DESC:HYDROSTATIC CENTERING ASSEMBLY FOR FRONT FORK

Field of invention:

The present invention relates to a front fork suspension assembly in two wheeled vehicles including motor cycles and scooters, and more particularly relates to a hydrostatic centering assembly for the front fork suspension assembly.

Background of the invention:

Two wheeler motor cycles and scooters are mounted with a set of front and rear suspension systems specially designed to a vehicle requirement to provide ride comfort. These are two critical parts of the vehicle which are undergoing movements while running on roads, piston rods of shock absorbers and inner tubes of the front forks which slide in and out experiencing maximum rubbing action and wear out. Even though Piston rods and Inner tubes are coated with Nickel and Hard Chrome plating for wear and corrosion resistance, wearing out of sliding parts have multiple cases which depends on mounting conditions, clearances between the sliding parts, structural material, its hardness and external conditions like mud, dust, etc., one of the causes of front fork inner tube waring out failure is the control on sliding clearances and mounting dimension control of wheel width, under bracket center distance and gap between front fork mounting face, and the like.

This creates a need by design to have a centralizing assembly provision which takes care of inner tube and outer tube clearances and does not exert excess side load resulting in abnormal rubbing and wearing out.

Accordingly, there exists need to provide a hydrostatic centering assembly for front fork, that can overcome the above-mentioned drawbacks in the prior art.

Object of the invention:

An object of the present invention is to provide a centralizing assembly unit for the front fork that takes care of inner tube and outer tube manufacturing tolerance on clearances from abnormal rubbing and wearing out.

Another object of the present invention is to enhance the life of the parts of front fork and avoid the in-convenience for replacement of whole Limb assembly.

Summary of the invention:

Accordingly, the present invention provides a hydrostatic centering assembly for front fork. The front fork of a motor cycle comprises an inner tube and an outer tube. The outer tube is placed at a bottom end (a wheel mounting side) of the front fork. The hydrostatic centering assembly comprises of a hydraulic chamber mounted on the outer tube of front fork at a top end thereof, a reservoir consisting of oil therein, a hydraulic hose, a piston rod mounted with a piston that pushes the oil in the reservoir during front fork compression movement and an under bracket arranged an intermediate part for joining a handle of the motor cycle and the front fork.

During every compression of the front fork, the oil in the reservoir is pumped into the hydraulic chamber creating a thin film of the oil with pressure that in-turn centralizes the inner tube with respect to the outer tube guiding clearance and the hydraulic chamber is guided upon the inner tube to provide support at nearest possible distance from rubbing area while the motor cycle is running, thereby avoiding metal to metal contact rubbing of the inner tube and outer tube and also avoiding unwanted crushing side pressure and scoring on oil seal.

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 the hydrostatic assembly front fork in accordance with the invention.

Detailed description of the invention:

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 hydrostatic centering assembly for front fork suspension of the motor vehicles that takes care of inner tube and outer tube clearances and does not exert excess side load, resulting in abnormal rubbing and wearing out. This feature enhances the life of the system which avoids an in-convince to replace the parts and experience a poor ride comfort.

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:
Component No: Component name:
100 Hydrostatic centering assembly
1 Hydraulic chamber
2 Reservoir
3 Inner tube
4 Outer tube
5 Hydraulic hose
6 Under bracket
7 Piston rod

Referring to the figure 1 a hydrostatic centering assembly (100) for a front fork (herein after referred to as “centering assembly (100)”) in accordance with the present invention is shown.

The front fork of a motor cycle comprises an inner tube (3) and an outer tube (4). The outer tube (4) is placed at a bottom end or a wheel mounting side of the front fork.

The centering assembly (100) comprises of a hydraulic chamber (1), a reservoir (2), a hydraulic hose (5), a piston rod (7) and an under bracket (6).

The hydraulic chamber (1) is mounted on the outer tube (4) of the front fork at a top end thereof. In an embodiment, the hydraulic chamber (1) takes a location in between an outer diameter of the inner tube (3) and an inner diameter of the outer tube (4).

The reservoir (2) consists of oil (not shown) filled therein. The oil inside the reservoir (2) pumps into the hydraulic chamber (1) during every compression of the front fork while driving.

The piston rod (7) is mounted with a piston (not shown) that pushes the oil in the reservoir (2) during front fork compression movement.

The under bracket (6) arranged as an intermediate part for joining a handle of the motor cycle and the front fork;

Again referring to the figure 1, in an operation of the centering assembly (100), the hydraulic chamber (1) is pressurized to a set value such that, the inner tube (3) gets a floating effect by the presence of a very thin hydraulic film between sliding parts of the inner tube (3) and the outer tube (4).

During every compression of front fork, the oil in the reservoir (2) is pumped into the hydraulic chamber (1) that creates a thin film of the oil with pressure. This thin film of the oil in-turn centralizes the inner tube (3) with respect to the outer tube (4) guiding clearance. The hydraulic chamber (1) is guided upon the inner tube (3) to provide support at the nearest possible distance from the rubbing area while the motor cycle is running. This helps the inner tube (3) and the outer tube (4) avoiding any chance of metal to metal contact rubbing. The hydraulic centralizing is only an external function to uniformly apply pressure between the inner tube (3) and the outer tube (4) during the movement of the front fork.

Advantages of the invention:

1. The hydrostatic centering assembly (100) avoids or minimizes physical rubbing of front fork parts.
2. The hydrostatic centering assembly (100) increases life of the front fork parts which is getting worn out leading to oil leakage.
3. The centralizing effect also avoids scoring and side pressure application on oil seal to have a better sealing function.

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 hydrostatic centering assembly (100) for a front fork, the front fork of a motor cycle comprising an inner tube (3) and an outer tube (4), wherein the outer tube (4) is placed at a bottom end (a wheel mounting side) of the front fork, the hydrostatic centering assembly (100) comprises of:
a hydraulic chamber (1) mounted on the outer tube (4) of the front fork at a top end thereof;
a reservoir (2) consisting of oil therein;
a hydraulic hose (5);
a piston rod (7) mounted with a piston that pushes the oil in the reservoir (2) during front fork compression movement;
an under bracket (6) arranged as an intermediate part for joining a handle of the motor cycle and the front fork; and
wherein, during every compression of the front fork, the oil in the reservoir (2) is pumped into the hydraulic chamber (1) creating a thin film of the oil with pressure that in-turn centralizes the inner tube (3) with respect to the outer tube (4) guiding clearance and the hydraulic chamber (1) is guided upon the inner tube (3) to provide support at nearest possible distance from rubbing area while the motor cycle is running, thereby avoiding metal to metal contact rubbing of the inner tube (3) and outer tube (4) tube and also avoiding unwanted crushing side pressure and scoring on oil seal.

2. The hydrostatic centering assembly (100) for the front fork as claimed in the claim 1, wherein the hydraulic chamber (1) takes a location in between an outer diameter of the inner tube (3) and an inner diameter of the outer tube (4).

3. The hydrostatic centering assembly (100) for the front fork as claimed in the claim 1, wherein the hydraulic chamber (1) is pressurized to a set value such that the inner tube (3) gets a floating effect by presence of a very thin hydraulic film between sliding parts of the inner tube (3) and the outer tube (4).

4. The hydrostatic centering assembly (100) for the front fork as claimed in the claim 1 is only an external function to uniformly apply pressure between the inner tube (3) and the outer tube (4) during the movement of the front fork.

Dated this on 22nd day of January 2019

Madhavi Vajirakar
(Agent for the applicant)
(IN/PA-2337)