Patent ID: 8702105

Claim:
A seal member, which is used in a heating furnace having an insertion port to which an end of a rod to be heated is inserted along an insertion axis of the insertion port and seals between the insertion port and a surface of an inserted rod in a substantially airtight manner, the seal member comprising: a plurality of seal chips arranged annularly along an inner surface of the insertion port in a substantially airtight manner, each seal chip having a first curved end held by the inner surface of the insertion port at an angle not orthogonal to the insertion axis, a second curved end elongated towards the insertion axis, and inclined sides connecting the first and second curved ends so that the second curved ends of the plurality of seal chips form a continuous inner surface facing the insertion axis, the second end of each of the plurality of seal chips adapted to press against the surface of the inserted rod and curve away from the insertion axis by means of elastic deformation, the plurality of seal chips are arranged as a curved surface shaped as a truncated cone side surface, wherein the angle is 60 degrees or smaller.