Patent ID: 7290397

Claim:
An apparatus for connecting or disconnecting a supply of a cryogenic fluid to or from a cryogenic cooling means mounted on a member and spaced apart from the supply of the cryogenic fluid, comprising: a plunger made at least in part of a first material having a first coefficient of thermal expansion, the plunger having an inlet in fluid communication with the supply of the cryogenic fluid, an outlet in fluid communication with the inlet, and an outer periphery; a socket made at least in part of a second material having a second coefficient of thermal expansion, the socket having a first port in fluid communication with the cryogenic cooling means, and a second port in fluid communication with the first port and having an inner periphery adapted to receive the outer periphery of the plunger, the inner periphery and the outer periphery being substantially similar in geometric shape; and an actuating means for inserting or withdrawing the outlet of the plunger into or out of the second port of the socket, wherein a difference between the first coefficient of thermal expansion and the second coefficient of thermal expansion enhances a seal between the outer periphery of the plunger and the inner periphery of the second port, wherein a leading portion of a stream of the cryogenic fluid is vented from the socket to a surrounding atmosphere before the seal becomes fluid tight.