US Patent 10107413 Self-contained gate valve column loading prevention mechanism

A valve assembly includes a valve body with a flow passage intersected by a valve cavity. A valve member is axially movable in the valve cavity between a closed position and an open position, the valve member having an opening that registers with the flow passage when the valve member is in the open position. A valve stem is threadingly connected to the valve member, the valve stem rotatable to move the valve member between the closed position and the open position. A collar assembly is located within a slot of the valve member and circumscribes the valve stem, the collar assembly having an annular collar shoulder. The valve stem has an annular load shoulder sized to engage the collar shoulder, limiting axial movement of the valve member.