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: A pillow that changes its height during lying on the back and lying sideways, automatically and reliably according to sleeping posture of a user. No adjustment is necessary, and the height is stable. A biasing device provided in a hollow of the head placement member of a pillow is equipped with a link mechanism including a load supporting link, a rear end side of which being placed slidably on an upper end portion of a rear side link and a front end side thereof being connected rotatably to a front end side of an upper side link, and a tension spring for biasing the load supporting link to push the same upwards.