Claims:We claim:
1. A hydraulic damper for a suspension system 500 comprising an outer tube 210, an inner tube 200, a piston rod 50, a banded piston 170, a rod guide 90, a rebound stopper 100, two valves 120 and 160, two valve springs 110 and 150, a rod bush 130, a sleeve 140 and a rebound spring 180, wherein said rod bush 130 creates a hydraulic lock with said sleeve 140 at the end of rebound stroke of said suspension system 500.
2. The said hydraulic damper for a suspension system 500 as claimed in claim 1, wherein said rod bush 130 is having two uniform internal diameter insertion area (CC1DE and E1F) for said piston rod 50, adjoined together by a chamfered area (EE1) and two orifices (BB1) each having uniform diameter from where hydraulic fluid enters a chamber (QP1PNMLQ) adjoined by sleeve 140 and said sleeve 140 has a uniform internal diameter area BC and two chamfered portions (AB and CD).
3. The said hydraulic damper for a suspension system 500 as claimed in claim 1, wherein during the rebound stroke, said rod bush 130 fits into said sleeve 140 and where said valve 110 in combination with said valve spring 120 prevents passage of hydraulic fluid from said orifice BB1 to said chamber (QP1PNMLQ) creating a hydraulic lock and thereafter hydraulic fluid seeps out from a gap (AQ and LKJ) created between said sleeve 140 and said rod bush 130 and releasing the hydraulic lock.
4. The said hydraulic damper for a suspension system 500 as claimed in claim 1, wherein said gap (AQ and LKJ) and said chamber (QP1PNMLQ) between the said sleeve 140 and said rod bush 130 is of pre-determined dimension suitable for creating additional damping force.
5. The said hydraulic damper for a suspension system 500 as claimed in claim 1, wherein said sleeve is having varying internal diameter (CD).
6. The said hydraulic damper for a suspension system 500 as claimed in claim 1, said rod bush 130 is removably attached to piston rod 50 and said sleeve 140 is removably attached to the rod guide 90.
7. The said hydraulic damper for a suspension system 500 as claimed in claim 1 and claim 5, wherein overall length (A to D) of said sleeve 140 is increased by a predetermined dimension to generated additional damping force in-between the rebound stroke.
8. A hydraulic damper for a suspension system 500 comprising an outer tube 210, an inner tube 200, a piston rod 50, a banded piston 170, a rod guide 90, a rebound stopper 100, two valves 120 and 160, two valve springs 110 and 150, a rod bush 130, a sleeve 140 and a rebound spring 180, wherein said rod bush 130 creates a hydraulic lock with said sleeve 140 during compression stroke of said suspension system 500.
9. A hydraulic damper comprising an inner tube 200 outer tube 210, base valve 230, wherein said inner tube 210 is filled with hydraulic fluid and rod bush 130 and sleeve 140 are placed in a compression chamber adjacent to the base valve 230 to create a hydraulic lock during the end of compression stroke.
10. The said hydraulic damper for a suspension system 500 as claimed in claim 9, said rod bush 130 is removably attached to piston rod 50 and said sleeve 140 is removably attached to the inner tube 200.
, Description:The invention will now be described with reference to the accompanying drawings which do not limit the scope and ambit of the invention. The description provided is purely by way of example and illustration.
Figure 1 illustrates a sectional view of a shock absorber in accordance with the present invention and is generally indicated by reference numeral 500. The shock absorber as shown in Figure 1 is in extended position and comprises an inner tube 200 placed inside an outer tube 210. A metal seal 60, dust seal 70 (for preventing dust and the likes to enter in the suspension system), oil seal 80 (for preventing the leakage of oil from the suspension system) along with the piston assembly is connected to the inner tube 200 and outer tube 210. The piston assembly comprising of a rod guide 90, rebound stopper 100, valve spring 110, valve 120, rod bush 130, sleeve (straight) 140, valve spring 150, valve 160, banded piston 170, rebound spring 180 and piston nut 190. Base valve assembly 230 is given at the bottom of the inner tube 200 for generating required damping force for the compression stroke. The assembly rests on a spring seat 220 and is attached to a bottom cap assembly 240. The other end of the shock absorber 500 is attached with a lock washer 10 and a cushion rubber 20. The said shock absorber 500 is protected by a dust cover 30 and bump stop 40. The inner tube 200 is filled with hydraulic fluid. As and when road irregularities such as a pit, surfaces before the vehicle, the piston rod 50 compresses thereby pushing the piston 170 towards the base valve 230, the hydraulic fluid passes from the compression chamber to the rebound chamber through the orifices made on the piston, by deflecting the valve 160 and simultaneously from the base valve to the outer tube 210 generating required damping force during compression stroke. On the rebound stroke the fluid in the rebound chamber passes through the rod bush 130. The valve 120 acts as a non- return valve on the rebound stroke thereby providing resistance to the flow of fluid on the rebound stroke. Just before the end of the rebound stroke the sleeve (straight 140 or tapered 145) in combination with the rod bush 130 provides additional resistance to the flow of fluid from rebound chamber to the compression chamber and creates a hydraulic lock. The said rod bush 130 and sleeve (Straight 140 or Tapered 145) are removably attached to the shock absorber 500 facilitating easy assembly or disassembly for the purpose of suiting the specific requirements.
Figure 2 illustrates an exploded sectional view of a hydraulic damper or shock absorber (in an extended position) in accordance with the present invention and is generally indicated by reference numeral 500. The exploded view comprises of the same components as depicted in Figure 1 and are herein incorporated by reference.
Figure 3A, 3B and 3C illustrates a perspective view, top view and front view of the proposed rod bush 130 respectively. As shown in the figure 3C, the rod bush 130 is having a uniform internal diameter x from point C1 to point D; from point E1 to point F the internal diameter changes to x1 (where x is greater than x1). The change in diameter is to facilitate assembly of rod bush 130 with the piston rod 50 (illustrated in figure 1 and 2). The point from E to E1 and point C to C1 has been appropriately chamfered to avoid any sharp edges and facilitate assembly of piston rod 50 (illustrated in figure 1 and 2). From point B to B1 the rod bush 130 has orifices, each having diameter y. The orifices provide a passage for the flow of fluid during the rebound stroke. The rod bush 130 along with the sleeve (straight 140 or tapered 145) creates a chamber marked by point QP1PNMLQ. The fluid from this chamber passes to the compression chamber through the narrow gap between the sleeve area marked by LKL and the chamfered opening KJK and the corresponding sleeve area. The rod bush 130 along with the sleeve provides additional resistance to the flow of oil from chamber to the compression chamber. This additional resistance creates a hydraulic lock and safeguards the suspension from topping/extending out, preventing metal-to-metal contact between the adjoining parts.
Figure 4A, 4B and 4C illustrates a perspective view, top view and front view of the proposed sleeve 140 respectively. As shown in the figure 4C, the sleeve 140 is having uniform internal diameter x at point B to point C. The point from A to B and C to D has been chamfered to avoid sharp edges and facilitate assembly of components. Also, the overall length AD of the sleeve can be increased to create hydraulic lock and generate additional damping force in between the rebound stroke.
Figure 5A, 5B and 5C illustrates a perspective view, top view and front view of the proposed sleeve 145 (another embodiment of the proposed sleeve 140) respectively. As shown in the figure 5C, the sleeve 145 is having uniform internal diameter x from point B to Point C and proportionately changing internal diameter from point C to x1 at point D. The change in internal diameter is to facilitate the variation of the damping force as and when required. The point from A to B has been chamfered to avoid sharp edges and facilitate assembly of components. Also, the overall length AD of the sleeve (Straight 140 or Tapered 145) can be increased to create hydraulic lock and generate additional damping force in between the rebound stroke.
Figure 6 illustrates a sectional view of a hydraulic damper in accordance with the present invention and is generally indicated by reference numeral 500. The shock absorber as shown in Figure 6 is in compressed position and comprises an inner tube 200 placed inside an outer tube 210. A metal seal 60, dust seal 70 (for preventing dust and the likes to enter in the suspension system), oil seal 80 (for preventing the leakage of oil from the suspension system) along with the piston assembly is connected to the inner tube 200 and outer tube 210. The piston assembly comprising a rod guide 90, rebound stopper 100, valve spring 110, valve 120, rod bush 130, sleeve (straight) 140, valve spring 150, valve 160, banded piston 170, rebound spring 180 and piston nut 190. Base valve assembly 230 is given at the bottom of the inner tube 200 for generating required damping force for the compression stroke. The assembly rests at spring seat 220 and is attached to the bottom cap assembly 240. The other end of the shock absorber is attached with lock washer 10 and cushion rubber 20. The said shock absorber 500 is protected by said dust cover 30 and bump stop 40. The inner tube 200 is filled with hydraulic fluid. As seen from the figure the sleeve (straight 140 or tapered 145) comes in contact with the rod bush 130 just before the end of the rebound stroke to create a hydraulic lock and to provide additional resistance to the flow of hydraulic fluid. The said rod bush 130 and sleeve (Straight 140 or Tapered 145) can be removably attached to the shock absorber 500 facilitating easy assembly or disassembly for the purpose of suiting the specific requirements.
In another embodiment the present assembly is used to create hydraulic lock during compression stroke of the said suspension system 500 to provide additional resistance to the flow of oil and prevent metal to metal contact of components which adversely affect the damping performance of the hydraulic damper. The said rod bush 130 and sleeve (Straight 140 or Tapered 145) can be removably attached to the piston rod 50 and the rod guide 90 respectively in the rebound chamber of the shock absorber 500 facilitating easy assembly or disassembly for the purpose of suiting the specific requirements.
In yet another embodiment the present rod bush 130 and sleeve 140 is placed adjacent to the base valve 230 in the inner tube 200 to create hydraulic lock during the end of the compression stroke to avoid metal to metal contact between piston assembly and the base valve 230. The said rod bush 130 and sleeve (Straight 140 or Tapered 145) can be removably attached to the piston rod 50 and the inner tube 200 respectively in the compression chamber of the shock absorber 500 facilitating easy assembly or disassembly for the purpose of suiting the specific requirements. The preferred embodiment safeguards the vehicle from excessive bottoming load which can even lead to failure of hydraulic damper, thus saving the life of the rider in such situations.