DESC:
Field of invention

The present invention relates to a steering-mode switch, particularly the present invention relates to a steering mode switch assembly for selecting steering-modes for an earth moving vehicle.

Background of invention

Steering-mode switches are provided in the existing vehicle for selecting steering mode for appropriate steering of front and rear wheels of the vehicles. The existing steering mode switch includes a knob which can be rotated normally in three different positions. Such switches are provided with an operating mechanism which allows immediate and appropriate steering of the wheels when the steering arm or steering wheel of the vehicle is rotated corresponding to the steering mode selected by the switch. However, if steering mode switch is operated accidentally then the same may result in undesired or wrong steering mode for wheels’ steering; and if the vehicle is operated with this undesired or wrong steering mode, the same may be hazardous to the surroundings. For example, if the vehicle is parked or stationed near a wall and the steering mode switch is accidentally operated to a undesired or wrong steering mode, the vehicle may damage the wall upon rotation of the steering wheel of the vehicle.

Summary of the Invention

Accordingly, the present invention provides a steering mode switch assembly for an earth moving vehicle. The steering mode switch assembly of the present invention comprises a knob, a base, a housing and a shaft. The knob comprises a cavity to accommodate a fastener and rotatable between plurality of positions defining steering modes. The housing comprises a neck portion and a detent profile provided with plurality of grooves corresponding to steering modes, formed on inner surface of the housing. The present switch assembly comprises a detent cover comprising a key way profile, accommodated in the housing. The shaft comprises a first end portion, a second end portion, a middle portion and a collar disposed at predefined locations on the shaft. The first end portion provided with a cavity to accommodate a fastener for fastening the shaft with the knob; the middle portion comprising a bore accommodating spring loaded balls being disposed between the first end portion and the second end portion of the shaft; the collar disposed between the middle portion and the first end portion. A plurality of keys being disposed on the shaft between the middle portion and the second end portion, which are engageable with the key way profile formed in the detent cover.

The shaft is moveable in a longitudinal direction in the housing between the detent cover and the neck portion of the housing. Upon pulling the knob away from the housing, the shaft moves in a direction away from the detent cover thereby disengaging the keys on the shaft from the key-way profile formed on the detent cover.

A magnet holder accommodating a magnet, being disposed between the second end portion and the base; the magnet holder is coupled with the shaft so that the magnet rotates upon rotation of the shaft by the knob.

Brief Description of Drawings

Further aspects and advantages of the present invention will be readily understood from the following detailed description with reference to the accompanying figures.

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 an exploded view of the steering mode switch assembly according to an embodiment of the present invention.
Figure 2 illustrates a sectional view of the switch assembly according to an embodiment of the present invention.
Figure 3 illustrates knob assembly and an exploded view of the knob assembly according to an embodiment of the present invention.
Figure 4 shows a sectional view of the knob assembly and shaft according to an embodiment of the present invention.
Figure 5 shows detent profile formed in the housing of the steering mode switch assembly according to an embodiment of the present invention.
Figure 6 shows a detent cover illustrating keyway profile according to an embodiment of the present invention.
Figure 7 illustrates positions of the knob assembly (a) before lifting of knob and (b) after lifting of knob according to an embodiment of the present invention.
Figure 8 (a)-(c) illustrate different steering modes of the steering mode switch assembly according to an embodiment of the present invention.

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.

Detail Description of Present Invention

Accordingly, it is an aim of the present invention to provide a steering-mode switch assembly which overcomes at least one of the above problems associate with the existing switches.

While the invention is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the figures 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 as defined by the appended claims.

Before describing in detail embodiments it may be observed that the novelty and inventive step that are in accordance with the present invention resides in steering-mode switch assembly for an earth moving vehicle. It is to be noted that a person skilled in the art can be motivated from the present invention and modify the various constructions of assembly. However, such modification should be construed within the scope and spirit of the invention.

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 elements in the system or apparatus. The following paragraphs explain present invention wherein a steering-mode switch assembly for an earth moving vehicle. The invention in respect of the same may be deduced accordingly.

Accordingly, the present invention provides a steering mode switch assembly for an earth moving vehicle comprising,
a knob having a cavity to accommodate a fastener and rotatable between plurality of positions defining steering modes;
a base;
a housing comprises:
a neck portion,
a detent profile provided with plurality of grooves corresponding to steering modes, formed on inner surface of the housing,;
a detent cover comprising a key way profile, accommodated in the housing;
a shaft comprises
a first end portion, a second end portion, a middle portion and a collar disposed at a predefined locations on the shaft; the first end portion provided with a cavity to accommodate a fastener for fastening the shaft with the knob; the middle portion comprising a bore accommodating spring loaded balls being disposed between the first end portion and the second end portion of the shaft; the collar disposed between the middle portion and the first end portion;
Plurality of keys being disposed between the middle portion and the second end portion, which are engageable with the key way profile formed in the detent cover;
the shaft is moveable in a longitudinal direction in the housing between the detent cover and the neck portion of the housing; wherein upon pulling the knob away from the housing, moves the shaft in a direction away from the detent cover thereby disengaging the keys on the shaft from the key-way profile formed on the detent cover.
A magnet holder accommodating a magnet, being disposed between the second end portion and the base; the magnet holder is coupled with the shaft so that the magnet rotates upon rotation of the shaft by the knob.

In an embodiment of the present invention the detent profile is provided with plurality of V-shape grooves for supporting the spring loaded balls with respect to each steering mode positions.

In another embodiment of the present invention the spring loaded balls provided in the bore are projected in lateral direction and supported on the grooves of the detent profile at plurality of positions.

In still another embodiment of the present invention the collar is provided with a washer for abutting with the neck portion to restrict the further movement of the shaft, at the neck portion of the housing, away from the detent cover.

In yet another embodiment of the present invention the detent cover has a circular shape and has a variable thickness with increasing thickness in radial direction away from centre of the circular shape.

In a further embodiment of the present invention the keyway profile formed on the detent cover comprises key-way grooves sized to receive the keys formed on the shaft to provide locking to the rotational movement of the shaft.

In a further more embodiment of the present invention the detent cover is provided with convex projections formed on abutting surfaces of the keyway profile.

In another embodiment of the present invention the housing comprises a horizontal board disposed in the housing above the base and PCB with Hall sensor unit mounted on the horizontal board facing the magnet of magnet holder.

In still another embodiment of the present invention the magnet is an Arc type sector magnet.

In yet another embodiment of the present invention the Hall sensor unit comprises two Hall sensors mounted on the horizontal board adjacent to each other which produces redundant (cross-over) output to observe more fail safe operation.

In a further embodiment of the present invention a chamfer is included at the root of the key provided on the shaft to avoid the rattling noise of shaft during the vibration conditions.

In a further more embodiment of the present invention a cup seal provided inside the neck portion of the housing and around the circumference of the shaft to create a seal against dust and water.

In another embodiment of the present invention knob is sealed after assembly of knob and shaft by means of a cover and suitable adhesive tape.

In yet another embodiment of the present invention the housing comprising:
an annular flange extending laterally outwardly from the housing; the flange comprises:
a top surface facing towards the knob and contiguous with the neck portion;
bottom surface opposite to the top surface and facing towards the base; and
side surface contiguous with the top surface and bottom surface.

In one more embodiment of the present invention the housing is provided with a sealing arrangement to provide sealing against the ingress of water and dirt; the sealing arrangement comprises:
a membrane being provided around the neck portion of the housing and extends over the top, bottom and side surfaces of the flange of the housing; and
an annular groove formed at the bottom surface of the flange for securing the membrane.

Accordingly, the present invention provides a steering-mode switch assembly for an earth moving vehicle. The switch assembly of the present invention has pull to rotate mechanism. The present switch assembly comprises knob, a shaft, housing, detent cover, base etc. according to an embodiment of the present invention.

The following paragraphs describes the present invention with reference to Figures 1-8

Referring to Figure 1, the steering mode switch assembly (1) comprising a housing (2) and a base (3) forming an encapsulation for the various parts or components of the switch assembly such as a shaft (5a), PCB assembly, LED, detent cover (15), sensors, magnet and magnet holder (17).

Referring to Figures 1 and 2, the housing (2) comprises an interior and an exterior. The housing (2) is provided with a neck portion (4). The neck portion (4) comprises annular flange section (4a) extending radially inwardly from an inner surface of the housing (2) formed on inner surface at the interior of the housing (2), and a hollow cylindrical section (4b) extending in longitudinal direction from edge of the flange section (4a) towards base (3) of the housing (2). The term ‘longitudinal direction’ herein refers to a direction along or parallel to axis of the shaft. It can be observed that cylindrical section (4b) and the shaft (5a) are coaxial i.e. share the same common axis. The shaft (5a) may be received in the cylindrical section (4b) and can be accessed via an opening (4c) provided on the neck portion (4). As can be observed from figure 2, the neck portion (4) also projects at exterior of the housing (2) and the said projection of neck portion (4) may be used for assembling a knob assembly (6).

Referring to figure 3, a knob assembly (6) comprises the knob (6a) having an opening on top surface and a circular cover (6b) to close the said top opening in knob (6a). The knob assembly (6) comprises a cylindrical over molding which encapsulates an insert forming the knob (6a). Inner portion of the knob (6a) is provided with a cavity so as to hold an end of shaft therein. The fastener (6c) is inserted through the opening provided on the top surface of the knob (6a). The shaft (5a) is assembled with the knob (6a) with the help of fastener(s) (6c). The shaft (5a) is assembled in such a way that the shaft (5a) is rotatable and reciprocatable with respect to the housing (2). The opening of the knob (6a) can be sealed after assembly of knob (6a) and shaft (5a) by the circular cover (6b) by means of suitable adhesive material (6d) or tape as shown in Figure 4.

Referring to figure 4, the shaft assembly comprises a shaft (5), a main spring (29), an auxiliary spring (7), and balls (8, 9) according to an embodiment of the present invention. The shaft (5a) is having a first end portion (5a), second end portion (5b) and a middle portion (5d). The knob (6a) is provided with a cavity centrally disposed at top surface and have predefined length extending in longitudinal direction and away from the top surface of the knob (6a) and the said cavity is provided to accommodate the first end portion (5a) of the shaft (5). The first end portion (5a) of the shaft (5) is provided with a recess (5c) extending in longitudinal direction to accommodate the fastener (6c) inserted through the cavity provided on the top of the knob (6a) for fastening the shaft (5) with the knob (6a). The shaft (5) comprises a first section (5d) which is defined between first end portion (5a) and the middle portion (5e). The main spring (29) is disposed surrounding the first section (5d) which energizes or de-energizes when the shaft (5) is pulled or released via the knob (6a). The shaft (5) comprises a second section (5f) which is defined between the middle portion (5e) and the second end portion (5b). The second section (5f) of the shaft (5) is provided with plurality of keys (10) (wherein the keys (10) having predetermined length extending in longitudinal direction over the second section (5f). The keys (10) having a dimension protruding radially and outwardly from the surface shaft (5). The edges of keys (10) may be chamfered or rounded.

Referring to Figures 2-4, the middle portion (5e) of the shaft (5) is disposed between the first section (5a) and the second section (5f). The middle portion (5e) is provided with a bore (11) extending in lateral direction. The term ‘lateral direction’ herein refers to a direction perpendicular to the longitudinal direction. In other words, the bore (11) having an axis perpendicular to the axis of the shaft (5). The bore (11) provided at the middle portion (5e) of the shaft (5) accommodates metallic balls (9, 8) and the auxiliary spring (7).

Referring to Figure 2 and Figure 5, a detent profile (12) is provided on the inner surface of the housing (2). The spring loaded balls (8, 9) accommodated in the bore (11) in the middle portion (5e) are supported on the detent profile (12). The detent profile (12) is formed in such a way that the shaft (5) is rotatable with the spring loaded balls (8, 9) supported on the detent profile (12). The detent profile (12) is provided with plurality of grooves defining rotational positions of the shaft (5). In other words, the shaft (5) is rotatable between plurality of positions defined by the grooves on the detent profile (12). These positions of the shaft (5) are corresponding to different steering modes. The grooves are preferable V shape groove. The detent profile (12) is formed on the inner surface of the housing (2) over a predetermined length so that the spring loaded balls (8, 9) are supported on the detent profile (12) uniformly for all the displacement of the shaft (5) in the longitudinal direction.

Referring to Figure 2-4, the shaft (5) is provided with a collar (13) disposed between the first end portion (5a) and middle portion (5e) of the shaft (5). The collar (13) is an extended diameter portion which may be formed adjacent and bordering to the middle portion (5e). Further, the diameter of the collar (13) is larger than the diameter of the first section (5d) of the shaft (5). The diameter of the collar (13) may be lesser than the lateral extension (14a, 14b) of the middle portion (5e) of the shaft (5). The diameter of the shaft (5) at first section (5d) and second section (5f) may be lesser than the lateral extension (14a, 14b) of the middle portion (5e) of the shaft (5).

Referring to Figures 1, 2, 6a and 6b, a detent cover (15) is accommodated in the housing (2). The detent cover (15) comprises a key-way profile (16) for accommodating the keys (10) of the shaft (5) at predefined positions. The key way profile (16) comprises keyways (16a) for receiving the keys (10) formed on the shaft (5). Thus the keys (10) on the shaft (5) are engageable with the keyway profile (16) formed in the detent cover (15). The detent cover (15) is rigidly secured in the housing (2) and therefore, when the keys (10) are engaged in the keyways (16a) formed in the detent cover (15), the rotation of the shaft (5) is restricted. In an embodiment, the keyways (16a) in the detent cover (15) are formed so as to receive the shaft (5) at plurality of positions of the shaft (5) which are corresponding to the steering modes. In other words, the keys (10) are received in the keyways (16a) so as to lock the rotation of the shaft (5) at different steering mode positions of the shaft assembly.

Referring to Figures 2 and 6, the shaft (5) is moveable in longitudinal direction by pulling the knob (6a) outwardly in longitudinal direction away from the housing (2). This movement of the shaft (5)results into disengagement of the keys (10) from the keyways (16a) formed on the detent cover (15) thereby allowing rotation of the knob (6a) and the shaft (5) to a particular steering mode position. As soon as the knob (6a) is released from the pulled position, the knob (6a) and the shaft (5) moves in longitudinal direction, under the force of main spring (29), towards the detent cover (15) and the keys (10) of the shaft (5) engages back with the keyways (16a) on the detent cover (15). During movement of the shaft (5) in the longitudinal direction towards the detent cover (15), ends the keys (10) of the shaft (5) may abut with top surfaces of keyway profile (16). To avoid this, the detent cover (15) may be provided with convex projections formed on abutting surfaces of the keyway profile (16) as shown in Detail A of Figure 6a. Also, the ends of the keys (10) may be rounded or chamfered so that when the ends of the keys (10) abut with the convex projections of the keyway profile (16), the keys (10) will tend to move towards the keyways (16a) ensuring engagement of the keys (10) with the keyways (16a). Chamfering may be provided at root of the keys (10) provided on the shaft (5) to avoid the rattling noise of shaft (5) during the vibration conditions.

Referring to Figure 6a, the detent cover (15) is a circular shaped plate having keyway profile (16) formed about center of the plate for receiving the keys (10) provided on the shaft (5). The detent cover (15) has a variable thickness with decreasing thickness in radially outwardly direction from center of the detent cover (15). The detent cover (15) may be provided with holes (15a, 15b) located at diagonally opposed positions for mounting the detent cover (15) with the housing (2).

Referring to Figures 1 and 2, the switch assembly of the present invention comprises a magnet holder (17) accommodating a magnet. The magnet holder (17) is mounted by using a clamp (18) in the housing (2). The magnet holder (17) is coupled with the second end portion (5b) of the shaft (5) so that the magnet holder (17) is rotatable with the shaft (5). The second end portion (5b) is movably inserted into the base (3). A magnet holder (17) is also disposed between second end portion (5b) and the base (3) in such a way that when the shaft (5) rotates, the magnet holder (17) will also rotate. The magnet holder (17) may be provided with an Arc type sector type magnet.

A horizontal board (19) may be disposed in the housing (2) such that axis of the shaft (5) is perpendicular to surface of the horizontal board (19). The horizontal board (19) may be provided with a hole for projecting there through the second section (5d) of the shaft (5). A PCB assembly (20) comprising Hall sensor unit may be mounted on a surface of the horizontal board (19) facing towards the magnet mounted on the magnet holder (17). The PCB assembly (20) may be accommodated in a PCB cover. The Hall sensor unit is configured to sense or detect a change in magnetic flux upon rotation of the shaft (5) to predefined rotational positions and provide signals to a vehicle’s controlling unit to activate the steering modes. In an embodiment, the Hall sensor unit comprises two Hall ICs configured to sense or detect the change in magnetic flux upon rotation of the shaft (5) to predefined rotational positions. Two Hall IC to produce redundant (cross-over) output to observe more fail safe operation.

In an embodiment, the housing is provided with plurality of apertures for fitment of various elements such as reflector (21) and lens (22). These apertures may be covered by a membrane (23) which is provided on external surface at exterior of the housing (2) after fitment of said various elements. The membrane (23) may be provided with plurality transparent or translucent portions for emanating the illumination of LEDs.
A LED PCB assembly (20a) may be mounted in the housing.

A plurality of illumination symbols may be formed for indicating different steering modes. A gasket (24) is disposed between the housing (2) and the base (3) for providing sealing.

In an embodiment, the steering-mode switch assembly comprises with plurality of sealing arrangement or portions.

Referring to Figure 2, a first sealing arrangement may be provided to seal the housing (2) from top i.e. to avoid entry of water or contamination from the knob (6a) side. The first sealing arrangement may be provide by the membrane (23) provided on external surface at the exterior of the housing (2). The housing (2) may be provided with an annular flange (2a) extending laterally outwardly from the housing (2). The flange (2a) comprises a top surface (2b), bottom surface (2c) and side surface (2d) contiguous with the top surface (2b) and bottom surface (2c). The top surface (2b) ( is facing towards the knob (6a) and contiguous with the neck portion (4) and the bottom surface (2c) is opposite to the top surface (2b) and facing towards the base (3). As shown in Figure 2, the membrane (23) is provided around the neck portion (4) of the housing (2) and extends over the top surface (2b), bottom surface (2c) and side surfaces (2d) of the flange (2a) of the housing (2). The bottom surface (2c) of the flange (2a) may be provided with an annular groove (25) for securing the membrane (23) to provide sealing against the ingress of dust, dirt and water from top. The membrane (23) may be made of any suitable polymeric materials which is preferably temperature and pressure resistant.

A second sealing arrangement is provided between the base (3) and the housing (2). The second sealing arrangement is formed by an annular seal or gasket (24). The second sealing arrangement prevents ingress of water and dust in the housing (2) from bottom. The annular seal or gasket (24) may be made of any suitable polymeric (Elastomeric) materials which is preferably temperature, pressure and chemical resistant.

A third sealing arrangement is provided between the neck portion (4) of the housing (2) and the shaft (5). The second arrangement may be provided by a cup seal (26) disposed in the opening of the neck portion (4) of the housing (2) and the cup seal (26) may be supported on the flange section (2a) of the neck portion (26). The opening of the neck portion (4) may be covered by a threaded cap (27). The threaded cap (27) may be provided with a hole for projecting there through the shaft’s end portion. The cup seal (26) is mounted in the opening so that cup seal (26) remains stationary when the shaft (5) rotates or moves in longitudinal direction. The cup seal (26) provides sealing of the housing (2) from the top and prevents ingress of water and dust in the housing (2) from the top. The cup seal (26) may be made of any suitable polymeric materials which is preferably temperature, chemical and pressure resistant.

The sealing arrangements together prevents the switch assembly from foreign contaminants as well prevent from other adverse condition such as high heat and high pressure.

Referring to Figures 1-8, the user pulls the knob (6a) outwardly when the steering mode of the wheel is required to be changed. Upon pulling the knob (6a), the shaft (5) assembly moves outwardly. This movement causes the keys (10) to move out from the key-way profile (16) so as to unlock the shaft assembly and allow the rotation of the shaft assembly in user’s desired direction. During the rotation, the metallic balls (8, 9) which are supported in the bore at the middle portion (5e) of the shaft (5) moves on the detent profile (12). The main spring (29) compresses as the shaft assembly moves outward. The further movement of shaft assembly is being stopped when the collar (13) abuts with end of cylindrical section of the neck portion (4) of the housing (2). The collar (13) may be provided with a washer (28) for abutting with the end of the cylindrical section of the neck portion (4). As the user rotates the knob (6a) in desired direction and release it, the knob assembly falls automatically due to restoration force of main spring (29) and the keys (10) of shaft (5) get locked in the keyway profile (16) provided in the detent cover (15) at predefined position as shown in figure 8 (c). The rotation of shaft (5) assembly also rotates the magnet holder (17) which houses the magnet. The magnet influences the Hall sensor unit mounted on the PCB in order to provide output to the vehicle controller for each position of the steering-mode switch.

Referring to Figures 7 and 8, in an embodiment, the knob of the steering mode switch assembly is rotatable between plurality of positions for example a first position, a second position and a third position indicative of different steering modes as shown in Figure 8(a). Referring to Figure 8(a), the first position of the knob (6a) is indicative of steering mode in which only the front wheels are steerable; the second position of the knob (6a) is indicative of steering mode in which the front and rear wheels are steered in opposite direction; the third position of the knob (6a) is indicative of steering mode in which the front and rear wheels are steered in same direction;

In an embodiment, a mounting clip (30) is provided for fitting the steering mode switch assembly in a panel of thickness ranging from 2.5amm to 3.00mm. The mounting clip (30) constructed to suit this requirement. Also does not allow vibration under the testing conditions and does not allow taking out the switch from panel with a force ranging 100N Minimum. The mounting clip (30) has to be squeezed-in to take out the device from panel. In an embodiment, the steering mode switch assembly is constructed to qualify the IP 69K which is a stringent test for testing a sealing of a device.
,CLAIMS:
1. A steering mode switch assembly for an earth moving vehicle comprising,
a knob having a cavity to accommodate a fastener and rotatable between plurality of positions defining steering modes;
a base;
a housing comprises:
a neck portion,
a detent profile provided with plurality of grooves corresponding to steering modes, formed on inner surface of the housing,;
a detent cover comprising a key way profile, accommodated in the housing;
a shaft comprises
a first end portion, a second end portion, a middle portion and a collar disposed at a predefined locations on the shaft; the first end portion provided with a cavity to accommodate a fastener for fastening the shaft with the knob; the middle portion comprising a bore accommodating spring loaded balls being disposed between the first end portion and the second end portion of the shaft; the collar disposed between the middle portion and the first end portion;
plurality of keys being disposed between the middle portion and the second end portion, which are engageable with the key way profile formed in the detent cover;
the shaft is moveable in a longitudinal and rotary directions in the housing between the detent cover and the neck portion of the housing; wherein upon pulling the knob away from the housing, moves the shaft in a direction away from the detent cover thereby disengaging the keys on the shaft from the key-way profile formed on the detent cover;
a magnet holder accommodating a magnet, being disposed between the second end portion and the base; the magnet holder is coupled with the shaft so that the magnet rotates upon rotation of the shaft by the knob.

2. The assembly as claimed in claim 1, wherein the detent profile is provided with plurality of V shape grooves for supporting the spring loaded balls with respect to each steering mode positions.

3. The assembly as claimed in claim 1, wherein the spring loaded balls provided in the bore are projected in lateral direction and supported on the grooves of the detent profile at plurality of positions.

4. The assembly as claimed in claim 1, wherein the collar is provided with a washer for abutting with the neck portion to restrict the further movement of the shaft, at the neck portion of the housing, away from the detent cover.

5. The assembly as claimed in claim 1, wherein the detent cover has a circular shape and has a variable thickness with increasing thickness in radial direction away from centre of the circular shape.

6. The assembly as claimed in claim 1, wherein the keyway profile formed on the detent cover comprises key-way grooves sized to receive the keys formed on the shaft to provide locking to the rotational movement of the shaft.

7. The assembly as claimed in claim 1, wherein the detent cover is provided with convex projections formed on abutting surfaces of the keyway profile.

8. The assembly as claimed in claim 1, wherein the housing comprises a horizontal board disposed in the housing above the base and PCB with Hall sensor unit mounted on the horizontal board facing the magnet of magnet holder.

9. The assembly as claimed in claim 1, wherein the magnet is a sector magnet.

10. The assembly as claimed in claim 8, wherein the Hall sensor unit comprises two Hall sensors mounted on the horizontal board adjacent to each other which produces redundant (cross-over) output to observe more fail safe operation.

11. The assembly as claimed in claim 1, wherein a chamfer is included at the root of the key provided on the shaft to avoid the rattling noise of shaft during the vibration conditions.

12. The assembly as claimed in claim 1, wherein a cup seal (7) provided inside the neck portion of the housing (9) and around the circumference of the shaft (14) to create a seal against dust and water.

13. The assembly as claimed in claim 1, wherein knob is sealed after assembly of knob and shaft by means of a cover and suitable adhesive tape (4).

14. The assembly as claimed in claim 1, wherein the housing (2) comprising:
an annular flange (2a) extending laterally outwardly from the housing (2); the flange (2a) comprises:
a top surface (2b) facing towards the knob (6a) and contiguous with the neck portion (4);
bottom surface (2c) opposite to the top surface (2b) and facing towards the base (3); and
side surface (2d) contiguous with the top surface (2b) and bottom surface (2c).

15. The assembly as claimed in claim 14, wherein the housing is provided with a sealing arrangement to provide sealing against the ingress of water and dirt; the sealing arrangement comprises:
membrane (23) being provided around the neck portion (4) of the housing (2) and extends over the top (2b), bottom (2c) and side surfaces (2d) of the flange (2a) of the housing (2); and
an annular groove (25) formed at the bottom surface (2c) of the flange (2a) for securing the membrane (23).