Patent ID: 8544762

Claim:
A thermo-element comprising: a casing having a bottom; a thermally expandable material filled in the casing, the thermally expandable material including paraffin capable of expanding and contracting due to temperature changes; an elastic sealing member sealingly enclosing the thermally expandable material in the casing; a piston movable in an axial direction thereof; a guide member fixed to an upper portion of the casing and formed with a sliding hole for slidably holding the piston; a liquid chamber defined internally by the elastic sealing member, the guide member and the piston; and a deformable, incompressible fluid received in the liquid chamber, wherein the piston is adapted to be moved along the sliding hole of the guide member in the axial direction, according to expansion and contraction of the thermally expandable material and through the incompressible fluid in the liquid chamber, the thermo-element being characterized in that the piston is internally formed with: a through-hole communicating with the liquid chamber; a check-valve chamber communicating with the through-hole and receiving therein a check-valve element of a check valve; and a communication hole communicating with the check-valve chamber and having an opening exposed to an outside of the thermo-element.