Patent ID: 6823575
Filing Date: 2004-11-30
Classification: B21D,B60N,Y10T

Abstract:
Procedure for attaching a headrest-tube to an elongate seatframe-piece of an automobile seat having an upper side and a lower side, including:providing a through-hole in the seatframe-piece, from the upper side to the lower side, for receiving the headrest-tube; making a subassembly of the headrest-tube in the through-hole, wherein the headrest-tube has an upper portion, which lies above the seatframe-piece, and a lower portion, which lies below the seatframe-piece; providing a die seat, which includes an upper punch and a lower punch, and arranging the subassembly in the die-set, with the headrest-tube vertical; providing the headrest-tube with an upper shoulder, which lies in contact with the upper side of the seatframe-piece over an upper annular margin of that upper side, being a margin surrounding the through-hole; pressing the headrest-tube vertically, in the die-set, with a lower-tube-collapsing-force; applying the lower-tube-collapsing-force in such manner as to collapse the lower portion of the headrest-tube, and thereby to expand the lower portion diametrally, at least over a region of the lower portion of the headrest-tube adjacent to the lower side of the seatframe-piece, thereby forming a lower shoulder of the headrest-tube; wherein the lower shoulder lies in contact with the lower side of the seatframe-piece, over a lower annular margin of the lower side of the seatframe-piece, surrounding the through-hole; the seatframe-piece being sandwiched between the upper and lower shoulders, then pressing the upper and lower shoulders together with a shoulder-coining-force; so arranging the die-set that the upper and lower punches do not bottom together while the shoulder-coining-force is being applied, thereby enabling the force of the press to be available as the shoulder-coining-force; applying the shoulder-coining-force at sufficient magnitude to coin the upper and lower shoulders together, onto the two sides of the seatframe-piece, whereby the seatframe-piece becomes gripped between the upper and lower shoulders of the headrest-tube; wherein the shoulder-coining-force is much larger than the lower-tube-collapsing-force; and then taking the sub-assembly out of the die-set.