Claims:We claim:

1. An assembly (100) for reducing aerodynamic drag on a wheel (1) of a vehicle, the assembly (100) comprising:
a base (3), removably connectable to a rim (2) of the wheel (1), wherein the base (3) is defined with a plurality of openings (3a), each corresponding to at least one air pocket (2a) in the rim (2) of the wheel (1);
a disc (4), including a plurality of vanes (4a), rotatably connected to the base (3), the disc (4) comprises:
a plurality of slots (4b) defined on the disc (4); and
a plurality of spring-loaded guide members (7), each of the plurality of spring-loaded guide members (7) is structured to slidably engage at least one of the plurality of slots (4b) such that each of the plurality of spring-loaded guide members (7) is configured to linearly displace along a corresponding slot of the plurality of slots (4b) based on centrifugal force acting on the bob-mass (7a);
wherein, linear displacement of each of the plurality of spring-loaded guide members (7) along the corresponding slot of the plurality of slots (4b) operates the disc (4) between a first position (FP) and a second position (SP), selectively opening and closing each of the plurality of air pockets (2a) to reduce the aerodynamic drag on the wheel (1).

2. The assembly (100) as claimed in claim 1, wherein the base (3) includes a hub (3b) to accommodate at least a portion of an inner periphery (4c) of the disc (4).

3. The assembly (100) as claimed in claim 1 comprises a closing plate (5) removably attached to the base (3) at an outer periphery (6), wherein the closing plate (5) includes a hub (5c) to accommodate at least a portion of an inner periphery (4c) of the disc (4).

4. The assembly (100) as claimed in claims 1 and 3, wherein each of the plurality of spring-loaded guide members (7) includes:
a bob-mass (7a) slidably disposed in the slot (4b); and
a spring (7b), having a first end, and a second end opposite to the first end, wherein the first end is fixed to the hub (5c) of the closing plate (5) accommodating the inner periphery (4c) of the disc (4), and the second end is loaded against the bob-mass (7a).

5. The assembly (100) as claimed in claim 4, wherein the spring (7b) is structured to displace between a contracted condition and an extended condition based on the centrifugal force acting on the bob-mass (7a).

6. The assembly (100) as claimed in claim 5, wherein:
the contracted condition (CC) of the spring (7b) depends on centrifugal force acting on the bob-mass (7a) corresponding to a vehicle speed lesser than or equal to a first threshold speed of the vehicle defined by a preload in the spring; and
the extended condition (EC) of the spring (7b) depends on the centrifugal force acting on the bob-mass (7a) corresponding to the vehicle speed equal to a second threshold speed of the vehicle;
wherein, the first threshold speed is less than the second threshold speed.

7. The assembly (100) as claimed in claim 1, wherein each of the plurality of vanes (4a) selectively opens and closes each of the plurality of air pockets (2a), during the linear displacement of each of the plurality of spring-loaded guide members (7) along the corresponding slot of the plurality of slots (4b).

8. The assembly (100) as claimed in claim 7, wherein closing of the plurality of air pockets (2a) by the plurality of vanes (4a) of the disc (4) inhibit flow of air around the plurality of air pockets (2a), and opening of the of the plurality of air pockets (2a) by the plurality of vanes (4a) permits flow of air around the plurality of air pockets (2a).

9. The assembly (100) as claimed in claim 3, wherein the closing plate (5) includes a plurality of counter-slots (5b), and each of the plurality of counter-slots (5b) is slidably engaged by one of the plurality of spring-loaded guide members (7).

10. The assembly (100) as claimed in claim 9, wherein engagement of the plurality of spring-loaded guide members (7) with the plurality of counter-slots (5b) permits rotation of the disc (4) relative to the closing plate (5).

11. The assembly (100) as claimed in claim 1, wherein each of the plurality of slots (4b) and each of the plurality of counter-slots (5b) comprise a stopper (7a) configured to limit the movement of the bob-mass (7a) beyond the corresponding slot.

12. A vehicle comprising an assembly (100) for reducing aerodynamic drag on a wheel (1) as claimed in claim 1.

Dated this 30th day of March 2021

GOPINATH A S
IN/PA 1852
OF K&S PARTNERS
AGENT FOR THE APPLICANT

, Description:FORM 2
THE PATENTS ACT, 1970
[39 OF 1970]
&
THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
[See section 10; rule 13]

TITLE: “AN ASSEMBLY FOR REDUCING AERODYNAMIC DRAG ON A WHEEL OF A VEHICLE”

Name and Address of the Applicant: TATA MOTORS LIMITED; Bombay House, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001 Maharashtra, India.

Nationality: IN

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 automobiles. Particularly, but not exclusively, the present disclosure relates to reduction of drag force acting on a wheel of a vehicle. Further, embodiments of the present disclosure disclose an assembly for reducing aerodynamic drag on a wheel of a vehicle, by selectively closing and opening air pockets in the wheel rim.

BACKGROUND OF THE DISCLOSURE

Aerodynamics is one of the important aspects, designers take into consideration while designing external anatomy of vehicles, since aerodynamics influences a number of factors associated with vehicle performance. A terrestrial vehicle is in a continuous state of tug-of-war between aerodynamic forces (particularly drag) and thrust provided by the engine to drive line. Drag force is mostly due to air resistance on minute imperfections present on the outer surface of the vehicle, which causes resistance to vehicle thrust, especially at high moving speeds. To overcome this resisting force, vehicle has to do work or spend energy to the air flow. Drag force acting on a vehicle may also be influenced by vehicle shape, as well as few intrinsic and add-on components on vehicle outer body like hood, windshield, roof-scoops, spoilers, wipers on windshields, door handles, side mirror casings, wheels and so on. While roof-scoops and spoilers are intended to reduce drag and serve as optional add-ons to a vehicle, all the other components are innately present in the vehicle and induce drag force to considerable extents.

Drag force happens to be one of the crucial attributes which impacts fuel consumption of a vehicle. This is because, engine has to burn more fuel (or spend more energy) to propel the vehicle in order to overcome drag force, especially at higher vehicle speeds. Continuous efforts are being made to minimize drag coefficient Cd, which determines the overall drag force in addition to other parameters such as air density, surface area of exposure and square of velocity, all related by the equation: F_D=C_d.1/2.?.A.v^2. From the equation, it is apparent that drag force varies as square of velocity of the vehicle, and varies linearly with drag coefficient, surface area and density. A slight decrease in drag coefficient value may result in immense reduction of drag force, consequently subsiding the fuel consumption. Of all the components, wheels and underside of the vehicle contributes roughly to 25% of overall drag force acting on the vehicle.

Several solutions have been proposed in the past to mitigate the drag force and its effects on different vehicle zones. A conventional approach is to develop more streamlined bodies such as a bluff-body configuration which aligns the vehicle in flow stream to minimize drag. Some OEMs also focus their attention on reducing rolling resistance and inertial mass of the vehicle, in addition to drag reduction, to achieve fuel economy. US Patent No. US9821862B2 discloses use of a plasma-based activation system having actuators provided in the vicinity of each of the wheels. Each actuator creates plasma region adjacent to wheel positions under the vehicle. The plasma regions so created reduce air disturbances across each of the wheels, thereby reducing drag force acting on the wheels. The plasma-based system, however, requires expensive plasma generation arrangement involving electrodes, power supply, dielectric layers and so on, which not only adds to weight of the vehicles, but also adds to overall cost, power consumption and maintenance of the vehicle.

The present disclosure is directed to overcome one or more limitations stated above or other such limitations associated with the prior arts.

SUMMARY OF THE DISCLOSURE

One or more shortcomings of conventional systems are overcome, and additional advantages are provided through the system as claimed in 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 as a part of the claimed disclosure.

In one non-limiting embodiment of the disclosure, an assembly for reducing aerodynamic drag on a wheel of a vehicle is disclosed. The assembly includes a base removably connectable to a rim of the wheel. The base is defined with a plurality of openings, each corresponding to at least one air pocket in the rim of the wheel. Further, a disc including a plurality of vanes is rotatably connected to the base. The disc further includes a plurality of slots defined on the disc, and a plurality of spring-loaded guide members. Each of the plurality of spring-loaded guide members is structured to slidably engage at least one of the plurality of slots, such that each of the plurality of spring-loaded guide members is configured to linearly displace along a corresponding slot of the plurality of slots based on centrifugal force acting on the wheel. The linear displacement of each of the plurality of spring-loaded guide members along the corresponding slot of the plurality of slots operates the disc between a first position and a second position, selectively opening and closing each of the plurality of air pockets to reduce the aerodynamic drag on the wheel.

In an embodiment of the disclosure, the base includes a hub to accommodate an inner periphery of the disc. Each of the plurality of spring-loaded guide members includes a bob-mass slidably disposed in the slot, and a spring, having a first end, and a second end opposite to the first end. The first end is fixed to a hub of the closing plate accommodating the inner periphery of the disc, and the second end is loaded against the bob-mass.

In an embodiment of the disclosure, each of the plurality of vanes selectively opens and closes each of the plurality of air pockets, during the linear displacement of each of the plurality of spring-loaded guide members along the corresponding slot of the plurality of slots. Further, closing of the plurality of air pockets by the plurality of vanes of the disc inhibit flow of air around the plurality of air pockets, and opening of the of the plurality of air pockets by the plurality of vanes permits flow of air around the plurality of air pockets.

In an embodiment of the disclosure, the system comprises a closing plate removably attached to the base at an outer periphery. The closing plate includes a plurality of counter-slots, and each of the plurality of counter-slots is slidably engaged by one of the plurality of spring-loaded guide members. Further, engagement of the plurality of spring-loaded guide members with the plurality of counter-slots permits rotation of the disc relative to the closing plate.

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 ACCOMPANYING DRAWINGS

The novel features and characteristics of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a mode of use, further objectives, and advantages thereof, will be best understood by reference to the following detailed description of an 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:

FIG. 1A illustrates front view of a wheel having an assembly to reduce aerodynamic drag, in accordance with an embodiment of the present disclosure;

FIG. 1B is a sectional view of the wheel along section A-A illustrating the assembly of FIG. 1A, in accordance with an embodiment of the present disclosure;

FIG. 2 is an exploded view of the assembly to reduce aerodynamic drag, including the base plate, the disc closing vane, and the closing plate, in accordance with an embodiment of the present disclosure,

FIG. 3 illustrates a schematic perspective view of the closing plate of FIG. 2, in accordance with an embodiment of the present disclosure,

FIGS. 4A and 4B illustrate front views of the wheel with the air pockets of the rim in completely opened and completely closed conditions respectively, in accordance with an embodiment of the present disclosure, and

FIGS. 5A-5D illustrate front views of a sequence of linear displacements of the spring-loaded guide members to operate the disc between a first position and a second position, in accordance with 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 systems illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

While the embodiments in the disclosure are subject to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the figures and will be described 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 scope of the disclosure.

It is to be noted that a person skilled in the art would be motivated from the present disclosure and modify various features of the assembly, without departing from the scope of the disclosure. Therefore, such modifications are considered to be part of the disclosure. Accordingly, the drawings show only those specific details that are pertinent to understand the embodiments of the present disclosure, so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skilled in the art having benefit of the description herein. Also, the assembly of the present disclosure may be employed in variety of vehicles such as passenger vehicles, commercial vehicles having different specifications. However, the other components associated with a wheel of the vehicle are not illustrated explicitly in the drawings of the disclosure for the purpose of simplicity.

The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover non-exclusive inclusions, such that an assembly, a method, a system, or a 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 an assembly, a method, a system, or a device. In other words, one or more elements in the assembly or the method or the system or the device proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the assembly or the method or the system or the device.

Embodiments of the present disclosure disclose an apparatus intended to reduce aerodynamic drag force acting on a wheel of a vehicle. Drag force acts on various sections of a vehicle when the vehicle is moving, particularly at high speeds, which may affect fuel economy. One such section which is susceptible to drag (air resistance) is the wheel of a vehicle. The assembly of the present disclosure is intended to address the limitations associated with drag force acting on the wheel of the vehicle. The assembly includes a base having a plurality of openings such that each of the openings may correspond to i.e., align with each of the plurality of air pockets defined in the rim of the wheel. The assembly further includes a disc which may be connected to the base in such a way that the disc may rotate relative to the base. In other words, the disc includes an inner periphery which may be fully or substantially accommodated on a hub portion of the base such that the disc may rotate about the hub of the base. The disc also includes a plurality of vanes, with each vane adapted to close each of the air pockets when the disc is set in rotational motion, which will be explained in detail in impending paragraphs.

The disc attached to the base further includes a plurality of slots defined on a surface facing away from the surface which contacts the base. The slots are defined in such a way that each slot accommodates a spring-loaded guide member, like a spring loaded-bob mass. The spring-loaded guide member may undergo linear displacement based on centrifugal force acting on it. A first end of the spring in the spring-loaded guide member is fixed to a hub of a closing plate, which may secure the inner periphery of the disc. In addition, the spring includes a second end opposite to the first end which is loaded with the bob-mass, so that the bob-mass can slide to undergo linear displacement inside the slot. The spring contracts and extends during the linear displacement of the bob-mass, and thereby assists the bob-mass to have linearly constrained motion relative to the slot depending on the centrifugal force acting on the wheel.

Linear displacement of the spring-loaded guide member in each of the slot also affects rotational movement of the disc between a first position and the second position. The first position of the disc corresponds to a position in which the spokes of the rim adjacent to the air pockets are completely aligned or eclipsed by the vanes, so that the air pockets are in a completely opened condition. On the other hand, the second position of the disc corresponds to a completely closed (or eclipsed) condition of the air pockets by the vanes. Also, the first position of the disc corresponds to a contracted condition of the spring, which in turn corresponds to a vehicle speed lesser than or equal to a first threshold speed. The first threshold speed indicates a speed ranging from vehicle standstill condition to a speed up to which drag force on the wheel is not substantial. Then again, second position of the disc corresponds to an extended condition of the spring, which corresponds to a vehicle speed equal to a second threshold speed. The first threshold speed indicates onset of effect of drag force on wheel, while the second threshold speed indicates a higher drag condition. The contracted and extended conditions of the spring is influenced by the centrifugal force acting on the bob-mass depending on vehicle speed conditions discussed above. In a completely closed condition of the air pockets by the vanes, air flow around and through the air-pockets is inhibited, while in a completely opened or substantially opened condition, air flow around and through the air pockets takes place.

The assembly further includes a closing plate, which may be removably attached to the disc while having positive fixing points along the circumference (outer periphery) and hub center with the base. The disc is sandwiched between the base and the closing plate, and the closing plate is intended to keep the disc in position during operation. In an embodiment, the entire assembly including the base, the disc and the closing plate maybe removably attached to the rim of the wheel. The closing plate includes a plurality of counter-slots which also accommodate a portion of the spring-loaded guide members. In other words, each of the spring-loaded guide members have a common engagement with the counter-slot of the closing plate and the slot of the disc, such that rotational motion of the disc relative to the closing plate is facilitated. Each slot may have a different orientation as that of the counter-slot to assist the rotational motion of the disc relative to the closing plate.

The following paragraphs describe the present disclosure with reference to FIGS.1 to 5. In the figures, the same element or elements which have similar functions are indicated by the same reference signs.

FIG. 1A portrays a wheel (1) of a vehicle including the assembly (100) for reducing aerodynamic drag. The wheel (1) consists of a rim (2) (hidden in FIG. 1A and shown in FIG. 1B) on which the tire (1a) is convened. The rim (2) includes a number of air pockets (2a) which may dissipate heat by convection from inside of the wheel assembly for cooling purposes, especially at low vehicle speeds. For example, heat generated during braking (friction) and by other sub-assemblies within the wheel assembly may be dissipated to the air circulating around the spokes and the air pockets (2a) of the rim (2). The rim (2) is also designed to take up loads during vehicle movement and standstill conditions. It can be seen in FIG. 1A, that the rim (2) is concealed by a closing plate (5), whose purpose is explained later.

Reference is now made to FIG. 1B which is a sectional view along A-A of FIG. 1A. The circulation of air around and through the air pockets (2a) of the rim (2) causes turbulence, especially at high vehicle speeds, which increases aerodynamic drag on the wheel (1). The drag is to be minimized to attain improved fuel efficiency. The sub-assemblies of the assembly (100) disclosed in the present disclosure are directed towards inhibiting circulation of air around and through the air pockets (2a) depending on vehicle speed. The assembly (100), as shown in FG. 1B, includes a base plate (3), which may be removably connectable or mounted or attached to the rim (2) of the wheel (1). The base plate (3) includes first set of holes (3c) which align with corresponding second set of holes (5d) (shown in FIG. 2) defined in a closing plate (5) of the assembly (100). Securing members (8) may be used to the secure assembly (100) to the rim (2), with the securing members (8) being inserted through the second set of holes (5d) and then through first set of holes (3c) into the rim (2), as shown in FIG. 1B. In an embodiment, the securing members (8) are wheel bolts, used for fixing the wheel (1) to the wheel hub.

Further, an outer periphery of the base (3) may be secured to a corresponding outer periphery of the closing plate (5) via elements (6). This results in both the base (3) and the closing plate (5) to remain fixed (no displacement) relative to each other, and also with respect to the rim (2) during operation. In alternate terms, the base (3) and the closing plate (5) rotate in unison with the rim (2) of the wheel (1). In an embodiment, the securing members (8) and the elements (6) include, but not limited to fasteners like bolts and screws, or clamps, or any other components used for securing purposes. In an embodiment, one or more elements (6) may be used to directly secure the assembly (100) to the wheel rim (2), instead of the securing member (8). Further, mechanical elements like clamps, brackets, and so on may be used to attach the base (3), and the assembly (100) as a whole, to the rim (2). Further, as shown, the base (3) includes a plurality of openings (3a) such that each of the openings (3a) may align with each of the plurality of air pockets (2a) defined in the rim (2) of the wheel (1). This is brought about by attachment of the base (3) with the rim (2) through the securing members (8) as discussed above. The base (3) also assists in firmly securing the assembly (100) to the rim (2) of the wheel (1) during wheel (1) rotation, and keeps the assembly (100) in an appropriate orientation relative to the rim (2). The base (3) may also include a hub (3b) (shown in FIG. 2) for securing a disc (4) of the assembly (100). The assembly (100) further includes a disc (4) which may be sandwiched between the base (3) and the closing plate (5), such that that the disc (4) may rotate in between the base (3) and the closing plate (5). The disc (4) includes an inner periphery (4c), which may be accommodated on the hub (3b) portion of the base (3). The disc (4) also includes a plurality of vanes (4a), with each vane (4a) adapted to selectively open or close each of the air pockets (2a) when the disc (4) is set in rotational motion. A spring-loaded guide member (7) may be provided in in slots formed on surfaces of both disc (4) and the closing plate (5). In an alternate embodiment of the present disclosure, the assembly (100) may include only the disc (4) and the closing plate (5) without the base (3), such that the closing plate (5) may be removably attached to the wheel rim (2) via the disc (4). In such a case, the disc (4) remains between the rim (2) and the closing plate (5), and selectively opens and closes the air-pockets (2a) of the rim (2).

FIG. 2 is an exemplary embodiment which shows exploded view of the assembly (100) without the spring-loaded guide member (7), securing members (8) and elements (6). As shown, the base (3) and the closing plate (5) may always have same orientation i.e., an opening (3a) of the base (3) may always coincide or align with a corresponding opening (5a) in the closing plate (5). The provision (6a) in the closing plate (5) through which the elements (6) are inserted to secure the base (3) may also be seen.

The disc (4) includes a plurality of slots (4b), each defined on at least one of the plurality of vanes (4). The plurality of slots (4b) are defined on a face (DS), which contacts the closing plate (5). The slots (4b) are defined in such a way that each slot accommodates a spring-loaded guide member (7), like a spring loaded-bob mass (7a). The spring-loaded guide member (7) may undergo linear displacement in the slot (4b) depending on the magnitude of centrifugal force acting on the wheel (1). The linear displacement is brought about by displacement (deformation) of the spring (7b) carrying the bob-mass (7a). The bob-mass (7a), in the slot (4b) experiences centrifugal force, and owing to its constraints within the slot (4b), will have only a linear (reciprocating) motion. The influence of centrifugal force on the bob-mass (7a) combined with elastic (resilient) nature of the spring (7b) facilitates the spring (7b) to stretch to an extended condition (EC), and reversibly come back to a contracted condition (CC). A plurality of counter-slots (5b) corresponding to the slots (4b) of the disc (4) are provided on a surface (CPS) (shown in FIG. 3) of the closing plate (5) which contacts the face (DS) of the disc (4). Further, the central opening (4d) which sits on the hub (3b) of the base (3) allows the disc (4) to freely rotate on the hub (3b) while sandwiched in between the disc (3) and the closing plate (5).

Reference is now made to FIG. 3, which illustrates the closing plate (5) with the surface (DPS) containing counter-slots (5b) to accommodate plurality of spring-loaded guide members (7). In a manner the central opening (4d) of the disc (4) sits on the hub (3b) of the base (3) on one side, the central opening (4d) is accommodated on a hub (5c) of the closing plate (5) on the opposite side. In other words, a portion of central opening (4d) sits on the hub (3b), while the remaining portion of the central opening (4d) sits on the hub (5c). This is apparent from exploded view shown in FIG. 2. This configuration allows the disc (4) to rotate on both hub (3b) and the hub (5c), while the hub (3b) and the hub (5c) remain in contact. The counter-slots (5b) are oriented relative to the slots (4b) such that each of the bob-mass (7a) may simultaneously engage both the slot (4b) and the counter-slot (5b). However, the spring (7b) may reside only in the slot (4b) during that time. In an embodiment, the counter-slot (5b) is angularly oriented relative to the slot (4b) so as to allow simultaneous engagement of the bob-mass with the slot (4b) as well as the counter-slot (5b). Furthermore, the positioning of the springs (7b) in the assembly (100) is such that a first end of the spring (7b) may be fixed to the hub (5c) of the closing plate (5), while the second end which is distal (opposite) to the first end may be loaded with the bob-mass (7a). Thus, second end of the spring (7b) loaded with the bob-mass (7a) may be stretched and released to achieve spring extension and contraction, respectively. A stopper (7c) may be provided in each of the counter-slots (5b) and slots (4b) to restrict maximum displacement of the bob-mass (7a) in the stretched (extended condition) of the spring (7b).

Further, each spring (7b) of the spring-loaded guide member (7) may remain in its default contracted condition (CC), also known by the terms “free state of the spring” or “relaxed condition” of the spring (7b), in the absence of centrifugal force. When the vehicle starts moving and with gradual increase in velocity, the centrifugal force on the wheel (1) increases in proportion to the vehicle velocity. This centrifugal force on the wheel (1) causes the bob-mass to linearly move away from the hub (5c) along the slot (4b) while also being present in counter-slot (5b). The linear displacement of the bob-mass (7a) away from the hub (5c) causes stretching of the spring (7b) inside and along the slot (4b). The stretching or elongation of the spring (7b) increases with the increase in centrifugal force acting on the bob-mass (7a). Conversely, the spring (7b) starts to contract when the magnitude of centrifugal force acting on the bob-mass decreases. In an embodiment, the response or sensitivity of each of the springs (7b) is dependent on the stiffness of the spring (7b), which is the centrifugal force required to produce unit elongation in this case. In an embodiment, the spring (7b) is a coil spring preferably an axial spring like a tension or a compression spring.

FIGS. 4A and 4B illustrate front views of the wheel (1) with plurality of air pockets (2a) in fully opened and fully closed condition, respectively. Reference is also made to FIG. 3 in conjunction with FIGS. 4A and 4B to illustrate opening and closing operations of the air pockets (2a) by the vanes (4a). When the centrifugal force acting on the bob-mass (7a) reaches its upper limit (depending on the speed of the vehicle), the spring (7b) will be in an (fully) extended condition (EC). In this state, further displacement of the bob-mass (7a) will be inhibited by the stopper (7c). In an embodiment, the contracted condition (CC) of each of the spring (7b) corresponds to a vehicle speed lesser than or equal to a first threshold speed of the vehicle. The first threshold speed may be a speed within which fuel economy is attained, for example, up to 40 kmph or 50 kmph. The lower limit of the first threshold speed of the vehicle is 0 kmph, which indicates vehicle standstill condition. Until the vehicle speed reaches the first threshold speed, each of the springs (7b) remains in contracted condition (CC), indicating that the centrifugal force acting on the bob-mass (7a) is not sufficient to overcome resistance of the spring (7b) to cause elongation. In other words, resistance to elongation of the spring (7b) is dominant than the centrifugal force acting on the bob-mass (7a) until vehicle speed becomes equal to the first threshold speed. Accordingly, below the first threshold speed of the vehicle, the disc (4) remains in a first position (FP), keeping all the air pockets (2a) in completely opened condition as shown in FIG. 4A. This indicates that the vanes (4a) of the disc (4) are completely concealed or eclipsed by the closing plate (5), as apparent from FIG. 4A. The completely opened condition of the air pockets (2a) below first threshold speed of the vehicle allows air circulation around and through the air pockets (2a) for cooling purposes. In addition, the completely opened condition of the air pockets (2a) below first threshold speed of the vehicle may not result in considerable drag force on the wheel (1).

Now, referring to FIG. 4B, closing condition of air pockets (2a) is discussed. As soon as the vehicle speed exceeds the first threshold speed, the centrifugal force acting on the bob-mass (7a) starts dominating the spring (7b) resistance, and each of the springs (7b) starts elongating inside the slot (4b). The elongation (or extension) continues with further increase in centrifugal force. Thus, at any instant of time, the deformation of the spring (7b) is directly proportional to the centrifugal force acting on the bob-mass (7a). The elongation continues until the vehicle speed becomes equal to second threshold speed. Once the vehicle speed exceeds the second threshold speed, the spring (7b) loaded with bob-mass (7a) will be in a completely extended (maximum displacement) (EC) condition, with stopper (7c) contacting the bob-mass (7a). The completely extended condition (EC) of the spring (7b) causes the bob-mass to actuate the disc (4) to a second position (SP), which is shown in FIG. 4B. In the second position (SP) of the disc (4), the vanes (4a) completely conceal or close or eclipse the air pockets (2a), and prevent air flow around and through the air pockets (2a). The suppression of air flow around and through the air pockets (2a) closed by vanes (4a) inhibits turbulence generation in the vicinity of air pockets (2a). This in turn minimizes the aerodynamic drag acting on the wheel (1) corresponding to higher vehicle speeds (higher than second threshold speed). In an embodiment, the second threshold speed of the vehicle may be 85 kmph, and preferably 80 kmph. The linear displacement of spring-loaded guide member (7), and consequently, the rotation of disc (4) may be calibrated to meet varying speed conditions of the vehicle. For example, if a vehicle is moving at 60 kmph, the linear displacement of the spring-loaded guide member (7) may be tuned such that the disc (4) may be rotated through a definite angle to partially close the air-pockets (2a). As the vehicle speed approaches 80 kmph, the disc (5) may rotate through a much higher angle, so that the air-pockets (2a) may be completely concealed. Thus, depending on the speed of the vehicle, displacement of spring-loaded guide member (7) and rotation of the disc (5) may be tuned or calibrated.

Reference is made to FIGS. 5A to 5D to illustrate an operational embodiment of the present disclosure. In FIGS. 5A-5D, the closing plate (5) is shown as a transparent body to depict the operation of the spring-loaded guide member (7) inside the assembly (100). Wheel (1) rotation is indicated by arrows (WD). In the first step, as shown in FIG. 5A, the spring (7b) is in fully contracted condition (CC) corresponding to a vehicle speed lesser than or equal to a first threshold speed. The vanes (4a) and the disc (4) remain in the First position (FP) which is the default original position. Consequently, air pockets (2a) are fully opened to allow air circulation, which is already discussed in the above paragraphs. In the next step, the vehicle speed exceeds the first threshold speed (slightly higher than first threshold speed), when the spring-loaded guide member (7) starts elongating, and consequently, actuates the disc (4) angularly. This causes the vanes (4a) of the disc (4) to gradually conceal the air pockets (2a), which increases as the vehicle speed increases further. A partially concealed condition of the air pockets (2a) by the vanes (4a) allowing smaller quantities of air circulation is shown in FIG. 5B. Extension of the spring (7b) in the slot (4b), and linear displacement of bob-mass in the slot (4b) relative to its engagement with the counter slot (5b) is also apparent from FIG. 5B.

A further increase in vehicle speed leads to the third step, where further closing of the air pockets (2a) by the vanes (4a) takes place. A substantially closed condition of the air pockets (2a) by the vanes (4a) is illustrated in FIG. 5C. The spring (7b) undergoes further extension, and the bob-mass (7a) undergoes further displacement away from the hub (5c) engaging the slot (4b) and the counter-slot (5b). In the fourth step, the spring (7b) elongates to a fully extended condition (EC), the bob-mass (7a) contacts the stopper (7c), and the air pockets (2a) are completely concealed by the vanes (4a) in the second position (SP), indicating a vehicle speed greater than the second threshold speed. As the speed reduces, centrifugal force action on the wheel (1) also reduces which pulls the spring-loaded guide member (7) to its rest position gradually. This results in opening of the air pockets (2a). In an embodiment, the assembly (100) may be secured to the rim (2) in a flipped manner, i.e., the closing plate (5) removably attached to the rim (2) while the base (3) is away from the rim (2). In another embodiment, the complete assembly (100), i.e., base (3), disc (4) and closing plate (5) can also be connected to wheel rim (2) directly using the fastening members such as wheel bolts or any other suitable joining means such locking ties, and the like.

The assembly (100) of the present disclosure may have inherent advantages. One of the advantages is utilization of centrifugal force acting on the wheel (1) to operate the spring-loaded guide member (7) and the disc (4), without need of external force or external power sources to achieve drag reduction. This not only saves power but also saves cost of maintenance or frequent replacement. Another advantage is that the assembly (100) may be provided on both inside and outside the wheel (1), without affecting the aesthetic appearance of the wheel (1). Yet another advantage is that materials including but not limited to light-weight composites may be used to manufacture the base (3), the disc (4) and the closing plate (5), which do not add significantly to the weight of the wheel assembly, and vehicle on the whole.

It is to be understood that a person of ordinary skill in the art may develop an assembly or a device or a system of similar configuration without deviating from the scope of the present disclosure. Such modifications and variations may be made without departing from the scope of the present invention. Therefore, it is intended that the present disclosure covers such modifications and variations provided they come within the ambit of the appended claims and their equivalents.

Equivalents:

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system (108) having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system (108) having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

Reference Numerals:

Assembly 100
Wheel 1
Tire 1a
Rim 2
Air pockets in the rim 2a
Base 3
Openings in the base 3a
Hub of the base 3b
First set of holes in the base 3c
Disc 4
Vanes 4a
Slots in the disc 4b
Inner periphery of the disc 4c
Central opening in the disc 4d
Closing plate 5
Openings in closing plate 5a
Counter-slots in closing plate 5b
Hub of closing plate 5c
Second set of holes in closing plate 5d
Elements 6
Provision in closing plate 6a
Spring-loaded guide member 7
Bob-mass 7a
Spring 7b
Stopper 7c
Securing members 8
Section A-A
First Position FP
Second Position SP
Contracted condition of spring CC
Extended condition of spring EC
Wheel rotation direction WD
Disc contacting surface DS
Closing plate contacting surface CPS