DESC:DAMPER SYSTEM WITH GAS FILLING ARRANGEMENT
Field of the invention
The present invention relates to a gas filled damping system of an automobile and more particularly, to a novel arrangement for gas filling in a damper system.
Background of the invention
In conventional dampers, the inner tube is filled with oil and houses the shaft and piston. Conventional dampers are designed with hydraulic flow of oil from one chamber to other and the controlled resistance to oil flow between them is converted into a dampening effect. This resistance is known as the damping force value. The base valve directs oil flow into the outer tube (reservoir) during compression, contributing to the damping rate. During rebound, oil returns from the reservoir to the main chamber via a check valve. During the reciprocating motion of the piston rod with piston, it is bound to have a direction changeover from expanding to compressing and vice versa. During this changeover, damper experiences a lag due to want of oil at piston for providing resistance. This drawback is overcome with an introduction of gas which will push oil, maintain a constant pressure and ensure oil during transition motion. The outer tube is partially filled with compressible gas, which compensates for the shaft volume during compression and forces oil from the outer tube into the inner tube during rebound. Based on the restriction of oil seal designs conventional methods of gas charging include providing a gas passage through the piston, filling through oil seal lip opening, end-cap, filling between the gap of outer diameter of oil seal and inner diameter of outer tube, etc. These methods require additional child parts. This confusion and constraint has given rise to non-standard and complicated process for each variety of gas filled dampers. As discussed above, the disadvantage of this type of damper is that the design is complicated and requirement of expensive parts into it, to achieve the special effect of no-lag damping, which is a challenge to be eliminated for a simple design, child parts and a common process.
Hence, there exists a need of a technical advancement in the prior art that will overcome the above disadvantages.
Object of the invention
An object of the present invention is to provide a damper system with a collapsible retainer for gas filling.
Another object of the present invention is to provide a gas filled damper system with minimum child parts and simplified design.
Still another object of the present invention is to provide a gas filled damper system that will utilize the existing gas filling system.
Yet another object of the present invention is to provide a gas filled damper system having simplified child parts and a communized product design.
Summary of the invention
The present invention discloses a damper system comprising a piston assembly, an inner tube and an outer tube. The piston assembly includes a piston and a rod connected thereto. The piston assembly is slidably fitted in the inner tube with the rod extending through an opening in a rod guide fitted on the inner tube. The inner tube along with the piston defines an oil chamber. The outer tube is positioned about the inner tube defining a reservoir there between. The inner tube and the outer tube are engaged to slide freely with respect to each other. An oil seal fitted on the outer tube is having a circular opening through which the rod extends. The oil seal is held on a retainer plate having slots configured thereon, forming a gap between the oil seal and the rod guide, prior to filling of pressurized gas in the gas chamber. The gap allows gas filling into the gas chamber. The oil seal is pressed against the retainer plate and pushed to rest above the rod guide after filling of pressurized gas in the gas chamber. This seals the space between oil seal and the outer tube.
Brief description of the drawings
The objectives and advantages of the present invention will become apparent from the following description read in accordance with the accompanying drawings wherein,
Figure 1 shows the detailed view of a damping system of a vehicle with requirement of complicated child parts, in accordance with the Prior art; and
Figure 2 shows the detailed view of a gas filled damper system in accordance with the present invention.
Detailed description of the embodiments:
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 embodiments.
The present invention provides a gas filled damper system that overcomes the drawbacks of existing systems like requirement of multiple child parts, complicated design, requirement of expensive parts, etc. The gas filled damper system of present invention has simple common design, single oil seal design and a common Gas filling process with minimum child parts and simplified design. A specially designed slotted retainer plate is placed between a rod guide and an oil seal for providing a designed gap between them to allow the pressurized gas during gas filling operation.
The 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 and in the table below.
Table 1 :
Ref No: Component Ref No: Component
10 Outer tube 40 Oil chamber
15 Reservoir 60 Base valve
20 Inner tube 70 Oil seal
30 Piston assembly 75 Retainer plate
32 Piston 50 Prior art damper system
34 Piston rod 100 Damper system of present invention
35 Rod guide
Referring to figures 2a and 2b, a damper system (100) with gas filling arrangement (hereinafter referred as “the system (100)”) is shown in accordance with the present invention. The system (100) comprises of an outer tube (10), an inner tube (20) and a piston assembly (30).
The inner tube (20) is carrying a piston assembly (30) slidably fitted therein. The piston assembly (30) is having a piston (32) and a rod (34) connected thereto. The inner tube (20) is fitted with a rod guide (35) at upper end thereof. The rod guide (35) is having an opening for the rod (34) to extend there through. The inner tube (20) along with the piston (32) defines an oil chamber (40). A base valve (60) is fitted at a lower end of the inner tube (20)
The outer tube (10) is positioned about the inner tube (20) defining a reservoir (15) there between. The inner tube (20) and the outer tube (10) are engaged to slide freely with respect to each other. The rod (34) extends through an opening of an oil seal (70) engaging the outer tube (10). The base valve (60) directs oil flow into the outer tube (10) during compression, contributing to the damping rate.
The oil seal (70) is held on a retainer plate (75) having slots configured thereon. Referring to figure 2, the retainer plate (75) is designed to have a flexible / slotted fins which can form itself to the space available with the Oil seal (70) pressing force. In an embodiment, the retainer plate (75) is made of spring steel. The retainer plate (75) is having thickness ranging from 0.1 mm to 0.5 mm and having outer diameter in such a way that it initially rests on the outer tube (10) and does not allow the oil seal (70) and parts above it to get inserted into the outer tube (10).
Prior to filling of pressurized gas in the gas chamber (40) the retainer plate (75) is seated on opening of the outer tube (10) forming a gap (G) between the oil seal (70) and the rod guide (35) thereby allowing gas filling operation. When the system (100) is subjected to a closed chamber of gas which gets filled to a set pressure, it occupies the gap (G) created by special retainer plate (75). While filling gas through the open end of the outer tube (10), the slots in the retainer plate (75) allow the gas to enter into the outer tube (10). Once the pressurized gas is filled in the system (100), the oil seal (70) is pressed against the retainer plate (75) and pushed to rest above the rod guide (35). The retainer plate (75) gets deformed while it is inserted into the outer tube (10) along with the Oil seal (70) thereby sealing the space between the oil seal (70) and the outer tube (10). The outer tube (10) gets crimped to retain the gas inside the chamber and to seal the oil seal (70) and parts above it inside the outer tube (10).
Gas filling is done without changing the existing gas filling process and without the usage of child parts.
Advantages of the invention
1. The retainer plate (75) can be fitted in any damping system of a vehicle without any major alterations.
2. The present invention provides a simplified single oil seal design with a common gas filling process requiring minimum child parts and design.
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 scope of the invention.

,CLAIMS:We claim:
1. A damper system (100) having an arrangement for gas filling, the damper system (100) comprising:
an inner tube (20) carrying a piston assembly (30) slidably fitted therein, the piston assembly having a piston (32) and a rod (34) connected thereto; the inner tube (20) fitted with a rod guide (35) having a rod opening with the rod (34) extending there through; the inner tube (20) along with the piston (32) defining an oil chamber (40);
an outer tube (10) positioned about the inner tube (20) defining a reservoir there between, the inner tube (20) and the outer tube (10) engaged to slide freely with respect to each other; and
an oil seal (70) engaging open end of the outer tube (10) and having a circular opening, having the rod (34) extending there through;
characterized in that,
a retainer plate (75) having thickness ranging from 0.1mm to 0.5mm and having slots configured thereon is seated on opening of the outer tube (10) with the oil seal (70) held thereon, thereby creating a gap (G) between the oil seal (70) and the rod guide (35) prior to filling of pressurized gas in the gas chamber (40) thereby allowing the gas to pass through the slots into the reservoir, wherein the oil seal (70) pressed against the retainer plate (75) and pushed to rest above the rod guide (35) after filling of pressurized gas in the gas chamber (40) seals the space between oil seal (70) and the outer tube (10).
2. The damper system (100) as claimed in claim 1, wherein the retainer plate (75) is having 0.1mm thickness.
3. The damper system (100) as claimed in claim 1, wherein the retainer plate (75) is made up of spring steel.
Dated this on 18th day of December, 2019

Ashwini Kelkar
(Agent for the applicant)
(IN/PA-2461)