Claims:We Claim

1 A seal (100) for suspension system of a vehicle comprising of a sealing element (10), a reinforcing metal insert (30), and a reinforcement ring (40); wherein,
- the sealing element (10) is moulded in an elastomeric material and is profiled to have a first seal lip (12), a second seal lip (14), a third seal lip (16), a containment structure (18), a support structure (22) and at least one jutted profile (20);
said jutted profile (20) locks in an opening (32) of the reinforcing metal insert (30);
the support structure (22) projects downwards from the outer edge of the reinforcing metal insert (30) along the inner face of outer tube;
the first seal lip (12) as provided on the sealing element (10) curves inwards from the top inner edge of reinforcing metal insert (30), the second seal lip (14) as provided on the sealing element (10) curves inwards from the bottom inner edge of the reinforcing metal insert (30), and the third seal lip (16) is formed below the second seal lip (14) and projects further inwards following the slope of the second seal lip (14);
the containment structure (18) projects downwards below the bottom surface of the reinforcing metal insert (30) and is located between the support structure (22) and the reinforcement ring (40);
- said reinforcing metal insert (30) has at least one opening (32) matching with the profile of said jutted profile (20) so as to tightly accommodate the jutted profile (20) therein; and
- the reinforcement ring (40) is accommodated in a grooved profile (24) of the sealing structure.

2 The seal for suspension system of a vehicle as claimed in claim 1 wherein the jutted profile (20) of the sealing element (10) is selected from the group of cylindrical, frustum of a cone, inverted frustum of a cone, stepped cylindrical and inverted stepped cylindrical profiles.

3 The seal for suspension system of a vehicle as claimed in claim 2 wherein said seal (100) is mounted above the metal guide (50) and is tightly held in its position by the crimped edges (1A) of the outer tube (1) of the shock absorber (1000) in such way that the base of the jutted profile (20) is mandatorily oriented above the mouth (50A) of the supply passage (50AB) in the metal guide (50).

4 A seal (200) for suspension system of a vehicle comprising of a sealing element (210), a reinforcing metal insert (230), a reinforcement ring (240), and at least one plugging element (260); wherein,
- the sealing element (210) is moulded in an elastomeric material and is profiled to have a first seal lip (212), a second seal lip (214), a third lip seal lip (216), a containment structure (218), and a support structure (222);
the support structure (222) projects downwards from the outer edge of the reinforcing metal insert (230) along the inner face of outer tube;
the first seal lip (212) as provided on the sealing element (210) curves inwards from the top inner edge of reinforcing metal insert (230), the second seal lip (214) as provided on the sealing element (210) curves inwards from the bottom inner edge of the reinforcing metal insert (230), and the third seal lip (216) is formed below the second seal lip (214) and projects further inwards following the slope of the second seal lip (214);
the containment structure (218) projects downwards below the bottom surface of the reinforcing metal insert (230) and is located between the support structure (222) and the reinforcement ring (240);
- the plugging element (260) is removably fitted in and locks an opening (232) of the reinforcing metal insert (230);
- said reinforcing metal insert (230) has at least one opening (232) matching with the profile of said plugging element (260) so as to tightly accommodate the plugging element (260) therein; and
- the reinforcement ring (240) is accommodated in a grooved profile (224) of the sealing structure (210).

5 The seal for suspension system of a vehicle as claimed in claim 4 wherein the profile of the plugging element (260) is selected from the group of cylindrical, frustum of a cone, inverted frustum of a cone, stepped cylindrical and inverted stepped cylindrical profiles.

6 The seal for suspension system of a vehicle as claimed in claim 5 wherein said seal (100) is mounted above the metal guide (250) and is tightly held in its position by the crimped edges (1A) of the outer tube (1) of the shock absorber (1000) in such way that the base of the plugging element (260) is mandatorily oriented exactly above the mouth (250A) of the supply passage (250AB) in the metal guide (250).

7 A seal (300) for suspension system of a vehicle comprising of a sealing element (310), a reinforcing metal insert (330), a reinforcement ring (340), a plugging element (360), and a casing (370) of the plugging element (360); wherein,
- the sealing element (310) is moulded in elastomeric material and is profiled to have a first seal lip (312), a second seal lip (314), a third lip seal lip (316), a containment structure (318), and a support structure (322);
the support structure (322) projects downwards from the outer edge of the reinforcing metal insert (330) along the inner face of outer tube;
the first seal lip (312) as provided on the sealing element (310) curves inwards from the top inner edge of reinforcing metal insert (330), the second seal lip (314) as provided on the sealing element (310) curves inwards from the bottom inner edge of the reinforcing metal insert (330), and the third seal lip (316) is formed below the second seal lip (314) and projects further inwards following the slope of the second seal lip (314);
the containment structure (318) projects downwards below the bottom surface of the reinforcing metal insert (330) and is located between the support structure (322) and the reinforcement ring (340);
- said reinforcing metal insert (330) has at least one opening (332) so as to tightly accommodate the casing (370) therein through a fastening means;
- the casing (370) has a pin-hole on its top surface and is removably fitted in the opening (332) provided on the reinforcing metal insert (330);
- the plugging element (360) is removably fitted in the casing (370) and locks its opening (370A); and
- the reinforcement ring (340) is accommodated in a grooved profile (324) of the sealing structure (310).

8 The seal for suspension system of a vehicle as claimed in claim 7, wherein top portion of the casing has collar and the outer surface of casing (370) is configured to have fastening means selected from threads, notches for snap fit and press fit matching with the respective threads, notches on the inner surface of the opening (332) on the reinforcing metal insert (330).

9 The seal for suspension system of a vehicle as claimed in claim 8, wherein
- the inner surface profile of the casing (370) is selected from the group of cylindrical, frustum of a cone, inverted frustum of a cone, stepped cylindrical and inverted stepped cylindrical profiles; and
- the profile of the plugging element (360) is selected from the group of cylindrical, frustum of a cone, inverted frustum of a cone, stepped cylindrical and inverted stepped cylindrical profiles so as to match with the inner profile of the casing (370).

10 The seal for suspension system of a vehicle as claimed in claim 9 wherein said seal is mounted above the metal guide (350) and is tightly held in its position by the crimped edges (1A) of the outer tube (1) of the shock absorber (1000) in such way that the base of the plugging element (360) is oriented exactly above the mouth (350A) of the supply passage (350AB) in the metal guide (350).

Dated this 3rd day of Feb. 2021

(Sahastrarashmi Pund)
Head – IPR
Endurance Technologies Ltd.
, 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
“SEAL FOR SUSPENSION SYSTEM OF A 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 relates to suspension system of a vehicle. More particularly, the present invention relates to a seal for emulsion shock absorbers of a two wheeled vehicle that impart the tight sealing along with the other advantages.

Background of the Invention

[002] Conventionally, emulsion shock absorbers are filled with air using a gas filling and crimping manufacturing setup. During manufacturing, this specialized manufacturing setup at first loosely positions a seal on top of the rod guide of the shock absorber. It then forces a gas into the shock absorber from the top, allowing the gas to flow past the outer edge of the seal, through the rod guide and into the gas filled chamber of the emulsion shock absorber. This setup then partially folds upper edges of the outer tube to prevent the seal from getting displaced due to the pressure being exerted by the gas inside the shock absorber. While the top edge is being folded there is always the risk of seal getting displaced from its position, leading to leakage of filled up gas from the shock absorber. Given the nature of the manufacturing setup it is not possible to stop it as this happens. After the partial folding of upper edge of the outer tube is complete, it is extremely hard to unfold the partially folded edges and refill additional gas. This inevitably leads process rejections of otherwise defect free shock absorbers in some cases.

[003] Alternatively, to avoid this problem, the gas is being filled using a gas filling needle which is inserted in between the piston rod and the seal (i.e. after the seal has been positioned on the rod guide and its lips displaced slightly to allow the gas filling needle to move past it). The gas filling needle used during the process is likely to put the scratches on the piston rod surface thereby setting up sharp surfaces, sliding over which the seal can get damaged during usage of the shock absorber. Even the seal may get prone to the leakages through these scratches formed by the needle. The gas filling needle can also cut the seal lips if the workmen does not take care to fold them before inserting the gas filling needle. A lot of care is therefore required to be taken to avoid occurrence of any damage to the surface of the piston rod and also to the lips of the seal. Such surface damages are therefore hard to avoid, and as it inevitably lead to damage to the seal, the overall life of the shock absorber is also reduced. Therefore, this process require a skilled person to operate the needle for gas filling. Due to there being no provision of filling gas through the seal itself, these manufacturing process steps are also hard to avoid.

[004] Given the limitations of the manufacturing processes available and the product features otherwise available in the prior art for easily filling air in an emulsion shock absorber, there is a long pending unmet need for an oil seal that allows gas to be easily and repeatedly filled through it without needing any specialized gas filling setup and skilled man-power.

Objects of the Present Invention

[005] The main objective of the invention is to provide a seal for suspension system of a vehicle.
[006] Another object of the present invention is to provide a seal for suspension system of a vehicle wherein the seal enables to fill the gas easily and repeatedly without imparting any damage to the system.
[007] Still another objective of the present invention is to provide a suspension seal that is durable and is not easily dislodged from its place by the pressure of the gas filled inside the shock absorber.
[008] It is yet another objective of the present invention to provide a seal which enables the gas to be filled in the suspension without requiring any specialized gas filling setup.
[009] Yet, the objective of the present invention to provide a seal for emulsion shock absorber that eliminates the requirement of skilled manpower for gas filling operation.
[0010] Yet, the another objective of the present invention is to provide a seal for suspension system that provides effective sealing, requires less time for assembly thereby improving the productivity.

Summary of the Invention

[0011] With above objectives in view, the current invention provides a seal for suspension system of a vehicle comprising of a sealing element, a reinforcing metal insert, and a reinforcement ring wherein, a sealing element is moulded in elastomeric material with an unique profile to have a first seal lip, a second seal lip, a third lip seal lip, a containment structure, a support structure and at least one jutted profile; said jutted profile locks in an opening of the reinforcing metal insert; the support structure projects downwards from the outer edge of the reinforcing metal insert along the inner face of outer tube; the first seal lip as provided on the sealing element curves inwards from the top inner edge of reinforcing metal insert, the second seal lip as provided on the sealing element curves inwards from the bottom inner edge of the reinforcing metal insert, and the third seal lip is formed below the second seal lip and projects further inwards following the slope of the second seal lip; the containment structure projects downwards below the bottom surface of the reinforcing metal insert and is located between the support structure and the reinforcement ring; said reinforcing metal insert has at least one opening matching with the jutted profile of the sealing element so as to tightly accommodate the jutted profile therein; and the reinforcement ring is accommodated in a grooved profile of the sealing structure.

[0012] Typically, the jutted profile is selected from the group of cylindrical, frustum of a cone, inverted frustum of a cone, stepped cylindrical and inverted stepped cylindrical profiles. The seal is mounted above the metal guide and is tightly held in its position by the crimped edges of the outer tube of the shock absorber in such way that the base of the jutted profile is oriented above the mouth of the supply passage in the metal guide.

Brief Description of the Drawings

[0013] This invention is illustrated in the accompanying drawings, throughout which like reference letters 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
Figure 1 illustrates an emulsion shock absorber with the seal as per the first embodiment of the present invention.
Figure 2 illustrates an expanded horizontal cut section view of the region of the shock absorber fitted with the seal as per the first embodiment of the present invention.
Figures 3a, 3b, 3c and 3d illustrate the horizontal cut section of seal disclosing various forms of jutted profile with other different projected profiles as per the first embodiment of the present invention.
Figure 4 illustrates an emulsion shock absorber with the seal as per the second embodiment of the present invention.
Figure 5 illustrates an expanded horizontal cut section view of the region of the shock absorber fitted with the seal as per the second embodiment of the present invention.
Figures 6a, 6b, 6c and 6d illustrate the horizontal cut section of seal disclosing various profiles of the plugging element as per the second embodiment of the present invention.
Figure 7 illustrates an emulsion shock absorber with the seal as per the third embodiment of the present invention.
Figure 8 illustrates an expanded horizontal cut section view of the region of the shock absorber fitted with the seal as per the third embodiment of the present invention.
Figure 9a and 9b illustrate the horizontal cut section of seal disclosing the casing with different profiles of the plugging element therein the casing as per the third embodiment of the present invention.
Figure 10a illustrates the perspective view of a seal in accordance with first and second embodiment of the present invention.
Figure 10b illustrates the perspective view of a seal in accordance with third embodiment of the present invention.

Detailed Description of the Present Invention

[0014] A seal (100) for suspension system of a vehicle in accordance with the first embodiment of the present invention (refer Fig. 2, 3a, 3b, 3c, 3d and 10a) comprises of a sealing element (10), a reinforcing metal insert (30), and a reinforcement ring (40). The sealing element (10) of the seal (100) is moulded in elastomeric material to derive an unique profile having a first seal lip (12), a second seal lip (14), a third seal lip (16), a containment structure (18), a support structure (22) and at least one jutted profile (20) thereon. The reinforcing metal insert (30) is fitted in the sealing element (10) by the suitable adhesion means.

[0015] Referring Fig. 2, it is stated that the first seal lip (12) as provided on the sealing element (10) and curves inwards from the top inner edge of reinforcing metal insert (30). The second seal lip (14) also curves inwards from the bottom inner edge of the reinforcing metal insert (30). The third seal lip (16), that is formed below the second seal lip (14) and projects further inwards following the slope of the second seal lip (14). The containment structure (18) of the sealing element (10) projects downwards below the bottom surface of the reinforcing metal insert (30) and is located between the support structure (22) and the reinforcement ring (40). The support structure (22) of the sealing element (10) projects downwards from the outer edge of the reinforcing metal insert (30) along the inner face of outer tube. The reinforcement ring (40) of the seal (100) is accommodated in a grooved profile (24) of the sealing structure through suitable bonding means.

[0016] The reinforcing metal insert (30) of the seal (100) has at least one opening (32) having its sectional profile matching with the profile of said jutted profile (20) so as to tightly accommodate the jutted profile (20) therein. The jutted profile (20) therefore locks into the opening (32) of the reinforcing metal insert (30). The jutted profile (20) is selected from the group of cylindrical, frustum of a cone, inverted frustum of a cone, stepped cylindrical and inverted stepped cylindrical profiles (refer Fig. 2, 3a, 3b, 3c and 3d, respectively).

[0017] The seal (100) with the features as described above, is mounted on the metal guide (50) and is tightly held in its position by the crimped edges (1A) of the outer tube (1) of the shock absorber (1000) in such way that the base of the jutted profile (20) is oriented above the mouth (50A) of the supply passage (50AB) in the metal guide (50). So, when the seal (100) is being assembled, the workmen just has to place the seal (100) above the metal guide (50) while ensuring that the jutted profile (20) is mandatorily situated above the mouth (50A) of the supply passage (50AB) (refer Fig. 1 and 2). This is done so as to ensure that when air filling needle pierces through the jutted profile (20), it has some space to travel across on the other side in the mouth (50A) before it reaches and touches the surface of metal guide (50). When the seal (100) is locked in its position on the metal guide (50) by crimping the edges (1A) of the outer tube (1), the support structure (22) of the sealing element (10) deforms and seals any empty space between the seal (100), the metal guide (50) and the outer tube (1). The deformed support structure (22) on the reinforcing metal ring (30) firmly supports the seal (100) against the metal guide (50) and resists its movement due to frictional interaction between the lips (12, 14 and 16) and the piston rod passing through its center. Given that seal (100) can be pierced by an air filling needle along the jutted profile (20), the seal (100) can be locked into its position by the workmen without filling the shock absorber (1000) with air.

[0018] When the shock absorber (1000) starts operating, the oil film stuck to the surface of the piston rod moves along with it. The third seal lip (16) is the first to encounter this oil film, and it is also the first to act so as to reduce the thickness of this oil film. As the third seal lip (16) follows the slope of the second seal lip (14) while also projecting further inwards than the second seal lip (14), it is the most effective feature of the seal (100) for reducing the thickness of the oil film on the piston rod. The oil that is removed by the third seal lip (16) accumulates in between the seal (100) and the metal guide (50) till the pressure of the accumulated oil rises to a point sufficient for deforming the containment structure (18). As soon as the containment structure (18) deforms, the oil flows past it and into the mouth (50A) and then via the supply passage (50AB) back into the shock absorber (1000) (refer Fig. 1 and 2). A secondary containment structure (18A) of the sealing element (10) projects downwards from the reinforcing metal ring (30) and is located between the containment structure (18) and the support structure (22). The secondary containment structure (18A) provided so as to aid the containment structure (18) in resisting its deformation under pressure of the accumulated oil.

[0019] The oil film that remains on the piston rod once it moves past the third seal lip (16) is sufficient to lubricate its frictional interaction with the second seal lip (14) and the first seal lip (12). The curved profile between the first seal lip (12) and the second seal lip (14) acts to retain some amount of oil so as to ensure that when the shock absorber (1000) is operated the first seal lip (12) and the second seal lip (14) are not damaged (refer Fig. 2, 3a, 3b, 3c and 3d). Together the first seal lip (12) and the second seal lip (14) ensure that only a bare minimum amount of oil remains on the piston rod surface after it has moved past the first seal lip (12).

[0020] The jutted profile (20) shown in Fig 2, 3a, 3b, 3c and 3d allow the gas filling needle to pierce through it while filling gas in the shock absorber (1000). Once the air filling needle is withdrawn, under the action of force exerted by the pressurized gas present inside the shock absorber (1000), the flexible jutted profile (20) deforms to fill up and close the gap left by the withdrawing gas filling needle. This aids in retention of pressurized gas inside the shock absorber (1000). In case of the first embodiment of the present invention the jutted profile (20) is an integral feature of the sealing element (10) and is inserted in the opening provided on the reinforcing metal ring (30). The integrated and uniquely profiled structure of the sealing element (10) gives it significant strength to resist being unwittingly removed from the seal (100) by the gas filling needle during gas filling operation. It also gives it imparts strength to resist being pushed out by the pressurized gas filled inside the shock absorber (1000).

[0021] Referring to Fig. 2, in one variant of the jutted profile (20) of the sealing element (10) that is inserted in the opening provided on the reinforcing metal insert (30) is provided with a cylindrical shape. This cylindrical shape gives a balanced performance in both resisting being pushed out by the gas under pressure and also being pulled or pushed out by the gas filling needle during the gas filling operation. Referring to Fig. 3a, in another variant of the jutted profile (20) of the sealing element (10) is provided with shape of frustum of a cone. This projected profile is better at resisting the gas pressure when it tries to push it out of the opening (32) in the reinforcing metal insert (30), and it is also better at resisting being pulled out by the gas filling needle while it is being withdrawn after completion of the gas filling operation. Referring to Fig. 3b, in still another variant of the jutted profile (20) of the sealing element (10) is provided with the shape of an inverted frustum of a cone. This inverted frustum of cone shape is better at resisting being pushed into the shock absorber (1000) during piercing of the seal (100) during gas filling operation. Referring to Fig. 3c, in yet another variant of the jutted profile (20) of the sealing element is provided with a stepped cylindrical profile. This stepped cylindrical profile is structurally stronger along its wider section. This particular shape makes the jutted profile superior at resisting being pushed out by gas under pressure or being pulled out by gas filling needle that is withdrawing after gas filling operation has been completed. Referring to Fig 3d, in a further variant the jutted profile (20) of the sealing element is provided with an inverted stepped cylindrical profile. This inverted stepped cylindrical profile is stronger along its wider section. This inverted stepped cylindrical shape is better at resisting being pushed into the shock absorber (1000) during piercing of the seal (100) during gas filling operation.

[0022] A seal (200) for suspension system of a vehicle in accordance with the second embodiment of the present invention (refer Fig. 5, 6a, 6b, 6c and 6d) comprises of a sealing element (210), a reinforcing metal insert (230), a reinforcement ring (240), and a plugging element (260). A sealing element (210) is moulded in elastomeric material to derive an unique profile having a first seal lip (212), a second seal lip (214), a third seal lip (216), a containment structure (218), and a support structure (222). The plugging element (260) is made of suitable elastomeric material.

[0023] Referring Fig 5, it is stated that the first seal lip (212) as provided on the sealing element (210) curves inwards from the top inner edge of reinforcing metal insert (230). The second seal lip (214) as provided on the sealing element (210) curves inwards from the bottom inner edge of the reinforcing metal insert (230). The third seal lip (216) is formed below the second seal lip (214) and projects further inwards following the slope of the second seal lip (214). The containment structure (218) projects downwards below the bottom surface of the reinforcing metal insert (230) and is located between the support structure (222) and the reinforcement ring (240). The support structure (222) projects downwards from the outer edge of the reinforcing metal insert (230) along the inner face of outer tube. The reinforcement ring (240) is accommodated in a grooved profile (224) of the sealing structure (210).

[0024] The reinforcing metal insert (230) has at least one opening (232) matching with the profile of said plugging element (260) to as to tightly accommodate the plugging element (260) therein. The plugging element (260) is removably fitted in and locks an opening (232) of the reinforcing metal insert (230). The profile of the plugging element (260) is selected from the group of cylindrical, frustum of a cone, inverted frustum of a cone, stepped cylindrical and inverted stepped cylindrical profiles (refer Fig. 5, 6a, 6b, 6c and 6d).

[0025] The seal (200) is mounted above the metal guide (250) and is tightly held in its position by the crimped edges (1A) of the outer tube (1) of the shock absorber (1000) in such way that the base of the plugging element (260) is oriented exactly above the mouth (250A) of the supply passage (250AB) in the metal guide (250). So, when the seal (200) is being assembled, the workmen just has to place the seal (200) above the metal guide (250) while ensuring that the plugging element (260) is situated above the mouth (250A) of the supply passage (250AB) (refer Fig. 4 and 5). This is done so as to ensure that when air filling needle pierces the plugging element (260) it has some space to travel across on the other side in the mouth (250A) before it reaches and touches the surface of metal guide (250). When the seal (200) is locked in its position on the metal guide (250) by the crimping the edges (1A) of the outer tube (1), the support structure (222) deforms and seals any empty space between the seal (200), the metal guide (250) and the outer tube (1). The deformed support structure (222) of the sealing element (210) firmly supports the seal (200) against the metal guide (250) and resists its movement due to frictional interaction between the lips (212, 214 and 216) and the piston rod passing through its center. Given that seal (200) can be pierced by an air filling needle along the plugging element (260), the seal (200) can be locked into its position by the workmen without filling the shock absorber (1000) with air.

[0026] When the shock absorber (1000) operates, the oil film stuck to the surface of the piston rod moves along with it. The third seal lip (216) is the first to encounter this oil film, and it is also the first to act so as to reduce the thickness of this oil film. As the third seal lip (216) follows the slope of the second seal lip (214) while also projecting further inwards than the second seal lip (214), it is the most effective feature of the seal (200) for reducing the thickness of the oil film on the piston rod. The oil that is removed by the third seal lip (216) accumulates in between the seal (200) and the metal guide (250) till the pressure of the accumulated oil rises to a point sufficient for deforming the containment structure (218). As soon as the containment structure (218) deforms, the oil flows past it and into the mouth (250A) and then via the supply passage (250AB) back into the shock absorber (1000) (refer Fig. 4 and 5). A secondary containment structure (218A) of the sealing element (210) projects downwards from the reinforcing metal ring (230) and is located between the containment structure (218) and the support structure (222). The secondary containment structure (218A) is provided so as to aid the containment structure (218) in resisting its deformation under pressure of the accumulated oil.

[0027] The oil film that remains on the piston rod once it moves past the third seal lip (216) is sufficient to lubricate its frictional interaction with the second seal lip (214) and the first seal lip (212). The curved profile between the first seal lip (212) and the second seal lip (214) acts to retain some amount of oil so as to ensure that when the shock absorber (1000) is operated the first seal lip (212) and the second seal lip (214) are not damaged (refer Fig. 5, 6a, 6b, 6c and 6d). Together the first seal lip (212) and the second seal lip (214) ensure that only a bare minimum amount of oil remains on the piston rod surface after it has moved past the first seal lip (212).

[0028] The plugging element (260) (shown in Fig 5, 6a, 6b, 6c and 6d) allows the gas filling needle to pierce it while filling gas in the shock absorber (1000). Once the air filling needle is withdrawn, under the action of force exerted by the pressurized gas present inside the shock absorber (1000), the plugging element (260) being flexible, deforms to fill up and close the gap left by the withdrawing gas filling needle. This aids in retention of pressurized gas inside the shock absorber (1000). The plugging element (260) is firmly fitted into the opening provided in the reinforcing metal insert (230).

[0029] Referring to Fig. 5, in one variant of the plugging element (260) fitted in the opening on the reinforcing metal insert (230) is provided with a cylindrical shape. This cylindrical profile of the plugging element gives a balanced performance in both resisting being pushed out by the gas under pressure and also being pulled or pushed out by the gas filling needle during the gas filling operation. Referring to Fig. 6a, in another variant of the plugging element (260) fitted in the opening on the reinforcing metal insert (230) is provided shape of frustum of a cone. This profile of the plugging element is better at resisting the gas pressure when it tries to push it out of the opening (232) in the reinforcing ring (230), and it is also better at resisting being pulled out by the gas filling needle while it is being withdrawn after completion of the gas filling operation. Referring to Fig. 6b, still another variant of the plugging element (260) fitted in the opening on the reinforcing metal insert (230) is provided with the shape of an inverted frustum of a cone. This inverted frustum of cone shape of the plugging element is better at resisting being pushed into the shock absorber (1000) during piercing of the seal (200) during gas filling operation. Referring to Fig. 6c, in yet another variant of the plugging element (260) fitted in the opening on the reinforcing metal insert (230) is provided with a stepped cylindrical profile. This stepped cylindrical profile is structurally stronger along its wider section. This particular profile makes the plugging element better at resisting being pushed out by gas under pressure or being pulled out by gas filling needle that is withdrawing after gas filling operation has been completed. Referring to Fig 6d, in a further variant of the plugging element (260) fitted in the opening on the reinforcing metal insert (230) is provided with the shape of an inverted stepped cylindrical profile. This inverted stepped cylindrical profile is stronger along its wider section. This inverted stepped cylindrical shape of the plugging element is better at resisting being pushed into the shock absorber (1000) during piercing of the seal (200) during gas filling operation.

[0030] A seal (300) for suspension system of a vehicle in accordance with the third embodiment of the present invention (refer Fig. 8, 9a, 9b and 10b) comprises of a sealing element (310), a reinforcing metal insert (330), a reinforcement ring (340), a plugging element (360), and a casing (370) of the plugging element (360) wherein, a sealing element (310) is moulded in elastomeric material and is profiled to have a first seal lip (312), a second seal lip (314), a third seal lip (316), a containment structure (318), and a support structure (322). The top side of the casing is provided with collar portion and a pin-hole at its center whereas the outer surface of the peripheral sides of the casing is provided with fastening means that can be selected from the thread, notches, snap fit, press fit, adhesives, bonding means and like.

[0031] The first seal lip (312) as provided on the sealing element (310) curves inwards from the top inner edge of reinforcing metal insert (330). The second seal lip (314) as provided on the sealing element (310) curves inwards from the bottom inner edge of the reinforcing metal insert (330). The third seal lip (316) is formed below the second seal lip (314) and projects further inwards following the slope of the second seal lip (314). The containment structure (318) projects downwards below the bottom surface of the reinforcing metal insert (330) and is located between the support structure (322) and the reinforcement ring (340) (refer Fig. 8, 9a and 9b) . The support structure (322) projects downwards from the outer edge of the reinforcing metal insert (330) along the inner face of outer tube. The reinforcement ring (340) is accommodated in a grooved profile (324) of the sealing structure (310).

[0032] The reinforcing metal insert (330) has at least one opening (332) so as to tightly accommodate the casing (370) therein through a suitable fastening means. The outer surface of casing (370) is configured to have fastening means selected from threads, notches for snap fit matching with the respective threads, notches on the inner surface of the opening (332) on the reinforcing metal insert (330). The top surface of the casing is provided with a pin-hole so that the gas filling needle is easily passed through. The inner surface profile of the casing (370) is selected from the group of cylindrical, frustum of a cone, inverted frustum of a cone, stepped cylindrical and inverted stepped cylindrical profiles. The plugging element (360) is removably fitted in the casing (370) and locks its opening (370A). The profile of the plugging element (360) is selected from the group of cylindrical, frustum of a cone, inverted frustum of a cone, stepped cylindrical and inverted stepped cylindrical profiles so as to match with the inner profile of the casing (370) (refer Fig. 8, 9a and 9b).

[0033] The seal is mounted above the metal guide (350) and is tightly held in its position by the crimped edges (1A) of the outer tube (1) of the shock absorber (1000) in such way that the base of the plugging element (360) is oriented exactly above the mouth (350A) of the supply passage (350AB) in the metal guide (350). So, when the seal (300) is being assembled, the workmen just has to place the seal (300) above the metal guide (350) while ensuring that the plugging element (360) is situated above the mouth (350A) of the supply passage (350AB) (refer Fig. 7 and 8). This is done so as to ensure that when air filling needle passes through the casing and then pierces the plugging element (360) therein, it has some space to travel across on the other side inside the mouth of the passage before it reaches and touches the surface of the metal guide (350). When the seal (300) is locked in its position on the metal guide (350) by the crimping the edges (1A) of the outer tube (1), the support structure (322) which is made up of flexible material deforms and seals any empty space between the seal (300), the metal guide (350) and the outer tube (1). The deformed support structure (322) on the reinforcing metal insert (330) firmly supports the seal (300) against the metal guide (350) and resists its movement due to frictional interaction between the lips (312, 314 and 316) and the piston rod passing through its center. Given that seal (300) can be pierced by an air filling needle through the pin-hole of the casing and along the plugging element (360) therein, the seal (300) can be locked into its position by the workmen without filling the shock absorber (1000) with air.

[0034] When the shock absorber (1000) starts operating, the oil film stuck to the surface of the piston rod moves along with it. The third seal lip (316) is the first to encounter this oil film, and it is also the first to act so as to reduce the thickness of this oil film. As the third seal lip (316) follows the slope of the second seal lip (314) while also projecting further inwards than the second seal lip (314), it is the most effective feature of the seal (300) for reducing the thickness of the oil film on the piston rod. The oil that is removed by the third seal lip (316) accumulates in between the seal (300) and the metal guide (350) till the pressure of the accumulated oil rises to a point sufficient for deforming the containment structure (318). As soon as the containment structure (318) deforms, the oil flows past it and into the mouth (350A) and then via the supply passage (350AB) back into the shock absorber (1000) (refer Fig. 7 and 8). A secondary containment structure (318A) of the sealing element (310) projects downwards from the reinforcing metal insert (330) and is located between the containment structure (318) and the support structure (322). The secondary containment structure (318A) is provided so as to aid the containment structure (318) in resisting its deformation under pressure of the accumulated oil.

[0035] The oil film that remains on the piston rod once it moves past the third seal lip (316) is sufficient to lubricate its frictional interaction with the second seal lip (314) and the first seal lip (312). The curved profile between the first seal lip (312) and the second seal lip (314) acts to retain some amount of oil so as to ensure that when the shock absorber (1000) is operated the first seal lip (312) and the second seal lip (314) are not damaged (refer Fig. 8, 9a and 9b). Together the first seal lip (312) and the second seal lip (314) ensure that only a bare minimum amount of oil remains on the piston rod surface after it has moved past the first seal lip (312).

[0036] The casing (370) with pin-hole and the plugging element (360) therein shown in Fig 8, 9a and 9b makes the gas filling needle to pass through the pin-hole of the casing (370) and then pierce the plugging element (360) while filling gas in the shock absorber (1000). Once the air filling needle is withdrawn, under the action of force exerted by the pressurized gas present inside the shock absorber (1000), the flexible plugging element (360) deforms to fill up and close the gap left by the withdrawing gas filling needle. This aids in retention of pressurized gas inside the shock absorber (1000). The plugging element (360) is firmly fitted into the casing (370) during the assembly of the seal (300) with the help of suitable adhesives and/or bonding means. The notches on the inside surface of the casing (370) aid in firmly holding the plugging element (360) inside the casing (370). The casing (370) is also firmly held by the reinforcing metal insert (330) as it has outer surface with fastening means selected from threads, notches for snap fit matching with the respective threads, notches on the inner surface of the opening (332) on the reinforcing metal insert (330). The said casing (370) can be fitted in the opening of the reinforcing metal insert (330) with the help of suitable fastening means, adhesives and bonding means and is held there tightly.

[0037] Referring to Fig. 8, in one variant of the casing (370) with the plugging element (360) fitted therein, the inner profile of the casing (370) is provided with the cylindrical shape. This cylindrical shape gives a balanced performance in both resisting being pushed out by the gas under pressure and also being pulled or pushed out by the gas filling needle during the gas filling operation. Referring to Fig. 9a, in another variant of the casing (370) with the plugging element (360) fitted therein, the inner profile of the casing (370) is provided with the shape of the frustum of a cone. This profile is better at resisting the gas pressure when it tries to push it out of the opening (332) in the reinforcing ring (330), and it is also better at resisting being pulled out by the gas filling needle while it is withdrawing after completion of the gas filling operation. Referring to Fig. 9b, in still another variant of the casing (370) with the plugging element (360) fitted therein, the inner profile of the casing (370) is provided with stepped cylindrical profile. This stepped cylindrical profile is structurally stronger along its wider section. This particular shape makes this projected profile better at resisting being pushed out by gas under pressure or being pulled out by gas filling needle that is withdrawing after gas filling operation has been completed. The plugging element (330) can likewise also be given the profiles of frustum of a cone and a stepped cylinder for obtaining commensurate advantages in durability and ease of filling gas in the shock absorber (1000) without using any specialized gas filling setup and the skilled human resource

[0038] The technical advancements and benefits offered by the present disclosure include:
- That the seal as per the embodiments of the present invention is durable and impart effective sealing for the emulsion shock absorbers of the vehicles.
- The seal of the invention enables easy and repeated gas filling in the shock absorber.
- The seal of the invention eliminates the requirement of skilled human resource and the dedicated set-up of gas filling.
- The seal of the invention makes the gas filling operation quite easy and economic enabling the operator to fill the gas even after the assembly of the shock absorber which was not possible at all prior to this invention.
- The seal of the invention drastically reduced the rejection and rework activity of the shock absorbers.
- The seal of the present invention provides the emulsion shock absorbers with the improved quality.
- The seal of the invention reduces the assembly time drastically thereby improving the productivity.

[0039] The foregoing description of the specific embodiments 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. 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.