Abstract: The core of the stalk is a metallic cylindrical body 1, such as a steel pipe. On an inner surface of the cylindrical body are layered a boron nitride coating 4, a mica sheet 6 which is airtight and thermal insulating, and a thermal insulating layer 7. On the outer surface of metallic cylindrical body 1 are layered a boron nitride coating 5, a wire gauze 10, a thermal insulating layer 12, a ceramic paper 13, and another boron nitride coating 15. The cylindrical body can be formed by a steel pipe is easily corroded and eroded by molten metal.

Abstract: In a wire dot print head having print wires extending through an opening of a guide nose, the guide nose comprises two halves. The print head may further comprise a wire guide which is fitted in the guide nose and through which the print wires extend, and the wire guide may be clamped by the two halves. In another embodiment, the half members have abutting surfaces provided with semi-circular grooves, which when the guide nose halves are assembled, form guide holes in which the print wires are slidably supported. The use of the two halves facilitates assembly of the print head and reduces noise.

Abstract: In a spring-charge wire-dot print head, a support part of a plate spring is clamped, at its outer periphery, between a protruding member disposed on the front surface of the outer periphery of a spacer and a protruding member disposed on the rear surface of the outer periphery of a yoke, and the support part of the plate spring is additionally supported, at the rear surface of its inner periphery, by a protruding member disposed on the front surface of the inner periphery of the spacer.