FORM 2
THE PATENT ACT 1970
&
The Patents Rules, 2003
COMPLETE SPECIFICATION (See section 10 and rule 13)
1. TITLE OF THE INVENTION
"Dual Port Mono Tube Suspension System"
2. APPLICANT
(a) NAME : GABRIEL INDIA LIMITED
(b) NATIONALITY: An Indian Company registered under the provisions of
The Companies Act, 1956
(c) ADDRESS : 29th, Milestone, Pune Nasik Highway,
Village: Kuruli, Tal: Khed, Dist: Pune-410 501 (MH)
3. PREAMBLE TO THE DESCRIPTION
COMPLETE
The following specification particularly describes the invention and the
manner in which it is to be performed.

Field of the invention
The present invention relates to a suspension system of an automobile, more particularly, the present invention relates to a monotube type shock absorber having a combination of gas and oil for automobiles such as bikes, scooter, passenger car and the like.
Background of the invention
In the conventional monotube type damper and coil spring suspension system, the tension and compression damping values are generated by piston with valve assembly. The suspension systems also has a combined gas and oil type or only oil type having reservoir or accumulator for storing fluid such as hydraulic oil under gas pressure or no gas pressure. Generally, the suspension system includes a movable piston, a fixed base valve, a sealing mechanism for avoiding oil leak and coil spring also is part of this suspension system.
The monotube type shock absorber, the tension and compression damping pressures are generated using valve across the piston, which require a special design and the cost is high.
Accordingly, there exist a need to provide a suspension system for automobiles, which overcomes abovementioned drawbacks.
Object of the invention
An object of the present invention is to provide a suspension system, which is capable of providing better ride comfort to the vehicle.
Another object of the present invention is to provide a suspension system, which is compact in construction and can be configured on the existing shock absorber.

Yet another object of the present invention is to provide a suspension system, which is very lean and enables to provide very compact arrangement in vehicle design.
Summary of the invention
Accordingly, the present invention provides a dual port mono tube suspension system for automobiles, the system comprising a first cylindrical tube having oil/gas to generate compression damping, a second cylindrical tube reciprocatably secured with the first cylindrical tube, a top mounting element secured to a top portion of the second cylindrical tube, a spring rest adjustably disposed on the first cylindrical tube, and a spring member disposed between the top mounting element and the spring rest, characterized in that the system comprises:
a boss case end element secured to the first cylindrical tube below the spring rest;
an oil filling opening configured over the boss case end element for refilling the oil therein;
a connecting means configured on the boss case end element, wherein the connecting means is an extended opening; and
an oil reservoir connected to the first cylindrical tube though a connecting pipe,
wherein when oil/gas pressure/quantity in the first cylindrical tube is dropped due to continues operation, the drop is oil/gas pressure/quantity is compensated by using the oil/gas from the oil reservoir thereby maintaining quantity or pressure of gas/oil in the first cylindrical tube to generate the compression damping.
Brief description of the drawings
Figure 1 shows a perspective view of a dual port monotube suspension system, in accordance with the present invention;

Figure 2 shows a cross-sectional view of the a dual port monotube suspension system of figure 1;
Figure 3 shows an enlarged view of a boss case end of the dual port monotube suspension system of figure 2;
Figure 4 shows an enlarged view of a base valve assembly of the dual port monotube suspension system of figure 2; and
Figure 5 shows an enlarged view of a pressure tube of the dual port monotube suspension system of figure 2.
Detailed Description of drawings and working mechanism:
The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiment.
Accordingly, the present invention provides a dual port monotube suspension system type shock absorber and coil spring suspension type system having an accumulator for storing fluid, such as hydraulic oil, under gas pressure or without pressure, having fluid communication across movable piston and stationary base valve with valves arrangement so that the fluid is continually being transferred between the accumulator, the piston with valving and base valve case with valving, thus generating damping force in response to movement of the wheels of the vehicle on road with which the system is associated in use of the vehicle.

This present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.
Referring now to figure 1, there is shown a perspective view of a suspension system (100) for automobile in accordance with the present invention. For the purpose of explanation, the suspension system (100) is a monotube shock absorber system. The suspension system (100) includes a first cylindrical tube (10), a second cylindrical tube (15), a top mounting element (20), a spring rest (30), and a spring member (40). The improvement in the system (100) comprises a boss case end element (50), an oil filling opening (60), a connecting means (70), an oil reservoir (80) and a connecting pipe (90).
The first cylindrical tube (10) includes oil/gas to generate compression damping. The second cylindrical tube (15) is reciprocatably secured with the first cylindrical tube (10). In an embodiment, the first and the second cylindrical tubes (10 and 15) may be of any shape obvious to a person skilled in the art.
Further, the top mounting element (20) is secured to a top portion of the second cylindrical tube (15). The top mounting element (20) enables connecting upper end the system (100) to the vehicle. The spring rest (30) is adjustably disposed on the first cylindrical tube and the spring member (40) is disposed between the top mounting element (20) and the spring rest (30). The spring member (40) provides additional force to take-up additional load variations on the automobile.
Referring now to figure 2, there is shown a cross-section of the suspension system (100) (shock absorber) in accordance with the present invention. Specifically internal arrangement of the suspension system (100) is illustrated. The second cylindrical tube (20) is configured on a piston (12) reciprocating inside the first

cylindrical tube (10). The piston (12) includes a piston rod (14), an oil seal (16), a guide rod (18), a piston head (22) and a spring (24).
Now again referring to figure 1, the improvement in the system (100) comprises a boss case end element (50) (shown in detail in figure 3) secured to the first cylindrical tube (10) below the spring rest (30). The oil filling opening (60) is configured over the boss case end element (50) for refilling the oil therein. Furthermore, the connecting means (70) is configured on the boss case end element (50). The connecting means (70) is an extending opening. Also, a bottom mounting element (75) is configured on the connecting means (70). The bottom mounting element (75) enables connecting the lower end of the system (100) to the vehicle.
Further, the oil reservoir (80) is connected to the first cylindrical tube (10) though the connecting pipe (90). In an embodiment, the connecting pipe (90) is made of flexible rubber material.
Further, the suspension system (100) includes a base valve assembly (52) and a sealing ring (54). In an embodiment, the sealing ring (54) is made of rubber. The base valve assembly (52) (shown in figure 4) in the boss case end element (50) with the sealing ring (54) there-between. The oil filling opening (60) is closed by a screw with sealing ring there-between to prevent leakage. However, it may be evident to those skilled in the art to use any other sealing mechanism for oil filling opening (60).
Due to continues operation, the oil/gas pressure or quantity in the first cylindrical tube (10) may drop, the drop is oil/gas pressure or quantity is compensated by using the oil/gas from the oil reservoir (80), thereby maintaining quantity or pressure of gas/oil in the first cylindrical tube (10) or to generate the compression damping.

In an embodiment, the boss case end element (50) is made of steel or aluminium which has multiple connection suitability, for example, to the oil reservoir (80), oil filling opening (60) and a positive stop for base valve assembly (52). The boss case end element (50) also includes grooves holding the sealing ring (54) therein.
Further, the base valve assembly (52) is made of a base valve case and valving parts. The base valve case performs multiple functions. The outer diameter (52a) of the base valve assembly (52) is matched to inner diameter (50b) of the boss case element (50) for press fit assembly. The face (52c) the base valve assembly (52) is designed to sit on face (50d) of the boss case element (50). Further, the face (10a) of the first cylinder tube (10) is resting on face (52e) of the base valve. An outer diameter (10b) of the first cylindrical tube (10) is sealed for preventing oil leakage by the sealing ring (54).
The suspension system (100) of the present invention is very lean and enables to provide very compact arrangement in vehicle design. Further, the suspension system (100) compensates the loss of oil/gas in the first cylinder tube (10) by using the oil/gas from the oil reservoir (80), thereby maintaining quantity or pressure of gas/oil in the first cylindrical tube (10) and generating the compression damping.
The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure, or matter. The embodiments of the invention as described above and the methods disclosed herein will suggest further

modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the spirit and scope of the invention.

We Claim
1. A dual port mono tube suspension system for automobiles, tbe system
comprising a first cylindrical tube having oil/gas to generate compression
damping, a second cylindrical tube reciprocatably secured with the first
cylindrical tube, a top mounting element secured to a top portion of the second
cylindrical tube, a spring rest adjustably disposed on the first cylindrical tube, and
a spring member disposed between the top mounting element and the spring rest,
characterized in that the system comprises:
a boss case end element secured to the first cylindrical tube below the spring rest;
an oil filling opening configured over the boss case end element for refilling the oil therein;
a connecting means configured on the boss case end element, wherein the connecting means is an extended opening; and
an oil reservoir connected to the first cylindrical tube though a connecting pipe,
wherein when oil/gas pressure/quantity in the first cylindrical tube is dropped due to continues operation, the drop is oil/gas pressure/quantity is compensated by using the oil/gas from the oil reservoir thereby maintaining quantity or pressure of gas/oil in the first cylindrical tube to generate the compression damping.
2. The dual port mono tube suspension system as claimed in claim 1, wherein the second cylindrical tube is configured on the piston assembly reciprocating inside the first cylindrical tube.
3. The dual port mono tube suspension system as claimed in claim 1, wherein boss case end element comprises a base valve assembly and a sealing ring.

4. The dual port mono tube suspension system as claimed in claim 1 and 3, wherein the base valve assembly is made of a base valve case and valving parts.
5. The dual port mono tube suspension system as claimed in claim 1, wherein the oil filling opening is closed by a screw with sealing ring therebetween to prevent leakage.

6. The dual port mono tube suspension system as claimed in claim 1, wherein the boss case end element further comprises grooves for holding a sealing ring therein.
7. The dual port mono tube suspension system as claimed in claim 1 wherein a bottom mounting element is configured on the connecting means.