DESC:FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2005

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

TITLE OF THE INVENTION
“FRONT FORK SUSPENSION OF A TWO WHEELED VEHICLE”

Endurance Technologies Limited
E-92, M.I.D.C. Industrial Area, Waluj,
Aurangabad – 431136, Maharashtra, India

The following specification describes the nature of this invention and ascertains the manner in which it is to be performed.

Field of Invention

[001] The present invention is related to a front fork suspension of a two wheeled vehicle. More particularly, the present invention relates to an inverted front fork suspension having the means for eliminating the damping lag during the rebound stroke of the suspension and imparting a jerk free operation thereby.

Background of the Invention

[002] In a two wheeled vehicle, a front wheel is attached to a front fork suspension having two legs connected to the front part of the vehicle body, and a rear wheel is attached to a rear suspension. When the vehicle is running, the impact caused by the vertical movement of the front and rear wheels that are in contact with the ground is transmitted to the vehicle body through the front fork and the rear suspension. It is necessary to minimize the impact that is transferred from the ground to the vehicle body in order to enhance riding comfort while vehicles.

[003] The front fork has at least one main spring to absorb the energy transferred from the motor vehicle’s wheel when it encounters a road surface irregularity. The main spring in such front fork is generally positioned in the fork pipe and is in abutment with the head of the seat pipe. The seat pipe is a hollow cylindrical damping tube configured with an integral piston head employed within the forks to achieve the required damping. The damping tube of the seat pipe is generally provided with a set of damping orifices wherein one of the damping orifices is positioned in the rebound chamber and the other orifice is positioned in the compression chamber of the inverted front forks. These rebound and compression damping orifices facilitates the controlled flow of damping fluid in the rebound and compression stroke, respectively of the inverted front fork. During the compression and rebound stroke of the conventional inverted front forks, the damping fluid from the compression chamber travels to the rebound chamber and vice versa through the compression and rebound damping orifices of the seat pipe respectively. The said damping fluid fills the respective chambers immediately after the completion of the stroke at the normal velocity conditions (smooth road surface) of the fork, but the not at the high velocity (irregular / uneven road surface) travel conditions of the fork. Thus during the high velocity conditions of the fork, the rebound chamber experiences the starvation of the damping fluid which ultimately results in damping lag during the rebound stroke of the conventional inverted front forks. This damping lag during the rebound stroke consequently results in a jerky ride leading to torturous and compromised ride for the rider.

[004] Therefore, to address the aforementioned limitations of the existing inverted front forks, there is a long pending unmet need to provide an intelligent, economical, and simple solution that ensures the elimination of the lag in the rebound stroke of the inverted front fork suspension in order to provide jerk-free and comfortable riding when the vehicle is running on any of the road surfaces.

Objectives of the Invention

[005] The main objective of the present invention is to provide an inverted front fork with optimized rebound damping force for suspension system of a two wheeled vehicle.

[006] Another objective of the present invention is to provide a uniquely profiled seat pipe with a poppet valve assembly housed therein for the inverted front fork suspension system of a two wheeled vehicle.

[007] Yet, another objective of the present invention is to provide an inverted front fork configured to generate optimized damping force and thereby eliminating the lag in the rebound stroke when the vehicle is continuously navigating with the uneven road surface or off-road.

[008] Yet, the objective of the present invention is to provide an inverted front fork configured to generate optimized damping force that improves the response of the inverted front fork with the road irregularity and also improves the riding comfort.

[009] Still, the objective of the present invention is to provide an inverted front fork configured to generate optimized damping force that reduces the noise of the front fork suspension system of a two wheeled vehicle.

Brief Description of the Drawings

[0010] This invention is illustrated in the accompanying drawings, throughout which like reference letters / numerals indicate corresponding parts in the various figures. The embodiments herein and advantages thereof will be better understood from the following description when read with reference to the following drawings, wherein

[0011] Figure 1 shows a sectional view of an inverted front fork of a two wheeled vehicle in its free condition as per the present invention.

[0012] Figure 2 shows a sectional view of an inverted front fork of a two wheeled vehicle in compressed condition in accordance with the present invention.

[0013] Figures 3a and 3b disclose an enlarged sectional view of a seat pipe along with poppet valve therein and the poppet valve, respectively of an inverted front fork of a two wheeled vehicle in accordance with the present invention in compressed condition.

[0014] Figures 4a and 4b show an enlarged sectional view of a seat pipe along with poppet valve therein and the poppet valve, respectively of an inverted front fork of a two wheeled vehicle in accordance with the present invention in its free condition.

[0015] Figure 5 shows a sectional view of a seat pipe of an inverted front fork of a two wheeled vehicle in accordance with the present invention.

[0016] Figure 6 shows a sectional view of a poppet valve of an inverted front fork of a two wheeled vehicle in accordance with the present invention.

[0017] Figures 7 and 8 show an isometric view and cut-sectional view, respectively of a screw cap of an inverted front fork of a two wheeled vehicle in accordance with the present invention.

[0018] Figures 9a and 9b disclose the performance curves (rebound damping at velocities) for the existing inverted front fork and the inverted front fork of the invention, respectively
Detailed Description of the Present Invention

[0019] The invention will now be described in detail with reference to the accompanying drawings which must not be viewed as restricting the scope and ambit of the invention. Referring to Figs. 1 and 2, the present invention discloses an inverted front fork (100) suspension system of a two wheeled vehicle comprising of an outer tube (10), a fork pipe (15), a main spring (20), a set of spacers (23), a sealing assembly (25), a seat pipe (30), a poppet valve (40), a rebound spring (50), a check valve (55), a bottom cap (BC), a screw cap (60), a bump stop (65), an axle clamp (70) and a fork bolt (75).

[0020] Referring to Fig. 05, the seat pipe (30) is configured to have a hollow cylindrical body (32B) and a piston head (32H) integrated at its lower end (32L). The cylindrical body (32B) of seat pipe (32) has a stem (34) projecting out from an upper surface (32US) of the cylindrical body (32B) at its upper end (32U). The diameter of the cylindrical body (32B) of the seat pipe (30) is greater than the diameter of the stem portion (34) of the seat pipe (30) and the said stem portion (34) facilitates the fastening of the seat pipe (30) with the fork bolt (75). The said stem portion (34) is fixed with the fork bolt (75) by the virtue of external threads provided on the outer peripheral surface of the stem portion (34) of the seat pipe (30) and matching internal threads provided on an annular collar (75C) of the fork bolt (75).

[0021] The cylindrical body (32) of the seat pipe (30) is configured to have a step (30CS) formed at its inner peripheral surface in a manner such that the said step (30CS) divides the bore (32BR) of cylindrical body (32B) in an upper bore (32BR1) and a lower bore (32BR2). The upper bore (32BR1) maintains a proportion l1 : l2 with the lower bore (32BR2) wherein the said proportion ranges from 3 : 2 to 7 : 3. The step (30CS) is configured to house the poppet valve (40) corresponding to the axial length l2 of the lower bore (32BR2) of the seat pipe (30). Further, the cylindrical body (32B) of the seat pipe (30) is configured to have a plurality of rebound damping orifices (R1 and R2), a plurality of compression orifices (C1, C2 and C3) and a damping orifice (A1) thereon so as to allow the fluid communication in between the fork pipe (15) and the outer tube (10). The rebound damping orifices (R1 and R2) are positioned in proximity to the piston head (32H) of the seat pipe in a manner such that the orifice (R1) is located above the orifice (R2). The compression orifice (C1) is positioned in the lower bore (32BR2) of the seat pipe (30) and the compression orifices (C2 and C3) are positioned in the upper bore (32BR1) of the seat pipe (30). The said compression orifices (C2 and C3) are provided in a same horizontal plane above the position of the damping orifice (R1). Further, the orifice (A1) is positioned above the orifices (C2 and C3) such that the vertical plane of the orifice (A1) is orthogonal to the vertical plane of the orifices (C2 and C3).

[0022] The poppet valve (40) comprises of an upper bush (40U), a lower bush (40L) and a spring (40S) (refer Fig 6). The lower bush (40L) is configured to have a cylindrical body (40LB) and a cylindrical stem portion (40P) orthogonally projecting out therefrom forming an inverted T-profiled unitary structure of the lower bush (40L). The upper bush (40U) is a hollow cylindrical body and is sleeved over the stem portion (40P) of the lower bush (40L) in a manner to have clearance fit. The spring (40S) is concentrically positioned in between the upper bush (40U) and the body portion (40LB) of the lower bush (40L) in a manner such that the upper bush (40U) is biased against the spring force of the spring (40) in non-operational condition of the poppet valve (40). The said upper bush (40U) is configured to slide over the stem portion (40P) of the lower bush (40L) when the spring (40S) is compressed by lower bush (40L), particularly by the body portion (40LB) of the lower bush (40L) under the influence of the fluid pressure in the high velocity condition during the compression stroke of the inverted front fork (100).

[0023] Referring to the Figs. 7 and 8, the screw cap (60) is configured to have an elongated annular cap shaped profile having an annular flange portion (60F) and an annular body portion (60B) projecting out in radial direction from a thorough annular cavity (60C). The annular flange portion (60F) is configured to have two across flat surfaces (60AF) positioned diametrically opposite to each other on it outer peripheral surface. The across flat surfaces (60AF) facilitates the torqueing and de-torqueing of the screw cap (60) for fixing it with the fork pipe (15), during the assembly of the inverted front fork (100). The annular body portion (60B) is configured to project out axially from the annular flange portion (60F) of the screw cap (60) in an integral manner. The annular body portion (60B) has a plurality of stepped portions viz. a first step portion (60S1), a second step portion (60S2) and a third step portion (60S3) formed over its outer peripheral surface. The first stepped portion (60S1) and the third stepped portion (60S3) of the screw cap (60) is configured to have external threads formed over its outer peripheral surface. The said stepped portions (60S1, 60S2 and 60S3) has the outer diameter in the order of ? 60S1 > ? 60S2 > ? 60S3. The annular cavity (60C) of the screw cap (60) is configured to have an internal step (60ST) formed at the interface of the second step portion (60S2) and a third step portion (60S3). The said internal step (60ST) houses the check valve (55).

[0024] The main spring (20) of the inverted front fork (100) is positioned in the fork pipe (15) between the piston head (32H) of the seat pipe (32) and the upper surface of the set of spacers (23) (refer Figs 1 and 2). The said spacers (23) are positioned on the top inner surface of the axle clamp (70) and the said axle clamp (70) is fixed to the lower end (15L) of the fork pipe (15) with the help of the external threads provided on the outer peripheral surface and the internal threads provided on the inner peripheral surface of the axle clamp (70). The seat pipe (30) is partially positioned within the fork pipe (15) and the outer tube (10) in a manner such that the cylindrical body (32B) of the seat pipe (30) passes from the annular cavity (60C) of the screw cap (60) by maintaining a radial clearance (60RC). In this condition, the stem portion (34) of the seat pipe (30) is fixed with the annular collar (75C) of the fork bolt (75) in the outer tube (10) and the piston head (32H) is positioned in the fork pipe (15). The poppet valve (40) is positioned in the step portion (30CS) of the seat pipe in a manner such that the upper bush (40U) abuts against the flat surface (32FS) of the step portion (30CS) of the seat pipe (30). The said poppet valve (40) is configured to cover the damping orifice (C1) of the seat pipe (30) in the normal condition of the inverted front fork (100).

[0025] The fork bolt (75) is fixed to the top end of the outer tube (10) with the help of threaded connection. The screw cap (60) is fixed to the mouth of the fork pipe (15) with the help of the threads on the outer peripheral surface of the first stepped portion (60S1) of the screw cap (60) and the internal threads on the inner peripheral surface of the mouth of the fork pipe (15). The bottom cap (BC) is threaded over the third stepped portion (60S3) of the screw cap (60) and the check valve (60) is axially sandwiched in between the third stem portion (60S3) of the screw cap (60) and the bottom cap (BC). A rebound spring (RS) is positioned between the upper surface (US) of the piston head (32H) of the seat pipe (32) and the bottom cap (BC). The bump stop (65) is affixed on the outer peripheral surface of the cylindrical body (32B) of the seat pipe (30) by means of a circlip (8) wherein the circlip (8) interferes with the inner peripheral surface of the bump stop (65) and a recess in the outer peripheral surface of the cylindrical body (32B) of the seat pipe (30). The guiding and sealing assembly (25) comprising of a cylindrical guide (26), a washer (27), an oil seal (28), a dust seal (29) and a holding cover (31) is positioned in that order in the recessed portion given along the lower opening of the outer tube (10).

[0026] The inverted front fork (100) as described above, has the fork pipe (15) positioned so as to have the same central axis as that of the outer tube (10) and the said fork pipe (15) is free to reciprocate telescopically within the outer tube (15) in its assembled condition. The said inverted front fork (100) is filled with damping fluid, preferably the fork oil and is configured to form a plurality of fluid chambers viz. a chamber (A), a chamber (B) and a chamber (C) in its assembled condition. The fluid chamber (A) is formed in between the top surface of the annular flange (60F) of the screw cap (60) and the lower surface of a fork bolt cavity (75C) of the fork bolt (75). The fluid chamber (B) (rebound chamber) is formed in between the upper surface (US) of the piston head (32H) of the seat pipe (30) and the lower surface of the bottom cap (BC). The fluid chamber (C) is formed in between the lower surface (LS) of the piston head (32H) of the seat pipe (30) and the top inner surface of the axle clamp (70).

[0027] As far as the working of the present invention is concerned, during the compression stroke of the vehicle on the smooth road surface or less bumpy surface, the velocity of the oil inside the fork is in low range i.e. less than 0.6 m/s. At this time the main spring (20) is compressed and the damping fluid travels from the chamber (C) to the chamber (A) by passing from the compression damping orifices (C2 and C3) of the seat pipe (30) without compressing the poppet valve (40). The damping fluid further travels to the chamber (B) from the chamber (A) by passing thorough the radial clearance (RC) by deflecting the check valve (55). At these low velocity conditions, the damping fluid easily travels to the chamber (B) from the chamber (C) and the inverted front fork (100) does not face any damping lag in the rebound condition since the damping fluid gets the sufficient time to fill the chamber (B) i.e. the rebound chamber.

[0028] During the compression stroke of the vehicle on highly uneven road surface, the velocity of the oil inside the fork is in high range i.e. greater than 0.6 m/s. In this condition, the damping fluid from the chamber (C) compresses the lower bush (40L) of the poppet valve (40) leading to the uncovering of compression damping orifice (C1) and the damping fluid from the chamber (C) passes to the chamber (A) via the compression damping orifice (C1). The said damping fluid quickly fills the chamber (B) due the lesser distance travelled by the damping fluid owing to the closer positioning of the compression damping orifice (C1) with respect to the chamber (B). Thus, the inverted front fork (100) does not experience the damping lag in its rebound condition at higher velocities also.

[0029] The inverted front fork (100) having the uniquely profiled seat pipe (30), screw cap (60) and the poppet valve (40) eliminates the problem of oil starvation as is prevalent in the existing inverted front forks and finally eliminating the damping lag therefrom as presented in Figs. 9a and 9b. The present invention was tested for simulation testing as per the test standards for its performance particularly for the rebound damping performance at high velocities. The Fig. 9a shows the performance curves of existing inverted front fork suspension whereas the Fig. 9b presents the performance curves of the present invention. It is being clearly seen from the Fig. 9b that the rebound damping curves at different velocities of the present invention are much superior over that of the existing inverted front fork resulting in elimination oil starvation problem and thereby the damping lag at high velocities (i.e. when the vehicle is continuously negotiating with rough terrain / road surface). Apart from elimination of the damping lag, the present invention imparts superior damping during compression stroke as being evidenced by the performance curves of the present invention as shown in Fig. 9b. A person skilled in the art can change the positioning of the poppet valve (40) without carrying out any significant change to the features of the inverted front fork (100). Hence, such changes in relation to the position poppet valve (40) within the seat pipe (30) must not be viewed as taking the emerging variants/embodiments out of the scope of claims of the disclosed invention.

[0030] The technical advancements and advantages derived from the novel features of the preferred embodiment of the present invention as disclosed and described above are as follows:
- It eliminates the lag in the rebound damping force during high velocity.
- It provides a jerk free riding comfort to the rider.
- It minimizes the noise from the inverted front fork and improve the response of the front fork by providing a poppet valve within the seat pipe.
- It improves the durability and reliability of the front fork.

[0031] It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
,CLAIMS:We Claim:

1. A front fork suspension (100) of a two wheeled vehicle comprising of an outer tube (10), a fork pipe (15), a main spring (20), a set of spacers (23), a sealing assembly (25), a seat pipe (30), a poppet valve (40), a rebound spring (50), a check valve (55), a bottom cap (BC), a screw cap (60), a bump stop (65), an axle clamp (70) and a fork bolt (75)
wherein,
- the seat pipe (30) is configured to have a hollow cylindrical body (32B) and a piston head (32H) integrated at its lower end (32L) and a stem (34) projecting out from an upper surface (32US) of the cylindrical body (32B) at its upper end (32U);
- said cylindrical body (32) of the seat pipe (30) is configured to have a step (30CS) formed at its inner peripheral surface and said step (30CS) divides the bore (32BR) of cylindrical body (32B) into an upper bore (32BR1) and a lower bore (32BR2);
- said upper bore (32BR1) maintains a proportion l1 : l2 with the lower bore (32BR2) and said proportion ranges from 3 : 2 to 7 : 3;
- the step (30CS) of the cylindrical body (32) of the seat pipe (30) is configured to house the poppet valve (40) corresponding to the axial length l2 of the lower bore (32BR2) of the seat pipe (30); and
- the said stem portion (34) of the seat pipe (30) is fixed with the fork bolt (75) by the virtue of external threads provided on the outer peripheral surface of the stem portion (34) and the matching internal threads provided on an annular collar (75C) of the fork bolt (75).
2. The front fork suspension (100) of a two wheeled vehicle as claimed in claim 1, wherein
- the poppet valve (40) is configured to comprise an upper bush (40U), a lower bush (40L) and a spring (40S);
- said lower bush (40L) has a cylindrical body (40LB) and a cylindrical stem portion (40P) orthogonally projecting out therefrom forming an inverted T-profiled unitary structure of the lower bush (40L);
- the upper bush (40U) is a hollow cylindrical body and is sleeved over the stem portion (40P) of the lower bush (40L) to have clearance fit; and
- the spring (40S) is concentrically positioned in between the upper bush (40U) and the body portion (40LB) of the lower bush (40L) thereby biasing the upper bush (40U) against the spring force of the spring (40) in non-operational condition of the poppet valve (40).

3. The front fork suspension (100) of a two wheeled vehicle as claimed in claim 2, wherein
- the upper bush (40U) of the poppet valve (40) is configured to slide over the stem portion (40P) of the lower bush (40L) in response to compression of the spring (40S) by the lower bush (40L) due to the influence of the fluid pressure in the high velocity condition during the compression stroke of the front fork (100);
- said poppet valve (40) is positioned in the step portion (30CS) of the seat pipe abutting against the flat surface (32FS) of the step portion (30CS) of the seat pipe (30); and
- said poppet valve (40) is configured to cover the damping orifice (C1) of the seat pipe (30) in the normal condition of the front fork (100).

4. The front fork suspension (100) of a two wheeled vehicle as claimed in claim 3, wherein
- the seat pipe (30) is configured to have a plurality of rebound damping orifices (R1 and R2), a plurality of compression orifices (C1, C2 and C3) and a damping orifice (A1) on its cylindrical body (32B) so as to allow the fluid communication in between the fork pipe (15) and the outer tube (10);
- the rebound damping orifices (R1 and R2) are positioned in proximity to the piston head (32H) of the seat pipe in a manner such that the orifice (R1) is located above the orifice (R2);
- the compression orifice (C1) is positioned in the lower bore (32BR2) of the seat pipe (30) and the compression orifices (C2 and C3) are positioned in the upper bore (32BR1) of the seat pipe (30);
- said compression orifices (C2 and C3) lie in the same horizontal plane above the position of the damping orifice (R1); and
- the orifice (A1) is positioned above the orifices (C2 and C3) making the vertical plane of the orifice (A1) orthogonal to the vertical plane of the orifices (C2 and C3).

5. The front fork suspension (100) of a two wheeled vehicle as claimed in claim 4, wherein
- the fork pipe (15) is configured to have a screw cap (60) fixed at its mouth with the help of the threads on the outer peripheral surface of the first stepped portion (60S1) of the screw cap (60) and the internal threads on the inner peripheral surface of the mouth of the fork pipe (15);
- said screw cap (60) is configured to have an elongated annular cap shaped profile having an annular flange portion (60F) and an annular body portion (60B) projecting out in radial direction from a thorough annular cavity (60C);
- said annular flange portion (60F) is configured to have two across flat surfaces (60AF) positioned diametrically opposite to each other on it outer peripheral surface; and
- the annular body portion (60B) is configured to project out axially from the annular flange portion (60F) of the screw cap (60) in an integral manner and has a plurality of stepped portions namely a first step portion (60S1), a second step portion (60S2) and a third step portion (60S3) formed over its outer peripheral surface.

6. The front fork suspension (100) of a two wheeled vehicle as claimed in claim 5, wherein
- the first stepped portion (60S1) and the third stepped portion (60S3) of the screw cap (60) is configured to have external threads formed over its outer peripheral surface;
- said stepped portions (60S1, 60S2 and 60S3) has the outer diameter in the order of ? 60S1 > ? 60S2 > ? 60S3;
- the annular cavity (60C) of the screw cap (60) has an internal step (60ST) formed at the interface of the second step portion (60S2) and a third step portion (60S3); and
- said internal step (60ST) is configured to house the check valve (55).

7. The front fork suspension (100) of a two wheeled vehicle as claimed in claim 5, wherein
- the fork pipe (15) is configured to house the main spring (20) in between the piston head (32H) of the seat pipe (32) and the upper surface of the set of spacers (23);
- said spacers (23) are positioned on the top inner surface of the axle clamp (70) and the said axle clamp (70) is fixed to the lower end (15L) of the fork pipe (15) with the help of the external threads provided on the outer peripheral surface and the internal threads provided on the inner peripheral surface of the axle clamp (70).
- the seat pipe (30) along with the piston head (32H) is partially positioned within the fork pipe (15) making the cylindrical body (32B) of the seat pipe (30) to pass through the cavity (60C) of the screw cap (60) maintaining a radial clearance (60RC);
- the stem portion (34) of the seat pipe (30) is fixed with the annular collar (75C) of the fork bolt (75) in the outer tube (10); and
- the diameter of the cylindrical body (32B) of the seat pipe (30) is greater than the diameter of the stem portion (34) of the seat pipe (30).

8. The front fork suspension (100) of a two wheeled vehicle as claimed in claim 7, wherein
- the fork bolt (75) is fixed to the top end of the outer tube (10) with the help of threaded connection;
- the bottom cap (BC) is threaded over the third stepped portion (60S3) of the screw cap (60) and the check valve (60) is axially sandwiched in between said third step portion (60S3) of the screw cap (60) and the bottom cap (BC);
- the rebound spring (RS) is positioned between the upper surface (US) of the piston head (32H) of the seat pipe (32) and the bottom cap (BC);
- the bump stop (65) is affixed on the outer peripheral surface of the cylindrical body (32B) of the seat pipe (30) by means of a circlip (8) wherein the circlip (8) interferes with the inner peripheral surface of the bump stop (65) and a recess in the outer peripheral surface of the cylindrical body (32B) of the seat pipe (30); and
- the guiding and sealing assembly (25) comprising of a cylindrical guide (26), a washer (27), an oil seal (28), a dust seal (29) and a holding cover (31) is positioned in that order in the recessed portion given along the lower opening of the outer tube (10).

9. The front fork suspension (100) of a two wheeled vehicle as claimed in claim 8, wherein the outer tube (10) is configured to receive the fork pipe (15) coaxially and telescopically therein thereby forming a plurality of fluid chambers (A, B, C) wherein the chamber (A) is formed in between the top surface of the annular flange (60F) of the screw cap (60) and the lower surface of a fork bolt cavity (75C) of the fork bolt (75), the fluid chamber (B) (rebound chamber) is formed in between the upper surface (US) of the piston head (32H) of the seat pipe (30) and the lower surface of the bottom cap (BC), and the fluid chamber (C) is formed in between the lower surface (LS) of the piston head (32H) of the seat pipe (30) and the top inner surface of the axle clamp (70).

Dated this 25th day of Mar. 2025

Sahastrarashmi Pund
Head – IPR
Endurance Technologies Ltd.

To,
The Controller of Patents,
The Patent Office, at Mumbai.