DESC:“FRONT FORK TOP SEALING SPACER”
Field of the invention
The present invention generally relates to front suspension of a vehicle, more particularly it relates to a top sealing spacer for the front fork.
Background of the invention
A suspension connects a vehicle to its wheels and allows relative motion between them. Performance of the front suspension depends upon the spring, oil and the air load. The top mounting part of the suspension, i.e. the bolt cap, plays an important role in sealing and locking support to spring action. The oil inside the suspension remains intact due to the bolt cap. Spacer of the suspension is a steel tube, sandwiched between the bolt cap and the spring and acting as space filler, reducing the spring length. Referring to Figure 1, a cross sectional view of a front fork top sealing steel spacer assembly (100) in accordance with the prior art is shown. The prior art front fork top sealing assembly (100) includes a spacer (30) housed in the inner tube (40) with a bolt cap (20) with ‘O’ ring (10) at one end and a spring (50) at the other end of the said spacer (30). The spacer (30) is preferably a steel rod. Thus, in prior art design, the spacer (30) due to its limited contact surface and location contributes to the buckling or rubbing noise. Even though the spring length is reduced, the noise during limb operation is amplified due to limited contact of the spacer (30).
Accordingly, there exists a need to provide a spacer for front fork sealing, which overcomes drawbacks of the prior arts.
Objects of the invention
An object of the present invention is to prevent the oil leak from the front fork top sealing and to dampen the noise during limb operation.
Another object of the present invention is to use a spacer with suitable material, preferably a suitable plastic material, having flexibility to have required shape.
Yet another object of the present invention is to provide a feasibility of assembling the spacer with O-Ring housing at the spring side which gives an advantage of reducing oil quantity in front fork depending on the design.
Summary of the invention
The present invention provides a modified top sealing assembly for the front fork suspension of a vehicle. The steel spacer in the existing design is replaced by a spacer of suitable plastic material, having flexibility to have required shape. The spacer is having a ‘O’ ring housing configured at its one end. The spacer mounted with the ‘O’ ring is inserted into the inner tube of the front fork such that the ‘O’ ring is either at spring side or at the bolt cap side. Bolt cap, O-ring groove machining is made simpler, the function which is obtained as molded Plastic Spacer. The modified assembly of the present invention prevents the oil leak from the front fork top sealing and dampens the noise during limb operation.
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 cross sectional view of a front fork top sealing steel spacer assembly in accordance with the prior art.
Figure 2 shows cross sectional view of a modified front fork top sealing spacer assembly, in accordance with the present invention.
Figure 3 shows cross sectional view of a modified front fork top sealing spacer assembly, in accordance with an embodiment of the present invention.
Detailed description of the invention
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 spacer integrated with O-Ring for front fork top sealing. The modified spacer assembly with integrated O-Ring housing prevents the oil leak and helps in noise dampening. The spacer is made of an engineering plastic having flexibility to have a required shape.
The present invention is illustrated with reference to the accompanying drawings, wherein numbers indicated in the bracket represent the components of the invention throughout the description.
Referring now to Figure 2 and 3, a cross sectional view of the modified front fork top sealing spacer assembly (200) in accordance with the present invention is shown. The modified front fork top sealing assembly (200) includes a spacer (130) housed in the inner tube (140) with a bolt cap (120) at one end and a spring (150) at the other end of the said spacer (130). The spacer profile is modified to have an ‘O’ ring housing at its one end and the spacer (130) is made up of any suitable engineering plastic material having flexibility to have required shape, the engineering plastic includes but not limited to polystyrene, PVC, polypropylene, polyethylene, Acrylonitrile butadiene styrene (ABS), Nylon 6, Nylon 6-6, Polyamides (PA), Polybutylene terephthalate (PBT), Polycarbonates (PC), Polyetherether ketone (PEEK), Polyetherketone (PEK), Polyethylene terephthalate (PET), polyimides, Polyoxymethylene plastic (POM / Acetal), Polyphenylene sulfide (PPS), Polyphenylene oxide (PPO), Polysulphone (PSU), Polytetrafluoroethylene (PTFE / Teflon), or thermoplastic polyester elastomers like Hytrel or Zytrel, etc.
The spacer (130) is mounted with ‘O’ ring (110) and inserted into the inner tube (140) after spring assembly (150) such that the ‘O’ ring housing is either at the bolt cap side as shown in figure 2 or at the spring side as shown in figure 3. After inserting the spacer (130), the bolt cap (120) torquing is done to arrest the leak and noise. This modification simplifies the bolt cap design and bolt cap now acts only as a spring locking support. The feasibility of assembling the spacer upside down (‘O’ ring at spring side) helps in reducing the oil quantity and air gap in the limb assembly.
The modified spacer assembly (200) in accordance with the present invention improves the vehicle performance regarding the noise, oil leakage from front suspension and reduced cost of front suspension.
Advantages of the invention:
• Simplification in bolt cap and inner tube manufacturing process.
• Multi-function of spacer to eliminate noise and leak through top mounting.
• Weight reduction on spacer.(Material:-Steel tube to Plastic Spacer.)
• Weight reduction on Bolt Cap ( Shortened to have only threads )
• Reduced over all fork weight (3% Approximate.)
• Reduced child part complexity and machining draw-backs.
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.
,CLAIMS:We claim:
1. A top sealing spacer assembly (200) of a front fork suspension of a vehicle, the top sealing spacer assembly (200) comprising:
an inner tube (140) having a spring assembly (150) and a spacer (130) inserted therein; the spacer having a ‘O’ ring housing configured at one end thereof;
a bolt cap (120) closing the inner tube (140); and
an ‘O’ ring (110),
wherein, the spacer (130) with the ‘O’ ring (110) is inserted into the inner tube (140) after the spring assembly (150), with the ‘O’ ring at any one of the bolt cap (120) side and the spring assembly (150) side.
2. The top sealing spacer assembly (200) as claimed in claim 1, wherein the spacer is of engineering plastic material.
Dated this 17th day of August, 2017

Ashwini Kelkar
(Agent of Applicant),
(IN/PA-2461)