Claims:We claim:
1. A front fork of a two wheeler comprising a fork tube and a bottom case, said fork tube has at least two chambers, a piston rod assembly, a spring, wherein a floating piston is provided between said two chambers.
2. The front fork of a two wheelers as claimed in claim1, wherein said floating piston is restricted from a gas chamber from one side and a damping fluid chamber from the other side.
3. The front fork of a two wheelers as claimed in claim1, wherein said gas chamber is pressurized through a gas filing screw located on said front fork.
4. The front fork of a two wheelers as claimed in claim1, wherein said floating piston is secured through O rings.
, Description:An embodiment of the present invention will be described with reference to the accompanying figs 1 to 6.
A front fork assembly (1) is provided on a motorcycle (500) and made up of a pair of telescopic shock absorber such as front fork members (10)(figure 1 and figure 2), each secured to the steering stem (not shown) of the motorcycle (500) at or adjacent to the top of the front fork member (10). Each front fork member (10) is made up of a fork tube (100) closed by a cap (104) at the top thereof and a bottom case (105) or which is telescopically, sealably movable with respect to the upper fork tube (100) inside a bottom case (105). The front fork assembly may either be telescopic or inverted.
Each front fork member (10) is provided with a hollow cylindrical damper rod having an axial damper chamber and secured such as by means of a bolt (107) at the lower closed end of the lower fork tube (100). A damper piston is provided on the upper end of the damper rod (109) including a piston ring engaging the inside surface of the upper fork tube (10) which telescopically moves within the bottom case (105). An incompressible fluid, such as oil or hydraulic fluid is contained within the front fork member (10) for movement between various chambers for damping.
A main spring (106) is positioned between the top of the damper piston and the spacer tube (108) which closes the upper end of the upper fork tube to hold the front fork member in extended position and return it to extended position after compression. A cap oil lock (110) is provided for creating hydraulic lock during compression stroke while in varying conditions of operation of the front fork (10).
According to the present invention as illustrated in Figure 4, a fork member (11) is provided with a fork tube (100) and a bottom case (105). The internal floating piston (202) has O ring to avoid any leakage from one chamber to another. The internal floating piston is limited by air/ gas pressure chamber (207) on one side and oil chamber (208) or any other damping fluid on the other side. Further, a spring (106) along with a spring locator (205) is provided for compression and preload. Damping liquid or oil is limited in said oil chamber (208) between said floating piston (202) and piston assembly (203) connected to a piston rod (204). Gas or air pressure maintains required charging of the damping fluid in said oil chamber (208) in the front fork tube (100). Gas is filled through a gas filing screw (201) in said gas chamber (207). A bump stop (206) is provided for cushioning during extreme bottoming loads. During the operation of the front fork in an uneven surface, when the spring (106) is relieved from compression, damping liquid/ oil is transferred via valving action across the piston assembly (203). As a result of which adequate damping is provided in the front fork (11). The pressurized gas across the floating piston helps in achieving better damping characteristics and comfort in high velocity and low amplitude conditions. The present invention also enables a conventional design for front fork with internal floating piston without major modifications. Additionally, this invention can also be used in both cartridge and non-cartridge conventional models of front forks of two wheelers.
Although the embodiments of the present invention is described above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the scope of claims.