US Patent 8479808 Downhole tools having radially expandable seat member

Apparatuses for restricting fluid flow through a well conduit comprise a tubular member having a radially expandable seat member disposed within the tubular member. The radially expandable seat member comprises one or more arcuate members, each having first and second ends. The radially expandable seat member comprises a first position in which the first and second ends are disposed relative to each other to provide a first inner diameter opening through the radially expandable seat member for receiving a plug element, and a second position in which the first and second ends are moved radially outward relative to one another to provide a second inner diameter opening through the radially expandable seat member, the second inner diameter being greater than the first inner diameter thereby facilitating the plug element passing through the radially expandable seat member.