Self-triggering cryogenic
heat flow switches are used particularly with cooling systems that require a redundant operation. The self-triggering cryogenic
heat flow switch has the simplest possible construction while providing a reliable, maintenance-free mode of operation, and ensures a self-switching connection between a
heat sink and an end use device or application that is to be cooled. The
heat flow switch includes an outer
hollow cylinder 1 that is connected with a
heat sink 9, and an inner body 2 that is arranged coaxially to the outer
hollow cylinder 1 and connected to the end use device or application to be cooled. When the
heat sink 9 is switched off, a concentric annular gap 4 fixed by spacers is provided between the
hollow cylinder 1 and the inner body 2. The linear
thermal expansion coefficient of the outer cylinder 1 is greater than that of the inner body 2, so that the outer cylinder 1 contracts into thermally conducting contact with the inner body 2 when the heat sink 9 is switched on to provide cooling.