FIELD OF THE INVENTION
The present invention belongs to control switches for automotive application including two wheelers and three-wheelers. More particularly, the invention relates to construction of blinker switch.
BACKGROUND OF THE INVENTION
Generally, vehicles are provided with various control switches for providing safe driving to the rider as well as to the other riders. One such important control switch is a blinker switch (interchangeably referred to as turn indicator switch) that signals the other riders of the direction in which the vehicle is going to turn. The failure of blinker switch may lead to accidents, especially when the switch fails to work at night.
Figure 1 illustrates a conventional blinker switch assembly of two/three wheeled vehicles. The blinker switch assembly is mounted on the handle bar of a two wheeled or three wheeled vehicle. In particular, the switch assembly is mounted on the control switch housing case located on the vehicle handle bar.
Figure 2 illustrates an exploded view of the components present in a conventional blinker switch assembly.
Typical blinker switch assembly includes a bracket (1) that encases a carrier (2) for supporting a moving contact (3). In addition to the moving contact (3), the carrier (2) also encases a spring (4) and a steel ball (5) such that the whole carrier casing moves together when operated. Further, a base (6) with one or more fixed contacts (7) mounted on the base (6) is disposed into the bracket (1) at a fixed location with respect to the moving contact (3). A lever assembly comprising a lever support (8) is locatable inside the bracket (1) and is being mounted with an operating lever (9) which traverses outside the bracket (1). The switch assembly further comprises a cover (10) mounted to at least partly cover the lever assembly.
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The lever support (8) houses a spring loaded ball or a plunger that acts as a follower. The follower moves over a profile of a CAM plate (11). The CAM plate (11) is made of steel and is sandwiched between the bracket (1) and the cover (10). A spring (12) and a steel ball (13) together referred to as cam follower is housed inside the lever support (8). The lever support (8) and the lever (9) together forming the lever assembly is operated by a knob (14) located outside the bracket. The knob is fixed to the lever (9) by means of a spring washer and a screw.
Further, the cover (10) and the cam plate (11) are provided with one or more holes or recesses for allowing self tapping screws (17) to pass through. The self tapping screws (17) are used to tightly fit the cover (10), the cam plate (11), and the bracket (1) together into a single element. In addition, a flange headed self tapping screw made of steel is used to tightly fit the lever assembly to the bracket (1). The flange headed screw allows inward/outward movement of the lever assembly, however, prohibits the upward or downward movement of the lever assembly.
The conventional blinker switch is open from all sides thereby exposing its components to dust, water and other contamination particles. Such dust and water upon entering the blinker switch accumulates over fixed and the moving contacts. Due to accumulation of dust, water and other contaminations on the contacts, an oxide or insulating layer is formed over the contacts. The presence of such layer diminishes the conduction between the contacts thereby, causing malfunctioning of the switch. Further, dust particles such as mud deposited on the contacts blocks the clearance made between the contacts and obstruct the free movement of the said contacts. Therefore, the reliability of the switch decreases and frequent replacement of the switch is needed.
Thus, there arises a need to construct a blinker switch that overcomes the above mentioned issues.
OBJECT OF THE INVENTION
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An object of the present invention is to provide a better and efficient sealing to the contacts in the blinker switch thus preventing entry of water, dust and contamination particles therefore addressing problems described in the prior art.
Another object of the present invention is to provide a blinker switch with better construction, such that the blinker switch has a longer life span.
SUMMARY OF THE INVENTION
Accordingly the present invention relates to a blinker switch assembly, comprising a bracket, a top cover and a bottom cover cooperating with each other to define a top chamber and a bottom chamber, a lever assembly traversing through the top chamber and exhibiting pivotal movement upon actuation; one or more fixed contacts provided inside the bottom chamber; a moving contact carrier assembly comprising one or more moving contacts, said moving contact carrier assembly being locatable inside the bottom chamber and being configured to exhibit bi-directional rotational movement around a vertical axis so as to selectively bring the said one or more fixed contacts in contact with the said one or more moving contacts; and a carrier cam cooperating with the lever assembly and the moving contact carrier assembly for translating the pivotal movement of the lever assembly into bi-directional rotational movement of the moving contact carrier assembly.
According to another embodiment of the present invention the switch assembly comprises of an auto-cancellation means that is provided in the top chamber to achieve the function of auto-cancellation, said auto cancellation means comprising a cam plate and a cam follower, wherein said cam plate is integrally mounted in the top chamber and is a V-shape cam.
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According to another embodiment of the present invention the switch assembly is provided with a cam follower comprising of a spring mounted with a steel ball, said steel ball is constantly in contact with the cam plate.
According to yet another embodiment of the present invention the switch assembly is provided with a lever assembly comprising of a lever support and an operating lever mounted on the said lever support.
According to one more embodiment of the present invention the switch assembly is provided with a pivot element located at a predetermined location on the lever assembly.
According to another embodiment of the present invention the switch assembly is provided with a lever support that comprises of a cylindrical engagement element disposed to engage with a cavity provided in the said carrier cam.
According to yet another embodiment of the present invention the switch assembly is provided with a knob that is provided at an end of the lever assembly traversing out of the top chamber, said knob attached to the lever assembly by fastening means.
According to one more embodiment of the present invention the switch assembly is provided with a top cover that is securely fitted onto the said bracket either by snap fitting or ultrasonic welding.
According to another embodiment of the present invention the switch assembly is provided with a ball detent mechanical arrangement that is provided in the bottom chamber, said ball detent mechanical arrangement comprises of a detent profile and a spring mounted with a steel ball.
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According to yet another embodiment of the present invention the switch assembly is provided with a detent profile that is provided on a side wall of the bottom chamber, said profile comprises of plurality of detent locations.
According to one more embodiment of the present invention the switch assembly is provided with a spring mounted with a steel ball disposed onto one detent location at a given time, said spring located in a recess provided in the said moving contact carrier assembly.
According to another embodiment of the present invention the switch assembly comprises of a moving contact carrier assembly that comprises of a carrier.
According to yet another embodiment of the present invention the switch assembly is provided with a moving contact and a fixed contact corresponding to the moving contact and the moving contact and fixed contact are located around a circle of predetermined radius.
According to one more embodiment of the present invention the switch assembly is provided with a moving contact that is provided with an inbuilt leaf spring.
According to another embodiment of the present invention the switch assembly is provided with a fixed contact that is formed on a PCB, said PCB is provided in the bottom cover.
According to yet another embodiment of the present invention the switch assembly is provided with a circular opening that is provided in a separation wall, said separation wall separating the top chamber and the bottom chamber.
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According to one more embodiment of the present invention the switch assembly is provided with a carrier that comprises of a hollow cylindrical portion at its top surface, said hollow cylindrical portion protrudes out of the circular opening in the separation wall.
According to another embodiment of the present invention the switch assembly comprises of at least one hook that is provided in the carrier cam, said hook engages with the hollow cylindrical protrusion provided in the said carrier.
According to yet another embodiment of the present invention the switch assembly is provided with a carrier cam that is provided in the top chamber.
According to one more embodiment of the present invention the switch assembly is provided with the bottom cover that is securely fitted onto the bracket either by snap fitting or by ultrasonic welding.
BRIEF DESCRIPTION OF THE DRAWINGS
Further aspects and advantages of the present invention will be readily understood from the following detailed description with reference to the accompanying drawings. Reference numerals have been used to refer to identical or functionally similar elements. 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 wherein:
Figure 1 illustrates a perspective view of a conventional blinker switch assembly. Figure 2 illustrates an exploded view of conventional blinker switch assembly. Figure 3 illustrates a perspective view of a sealed blinker switch assembly in accordance with an embodiment of the present invention.
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Figure 4 illustrates a sectional view of the blinker switch assembly in accordance with
an embodiment of the present invention.
Figure 5 illustrates an exploded view of sealed blinker switch assembly.
Skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the drawings may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
While the invention 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 invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternative falling within the spirit and the scope of the invention.
Before describing in detail embodiments it may be observed that the novelty and inventive step that are in accordance with the present invention reside in the construction of sealed blinker switch, accordingly, the drawings are showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.
The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such setup or device. In other words, one or more elements in a system or apparatus proceeded by "comprises... a" does not, without more constraints, preclude the existence of other elements or additional
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elements in the system or apparatus. The following paragraphs explain various aspect of the present invention with reference to figures.
The present invention relates to a blinker switch assembly mounted on a control switch housing case located on the handle bar of two or three wheeled vehicles, ATU, snow mobile trucks. In one embodiment, the switch assembly is constructed so as to provide protection to various operating parts of the switch from direct entry of water, dust and other contamination particles. Further, the switch assembly is designed so as to eliminate metal friction and corrosive environment, thereby increasing the reliability of the switch assembly. In addition, the switch assembly is constructed with less number of parts, hence cheap and easy to manufacture.
Figure 3 illustrates an exemplary view of blinker switch assembly in accordance with an embodiment of the present invention. Figure 4 illustrates a sectional view of the blinker switch assembly in accordance with an embodiment of the present invention.
The blinker switch assembly provides an input signal to an electromechanical relay circuit in response to the operation of a knob by the rider. The relay circuit enables the left or right blinker to emit light (i.e., ON condition) depending on the direction in which the knob is actuated. When the knob is pressed in either left or right direction, the moving contact housed inside the bottom chamber of the blinker switch overlaps with the fixed contacts, thereby making contact and causing conduction between the contacts. In order to break the contact and to set the left and right blinkers at OFF condition, the knob is pushed linearly to a specified distance to return to a neutral position where the moving contact does not overlap any of the fixed contacts.
Figure 5 illustrates an exploded view of the blinker switch assembly in accordance with an embodiment of the present invention.
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In an embodiment of the present invention, the blinker switch assembly comprises a bracket (6), a top cover (1) and a bottom cover (16) such that on assembling them they define a top chamber and a bottom chamber. The top chamber comprises of a lever assembly which exhibits pivotal movement upon actuation. The bottom chamber comprises of one or more fixed contacts (15). A moving contact carrier assembly is provided in the bottom chamber which is configured to exhibit bi-directional rotational movement around a vertical axis so as to selectively bring said one or more moving contacts (14) in contact with the said one or more fixed contacts (15). A carrier cam (13) provided in the top chamber cooperates with the lever assembly for translating the pivotal movement of the lever assembly into bi-directional movement of the moving contact carrier assembly.
Elaborating the invention further, the top chamber comprises of an auto-cancellation means whose function is to achieve auto-cancellation. The auto-cancellation means comprises of a cam plate and a cam follower. The cam plate is integrally molded in the top chamber. The profile of the cam plate is V in shape. The cam follower comprises of a steel ball (5) mounted at one end of a spring (4). In another embodiment the cam follower may comprise of a U-shaped steel member mounted at an end of a spring (4). The steel ball (5) or the U-shaped steel member is disposed on the cam plate's V-profile. In other words, the steel ball (5) or the U-shaped steel member is in constant contact with the cam plate's V-profile and moves over the said profile whenever the rider of the vehicle moves the knob (18).
Further, the cam follower forms part of the lever assembly. The lever assembly comprises of a lever support (2) and an operating lever (3) which is mounted on the said lever support (2). The lever support (2) is provided with a holding means for securely holding the cam follower. In another embodiment the holding means also securely holds the U-shaped steel member. The lever support (2) further comprises of an engagement element disposed to engage with the carrier cam (13). The lever assembly is
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further provided with a pivot element at a predetermined location so as to let the lever assembly exhibit a pivotal movement upon actuation. The top cover (1) is provided with an elliptical channel and a side wall in the top cover (1) with a semi-elliptical channel for allowing the pivot element to exhibit a pivotal movement. The channel allows movement along the direction of the channel and restricts any movement in other directions such as upwards and downwards.
The operating lever (3) traverses out from an opening in the side wall of the said top chamber. The operating lever (3) is provided with a knob (18) at an end which traverses out of the top chamber. The knob (18) is attached to the lever assembly by a fastening means. Alternatively, the knob (18) may be attached to the lever assembly by snap fitting. The opening in the side wall through which the lever assembly traverses out of the top chamber is of a predetermined width, said predetermined width further defines the extent to which the lever assembly is allowed to exhibit pivotal movement.
The bottom chamber is provided with a ball detent mechanical arrangement. The ball detent mechanical arrangement comprises of a detent profile on the inside wall of the bracket (6) so as to provide a clear and better auditory feedback when the moving contact (14) is operated. The detent profile comprises of plurality of detent locations and enables enhanced auditory feedback when the moving contact (14) moves from one position to next position. The ball detent mechanical arrangement further comprises of a spring (11) and a steel ball (12). The steel ball (12) is mounted on the spring (11) and at any point of time is disposed on at least one detent location. The other end of the spring (11) is provided on a recess provided on a carrier (10). The carrier (10) is a part of moving contact carrier assembly.
The moving contact (14) is provided at the base of the carrier (10). The moving contact (14) is provided on a copper strip with a plurality of arms wherein the plurality of arms is provided with a leaf spring so as to maintain uniform contact pressure with one or
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more fixed contacts (15). The one or more fixed contact (15) is provided on a PCB in the bottom cover (16). Alternatively, instead of providing fixed contact (15) on the PCB, copper contacts can be insert molded within the base cover. Also, instead of moving contact (14) being provided on a copper strip with a leaf spring, copper contacts can be insert molded on the base of the carrier (10). In one embodiment, the moving contact (14) and the fixed contact (15) form a butt contact upon coming in contact with each other. Also, as it can be inferred from the figure that the carrier (10), the moving contact (14) and the fixed contact (15) corresponding to the moving contact (14) are located around a circle of predetermined radius. A wire seal (17) for carrying wires out of the blinker switch is provided in the base cover (16) to allow wires to be withdrawn there through. Alternatively, instead of providing wire seal (17) for sealing, insert molding of wire or terminal to be preferably done.
The top chamber and the bottom chamber are separated by a separation wall. A circular opening is provided within the separation wall. The carrier (10) in the moving contact carrier assembly comprises of a hollow cylindrical protrusion at its top surface. This hollow cylindrical protrusion protrudes out of the circular opening provided in the separation wall. An area left between the hollow cylindrical protrusion and the perimeter of the circular opening is securely sealed by a circular insert (7). The insert (7) is made up of steel so as to have finished circular configuration. On the other hand, the insert (7) may not be needed in cases in which a finished circular configuration of the circular opening can be obtained in plastic. A rotary seal (8) is provided between inner surface of insert (7) and outer surface of hollow cylindrical protrusion provided on top surface of the carrier (10). Also, a wave washer (9) is provided on inside of the bottom portion of the bracket (6) to minimize play, damping the vibration.
The carrier cam (13) is at least provided with at least one hook which engages with the hollow cylindrical protrusion provided in the carrier (10). This at least one hook is permanently welded to the hollow cylindrical protrusion. The welding used can be
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ultrasonic welding. Alternatively, the hook may be permanently snap fitted to the hollow cylindrical protrusion. As it is evident the carrier cam (13) is provided in the top chamber.
The blinker switch is perfectly sealed. More particularly, the top cover (1) and the bottom cover (16) are securely fitted on to the said bracket (6). In one embodiment, the top and the bottom cover (16) are snap fitted onto the bracket (6). Alternatively, the top and the bottom cover (16) are ultrasonically welded onto the bracket (6). If however any water droplets or dust enters top portion of the bracket (6), the same is drained through at least one drain hole present in the separation wall, thus eliminating any chance of water or dust entering the bottom chamber of the switch where the moving and the fixed contacts (15) are located.
In order to switch ON either left or right blinker of the vehicle the rider of the vehicle presses the knob (18) radially in either left or right direction. This moves lever support (2) in the opposite direction and activates the auto-cancellation means. The auto-cancellation means which comprises of the cam follower moves against the V-shaped cam profile of the cam plate. The auto-cancellation mechanism helps in self returning of knob (18) along with lever support (2) and operating lever (3) to center position every time it is pressed. The movement of cam follower over the cam plate moves the cylindrical engagement element disposed in the carrier cam (13), thus moving the carrier cam (13). The carrier cam (13) further transfers this motion to the moving contact carrier assembly. This motion transfer happens via at least one hook which is fitted in the hollow cylindrical protrusion provided in the carrier (10). It is to be further noted that carrier cam (13) transfer the linear motion of lever assembly to bi-directional circular motion of the moving contact carrier assembly. The moving contacts (14) comprised within the moving contact carrier assembly move and come in contact with the corresponding fixed contact (15) thereby completing the circuit and causing the flow of conduction current between the moving and fixed contacts (15). The conduction
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current is supplied as a trigger signal to the electromechanical relay circuit which enables either of left or right blinkers to emit light based on the direction in which the knob (18) is pressed. In order to stop the flow of current and to break the contact, the knob (18) is pressed linearly so as to bring the carrier cam (13) to rest at a center position. The carrier cam (13) is brought to the center position by means of the auto cancellation means. Also, the motion is transferred to the steel ball (12) mounted on the spring (11) which moves from one detent location to another provided in the detent profile in the bottom chamber. When the knob (18) is at the center position, the moving contact (14) in the carrier (10) does not overlap with any of the fixed contacts (15), thus bringing the blinker switch to an off state.
Thus, it can be inferred from figure 5 and the above description that the blinker switch provides effective sealing to the contacts, prevents corrosion of contacts and deposition of dust and mud on the contact rivet and base sliding surface.
ADVANTAGES OF PRESENT INVENTION
• The blinker switch assembly is constructed with less number of parts and components with less weight.
• Design of the bracket of the blinker switch assembly enables complete sealing of contacts thus protecting components from entry of water and dust particles.
• Leaf spring provided in the moving contact enables to maintain uniform contact pressure.
• Use of plastic cam plate eliminates metal to metal friction, thereby avoiding rusting and formation of corrosive environment.
• Eliminating the use of flange headed self tapping screw by sandwiching the lever assembly between the bracket and the cover also avoids metal friction.
• Enhanced life cycle and reliability of the switch assembly.
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The foregoing detailed description has described only a few of the many possible implementations of the present invention. Thus, the detailed description is given only by way of illustration and nothing contained in this section should be construed to limit the scope of the invention.
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WE CLAIM:
1. A blinker switch assembly, comprising:
a bracket (6), a top cover (1) and a bottom cover (16) cooperating with each other to define a top chamber and a bottom chamber,
a lever assembly traversing through the top chamber and exhibiting pivotal movement upon actuation;
one or more fixed contacts (15) provided inside the bottom chamber;
a moving contact carrier assembly comprising one or more moving contacts (14), said moving contact carrier assembly being locatable inside the bottom chamber and being configured to exhibit bi-directional rotational movement around a vertical axis so as to selectively bring the said one or more fixed contacts (15) in contact with the said one or more moving contacts (14); and
a carrier cam (13) cooperating with the lever assembly and the moving contact carrier assembly for translating the pivotal movement of the lever assembly into bi-directional rotational movement of the moving contact carrier assembly.
2. The switch assembly as claimed in claim 1, wherein an auto-cancellation means is provided in the top chamber to achieve the function of auto-cancellation, said auto cancellation means comprising a cam plate and a cam follower, wherein said cam plate is integrally mounted in the top chamber and is a V-shape cam.
3. The switch assembly as claimed in claim 2, wherein the cam follower comprises of a spring (4) mounted with a steel ball (5), said steel ball (5) is constantly in contact with the cam plate.
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4. The switch assembly as claimed in claim 1, wherein the lever assembly comprises of a lever support (2) and an operating lever (3) mounted on the said lever support (2).
5. The switch assembly as claimed in claim 1, wherein a pivot element is provided at a predetermined location on the lever assembly.
6. The switch assembly as claimed in claim 4, wherein the lever support (2) comprises of a cylindrical engagement element disposed to engage with a cavity provided in the said carrier cam (13).
7. The switch assembly as claimed in claim 1, wherein a knob (18) is provided at an end of the lever assembly traversing out of the top chamber.
8. The switch assembly as claimed in claim 1, wherein the top cover (1) is securely fitted onto the said bracket (6) either by snap fitting or by ultrasonic welding.
9. The switch assembly as claimed in claim 1, wherein a ball detent mechanical arrangement is provided in the bottom chamber, said ball detent mechanical arrangement comprises of a detent profile and a spring (11) mounted with a steel ball (12).
10. The switch assembly as claimed in claim 9, wherein the detent profile is provided on a inside wall of the bottom chamber, said profile comprises of plurality of detent locations.
11. The switch assembly as claimed in claim 9, wherein the spring (11) mounted with a steel ball (12) is disposed onto one detent location at a given time, said spring (11) located in a recess provided in the said moving contact carrier assembly.
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12. The switch assembly as claimed in claim 1, wherein moving contact carrier assembly comprises of a carrier (10).
13. The switch assembly as claimed in claim 1, wherein the moving contact (14), the fixed contact (15) corresponding to said moving contact (14) and the carrier (10) are located around a circle of predetermined radius.
14. The switch assembly as claimed in claim 1, wherein the moving contact (14) is provided with an inbuilt leaf spring.
15. The switch assembly as claimed in claim 1, wherein the fixed contact (15) is formed on a PCB, said PCB is provided in the bottom cover (16).
16. The switch assembly as claimed in claim 1, wherein a circular opening is provided in a separation wall, said separation wall separating the top chamber and the bottom chamber.
17. The switch assembly as claimed in claim 12, wherein the carrier (10) comprises of a hollow cylindrical portion at its top surface, said hollow cylindrical portion protrudes out of the circular opening in the separation wall.
18. The switch assembly as claimed in claim 1, wherein at least one hook is provide in the carrier cam (13), said hook engages with the hollow cylindrical protrusion provided in the said carrier (10).
19. The switch assembly as claimed in claim 1, wherein the carrier cam (13) is provided in the top chamber.
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20. The switch assembly as claimed in claim 1, wherein the bottom cover (16) is
securely fitted onto the bracket (6) either by snap fitting or ultrasonic welding.
21. The switch assembly substantially as herein described with reference to the
foregoing description and accompanying drawings.