FORM 2
THE PATENTS ACT 1970 (39 of 1970)
COMPLETE SPECIFICATION
(See Section 10; rule 13)
TITLE
A ROOF RETRACTION MECHANISM AND A METHOD FOR RETRACTING AND REPLACING A ROOF OF AN AUTOMOBILE
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.
INVENTOR
SIDDIQUI FIROZ an Indian National 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, an Indian Company
The following specification particularly describes the nature of this invention and
the manner in which it is to be performed

FIELD OF THE INVENTION
The invention provides a roof retraction mechanism and a method for retracting and replacing a roof of an automobile. More particularly, the present invention provides a roof retraction mechanism and a method for retracting and replacing the roof of a sports utility vehicle, (SUV), to transform a normal SUV into a convertible SUV.
BACKGROUND OF THE INVENTION
The concept of convertible cars is not new. It has been there for quite some time. The sole purpose of having a convertible car is to open up the roof of the car and provide an open view to the passengers much to their delight. There are some convertible cars that have rather unconventional designs. Some have soft roofs, the roofs which are not metal, that can be retracted into the rear hood where luggage is normally kept. They have a swing arm fitted that can be brought back as and when required. Some cars have roof-retracting mechanism, consisting of three-part roof, which folds into the rear hood of the vehicle. Opening the top provides a panoramic view for the driver and passengers while traveling. Recently, a car has been proposed with a roof that simply slides into the rear hood as the contour of the car is designed for this purpose; the roof contour is in continuation with the rear hood profile, leaving the car roof less. Some cars have glass roofs, which slide sideways opening the roof. Slidable plastic roofs are provided with some cars which may slide into the middle roof so as to provide room for placing a
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cupboard or fridge or the like.
However, most of these convertibles are small compact cars or little larger luxury cars or sedans, built mostly for city driving. SUVs are a set of vehicles that are much larger than these cars, and are built taller, tougher, and more suited for rough terrain. A convertible SUV is a new approach, which has not been previously implemented mostly owing to its large size and complicated designing. The object of this invention is therefore to provide a roof retraction mechanism and a method for retracting and replacing the roof of an automobile, i.e. Convertible Sports Utility Vehicle.
SUMMARY OF THE INVENTION
The present invention provides a roof retraction mechanism and a method for retracting and replacing the roof of an automobile. In particular, the invention relates to SUVs. The roof of the SUV is divided into a front roof portion, middle roof portion and rear roof arrangement. The front roof portion is attached to the windshield at one end. When a trigger is initiated, the front roof portion slides below the middle roof portion. The middle roof portion then slides below the upper portion of the rear roof arrangement. The rear roof arrangement is an integrated piece having fixed pillars and fixed glasses on both sides of the SUV and a sliding or winding rear glass. The rear roof arrangement is moveable vertically downwards after the front roof portion and middle roof portion have
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finished sliding below the upper portion of the rear roof arrangement. Pneumatic pillars,
which are used to support the middle roof portion, are then triggered to start its descent into the body of the vehicle. Thus, what is left is an SUV with an open top. When the roof needs to be put back in place a switch is initiated and the rear roof arrangement as a whole is moved vertically upwards. The sliding rear glass, and middle roof portion, then start to slide upwards and outwards respectively. Then, the front roof portion slides out until it makes contact with the windshield of the SUV. The pneumatic pillars are then moved vertically upward to regain its original position.
Accordingly, the present invention provides a roof retraction mechanism for retracting and replacing the roof of an automobile, said roof comprising a front roof partition, a middle roof partition and a rear roof arrangement wherein said front roof portion is slidably connected to the middle roof portion, the middle roof portion is slidably connected to the rear roof arrangement, said rear roof arrangement comprising an upper portion, a pair of fixed frames extending below the upper portion for supporting fixed glasses and a rear glass capable of sliding into the rear door of the automobile, in combination with the front roof portion and the middle roof portion, said rear roof arrangement being capable of downward and upward vertical movement.
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BRIEF DESCRIPTION OF THE DRAWINGS:
Fig 1 shows a diagram of the different components of the roof retraction mechanism according to the present invention.
Figs. 2 to Fig. 3 shows schematic diagrams of various operational stages of the retraction mechanism according to the present invention and the arrangement of the front, middle, rear roof portions
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a roof retraction mechanism for retracting and replacing the roof of an automobile. The present invention also relates to a method for retracting the roof of an automobile, and a method for replacing the roof of an automobile. In particular, this invention deals with larger automobiles, specifically sports utility vehicles (SUVs).
The constructional features of the retraction mechanism according to the present invention are shown in Fig. 1. The roof of the automobile is divided into three parts, i.e. Front roof portion (1), middle roof portion (2) and rear roof arrangement (3), the front roof portion (1) being towards the windshield (A). The rear glass (7) on the rear roof
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arrangement is a winding glass or a sliding glass and not a fixed one. The winding mechanism lies embedded between the rear door (E) trims. The sliding rear glass (7) slides in between the inner and outer panels of the rear door (E) of the automobile. The rear roof arrangement (3) is an integrated single piece construction incorporating an upper portion (3 a), fixed pillars (C, D) with fixed glasses (6) in between, the whole frame being free to move vertically upwards or downwards. A pneumatic pillar (B) is provided to support the middle roof portion (2). The pneumatic pillar (B) is actually a pneumatic activated piston cylinder arrangement that enables the pillar (B) to move downward to the level of the door trims and upwards towards the middle roof portion (2).
The whole retraction mechanism for retracting the roof of the automobile is explained as follows:
When an electronic trigger in the form of a switch is initiated, the front roof portion (1) detaches itself from the windshield (A) and starts its slide into the middle roof portion (2). The middle roof portion (2) is designed in such a way that it is above the front roof portion (1) as shown in Fig.2. The ends of the front roof portion and the middle roof portion have circular cross sections in order that the sliding is made easy as well as the structure remains rigid.
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As the front roof portion (1) slides 75 % of its travel into the middle roof portion (2), the middle roof portion (2) starts its sliding movement into the rear roof arrangement (3). Here again, the upper portion (3 a) of the rear roof arrangement (3) is above the middle roof portion (2). At the end of it, what we observe is a combination of the front roof portion (1) below the middle roof portion (2), which is in turn below the upper portion (3a) of the rear roof arrangement (3), thus opening up the roof completely above the passengers. This is shown in Fig.3. The dimensions of the SUV are such that when viewed from the top, the upper portion (3 a) of the rear roof arrangement is few inches behind the second row of seats in the SUV.
The sliding rear glass (7) is then triggered to start its descent into the inner and outer panel of the rear door (E) of the SUV. The dimensions of the SUV are such that the height of the rear door is slightly more than that of the sliding rear glass (7). The necessity of the rear glass (7) to be a sliding one or a winding one arises because of the fact that access to the luggage compartment has to be given, since this compartment is positioned behind the passenger seats. If the rear glass had been a fixed one connected to the fixed pillar (D), then access to the luggage compartment would have been completely blocked.
After the sliding of the rear sliding glass (7) all that remains is the rear roof
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arrangement (3) comprising the fixed pillars (C, D) supporting the fixed glass (6), the upper portion (3a) and a combination of the front roof portion (1) and middle roof portion (2). This entire set begins its descent and stops when the upper portion (3 a) reaches the head restraint height or the top portion of the passenger seats.
The pneumatic pillar (B) slides down and is designed to stop till the top of the pneumatic pillar (B) reaches the outer trim level of the side door B. When viewed from the side of the automobile, except for the door window, everything else is hidden from view, thus making it an open roof automobile, or a convertible SUV.
The reversal process is not quite the same. The mechanism for replacing the roof of the automobile (i.e.) SUV is explained as follows:
This process is initiated with the help of an electronic switch or a trigger. The rear roof arrangement (3) in combination with the front roof portion (1) and middle roof portion (2) is raised to its original height. Then, the outward slide of the middle roof portion (2) from below the upper portion (3a) along with the front roof portion (1) is initiated. Simultaneously the upward sliding movement of the sliding rear glass (7) is triggered. After this, the outward sliding movement of the front roof portion (1) from the middle roof portion (2) is triggered until it reaches the windshield (A) of the automobile.
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Finally, the upward movement of the pneumatic pillar (B) is initiated. The pneumatic pillar (B) ends its travel when it firmly supports the middle roof portion (2). This step is
necessarily the final step of the roof replacing process because if it were to be raised to its original height before the travel of the front roof portion (1), there is a good chance of the
pneumatic pillar (B) becoming a hindrance in the smooth outward slide of the front roof portion (1).
The exact sequence in timings of triggering and initiating the various steps of this mechanism according to the present invention is a vital aspect of the roof retracting mechanism. The triggering system is enabled through the use of embedded systems and microprocessors. There are various triggers used for each and every step.
As the front roof portion (1) begins to slide into the middle roof portion (2) at 75% of its travel, a trigger is switched on initializing the beginning of the middle roof portion's (2) slide into the rear roof arrangement (3). As the middle roof portion (2) completes 75% of its travel, another trigger marks the beginning of the sliding rear glasses (7) travel downwards. When the middle roof portion (2) completes its slide into the rear roof arrangement (3), only then a trigger for the downward descent of the rear roof arrangement (3) is initiated. This will ensure that all three parts of the roof are one below the other. As soon as the rear roof arrangement (3) completes 50% of its descent,
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another trigger initiates the downward descent of the pneumatic pillar (B)
The triggering system in the reverse process also changes as the roof is to be brought back to its original state. At the initial stage when the upward movement of the rear roof arrangement (3) is started, a trigger is initiated at 75% of the rear roof arrangement's (3) travel, in order to start the upward movement of the rear sliding glass (7). This rear sliding glass (7) triggers the outward movement of the middle roof portion (2) at 75% of its travel, as the middle roof portion (2) completes 75% of its outward travel, a simultaneous trigger starts the upward movement of the pneumatic pillar (B) and also the outward movement of the front roof portion (1).
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WE CLAIM:
1 A roof retraction mechanism for retracting and replacing the roof of an
automobile, said roof comprising a front roof portion, a middle roof portion and a rear roof arrangement wherein the front roof portion is slidably and telescopically connected to the middle roof portion and the said middle roof portion is telescopically and slidably connected to the rear roof arrangement, which comprises an upper portion, mounted on a pair of supports for supporting glasses fixed therein and a rear glass capable of sliding into the rear door of the automobile, said rear roof arrangement in combination with the front roof portion and the middle roof portion, being capable of downward and upward vertical movement, activating means provided for activating the desired movements of the roof portion to open and closed positions.
2. The mechanism as claimed in claim 1 , wherein activated support means are provided on either side for supporting the middle roof portion, said support means preferably being pneumatically active pillars capable of being moved upwards and downwards.
3. The mechanism as claimed in claim 1, wherein the front roof portion is connected to the windshield of the automobile at one end, and is arranged to slide below the middle roof portion on the other end, said middle roof portion being arranged to slide below the
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upper portion of the rear roof arrangement.
4. A method for retracting the roof of an automobile, said roof having a front roof
portion, a middle roof portion and a rear roof arrangement, said rear roof arrangement
having an upper portion, fixed pillars to support fixed glasses, and a sliding rear glass,
said method comprising the steps of:
activating the front roof portion to detach itself from the windshield of the
SUV and to slide below the middle roof portion;
activating the middle roof portion in combination with the front roof portion to
slide below the upper portion of the rear roof arrangement;
initiating downward movement of the sliding rear glass of said rear roof
arrangement into the rear door of the automobile; and
initiating downward movement of the rear roof arrangement in combination
with the front roof portion and the middle roof portion.
5. The method as claimed in claim 4, comprising the step of initiating downward
movement of pneumatic pillars provided on either sides of the automobile for supporting
the middle roof portion.
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6. The method as claimed in claim 4, wherein the downward movement of the rear roof arrangement is halted when the upper portion of said rear roof arrangement is in line with the top of said passenger seats.
7. A method for replacing the roof of an automobile, said roof having a front roof portion, a middle roof portion and a rear roof arrangement, said rear roof arrangement having an upper portion, fixed pillars to support fixed glasses, and a sliding rear glass, said method comprising the steps of:
initiating upward movement of the rear roof arrangement in combination with
the front roof portion and the middle roof portion until the upper portion of
said arrangement reaches original height of the automobile;
sliding the sliding rear glass in an upward direction towards the upper portion
of the rear roof arrangement;
sliding the middle roof portion in combination with the front roof portion
outwards from the upper roof portion at the same instance when the upward
sliding of said sliding rear glass is performed; and
sliding the front roof portion outwards from the middle roof portion until said
front roof portion reaches the windshield of the automobile.
8. The method as claimed in claim 7, comprising the step of initiating the upward
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movement of pneumatic pillars placed on either side of the automobile until it reaches the middle roof portion.
9. The method as claimed in claims 4 or 7, wherein the method is triggered by electronic switch.
10. The method as claimed in claim 9 wherein said method is controlled by a trigger mechanism having an inbuilt triggering sequence operable at predetermined time intervals.
11. A roof retraction mechanism for retracting and replacing the roof of an automobile, substantially as herein described, with reference to the accompanying drawings.
Dated this 30th day of May 2005

(Karuna Goleria)
of DePENNING & DePENNING Agent for the Applicants
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ABSTRACT
This invention provides a roof retraction mechanism for retracting and replacing the roof of an automobile and a method for retracting and replacing the roof of an automobile. Particularly the invention relates to Sports Utility Vehicles (SUV's) The roof of the automobile is divided into a front roof portion, a middle roof portion and a rear roof arrangement .The front roof portion is slidably connected to the middle roof portion and the middle roof portion is slidably connected to the rear roof arrangement. The rear roof arrangement comprising an upper portion, a pair of fixed pillars for supporting fixed glasses and a sliding rear glass, which is capable of sliding into the rear door of the automobile. The entire rear roof arrangement, in combination with the front roof portion and the middle roof portion is capable of downward and upward vertical movement.
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