Claims:We Claim:

1. An inverted front fork (100) with damping control for suspension system of a motor vehicle comprising of an outer tube (15), a seat pipe (18), an inner tube (20), a bracket (25), a main spring (30), a bolt (10) and a guiding and sealing assembly (50)
wherein,
- the seat pipe (18) is rotationally locked with the bolt (10) with the help of locking means (14), preferably a nut (14); and said seat pipe (18) is concentrically fitted with an adjustment pipe (16) therein, and the adjustment pipe (16) is locked into its position within the seat pipe (18) by a locking means (16c), preferably circlip;
- the inner tube (20) is positioned so as to have the same central axis (X-X) as the outer tube (15) and is free to reciprocate telescopically within the outer tube (15);
- the lower end of the inner tube (20) is connected to the bracket (25); and a set of spacers (23) is positioned concentrically within the inner tube (20) and located above the bracket (25);
- the main spring (30) is positioned between the top portion of the seat pipe (18) and the upper surface of the set of spacers (23); and a rebound spring (31) is positioned between the lower surface of the piston shaped portion of the seat pipe (18) and a seat (20s) provided at the upper open end of the inner tube (20);
- the bolt (10) has an opening on each of its opposite flat surfaces, the said openings are concentric and forms a cavity therein to accommodate an adjustment means (5) and the said bolt (10) is mounted on the upper opening of the outer tube (15); and
- the guiding and sealing assembly (50) comprising of a cylindrical guide (51), a washer (52), an oil seal (53), a circlip (54), a dust seal (55) and a holding cover (56) is positioned in that order in the recessed portion given along the lower opening of the outer tube (15).

2. The inverted front fork (100) as claimed in claim 1, wherein
- the adjustment means (5) is connected to top portion of an adjustment rod (6);
- the adjustment rod (6) accommodates within its central opening a set of spherical balls (6b) with a spring (6s) given in between them, the spherical balls (6c) lock with matching notches given within a cylindrical piece (7);
- the cylindrical piece (7) is mounted concentrically with the lower portion of the adjustment rod (6) within the cavity of the bolt (10) and the lower end of an adjustment pipe (16) is located and fixed on the lower portion of the adjustment rod (6);
- the adjustment rod (6) and the adjustment pipe (16) form a positive lock in D-shaped interlock between the outer profile of the adjustment rod (6) and an inner profile of the adjustment pipe (16); and
- the seat pipe (18) accommodates the adjustment pipe (16) in a recessed portion given within the seat pipe (18) and said seat pipe (18) has a hollow cylindrical shape with a top portion having profile of a centrally open piston on the periphery of which a piston ring (19) is mounted.

3. The inverted front fork (100) as claimed in claim 2, wherein
- an O-ring stack (16rs) is positioned in recesses given on the curved outer surface of the adjustment pipe (16) so as to be located between the adjustment pipe (16) and the recessed inner curved surface of the seat pipe (18);
- an O-ring (11) is positioned in a recess given on the curved outer surface of the bolt (10) so as to be located between the bolt (10) and the inner surface of the outer tube (15);
- an O-ring (6r) is positioned in a recess given on the curved outer surface of the adjustment rod (6) so as to be located between the adjustment rod (6) and the inner curved surface of the bolt (10);
- an O-ring (7r) is positioned in recess given in the curved inner surface of the bolt (10) so as to be located between the cylindrical piece (7) and the bolt (10); and
- an O-ring (18r) is positioned in a recess given on the curved inner surface of the seat pipe (18) so as to be located between the adjustment pipe (16) and the seat pipe (18).

4. The inverted front fork (100) as claimed in claim 3, wherein
- a plurality of orifice (16ou) are evenly distributed along the same horizontal plane (y’-y’) in a top portion of the curved surface of the adjustment pipe (16), the orifices from the plurality of orifice (16ou) are configured to be in alignment with orifice (18ou) of the seat pipe (18) which is provided in the same horizontal plane (y’-y’) as the orifices (16ou); and
- a plurality orifice (16od) are evenly distributed along the same horizontal plane (y’’’-y’’’) in a lower portion of the curved surface of the adjustment pipe (16); the orifices from the plurality of orifices (16od) are configured to be in alignment with orifice (18od) of the seat pipe (18) which is provided in the same horizontal plane (y’’’-y’’’) as the orifices (16od).

5. The inverted front fork (100) as claimed in claim 3, wherein
- a plurality of orifice (16ou) are evenly distributed along the same horizontal plane (y’-y’) in a top portion of the curved surface of the adjustment pipe (16), the orifices from the plurality of orifice (16ou) are configured to be in alignment with orifice (18ou) of the seat pipe (18) which is provided in the same horizontal plane (y’-y’) as the orifices (16ou); and
- a plurality orifice (16od) are evenly distributed so as to form a spiral along the lower portion of the curved surface of the adjustment pipe (16), the orifice from plurality of orifices (16od) are configured to be in alignment with the orifice from plurality of orifice (18od) that are linearly arranged on lower portion of the seat pipe (18) so as to be in the same horizontal planes as the orifice from the plurality of orifice (16od).

6. The inverted front fork (100) as claimed in claim 3, wherein
- a plurality orifice (16ou) are evenly distributed so as to form a spiral along the top portion of the curved surface of the adjustment pipe (16), the orifices from plurality of orifices (16ou) are configured to be in alignment with the orifice from plurality of orifice (18ou) which are linearly arranged on top portion of the seat pipe (18) so as to be in the same horizontal planes as the orifice from the plurality of orifice (16ou); and
- a plurality orifice (16od) are distributed so as to form a spiral along the lower portion of the curved surface of the adjustment pipe (16), the orifices from plurality of orifices (16od) are configured to be in alignment with the orifice from plurality of orifice (18od) which are linearly arranged on lower portion of the seat pipe (18) so as to be in the same horizontal planes as the orifice from the plurality of orifice (16od).

7. The inverted front fork (100) as claimed in any of the claims 4 to 6, wherein a bump stop (9) having an elastic portion and a plastic portion is positioned on the outer curved surface of the seat pipe (18) by means of a circlip (8); and said circlip (8) interferes with the inner curved surface of the plastic portion of the bump stop (9) and a recess given in the outer curved surface of the seat pipe (18).

8. The inverted front fork (100) as claimed in claim 7, wherein
- a collar (17), a block (21), a leaf spring (22) and the seat (20s) given in that order, are fitted in a recessed portion along the open top end of the inner tube (20);
- a guide (20g) is positioned in a recess on the outer curved surface of the inner tube (20) below the open top end of the inner tube (20) so as to be located between the outer tube (15) and the inner tube (20); and
- a plurality of orifices (20h) is located and evenly distributed along a horizontal plane (y’’-y’’) below the guide (20g) of the inner tube (20).

9. The damping adjustable inverted front fork (100) as claimed in claim 8, wherein the adjustment means (5) is selected from a hand operated knob, hand operated lever and an electronically operated motor.

Dated this 28th day of October 2021.

Sahastrarashmi Pund
Head – IPR
Endurance Technologies Ltd.

To,
The Controller of Patents,
The Patent Office, at Mumbai. , Description: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
“AN INVERTED FRONT FORK WITH DAMPING CONTROL FOR SUSPENSION SYSTEM OF A MOTOR VEHICLE”

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

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

[001] The present invention is related to suspension system of a motor vehicle. More particularly, the present invention relates to an inverted front fork with damping control for suspension system of a two wheeled motor vehicle.

Background of the Invention

[002] The conventional inverted 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. It also has at least a damping assembly that dissipates the energy absorbed by the main spring during its compression and expansion. This damping assembly prevents excessive oscillations that would result from undamped compression and expansion of the main spring. Given the difficulty in altering the characteristics of the main spring and the damping assembly after the inverted front fork is assembled, engineers and/or persons skilled in the art ordinarily have to decide and fix one general purpose setting for both the main spring’s preload and the damping assembly’s compression and rebound damping. The predefined general purpose setting decide the suitability of driving a vehicle in a given loading and driving surface condition. Hence, it tends to affect the vehicle’s classification as well viz. off-road vehicles, racing vehicles, etc.

[003] During development of such conventional inverted front fork, multiple prototypes have to be built and tested in order to arrive at the ideal damping force settings. This need for building and testing multiple prototypes arises primarily because it is not possible to arrive at an accurate figure for damping force generated by an inverted front fork by using only theoretical methods. Ordinarily, a single set of inverted front fork is therefore repeatedly disassembled and reassembled with new sub-components and tested again and again until the ideal value of damping force is achieved. This manner of developing an inverted front fork to arrive at an ideal damping force setting consumes both time and money before a version of an inverted front fork is finalized. Even after extensive prototyping and testing the finalized inverted front fork cannot be said to be ideally suited for driving in any condition other than the driving condition in which it was tested.

[004] While the inverted front fork damping settings get fixed after the development phase, the requirement of a motor vehicle user don’t always remain the same. Expert riders, depending upon their determined requirement for a particular trip, may want to adjust damping settings of their suspensions. These changes may be carried out in coordination with engineers at well-equipped garages. In order to ensure safety of operation, such post manufacturing changes require excessive expenditure of both time and money. As such, even though the change may be required for a trip, the required expenditure of time and money makes the same unjustifiable for most of the riders. The conventional solutions to this problem require provision of complex mechanisms that make the inverted front fork difficult and harder to manufacture and quite costlier to provide in low end motor vehicles. Hence, there exists a long pending unmet requirement of providing an inverted front fork wherein damping settings can be adjusted safely and conveniently with ease of operation by the rider and is economic in nature.

Objectives of the Invention

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

[006] Another objective of the present invention is to provide an inverted front fork with damping control wherein the damping settings can be adjusted safely, conveniently and at ease of the motor vehicle users/riders and also is an economical solution.
[007] Yet, another objective of the present invention is to provide an inverted front fork with a damping control mechanism that can be easily adjusted during the development phase of the fork without requiring reworking of internal sub-components of the inverted front fork.

[008] Still another objective of the present invention is to reduce the development time and cost of an inverted front fork.

[009] Yet the objective of the present invention is to provide an inverted front fork with damping control system that is easy to manufacture and is an economical solution for low end motor vehicles.

[0010] Further objective of the present invention is to provide better ride comfort to the user / rider of the vehicle at low cost.

Summary of the Invention

[0011] In order to achieve the stated objectives, an inverted front fork (100) with damping control for suspension system of a motor vehicle has been provided which comprises of a bolt (10), an outer tube (15), a seat pipe (18), an inner tube (20), a bracket (25), a main spring (30), a guiding and sealing assembly (50). The bolt (10) has an opening on each of its opposite flat surfaces, the said openings are concentric and forms a cavity therein to accommodate an adjustment means (5) and the said bolt (10) is mounted on the upper opening of the outer tube (15). The seat pipe (18) is rotationally locked with the bolt (10) with the help of locking means (14), preferably a nut (14); and said seat pipe (18) is concentrically fitted with an adjustment pipe (16) therein, and the adjustment pipe (16) is locked into its position within the seat pipe (18) by a locking means (16c), preferably circlip. The inner tube (20) is positioned so as to have the same central axis (X-X) as the outer tube (15) and is free to reciprocate telescopically within the outer tube (15). The lower end of the inner tube (20) is connected to the bracket (25); and a set of spacers (23) is positioned concentrically within the inner tube (20) and located above the bracket (25). The main spring (30) is positioned between the top portion of the seat pipe (18) and the upper surface of the set of spacers (23); and a rebound spring (31) is positioned between the lower surface of the piston shaped portion of the seat pipe (18) and a seat (20s) provided at the upper open end of the inner tube (20). The guiding and sealing assembly (50) comprising of a cylindrical guide (51), a washer (52), an oil seal (53), a circlip (54), a dust seal (55) and a holding cover (56) is positioned in that order in the recessed portion given along the lower opening of the outer tube (15).

[0012] Typically, the adjustment means (5) is connected to top portion of an adjustment rod (6). The adjustment rod (6) accommodates within its central opening a set of spherical balls (6b) with a spring (6s) given in between them, the spherical balls (6b) lock with matching notches given within a cylindrical piece (7). The cylindrical piece (7) is mounted concentrically with the lower portion of the adjustment rod (6) within the cavity of the bolt (10) and the lower end of an adjustment pipe (16) is located and fixed on the lower portion of the adjustment rod (6). The adjustment rod (6) and the adjustment pipe (16) form a positive lock in D-shaped interlock between the outer profile of the adjustment rod (6) and an inner profile of the adjustment pipe (16) and the seat pipe (18) accommodates the adjustment pipe (16) in a recessed portion given within the seat pipe (18) and said seat pipe (18) has a hollow cylindrical shape with a top portion having profile of a centrally open piston on the periphery of which a piston ring (19) is mounted.

[0013] A plurality of orifices (16ou) are evenly distributed along the same horizontal plane (y’-y’) in a top portion of the curved surface of the adjustment pipe (16) and said orifices from the plurality of orifice (16ou) are configured to be in alignment with orifice (18ou) of the seat pipe (18) which is provided in the same horizontal plane (y’-y’). In another embodiment, a plurality of orifice (16ou) are evenly distributed along the same horizontal plane (y’-y’) in a top portion of the curved surface of the adjustment pipe (16), the orifices from the plurality of orifice (16ou) are configured to be in alignment with orifice (18ou) of the seat pipe (18). Yet in another embodiment, a plurality orifice (16ou) are evenly distributed so as to form a spiral along the top portion of the curved surface of the adjustment pipe (16) and the orifices from plurality of orifices (16ou) are configured to be in alignment with the orifice from plurality of orifice (18ou) which are linearly arranged on top portion of the seat pipe (18) so as to be in the same horizontal planes as the orifice from the plurality of orifice (16ou) and a plurality orifice (16od) are distributed so as to form a spiral along the lower portion of the curved surface of the adjustment pipe (16). The adjustment means (5) is selected from a hand operated knob, hand operated lever and an electronically operated motor.

Brief Description of the Drawings

[0014] 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

[0015] Figure 1 shows the isometric view of the inverted front fork in accordance with the present invention.

[0016] Figure 2 discloses a cut sectional view of the inverted front fork of Fig. 1 in accordance with the present invention.

[0017] Figure 3 shows an exploded view of the damping control system (40) shown in Fig. 2 in accordance with the present invention.

[0018] Figure 4 shows an exploded view of the sub-assembly provided in the inverted front fork that performs the damping control function as per the present invention.

[0019] Figure 5 presents a horizontal cut sectional view of the locking means provided with damping control system along the Y-Y plane of the inverted front fork shown in Fig. 3.

[0020] Figures 6a, 6b and 6c present an isometric view, a vertical cut sectional view and horizontal cut sectional views respectively of a seat pipe with a sleeve in accordance with the second embodiment of the present invention.

[0021] Figures 7a, 7b and 7c show an isometric view of a seat pipe, a sleeve and a vertical cut sectional view of the seat pipe with the sleeve, respectively in accordance with the third embodiment of the present invention.

[0022] Figure 8 shows top view of the inverted front fork with a damping control system in accordance with an embodiment of the present invention.

[0023] Figure 9 shows the perspective view of the top portion of the adjustment pipe (16) in accordance with the present invention.

Detailed Description of the Present Invention

[0024] 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. In accordance with the disclosed embodiments of the present invention, an inverted front fork (100) with damping control for suspension system of a motor vehicle comprises of an outer tube (15), a seat pipe (18), an inner tube (20), a bracket (25), a main spring (30), a bolt (10) and a guiding and sealing assembly (50) as shown in Figs. 1 and 2.

[0025] The main spring (30) of the inverted front fork (100) is positioned between the top portion of the seat pipe (18) and the upper surface of the set of spacers (23) (refer Figs 2 and 3). A rebound spring (31) is positioned between the lower surface of the piston shaped portion of the seat pipe (18) and a seat (20s) provided at the upper open end of the inner tube (20). The guiding and sealing assembly (50) comprising of a cylindrical guide (51), a washer (52), an oil seal (53), a circlip (54), a dust seal (55) and a holding cover (56) is positioned in that order in the recessed portion given along the lower opening of the outer tube (15).

[0026] The bolt (10) has an opening on each of its opposite flat surfaces, the said openings are concentric and forms a cavity therein to accommodate an adjustment means (5). The said bolt (10) is mounted on the upper opening of the outer tube (15). The seat pipe (18) is rotationally locked with the bolt (10) with the help of locking means (14), preferably a nut (14). The said seat pipe (18) is concentrically fitted with an adjustment pipe (16) therein, and the adjustment pipe (16) is locked into its position within the seat pipe (18) by a locking means (16c), preferably circlip. The circlip that performs locking can be replaced with a hollow cylindrical piece/spacer. The inner tube (20) is positioned so as to have the same central axis (X-X) as the outer tube (15) and is free to reciprocate telescopically within the outer tube (15). The lower end of the inner tube (20) is connected to the bracket (25). A set of spacers (23) is positioned concentrically within the inner tube (20) and located above the bracket (25). The spacers (23) permit/enable the utilization of a main spring (30) having shorter length. The bracket (25) has a plurality of mounting points (25a, 25b, 25c and 25d) that are utilized for attaching sensor(s) for a brake fluid pressure regulation system, for locating the wheel axle (within 25b) and for attaching a brake caliper.

[0027] The adjustment means (5) is connected to top portion of an adjustment rod (6) as shown in Fig. 3. The adjustment rod (6) accommodates within its central opening a set of spherical balls (6b) with a spring (6s) given in between them, the spherical balls (6b) lock with matching notches given within a cylindrical piece (7) as shown in Fig. 5. The cylindrical piece (7) is mounted concentrically with the lower portion of the adjustment rod (6) within the cavity of the bolt (10) and the lower end of an adjustment pipe (16) is located and fixed on the lower portion of the adjustment rod (6). The adjustment rod (6) and the adjustment pipe (16) form a positive lock in D-shaped interlock between the outer profile of the adjustment rod (6) and an inner profile of the adjustment pipe (16) (refer Figs. 3 and 9). This feature prevents any slippage between the adjuster rod (6) and the adjustment pipe (16) when the adjuster rod (6) is rotated. The seat pipe (18) accommodates the adjustment pipe (16) in a recessed portion given within the seat pipe (18) and said seat pipe (18) has a hollow cylindrical shape with a top portion having profile of a centrally open piston on the periphery of which a piston ring (19) is mounted.

[0028] The O-ring stack (16rs) is positioned in recesses given on the curved outer surface of the adjustment pipe (16) so as to be located between the adjustment pipe (16) and the recessed inner curved surface of the seat pipe (18) as referred in Figs. 3 and 4. An O-ring (11) is positioned in a recess given on the curved outer surface of the bolt (10) so as to be located between the bolt (10) and the inner surface of the outer tube (15). An O-ring (6r) is positioned in a recess given on the curved outer surface of the adjustment rod (6) so as to be located between the adjustment rod (6) and the inner curved surface of the bolt (10). An O-ring (7r) is positioned in recess given in the curved inner surface of the bolt (10) so as to be located between the cylindrical piece (7) and the bolt (10). An O-ring (18r) is positioned in a recess given on the curved inner surface of the seat pipe (18) so as to be located between the adjustment pipe (16) and the seat pipe (18).

[0029] In first embodiment of the inverted front fork (100), a plurality of orifices (16ou) are evenly distributed along the same horizontal plane (y’-y’) in a top portion of the curved surface of the adjustment pipe (16), the orifices from the plurality of orifice (16ou) are configured to be in alignment with orifice (18ou) of the seat pipe (18) which is provided in the same horizontal plane (y’-y’) as the orifices (16ou) (refer Figs. 3 and 4). A plurality orifice (16od) are evenly distributed along the same horizontal plane (y’’’-y’’’) in a lower portion of the curved surface of the adjustment pipe (16); the orifices from the plurality of orifices (16od) are configured to be in alignment with orifice (18od) of the seat pipe (18) which is provided in the same horizontal plane (y’’’-y’’’) as the orifices (16od). The adjustment pipe (16) and the seat pipe (18) of this embodiment are easy to manufacture. They allow inverted front fork (100) to provide damping adjustment setting options that are only limited by the number of orifices that can be safely provided along the horizontal planes (y’-y’, y’’’-y’’’).

[0030] In the second embodiment of the inverted front fork (100), a plurality of orifice (16ou) are evenly distributed along the same horizontal plane (y’-y’) in a top portion of the curved surface of the adjustment pipe (16), the orifices from the plurality of orifice (16ou) are configured to be in alignment with single orifice (18ou) of the seat pipe (18) which is provided in the same horizontal plane (y’-y’) as the orifices (16ou) (refer Figs. 6a, 6b and 6c). A plurality orifice (16od) are evenly distributed so as to form a spiral along the lower portion of the curved surface of the adjustment pipe (16), the orifice from plurality of orifices (16od) are configured to be in alignment with the orifice from plurality of orifice (18od) that are linearly arranged on lower portion of the seat pipe (18) so as to be in the same horizontal planes as the orifice from the plurality of orifice (16od). Figures 6b and 6c specifically highlight the distribution of orifices along the different section (1-1, 2-2 and 3-3) of the adjuster pipe (16) and the seat pipe (18) of this embodiment. The adjustment pipe (16) and the seat pipe (18) of this embodiment allow inverted front fork (100) to provide comparably more damping adjustment setting options as the orifices can be more widely and evenly distributed to prevent excessive weakening of the seat pipe (18).

[0031] In the third embodiment of the inverted front fork (100), a plurality orifices (16ou) are evenly distributed so as to form a spiral along the top portion of the curved surface of the adjustment pipe (16), the orifices from plurality of orifices (16ou) are configured to be in alignment with the orifice from plurality of orifice (18ou) which are linearly arranged on top portion of the seat pipe (18) so as to be in the same horizontal planes as the orifice from the plurality of orifice (16ou) (refer Figs. 7a, 7b and 7c). A plurality orifices (16od) are distributed so as to form a spiral along the lower portion of the curved surface of the adjustment pipe (16), the orifices from plurality of orifices (16od) are configured to be in alignment with the orifice from plurality of orifices (18od) which are linearly arranged on lower portion of the seat pipe (18) so as to be in the same horizontal planes as the orifice from the plurality of orifice (16od). The adjustment pipe (16) and the seat pipe (18) of this embodiment have orifices that are more widely and evenly distributed both along the top and lower portion of these sub-components, thereby allowing the inverted front fork (100) to provide the largest number of damping adjustment setting options. The wider distribution orifices in this embodiment prevent excessive weakening of the seat pipe (18).

[0032] In above embodiments of the invention, in the phrase ‘plurality of orifices’ the word plurality refers to any number in the range of two to twelve wherein both the numbers, starting number and ending number, are included. All the three embodiments of the inverted front fork (100), having different configurations of orifices on the adjustment pipe (16) and the seat pipe (18) (refer Figs. 4, 6a, 6b, 6c, 7a, 7b and 7c), are provided with a bump stop (9). The bump stop (9) having an elastic portion and a plastic portion is positioned on the outer curved surface of the seat pipe (18) by means of a circlip (8), the circlip (8) interferes with the inner curved surface of the plastic portion of the bump stop (9) and a recess given in the outer curved surface of the seat pipe (18) (refer Fig. 3). The inverted front fork (100) is also provided with, a collar (17), a block (21), a leaf spring (22) and the seat (20s) given in that order, that are fitted in a recessed portion along the open top end of the inner tube (20). A guide (20g) is positioned in a recess on the outer curved surface of the inner tube (20) below the open top end of the inner tube (20) so as to be located between the outer tube (15) and the inner tube (20). A plurality of orifices (20h) is located and evenly distributed along a horizontal plane (y’’-y’’) below the guide (20g) of the inner tube (20).

[0033] The adjustment means (5) of the inverted front fork (100) is selected from a hand operated knob, hand operated lever and an electronically operated motor (refer Figs. 1 and 8 for the knob). Unlike the knob shown in Fig. 8, the hand operated lever has only one gripping handle that extends radially outwards from the central axis of the inverted front fork (100). The hand operated lever provides greater leverage and hence makes it easier to rotate the adjuster rod (6) of the inverted front fork (100). If the electronically operated motor is opted for instead of the hand operated knob and the hand operated lever, it is the rotating central shaft of the motor that is connected with the top portion of the adjustment rod (6). Utilizing electronically operated motor can allow for greater degree of automation to be achieved in carrying out the damping adjustment in the inverted front fork (100).

[0034] When the adjustment means (5) of the inverted front fork (100) is operated/rotated, the adjustment rod (6) connected with the adjustment means (5) is also rotated (refer Fig. 3). This causes the spring (6s) to be compressed by the spherical balls (6b) as said balls (6b) climb and then descend into an adjacent internal notch of the cylindrical piece (7) (refer Fig. 5). The movement of the spherical balls (6b) into the adjacent notch of the cylindrical piece (7) fixes the adjustment rod (6) in the newly achieved orientation until the adjustment means (5) is operated/rotated again. The rotation of the adjustment rod (6) also causes rotation of the adjustment pipe (16) without causing any change in orientation of the seat pipe (18) itself. This change in orientation brings a fresh set of orifices (16ou and 16od) in alignment with the orifices (18ou and 18od) respectively. This change, alters the damping force achieved through the seat pipe (18) in the inverted front fork (100). The change in damping force has a direct relation with the selected size of the orifices of the adjustment pipe (16) and the seat pipe (18). This description pertaining to working of sub-components is applicable across all the described embodiments having different distribution of orifices on the adjustment pipe (16) and the seat pipe (18).

[0035] As the wheel of the motor vehicle moves over a bump on the road surface, the inner tube (20) moves telescopically into the outer tube (15). This compresses the main spring (30) and also causes the damping fluid to flow into the outer tube (15) through the opening of the centrally open piston of the seat pipe (18) and exit through the orifices (16ou, 18ou, 16od and 18od). Some of the damping fluid also flows past the collar (17) and block (21) and into the chamber formed between the seat (20s) and the lower surface of the centrally open piston of the seat pipe (18) after causing the block (21) to compress the leaf spring (22) that is located between the block (21) and the seat (20s). The set of orifices on adjustment pipe (16) and the seat pipe (18) that are aligned due to operation/rotation of adjustment means (5) determines the range of damping force values that are obtained during compression of the inverted front fork (100).

[0036] When the inner tube (20) moves further into the outer tube (15) and approaches the end of the full stroke length of the inverted front fork (100), the elastic portion of the bump stop (9) comes into contact with the lower end of the collar (17). Now if the inner tube (20) continues to move further into the outer tube (15), then the elastic portion of the bump stop (9) gets gradually compressed to bring any further vertically upwards movement of the inner tube (20) to a stop. Therefore, it prevents any metal to metal contact that may happen between the collar (17) and the bolt (10). The plastic/hard portion of the bump stop (9) (upon which the elastic portion is attached) transmits the load applied through the collar (17) onto the seat pipe (18) (via. the circlip (8)).

[0037] When the wheel has moved over the bump on road surface, the main spring (30) starts expanding to release its stored energy. This causes the inner tube (20) to begin moving vertically downwards and out of the outer tube (15). This change in direction of vertical movement also causes the flow of damping fluid to reverse. The damping fluid now flows into the seat pipe (18) through the orifices (18ou and 16ou, 18od and 16od) and exits into the inner tube (20) through the centrally open piston of the seat pipe (18). The valve formed by the collar (17), the block (21), the leaf spring (22) and the seat (20s) remains closed during expansion of the inverted front fork (100) allowing only extremely little amount of damping fluid to leak past it. The set of orifices on adjustment pipe (16) and the seat pipe (18) that become aligned due to operation/rotation of adjustment means (5) now determine the range of damping force values that are during expansion of the inverted front fork (100). As the expansion stroke approaches its end, the rebound spring (31), positioned between the lower surface of the piston shaped portion of the seat pipe (18) and a seat (20s) provided at the upper open end of the inner tube (20), compresses to absorb some of the energy during expansion of the main spring (30). This avoids metal to metal contact between the lower surface of the piston shaped portion of the seat pipe (18) and the seat (20s) of the inner tube (20).

[0038] The orifice(s) (20h) given on the inner tube (20) ensure that the guide (20g) remains lubricates by providing a path for the damping fluid to flow towards it. The guides (51 and 20g) guide the movement of the inner tube (20) and ensures perfect alignment of its central axis with the central axis of the outer tube (15). This reduces any chances of scratching of the curved surface the inner tube (20) during its reciprocating movement within the outer tube (15). This enhances the life of the oil seal (53) and the dust seal (55) as the chances of them getting damaged because of movement over scratched curved surface of the inner tube (20) is reduced. The holding cover (56) provides an additional degree of protection against damage that may be caused by dust, stones or any other foreign objects.

[0039] The O-ring stack (16rs) that is positioned in recesses given on the curved outer surface of the adjustment pipe (16) so as to be located between the adjustment pipe (16) and the recessed inner curved surface of the seat pipe (18), prevents flow of any damping fluid flow from in between the clearance provided between the adjustment pipe (16) and the seat pipe (18). The O-ring (11) that is positioned in a recess given on the curved outer surface of the bolt (10) so as to be located between the bolt (10) and the inner surface of the outer tube (15) works to prevent leakage of any damping fluid from in between the bolt (10) and the outer tube (15).

[0040] The O-ring (6r) that is positioned in a recess given on the curved outer surface of the adjustment rod (6) so as to be located between the adjustment rod (6) and the inner curved surface of the bolt (10), prevents any leakage of damping fluid from in between the adjustment rod (6) and the bolt (10). Similarly, the O-ring (7r) that is positioned in recess given in the curved inner surface of the bolt (10) so as to be located between the cylindrical piece (7) and the bolt (10) prevents any damping fluid leakage from in between the bolt (10) and the cylindrical piece (7). Lastly, the O-ring (18r) that is positioned in a recess given on the curved inner surface of the seat pipe (18) so as to be located between the adjustment pipe (16) and the seat pipe (18), prevents leakage of any damping fluid from in between the adjustment pipe and the seat pipe (18).

[0041] The provision of intelligently positioned O-rings as described above reduces/eliminates the chances of any leakage from in between relatively moving/stationary sub-components of the inverted front fork (100).

[0042] The technical advancements and advantages derived from the novel features of the embodiments of the present invention as disclosed and described above are as follows:
- It reduces the need for repeated disassembling and reassembling of the inverted front fork with new sub components during its development phase.
- It gives the user the option of safely changing the damping settings without having to open and alter sub-components of the inverted front fork.
- It reduces/eliminates the chances of leakage of damping fluid from in between the relatively moving/stationary sub-components of the suspension unit.
- The inverted front fork has a damping control that can be very easily made fully automatic.
- Its features can be utilized to reduce the need to rework or scrap an inverted front fork during post manufacturing damping test.

[0043] It must be noted that the disclosed invention hence achieves all its stated objectives. It provides a technologically advanced inverted front fork (100) and enables easy adjustment of damping settings by the rider of the vehicle as per the convenience. Any person skilled in the art can arrive at different options for the adjustment means (5), the locking means (14) and the locking means (16c) and incorporate them on the inverted front fork (100) without altering the functioning of the inverted front fork (100) in any significant manner. All such alterations must hence be considered to be lying within the scope of this invention. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.