US Patent 7841357 Connection state sensing for coupling device

A coupling device includes a main body defining a fluid flow passage, and a valve member moveable between an unconnected state and a connected state. The coupling device also includes a magnet coupled to the valve member, and a sensor coupled to the main body, the sensor being configured to sense a change in a magnetic flux of the magnet as the valve member moves between the unconnected state and the connected state to determine a connection state of the coupling device.