Abstract: A pipe element tube 23 is manufactured by a manufacturing method including step S1-1 for obtaining the pipe element tube 23 by rolling a stainless steel plate material 21 and welding an abutting portion, a core drawing step S1-2 for reducing a diameter and adjusting a thickness of the pipe element tube 23 by using a cored bar 24, and a tube drawing step S1-3 for reducing the diameter and adjusting an outer form of the pipe element tube 23 without using a cored bar. By adjusting repetition times of the core drawing step S1-2 and the tube drawing step S1-3, a uniform concavity and convexity are provided on an inner circumferential surface of the pipe element tube 23. Then a pipe 12 having an annular shaped cross section obtained by cutting the pipe element tube 23 and a linear material 11 having a circular cross section are joined (S2).

Abstract: A pipe element tube 23 is manufactured by a manufacturing method including step S1-1 for obtaining the pipe element tube 23 by rolling a stainless steel plate material 21 and welding an abutting portion, a core drawing step S1-2 for reducing a diameter and adjusting a thickness of the pipe element tube 23 by using a cored bar 24, and a tube drawing step S1-3 for reducing the diameter and adjusting an outer form of the pipe element tube 23 without using a cored bar. By adjusting repetition times of the core drawing step S1-2 and the tube drawing step S1-3, a uniform concavity and convexity are provided on an inner circumferential surface of the pipe element tube 23. Then a pipe 12 having an annular shaped cross section obtained by cutting the pipe element tube 23 and a linear material 11 having a circular cross section are joined (S2).

Abstract: The invention provides a pillow capable of having the height thereof adjusted automatically so that the height of the back of the head of a user in a face-up lying position is slightly higher than his/her back, and also capable of having the height thereof varied automatically between a face-up lying position and a side lying position. A hollow portion 8 having a biasing mechanism 9 disposed therein is formed in a head placement member 3, and when the head is placed face-up on the head placement member 3, the hollow portion 8 is depressed so that the distance between the lowermost portion of the head and the bottom member 2 is in the range of 10 mm to 30 mm. The biasing mechanism has X-shaped links 11 disposed laterally spaced apart in the hollow portion 8. Each X-shaped link is composed by pivotally connecting a first link member 12 slanted upward toward the front and a second link member 13 slanted upward toward the rear by an intermediate link shaft 16.