118) is essentially an extension or a protrusion which extends taperedly from outer peripheral wall of the casing (110), as clearly shown in FIG. 1. When casing (110) is seated or accommodated in the connector (140), the tapered projection (118) gets locked in a slot (144) configured in the lower region of the connector (140). The locking of casing (110) with connector (140) through tapered projection (118) arrests relative movement between casing (110) and the connector (140). The presence of tapered projection (118) inside the connector slot (144) prevents entry of water from bottom of the connector (140) inside the switch assembly (100).

FIGS. 5, 6A and 6B are exemplary embodiments which illustrate sectional front view, front view and side view of the switch assembly (100). As shown in FIG. 5, the illuminating ring (116) which is accommodated in the gap (114) of casing (110) provides a fluid tight gap to ensure that no water or dust or any other foreign particles enter into the casing (110) from top from external environment. Also, as it can be seen in FIG. 5, the terminals (130) are assembled or mounted to one of the discs (124) to establish electrical contact with PCB (120). In addition, the PCB (120) along with terminals (130) are sandwiched between the casing (110) and connector (140), thereby serving as electrical bridgeway or pathway between them. Also, the tapered projection (118) of the casing (110) are accommodated in the slot (144) to lock the casing (110) with respect to connector (140). Both these arrangements viz. locking of tapered projection (118) inside slot (144) of connector (140) and illuminating ring (116) accommodated in the gap (114) prevents penetration of water inside the switching assembly (100), thereby protecting the PCB (120) from coming in contact with water. The potential sites from where water and dust particles can enter into the assembly (100) can is depicted in FIGS. 6A and 6B.

FIG. 7 is an exemplary embodiment of the present disclosure which illustrates a portion of casing (110A) which resides inside the receiving annular recess (146) of the connector (140). As shown in FIG. 7, the portion (110A) which resides inside the annular gap (146) is provided with a draft, including but not limited to tapered edges and wedge-shaped contour to provide effective sealing between casing (110) and connector (140) during knob (112) movement. This ensures no water enters into the connector (140) during movement of knob (112) between first and second positions. In another embodiment of the present disclosure, as shown in FIG. 7, the connector (140) is provided with a receiving annular recess (146) to receive a portion (110A) of the casing (140), for example, the wall of casing. In still another embodiment of the present disclosure, the receiving annular recess (146) is configured with a draft angle to provide interference fit between the at least a portion of the casing (110A) and the annular gap (146) of the connector (140). The interference fit between the at least a portion (110A) of the casing (110) and the annular gap (146) of the connector (140) prevents water from entering into the connector (140).

FIG. 8 illustrates sectional view of the switch assembly (100) and a magnified view of a locking mechanism (200), according to an embodiment of the present disclosure. The locking mechanism (200) may be intended to facilitate locking of the switch assembly (100) described in above paragraphs with at least one supporting member of the vehicle. The locking mechanism (200) comprises at least one locking member (202) removably configured on peripheral surface of the switch assembly (100). The locking mechanism (200) comprises a channel (204) configured along its longitudinal axis to allow flow of water. The channel (204) comprises an inlet (206) which is provided proximal to the knob (112) of the switch assembly (100), and an outlet (208) provided proximal to bottom of the connector (140). Water entering from inlet (206) of the channel (204) flows towards the outlet (208), and then out of the casing (110), thereby preventing its entry inside the connector (140). In one embodiment, the channel (204) is a through hole configured along the longitudinal axis of the at least one locking member (22) which fluidly communicates between the inlet (206) and the outlet (208) to discharge water entering from the inlet side (206) towards outlet (208) side.

FIG. 9 illustrates exploded perspective view of the switch assembly (100) of FIGS. 1-6 with polymeric sealing (250) for preventing entry of water and dust, according to an embodiment of the present disclosure. The polymeric sealing (250) may be interposed between the casing (110) and the connector (140). In an embodiment, the material used to manufacture the polymeric sealing (250) is selected from a group of polymeric materials, including but not limited to ABS, Polythene, rubber and other materials so that there is required flexibility and adaptability to meet assembly requirements, as well as to ensure leak proof joint between the assembly elements. In an embodiment, the polymeric sealing (250) can deform over a range of 0.3 millimeter and 0.5 millimeter.

In an embodiment, the present disclosure provides a switch assembly in which an arrangement is provided to prevent entry of foreign particles into the switch assembly thereby prevents damage to the electronic components/circuitry.

Equivalents:
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

Any discussion of documents, acts, materials, devices, articles and the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.

While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

CLAIMS:We claim:
1. A switch assembly (100) for an automobile comprising:
a casing (110) to house a knob (112) and printed circuit board (PCB) (120) of the switch assembly (100), wherein the casing (110) comprises at least one tapered projection (118) on its outer periphery;
a connector (140) configured to accommodate the casing (110), wherein the connector (140) comprises at least one slot (144) to accommodate the at least one tapered projection (118); and
a polymeric sealing (250), interposed between the knob (112) and the connector (110),
wherein, provision of the polymeric sealing (250) between the knob (112) and the connector (110) and assembly of the at least one tapered projection (118) with the at least one slot (144) prevents ingress of foreign particles into the switch assembly (100).

2. The switch assembly (100) as claimed in claim 1 comprises an illumination ring (116) insert molded in an annular gap (114) between the knob (112) and the casing (110).

3. The switch assembly (100) as claimed in claim 2, wherein the illumination ring (116) is configured to prevent ingress of the foreign particles to the switch assembly (100).

4. The switch assembly (100) as claimed in claim 1 comprises a locking mechanism (200) provided on a peripheral surface of the casing (110).

5. The switch assembly (100) as claimed in claim 4, wherein the locking mechanism (200) comprises a channel (204) including an inlet (206) and an outlet (208).

6. The switch assembly (100) as claimed in claim 5, wherein the channel (204) is adapted to receive the foreign particles entering the switch assembly and guides the foreign particles away from the switch assembly.

7. The switch assembly (100) as claimed in claim 1 comprises a plurality of terminals (130), wherein one end each of the plurality of terminals (130) is soldered to the PCB (120).
8. The switch assembly (100) as claimed in claim 7, wherein the connector (140) comprises a plurality of terminal slots (142) for insert molding the plurality of terminals (130).

9. The switch assembly (100) as claimed in claim 1 is a capacitive touch type switch operable between start and stop operating conditions.