Shuttle Valve, Directional Control Valve Module, and Pneumatic or Hydraulic Assembly
Taylor & Edelstein obtains patent for client Voith for Shuttle Valve
This introduces an advanced shuttle valve designed for safety-critical hydraulic or pneumatic systems that control double-acting cylinders, such as those found in industrial presses, mobile machinery, aircraft flight controls, and heavy vehicle steering or braking systems. In these applications, two independent directional control valves are typically used in parallel for redundancy. However, conventional shuttle valves simply select the higher of two pressures, which creates a serious risk: if one directional valve fails and unintentionally applies full supply pressure to the cylinder, a standard shuttle valve will transmit that fault directly, causing the actuator to move uncontrollably at maximum speed or force.
The core innovation lies in a mechanically coupled dual-spool design with deliberately unequal pressure-acting surfaces. The valve has four inlet ports: two carrying the intended pressure for each side of the cylinder, each fed by one of the redundant directional valves. The two valve elements are positively linked, and the effective areas exposed to pressure on one element are significantly larger than those on the other. This area imbalance, combined with the mechanical coupling, ensures that the correctly functioning directional valve always dominates, even if the faulty valve outputs full system pressure on both lines.
As a result, the system remains fully controllable using only the healthy valve, without requiring electronic monitoring or additional switch-over logic. The design effectively implements a fast, purely fluidic “2-out-of-2” voting mechanism that blocks erroneous high-pressure signals while maintaining precise proportional control from the operational valve. This provides a compact, fail-operational solution for high-integrity positioning tasks, making it particularly valuable in applications where sudden loss of control could cause injury or major damage.
