Shock absorber with an adjustable lock-out value and two-stage flow restriction

Abstract

A suspension system with a shock absorber having a manually adjustable lock-out valve and a blow-off valve for controlling damping characteristics suitable for a wide variety of large, medium, and small bumps, and rider induced suspension action, while selectively providing a stiff suspension for increased drive line efficiency. The shock absorber includes a damper containing a non-compressible fluid. A piston dividing the chamber into two portions has a primary channel and a secondary channel. A lock-out valve is coupled to the primary channel and is manually movable from an open position to a closed position. In the closed position, the hydraulic fluid is blocked from flowing through the primary channel to provide stiffened damping characteristics of the damper. In the open position, the hydraulic fluid can flow through the primary channel to provide softened damping characteristics. A blow-off valve is positioned in the chamber's second portion adjacent to the secondary channel to block the secondary channels. The blow-off valve is movable relative to the secondary channel between closed and open position. Movement of the blow-off valve to the open position occurs when a critical hydraulic pressure is reached in the chamber to overcome the biasing member acting against the blow-off valve. A small gap is provided between the blow-off valve and the damper body to provide for smooth hydraulic fluid passage and to achieve supple shock absorber action when the blow-off valve is in the open position.