DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2005

COMPLETE SPECIFICATION
(See section 10, rule 13)

1. TITLE OF THE INVENTION:

HIGH PRECISION FLOATING PISTON DAMPER

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, Maharashtra, India

3. PREAMBLE OF THE DESCRIPTION:

PROVISIONAL
The following specification describes the invention. COMPLETE
The following specification particularly describes the invention and the manner in which it is to be performed.

HIGH PRECISION FLOATING PISTON DAMPER

Field of the invention:

The present invention relates to shock absorbers and more particularly relates to a high precision floating piston damper.

Background of the invention:

Normally, the vehicles are mounted with suspension systems specially designed according to the vehicle requirements for providing ride comfort. Shock absorbers are better performed for its function when gas is charged along with the oil for its lag free damping changeovers and providing improved ride comfort. Rear shock absorbers are usually twin tube construction with variety of functional options, like only oil filled, gas filled by emulsion type and mono tube construction with bellow type or floating piston design. In all the above concepts either durability or mounting envelope space is a constraint, which is dependent on vehicle configuration. Looking into the recent designs, there is a need to develop gas charged damper with a shrinked space consideration to accommodate the new requirement. Floating piston designs are built with a constrain of gas filling chamber space and Gas filling pressure.

Accordingly, there exists need to provide an additional feature to the shock absorber that can overcome the drawbacks in the prior art.

Objects of the invention:

An object of the present invention is to accommodate the floating piston damper components in a limited space available inside the damper envelope.

Another object of the present invention is to provide a damper that can handle maximum gas filling to perform at the required minimum and maximum strokes.

Yet another object of the invention is to provide superior ride comfort to all vehicle segments with gas charged suspension.

Summary of the invention:

Accordingly, the present invention provides a high precision piston damper comprises a damper tube, a floating piston, a bellow and a mounting unit. The damper tube a top end and a bottom end. The floating piston is slidably inserted inside the damper tube such that a first chamber is formed between the bottom end of the damper tube and the floating piston and a second chamber is formed between the top end of the damper tube and the floating piston. The first chamber is filled with gas therein by using a nipple provided thereon. The second chamber is filled with oil therein.

A specially designed bellow is fixed to the floating piston. Specifically, the floating piston is configured with grooves thereon for fixing the bellow thereto. The bellow is a flexible membrane capable of expanding and suppressing inside the damper tube. Initially, the bellow expands toward the floating piston due to the pressure exerted by the gas. When the floating piston moves downwards, the bellow experiences pressure therefrom and starts expanding towards top end of the damper tube. This action provides gas pressure compensation to the damper.

This double action of the bellow also provides sufficient space inside the damper tube and facilitates more space for gas filling accordingly.

Brief description of the drawings:

The objects and advantages of the present invention will become apparent when the disclosure is read in conjunction with the following figures, wherein

Figure 1 shows longitudinal cutaway view of a high precision floating piston damper in accordance with the present invention;

Figure 2 shows perspective view of working of the floating piston damper in rebound stroke in accordance with the present invention;

Figure 3 shows perspective view of working of the floating piston damper in compression stroke in accordance with the present invention;

Figure 4 shows perspective sectional view of working of the floating piston damper in rebound stroke in accordance with the present invention;

Figure 5 shows perspective sectional view of working of the floating piston damper in compression stroke in accordance with the present invention;

Figure 6 shows a perspective view of a floating piston in accordance with the present invention;

Figure 7 shows a perspective view of a bellow in accordance with the present invention;

Figure 8 shows perspective and sectional views of working of the bellow in the rebound stroke in accordance with the present invention; and

Figure 9 shows perspective and sectional views of working of the bellow in the compression stroke in accordance with the present invention.

Detailed description of the embodiments:

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 embodiments.

The present invention provides a high precision floating piston damper that overcomes the constraints of gas filling chamber space and gas filling pressure inside the damper tube. The damper provides superior damping function within the space available.

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.

Component name: Component No:
High precision floating piston damper 100
Damper tube 10
Double action Bellow 11
First Chamber 12
Floating Piston 13
Second Chamber 14
Nipple 15
Mounting unit 16

Referring to the figures 1 to 9, there is shown a high precision piston damper (100) (hereinafter referred as, ‘the damper (100)’), in accordance with the present invention. The damper (100) comprises a damper tube (10), a bellow (11), a first chamber (12), a floating piston (13), a second chamber (14) and a mounting unit (16).

The damper tube (10) has a top end (not numbered) and a bottom end (not numbered). The mounting unit (16) is secured at the bottom end of the damper tube (10).

The floating piston (13) is slidably inserted inside the damper tube (10) such that the first chamber (12) is formed between the bottom end of the damper tube (10) and the floating piston (13) and the second chamber (14) is formed between the top end of the damper tube (10) and the floating piston (13). The first chamber (12) is filled with gas therein and the second chamber (14) is filled with oil therein. The first chamber (12) is provided with a nipple (15) that fills gas therein. The oil in the second chamber (14) experiences pressure in accordance with the floating piston (13) movements.

The floating piston (13) is fitted / fixed with the bellow (11). Specifically, the floating piston is configured with grooves (not numbered) (ref. Fig. 6) thereon for fixing the bellow (11) thereto.

The bellow (11) is a flexible membrane capable of expanding and suppressing inside the damper tube (10). Initially, the bellow (11) expands toward the floating piston (13) due to the pressure exerted by the gas. When the floating piston (13) moves downwards, the bellow (11) experiences pressure therefrom and starts expanding towards the top end of the damper tube (10). This action provides gas pressure compensation to the damper. This double action of the bellow (11) also provides sufficient space inside the damper tube (10) and facilitates more space for gas filling accordingly.

The elastic property of bellow (11) gets compressed upon inserting into the damper tube (10). This ensures that the bellow (11) is retained even during the movements in the damper tube (10). The direction and sequence of the movement of the damper tube (10) are taken so that gas will be retained between the bottom end of the damper tube (10) and the floating piston (13).

In the damper (100), the gas content in the first chamber (12) withstands the oil pressure generated by the floating piston (13) movements during compression and also to perform at the required minimum and maximum strokes.

The damper design is applicable for rear shock absorbers for both two wheeler and four wheeler applications.

Advantages of the invention:

1. A high gas pressure is achieved with a small damper envelope.
2. The damper (100) provides a unique design to accommodate all shock absorber applications with stroke constrains.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the scope of the claims of the present invention. ,CLAIMS:We claim:

1. A high precision floating piston damper (100) comprising:
a damper tube (10) having a top end and a bottom end;
a floating piston (13) slidably inserted inside the damper tube (10) such that,
• a first chamber (12) formed between the bottom end of the damper tube (10) and the floating piston (13), the first chamber (12) filled with gas therein, and
• a second chamber (14) formed between the top end of the damper tube (10) and the floating piston (13), and the second chamber (14) filled with oil therein,
characterized in that,
a bellow (11) fixed to the floating piston (13),
wherein, the bellow (11) is a flexible membrane capable of expanding and suppressing inside the damper tube (10) such that initially, the bellow (11) expands toward the floating piston (13) due to the pressure exerted by the gas and when the floating piston (13) moves downwards, the bellow (11) experiences pressure therefrom and starts expanding towards top end of the damper tube (11) thereby providing gas pressure compensation and also sufficient space inside the damper tube (10) to facilitate more space for gas filling.

2. The high precision piston damper (100) as claimed in claim 1, wherein the first chamber (12) is provided with a nipple (15) that fills gas therein.

3. The high precision piston damper (100) as claimed in claim 1, wherein the oil in the second chamber (14) experiences pressure based on movements of the floating piston (13).

4. The high precision piston damper (100) as claimed in claim 1, wherein the floating piston (13) is provided with grooves thereon for fixing the bellow (11) thereto.

5. The high precision piston damper (100) as claimed in claim 1, wherein a mounting unit (16) is secured at the bottom end of the damper tube (10).

6. The high precision piston damper (100) as claimed in claim 1, wherein the elastic property of the bellow (11) gets compressed upon inserting into the damper tube (10) to ensure that the bellow (11) is retained even during the movements in the damper tube (10).

Dated this 22nd day of June 2020

Madhavi Vajirakar
(Agent for Applicant)
IN/PA-2337