Patent attributes
The invention is a dual spreading link mechanism for application with gate valves. The invention also extends to gate valves employing the inventive dual spreading link. In one application to pendulum gate valves, a valve carriage assembly moves in a pendular manner within a gate valve housing and operates to seal off the flow channel of the housing. The valve carriage assembly is comprised of a valve plate having a valve seat face for engaging with the housing in a sealing manner, a tensioning member which along with a plurality of clip springs provides a contracting force to the valve carriage assembly, and an actuating member which moves laterally within the carriage assembly to alternately spread and contract the assembly. The actuating member is stacked between the valve plate and tensioning member and the actuating member is coupled to the valve plate and tensioning member by a plurality of oblong rotatable links which comprise the dual spreading link.