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
“INVERTED FRONT FORK SUSPENSION FOR TWO AND THREE WHEELED VEHICLES”

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 an inverted front fork suspension for a vehicle. More particularly, the invention is related to an inverted front fork adapted to generate high bottoming load so as to avoid the metal-to-metal contact and provide a comfortable ride to the user thereby.

Background of the Invention

[002] The two wheeler front forks are generally constructed using telescopic fork tubes disposed in the outer tubes either in the upright or upside down conditions. The upside down / inverted front forks have gained a much of popularity in the recent years due to its excellent rigidity and maneuverability. The said inverted front forks usually employ seat pipe or cartridge tubes as a damping mechanism and are used in accordance with the specific requirements.

[003] The cartridge type inverted front forks have the cartridge tube fixed concentrically within the fork pipe and the said fork pipe is telescopically mounted within the outer tube. The cartridge tube is closed at its top end by an adaptor bush and a main spring is positioned in between the adaptor bush and a fork bolt which is used to close the top end of the outer tube. A piston assembly is telescopically disposed within the cartridge tube wherein the said piston assembly generates the required damping force during the compression and rebound stroke of the front fork. During the compression stroke, the fork pipe slides within the outer tube and the piston assembly slides within the cartridge tube so as to generate the required damping forces. The fork pipe tends to contact with the fork bolt which leads to the generation of unwanted cyclic noise and also an early failure of the fork pipe. This problem is usually solved by creating the hydraulic lock in between an adaptor bush placed at the top end of the cartridge tube and a spring guide fixedly coupled to the fork bolt assembly. The hydraulic lock is capable of preventing the bottoming of the fork pipe wherein the damping forces are of less magnitude. Also, the hydraulic lock imparts a hard ride feel to the user due to the low compressibility of the damping oil present in the front forks.

[004] To address the aforementioned problem, there is a long pending unmet need to provide a solution that will ensure to provide the required bottoming load in high damping conditions, and provide a cushioning effect at the extreme compression stroke of the front fork.

Objectives of the Invention

[005] The main object of the present invention is to provide an inverted front fork for a two / three wheeled vehicle.

[006] Another object of the present invention is to provide an inverted front fork configured to have an adaptor bush with a floating piston disposed within the adaptor bush to provide high bottoming load.

[007] Yet another object of the present invention is to provide an inverted front fork that provides a superior cushioning effect in compression stroke.

[008] Still another object of the present invention is to provide an inverted front fork capable of generating the compression damping and rebound damping in different fork legs.
[009] Yet, another object of the present invention is to provide an inverted front fork wherein the adaptor bush of the inverted front fork is configured to provide constant bottoming load in high damping conditions.

[0010] Yet, another object of the present invention is to provide inverted front fork having reduced number of parts thus providing a cost effective solution.

Brief Description of the Drawings

[0011] This invention is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiment/s herein and advantages thereof will be better understood from the following description when read with reference to the following drawings, wherein

[0012] Figure 1 discloses an assembled isometric view of the inverted front fork of the vehicle in accordance with the present invention.

[0013] Figure 2 discloses an assembled front view of a compression / rebound leg assembly of the inverted front fork of the vehicle in accordance with the present invention.

[0014] Figure 3 discloses a sectional view of a compression leg assembly of the inverted front fork of the vehicle in accordance with the present invention.

[0015] Figures 4a and 4b disclose a break view of a compression leg assembly and enlarged view showing the adaptor bush and floating piston, respectively of the inverted front fork of the vehicle in accordance with the present invention.
[0016] Figure 5 discloses a sectional view of a rebound leg assembly of the inverted front fork of the vehicle in accordance with the present invention.

Detailed Description of the Present Invention

[0017] 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 the Figs. 1 to 5, the present invention discloses the inverted front fork suspension (1000) for two wheeled vehicles. The said inverted front fork suspension comprises of a compression leg assembly (200), a rebound leg assembly (400), a triple clamp (10C), and a steering shaft (12). The compression leg assembly (200) is configured to generate the damping in the compression stroke of the said front fork suspension (1000) while the rebound leg assembly (400) is configured to generate the damping in the rebound stroke of front fork suspension (1000). The compression leg assembly (200) and the rebound leg assembly (400) are filled with damping fluid and are joined through the triple clamp (10) to form the inverted front fork suspension (1000). The steering shaft (12) connects the inverted front fork (1000) with the handle bar of a two wheeled vehicle.

[0018] The compression leg assembly (200) includes an outer tube (10), an inner tube (20), a fork bolt (30), a first spacer (SP1), a second spacer (SP2), a sealing and guiding assembly (40), a floating piston (55), a piston ring (55R), a circlip (35), a bottom axle bracket (60), a main spring (70), a spring guide (80), a cartridge tube assembly (120T), a piston rod assembly (120C), and a damping adjustment assembly (DA). The cartridge tube assembly (120T) of the compression leg assembly (200) includes a cartridge tube (100), an adapter bush (90), a base valve (BV), a base tap (BT) and a lock bolt (50).

[0019] The said compression leg assembly (200) has the inner tube (20) positioned so as to have the same central axis as that of the outer tube (10) and is free to reciprocate telescopically within the outer tube (10). The lower end of the inner tube (20) is fixedly connected to the bottom axle bracket (60) and the upper end of the said inner tube (20) is free to slide in a telescopic manner within the outer tube (10). The cartridge tube assembly (120T) is positioned in the inner tube (20) and said cartridge tube (100) of the cartridge tube assembly (120T) is a hollow cylindrical tube having a lower open end (E1) and an upper open end (E2) and is fixed concentrically within the inner tube (20). The said cartridge tube (100) is configured to have two damping orifices (H) formed at its lower end (E1) and is fixed within the inner tube (20) in a manner such that the outer peripheral surface of the cartridge tube (100) forms an annulus fluid chamber (C1) with the inner peripheral surface of the inner tube (20).

[0020] The base tap (BT) is fixed within the cartridge tube (100) at its lower end and locked there with the help of the lock bolt (50). The base valve (BV) is concentrically placed over a stem portion of the base tap (BT) and locked there with the help of a locking bolt (50) wherein the locking bolt is screwed with the stem portion of the base tap (BT). The adapter bush (90) is fitted to the upper open end (E2) of the cartridge tube (100) and is positively locked there with the help of spinning process. The adaptor bush (90) is configured to have a cylindrical body (90B) at its lower end wherein a circular flange (90F) extends radially around the top end of the cylindrical body (90B). An annular collar (90C) projects out from the circular flange (90F) in a manner such that a fluid reservoir (90R) is formed within the inner peripheral surface of the annular collar (90C). The cylindrical body (90B) has a central opening to facilitate the passage of a piston rod (110) of the piston rod assembly (120C). The said adaptor bush (90) is made of a material selected from aluminum or sintered steel.

[0021] The damping adjustment assembly (DA) comprises of an adjuster knob (5), an adjuster screw (7), a locking bush (9), a set of spherical balls (B), a tube retainer (11), a detent spring (not shown) and an adjuster tube (13). The adjuster knob (5) is connected to the top portion of an adjuster screw (7) as shown in Figs. 2 and 3. The adjuster screw (7) accommodates the set of spherical balls (B) and the detent spring within its central opening. The spherical balls (B) lock with matching notches given within the locking bush (9). The locking bush (9) is mounted concentrically with the lower portion of the adjuster screw (7) within a cavity of the fork bolt (30). The said adjuster screw (7) is threadedly connected with the tube retainer (11) at its lower end. The tube retainer (11) is fixedly connected with the adjuster tube (13) so as to form a positive lock in D-shaped interlock between the outer profile of the tube retainer (11) and an inner profile of the adjuster tube (13). This feature prevents any slippage between the tube retainer (11) and the adjustment tube (13) when the adjuster screw (7) is rotated with the help of adjustment knob (5).

[0022] The piston rod (110) of the piston rod assembly (120C) is configured to house the adjuster tube (13) of the damping assembly (DA). The piston rod assembly (120C) includes the piston rod (110), a tap slit (17), a piston (85), a needle (19), a rebound spring (86), a stack of compression shims (120CS) and a needle spring (87). The piston rod (110) of piston rod assembly (120C) is locked with the fork bolt (30) at its top end with the help of a circlip (30C) and the adjuster tube (13) is housed within the piston rod (110) in a manner such that top end of said adjuster tube (13) is locked with the tube retainer (11) and the bottom end is configured to house the needle (19). Further, the bottom end of the piston rod (110) is fitted with the tap slit (17) wherein the piston (85) is concentrically fitted over the tap slit (17) in a manner such that the stack of compression shims (120CS) is positioned in between the tap slit (17) and the piston (85). The piston (85) is locked there with the help of a locking nut (85N).

[0023] The tap slit (17) is configured to have a longitudinal groove and a transverse groove wherein the longitudinal groove houses the needle (19). The said needle (19) is fitted with the adjuster tube (13) at its upper end and is configured to move telescopically within the longitudinal groove of the tap slit (17). The needle (19) and the tap slit (17) are jointly housed within the piston rod (110) in a manner such that the needle spring (87) is positioned in between the tap slit (17) and an annular collar of the needle (19). The needle spring (87) helps the needle (19) to regain its position during the damping adjustment. The piston (85) of the piston rod assembly (120C) is telescopically disposed within the cartridge tube (100) of the cartridge tube assembly (120T) thus forming a fluid chamber (C2) and a fluid chamber (C3) in the cartridge tube (100). The fluid chamber (C2) is formed in between the lower surface of the said piston (85) and the upper surface of the base valve (BV) and the fluid chamber (C3) is formed in between the upper surface of the said piston (85) and lower surface of the cylindrical body (90B) of the adaptor bush (90).

[0024] The floating piston (55) is positioned within the annular collar (90C) of the adaptor bush (90) in a telescopically slidable manner with the extreme upper position of the said floating piston (55) being fixed by a circlip (35). The floating piston (55) forms a fluid chamber (C4) and a fluid chamber (C5). The said chamber (C4) is formed in between the upper surface of the floating piston (55) and the lower surface of the fork bolt (30) and the chamber (C5) is formed in between the lower surface of the floating piston (55) and the upper surface of the cylindrical body (90B) of the annular collar (90C) of the adaptor bush (90). The said floating piston (55) has a circular cross-sectional shape and has a circumferential groove (55G) formed over its outer peripheral surface. The said groove (55G) is configured to house a piston ring (55R) which allows the passage of the damping fluid through it by the virtue of a plurality of orifices (not shown) formed over its outer peripheral surface. The floating piston (55) is configured to generate the bottoming load and prevent the metal to metal contact during the extreme compression stroke of the inverted front fork suspension (1000). During the extreme compression stroke, the spring guide (80) comes in contact with the upper surface of the floating piston (55) leading to the compression of the floating piston (55) within chamber (C5) formed in the annular collar (90C) of the adaptor bush (90). The compression of the floating piston (55) within the chamber (C5) leads to the displacement of the damping fluid from the chamber (C5) to the chamber (C4) with the help of the orifices provided in the piston ring (55R) thus generating the bottoming load. The piston ring (55R) having orifices allows the oil to squeeze gently through it and hence provides a cushioning effect along with the required bottoming load.

[0025] The circular flange (90F) of the adapter bush (90) is configured to accommodate the second spacer (SP2) provided therein to increase the pre-compression of the main spring (70). The said main spring (70) is positioned between the second spacer (SP2) and the first spacer (SP1) in a manner such that the top end (S1) of the main spring (70) abuts against the lower surface of the first spacer (SP1) and the bottom end (S2) of the said main spring (70) rests over the top surface of the second spacer (SP2). The spring guide (80) is concentrically placed in between the outer peripheral surface of the piston rod (110) and the inner diameter of the main spring (70) in a manner such that the said spring guide (80) is fixed with the piston rod (110) at its top end. The guiding and sealing assembly (40) comprising of a dust seal (106), an oil seal (107), a guide bush (108) and a holding cover (109) is positioned in that order in the recessed portion formed at the annular opening in between the outer tube (10) and inner tube (20).

[0026] The rebound leg assembly (400) includes an outer tube (10), an inner tube (20), a fork bolt (30), a spacer (SP), a sealing and guiding assembly (40), a floating piston (55), a piston ring (55R), a circlip (35), a bottom axle bracket (60), a main spring (70), a spring guide (80), a cartridge tube assembly (120R), a piston rod assembly (120D), and a damping adjustment assembly (DA). The cartridge tube assembly (120R) of the rebound leg assembly (400) includes a cartridge tube (100) and an adapter bush (90). The piston rod assembly (120D) includes the piston rod (110), a tap slit (17), a piston (85), a stack of rebound shims (120RS), a needle (19), a rebound spring (86), and a needle spring (87).

[0027] The rebound leg assembly (400) has the same configuration as the compression leg assembly (200) except for the fact that the piston rod assembly (120D) of the rebound leg assembly (400) has a stack of rebound shims (120RS) and the cartridge tube assembly (120R) of the rebound leg assembly (400) does not require the base valve (BV). The stack of rebound shims (120RS) is positioned on the lower surface of the piston (85) and locked there with the help of the lock nut (85N). This stack of rebound shims (120RS) facilitates the generation of rebound damping in the rebound stroke of the inverted front fork suspension (1000).
[0028] This unique construction of the inverted front fork suspension assembly (1000) of the present invention leads to complete elimination of components, viz. base valve, base tap and the stack of rebound shims in the compression leg assembly and the elimination of the stack of compression shims in the rebound leg assembly. Further, the floating piston positioned in the adaptor bush of the compression and rebound legs, helps to generate at par bottoming load in combination with the jerky effect as is prevalent in the conventional art of the inverted front fork suspension.

[0029] As far as the working of the present invention is concerned, the inner tube (20) along with the cartridge tube assembly (120T, 120R) slides in upward direction within the outer tube (20) of the compression leg assembly (200) and rebound leg assembly (400), respectively. At this time, the damping fluid from the chamber (C2) travels to the chamber (C1) through the base valve (BV) and the orifices (H) of the cartridge tube (100) in the compression leg assembly (200). Simultaneously, some of the damping fluid also travels from the chamber (C2) to chamber (C3) by deflecting the stack of compression shims (120CS) in the compression leg (200). At the same time, the damping fluid in the rebound leg assembly (400) travels from the chamber (C2) to the chamber (C1) through orifices (H) without any significant resistance. Thus during the compression stroke, only the compression leg assembly (200) is configured to generate the damping by the virtue of the base valve (BV) and the stack of compression shims (120CS).

[0030] The inner tube (20) along with the cartridge tube assembly (120T, 120R) slides in downward direction within the outer tube (20) of the compression leg assembly (200) and rebound leg assembly (400), respectively during the rebound stroke of the inverted front fork suspension (1000). At this time, the damping fluid from the chamber (C1) travels to the chamber (C2) through the base valve (BV) and the orifices (H) of the cartridge tube (100) in the compression leg assembly (200). The damping fluid in the rebound leg assembly (400) travels from the chamber (C1) to the chamber (C2) through orifices (H) while some of the damping fluid also travels from the chamber (C3) to chamber (C2) by deflecting the stack of rebound shims (120RS) in the rebound leg (200). Thus during the rebound stroke, only the rebound leg assembly (400) is configured to generate the damping by the virtue of stack of rebound shims (120RS).

[0031] The system of the present invention, in accordance with the discussed embodiments, provides the following technical advantages that contribute to the technical advancement:
- Provides high bottoming load along with the cushioning effect.
- The adaptor bush of the inverted fork of the present invention has a conical portion for receiving the main spring so that the active coil of the spring will not go under friction.
- The conical portion of the adaptor bush provides ease of sleeving / mounting of the spring over the adaptor bush.
- The adaptor bush of the inverted fork of the present invention is made with sintered metal, such as steel, which improves production efficiency and reduces costs due to less material waste and negligible machining required.
- Requires lesser number of parts thus providing cost effective solution.

[0032] The foregoing description of the specific embodiment of the invention will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. 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. An inverted front fork suspension (1000) for two wheeled vehicles comprising of a compression leg assembly (200), a rebound leg assembly (400), a triple clamp (10C), and a steering shaft (12), wherein
- the compression leg assembly (200) has a cartridge tube assembly (120T) positioned in an inner tube (20) and a piston rod assembly (120C) telescopically disposed within a cartridge tube (100) of the cartridge tube assembly (120T) thus forming a fluid chamber (C2) and a fluid chamber (C3) in the cartridge tube (100);
- the rebound leg assembly (400) has a cartridge tube assembly (120R) positioned in an inner tube (20) and a piston rod assembly (120D) telescopically disposed within a cartridge tube (100) of the cartridge tube assembly (120R) thus forming a fluid chamber (C2) and a fluid chamber (C3) in the cartridge tube (100);
- said the cartridge tube (100) of the cartridge tube assembly (120T, 120R) is configured to have an adapter bush (90) fitted to an upper open end (E2) and positively locked there with the help of spinning process;
- said adaptor bush (90) is configured to have a floating piston (55) positioned therein in a telescopically slidable manner with the extreme upper position of the said floating piston (55) being fixed by a circlip (35) thereby forming a fluid chamber (C4) and a fluid chamber (C5); and
- said compression leg assembly (200) and the rebound leg assembly (400) filled with damping fluid and joined to each other through the triple clamp (10) to form the inverted front fork suspension (1000) and the steering shaft (12) configured to connect the inverted front fork (1000) with the handle bar of a two wheeled vehicle.

2. The inverted front fork suspension (1000) as claimed in claim 1, wherein
- the cartridge tube assembly (120T) of the compression leg assembly (200) has a base tap (BT) fixed within the cartridge tube (100) at its lower end and locked there with the help of the lock bolt (50), and the base valve (BV) is concentrically placed over a stem portion of said base tap (BT) and locked there with the help of a locking bolt (50) wherein the locking bolt is screwed with the stem portion of the base tap (BT);
- said cartridge tube (100) is configured to have two damping orifices (H) formed at its lower end (E1) and is fixed within the inner tube (20) in a manner such that the outer peripheral surface of the cartridge tube (100) forms an annulus fluid chamber (C1) with the inner peripheral surface of the inner tube (20); and
- said inner tube (20) is fixedly connected to the bottom axle bracket (60) at its lower end and the upper end of the said inner tube (20) is free to slide in a telescopic manner within the outer tube (10).

3. The inverted front fork suspension (1000) as claimed in claim 2, wherein
- the adaptor bush (90) is configured to have a cylindrical body (90B) at its lower end and a circular flange (90F) extending radially around the top end of said cylindrical body (90B);
- the circular flange (90F) is configured to have an annular collar (90C) projecting out from it thereby forming a fluid reservoir (90R) within the inner peripheral surface of the annular collar (90C);
- said cylindrical body (90B) has a central opening to facilitate the passage of a piston rod (110) of the piston rod assembly (120C, 120D); and
- said adaptor bush (90) is made of a metal selected from aluminum and sintered steel.

4. The inverted front fork suspension (1000) as claimed in claim 3, wherein
- the piston rod assembly (120C) has a piston rod (110), a tap slit (17), a piston (85), a needle (19), a rebound spring (86), a stack of compression shims (120CS) and a needle spring (87);
- the piston rod assembly (120D) has the piston rod (110), a tap slit (17), a piston (85), a needle (19), a rebound spring (86), and a needle spring (87);
- said piston rod (110) of piston rod assembly (120C, 120D) is locked with the fork bolt (30) at its top end with the help of a circlip (30C) and an adjuster tube (13) of a damping adjustment assembly (DA) is housed within the piston rod (110) in a manner such that top end of said adjuster tube (13) is locked with the tube retainer (11) and the bottom end is configured to house the needle (19); and
- said tap slit (17) is fitted at the bottom end of the piston rod (110) and the piston (85) is concentrically fitted over the tap slit (17) and is configured to have a longitudinal groove and a transverse groove wherein the longitudinal groove is configured to house the needle (19).

5. The inverted front fork suspension (1000) as claimed in claim 4, wherein
- said needle (19) is fitted with the adjuster tube (13) at its upper end and is configured to move telescopically within the longitudinal groove of the tap slit (17) and the needle (19) and the tap slit (17) are jointly housed within the piston rod (110) in a manner such that the needle spring (87) is positioned in between the tap slit (17) and an annular collar of the needle (19);
- the needle spring (87) is configured to regain the needle (19) to its position during the damping adjustment;
- the stack of compression shims (120CS) of the is piston rod assembly (120C) is positioned in between the tap slit (17) and an upper surface of the piston (85) in the compression leg assembly (200);
- said stack of compression shims (120RS) of the is piston rod assembly (120D) is positioned in between the tap slit (17) and a lower surface of the piston (85) in the rebound leg assembly (400); and
- said piston (85) is locked there with the help of a locking nut (85N).

6. The inverted front fork suspension (1000) as claimed in claim 4, wherein
- the damping adjustment assembly (DA) is configured to comprise an adjuster knob (5), an adjuster screw (7), a locking bush (9), a set of spherical balls (B), a tube retainer (11), a detent spring and an adjuster tube (13);
- said adjuster knob (5) is connected to the top portion of an adjuster screw (7) and said adjuster screw (7) is configured to house a set of spherical balls (B) and the detent spring within its central opening;
- said spherical balls (B) are configured to lock with the matching notches given within the locking bush (9) and the locking bush (9) is mounted concentrically with the lower portion of the adjuster screw (7) within a cavity of the fork bolt (30);
- said adjuster screw (7) is threadedly connected with the tube retainer (11) at its lower end and the tube retainer (11) is fixedly connected with the adjuster tube (13) so as to form a positive lock in D-shaped interlock between the outer profile of the tube retainer (11) and an inner profile of the adjuster tube (13); and
- said positive locking is configured to prevent the slippage between the tube retainer (11) and the adjustment tube (13) when the adjuster screw (7) is rotated with the help of adjustment knob (5).

7. The inverted front fork suspension (1000) as claimed in claim 6, wherein
- the fork bolt (30) is configured to form the fluid chamber (C4) in the outer tube (20) in between the lower surface of the said fork bolt (30) and the upper surface of the floating piston (55);
- the piston (85) is configured to form a fluid chamber (C2) in between the lower surface of the said piston (85) and the upper surface of the base valve (BV) in the compression leg assembly (200) and in in between the lower surface of the said piston (85) and the upper surface of the base tap (BT) in rebound leg assembly (400);
- the fluid chamber (C3) is formed in between the upper surface of the piston (85) and lower surface of the cylindrical body (90B) of the adaptor bush (90) in the leg assembly (200, 400); and
- the chamber (C5) is formed in between the lower surface of the floating piston (55) and the upper surface of the cylindrical body (90B) of the annular collar (90C) of the adaptor bush (90) in the leg assembly (200, 400).
8. The inverted front fork suspension (1000) as claimed in claim 7, wherein
- the floating piston (55) has a circular cross-sectional shape and has a circumferential groove (55G) formed over its outer peripheral surface;
- said groove (55G) is configured to house a piston ring (55R) configured to allow the passage of the damping fluid through it by the virtue of a plurality of orifices formed over its outer peripheral surface and said floating piston (55) is configured to generate the bottoming load and prevent the metal to metal contact during the extreme compression stroke of the inverted front fork suspension (1000);
- the spring guide (80) is configured to come in contact with the upper surface of the floating piston (55) to the compress the floating piston (55) within chamber (C5) formed in the annular collar (90C) of the adaptor bush (90), during the extreme compression stroke of the inverted front fork suspension (1000);
- said compression of the floating piston (55) within the chamber (C5) displaces the fluid from the chamber (C5) to the chamber (C4) with the help of the orifices provided in the piston ring (55R) and thereby generating the bottoming load; and
- said piston ring (55R) having orifices is configured to allow the oil to squeeze gently through it and hence provides a cushioning effect along with the required bottoming load.

9. The inverted front fork suspension (1000) as claimed in claim 8, wherein
- the adapter bush (90) houses a spacer (SP2) at its circular flange (90F) to increase the pre-compression of the main spring (70);
- said main spring (70) is positioned between the spacer (SP2) and the spacer (SP1) in a manner such that the top end (S1) of the main spring (70) abuts against the lower surface of the spacer (SP1) and the bottom end (S2) of the said main spring (70) rests over the top surface of the spacer (SP2);
- the spring guide (80) is concentrically placed in between the outer peripheral surface of the piston rod (110) and the inner diameter of the main spring (70) in a manner such that the said spring guide (80) is fixed with the piston rod (110) at its top end; and
- a guiding and sealing assembly (40) comprising of a dust seal (106), an oil seal (107), a guide bush (108) and a holding cover (109) is positioned in that order in the recessed portion formed at the annular opening in between the outer tube (10) and inner tube (20).

10. The inverted front fork suspension (1000) as claimed in claim 9, wherein
- the inner tube (20) along with the cartridge tube assembly (120T, 120R) is configured to slides in upward direction within the outer tube (20) of the leg assembly (200, 400) during the compression stroke of the inverted front fork suspension (1000);
- the damping fluid from the chamber (C2) travels to the chamber (C1) through the base valve (BV) and the orifices (H) of the cartridge tube (100) in the compression leg assembly (200) and simultaneously from the chamber (C2) to chamber (C3) by deflecting the stack of compression shims (120CS) in the compression leg (200);
- the damping fluid in the rebound leg assembly (400) travels from the chamber (C2) to the chamber (C1) through orifices (H) without any significant resistance and during the compression stroke; and
- said compression leg assembly (200) only is configured to generate the damping by the virtue of the base valve (BV) and the stack of compression shims (120CS).

11. The inverted front fork suspension (1000) as claimed in claim 10, wherein
- the inner tube (20) along with the cartridge tube assembly (120T, 120R) is configured to slide in downward direction within the outer tube (20) of the leg assembly (200, 400) during the rebound stroke of the inverted front fork suspension (1000);
- the damping fluid from the chamber (C1) travels to the chamber (C2) through the base valve (BV) and the orifices (H) of the cartridge tube (100) in the compression leg assembly (200);
- the damping fluid in the rebound leg assembly (400) travels from the chamber (C1) to the chamber (C2) through orifices (H) and some of the damping fluid also travels from the chamber (C3) to chamber (C2) by deflecting the stack of rebound shims (120RS) in the rebound leg (200); and
- the rebound leg assembly (400) is configured to generate the damping by the virtue of stack of rebound shims (120RS) in the rebound stroke of the inverted front fork suspension (1000).

Dated this 28th day of Mar. 2025

(Sahastrarashmi Pund)
Head – IPR
Endurance Technologies Ltd.

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