FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE OF THE INVENTION
Spare Wheel Cover Assembly
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
Vilas Kangutkar and Parag Samant both Indian Nationals
of TATA MOTORS LIMITED, an Indian company having
its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following complete specification particularly describes the invention and the manner in which it is to be performed.
3 AUG 2006

Field of Invention
This invention relates to a novel single piece spare wheel cover assembly. The spare wheel cover is durable and is easy to clasp and remove.
Background of Invention
Presently available spare wheel covers are with two-piece constructions. They use tyre tread surface as support for mounting. Such spare wheel covers are made of either plastic or steel strip or rexin or any combination of them.
In a plastic-cum-rexin cover, the plastic portion covers half of the tyre and rexin portion covers the remaining half of the tyre. Rexin wraps on the tyre to ensure fitment. Major drawback of such type of cover is that it is prone to easy wear and tear, less durable, difficult in assembling and lacks good aesthetic appearance.
In steel strip-cum—plastic cover, the circumference of the tyre and ends of the strip are bolted with support on the tyre circumference. Plastic cover is engaged in the steel strip on sides to cover the facing side of the tyre-rim. Such a cover requires tool to assemble and dissemble. Time consumption for assembling the cover is quite high. Moreover, the components cost involved in assembly is also high.
In some vehicles, there is a plastic cover used for covering the facing side of the tyre-rim. This cover is bolted along with spare wheel. But such a cover does not entirely cover the tyre. Tyre tread surface is seen. The visibility of the tyre surface reduces the aesthetics of the vehicle.
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Summary of Invention
The spare wheel cover assembly according to the present invention comprises of a spare wheel cover and an assembly disc. Spare wheel cover is made of plastic or similar material. Inside the spare wheel cover are mounted (i) two numbers of lug base, each having three lugs fixed in a circular path holding a circular spring (ii) a locator and (iii) a layer of foam. The assembly disc is bolted with the spare tyre to the spare wheel mounting bracket that is bolted to the tailgate by bolts. Assembly disc is made of fabricated sheet metal component having high bending and strength properties. It has a contoured shape providing two groove sectors on the opposite side rims and a locating hole near the center and nut holes near the rims. Assembly disc mounts / latches the spare wheel cover. The two groove sectors are circular in path and are designed to latch the lugs.
Spare wheel cover is mounted or latched on to the assembly disc. The circular spring provides necessary restraining pressure for the lugs to remain in assembled position. Two numbers of lug base are mounted on inside of spare wheel cover at the determined locations by screws matching the groove sectors on assembly disc. Each lug base has three lugs. The lugs get latched in groove sectors of assembly discs. The lugs also provides holding for circular spring. This circular spring holds all the lugs together and provides spring tension during the insertion and after spare wheel cover gets latched. A layer of polyurethane foam is provided adhesively at the inner surface of the spare wheel cover.
The present invention relates to a spare wheel cover assembly comprising: a spare wheel cover, said spare wheel cover comprising: at least two lug bases mounted inside the said cover, each of the said lug bases having at least three lugs fixed in a circular path; a locator inserted into the said cover; means to hold the said at least
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three lugs together and to provide necessary restraining pressure for the lugs to remain in assembled position; an assembly disc bolted with the spare tyre to a spare wheel mounting bracket which is subsequently bolted to the vehicle tailgate, said assembly disc having a contoured profile and provided with at least two groove sectors on the opposite side rims to latch the said lugs, said profile of the assembly disc configured to correspond to the lug profile.
Brief Description of the Drawings
Figure 1 shows the cross section of the spare wheel cover mounting according to the invention
Figure 2 shows the cross section of the mounting device according to the invention.
Figure 3 shows the commonly available sections of lugs.
Figure 4 shows the cross section of the spare wheel cover mounting showing locator
Detailed Description of Invention
Referring to Figures 1, 2 and 4 of the accompanying drawings, assembly disc (2) is bolted with spare tyre (T) to spare wheel mounting bracket (5) that is bolted to tailgate by bolts. The assembly disc has a contoured shape providing two groove sectors on the opposite side rims (6). Spare wheel cover (1) is mounted or latched on to the assembly disc (2). Lugs (lb) of the spare wheel cover are latched into the sectors of groove (2a) of the assembly disc. These groove sectors are circular in path. The groove has guide (2c) to assist and guide the lugs (lb) during the assembly of the cover. A circular spring (3) is provided to hold all the lugs together and to provide spring tension during the insertion and after the cover gets
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assembled or latched. Circular spring (3) provides necessary restraining pressure for the lugs to remain in assembled position and not allowing the lug to come out due to the vibration of the cover or air pressure force acting during the vehicle movement.
At least two lug base (la) each having at least three lugs (lb) are provided in a circular path. Each base is mounted to inside spare wheel cover at the determined locations by screws matching the groove sectors (2a) on assembly disc. The lugs get latched in groove on sectors of assembly disc. The lugs also provides holding for circular spring. This circular spring holds all the lugs together and provides spring tension during the insertion and after cover gets assembled or latched. The purpose of bolting the lug bases to spare wheel cover is to facilitate replacement if required. A layer of polyurethane foam (4) is adhesively provided at the inner surface of the spare wheel cover (tyre width area) to avoid rattling of the cover surface.
Lugs (lb) have a defined profile thereby giving advantage of easy sliding of lug into the groove (2a) during assembly and removal of the spare wheel cover. During assembly or removal, the lugs bend radially inside against circular spring force allowing lug sliding in or out depending upon the operation. Once inserted in the groove (2a), the lug profile hugs the groove (2a). The circular spring (3) exerts sufficient pressure to hold the lug in position not allowing the lug come out due to the vibration of the cover or air pressure force acting during the vehicle movement. The groove (2a) has a defined profile along the periphery of the assembly disc (2) in two sectors and matches with the profile of mating lug profile. Groove provides the support and holding of the lug against the force exerted by the circular spring.
During the assembly, the spare wheel cover (1) is located on assembly disc (2) by inserting a locator (L) on the cover (1) in locating hole of assembly disc (2). After locating, the cover (2) is pushed on to the assembly disc (1). The lugs (lb) get
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radially compressed inside due to the compression of the circular spring (3). After lugs (lb) have entered into the groove (2a), they are forced to retain in position by the spring force provided by the circular spring (3). There is a latching sound that ensures the proper latching of lugs (lb) to the assembly disc (2). Due the radial outward force on lugs (lb) provided by the circular spring (3), the latching of the cover (1) is ensured. By pulling the cover (1) with suitable forces on sides axially, the cover (1) can be easily disassembled.
The latching device (i.e.) lug and groove have profiles (Fig 2), which are specially designed for spare wheel cover application. The latching device is very unique and is uncommon compared to some of the applications used today. Figure 3 shows some of the cross section profiles of the lugs.
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We Claim:
1. A spare wheel cover assembly comprising:
a spare wheel cover, said spare wheel cover comprising:
at least two lug bases mounted inside the said cover, each of the said lug bases having at least three lugs fixed in a circular path; a locator inserted into the said cover;
means to hold the said at least three lugs together and to provide necessary restraining pressure for the lugs to remain in assembled position;
an assembly disc bolted with the spare tyre to a spare wheel mounting bracket which is subsequently bolted to the vehicle tailgate, said assembly disc having a contoured profile and provided with at least two groove sectors on the opposite side rims to latch the said lugs, said profile of the assembly disc configured to correspond to the lug profile.
2. The spare wheel cover assembly as claimed in claim 1, wherein the spare wheel cover comprises a locator inserted into a locating hole provided in the assembly disc to position the spare wheel cover on the assembly disc.
3. The spare wheel cover assembly as claimed in claim 1, wherein each of the said at least two groove sectors has a guide to assist the lugs during the assembly of the cover.
4. The spare wheel cover assembly as claimed in claim 1, wherein a layer of polyurethane foam is adhesively provided at the inner surface of the spare wheel cover to avoid rattling of the cover surface.
5. The spare wheel cover assembly as claimed in claim 1, wherein the said means to hold the said at least three lugs together is a circular spring.
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6. A spare wheel cover assembly substantially as hereinabove described with reference to the accompanying drawings.
Dated this 2nd day of August 2006
TATA MOTORS LIMITED
By their Agent and Attorney
(KARUNA GOLERIA) Of DePENNING & DePENNING
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ABSTRACT
("A spare wheel cover assembly")
The spare wheel cover assembly according to the present invention comprises of a spare wheel cover and an assembly disc. Spare wheel cover is made of plastic or similar material. Inside the spare wheel cover are mounted (i) two numbers of lug base, each having three lugs fixed in a circular path holding a circular spring (ii) a locator and (iii) a layer of foam. The assembly disc is bolted with the spare tyre to the spare wheel mounting bracket that is bolted to the tailgate by bolts. Assembly disc is made of fabricated sheet metal component having high bending and strength properties. It has a contoured shape providing two groove sectors on the opposite side rims and a locating hole near the center and nut holes near the rims. Assembly disc mounts / latches the spare wheel cover. The two groove sectors arc circular in path and are designed to latch the lugs.