Method for forming a trim cover assembly of a donut-like or annular headrest for a vehicle seat

A method for forming trim cover assembly of a donut-like headrest, comprising the steps of:

• providing a first cover section material means which is of generally inverted-U-shaped and three-dimensional configuration, having an inward opened side define inwardly thereof, and a pair of outward openings defined at one side thereof;
• providing a second cover section material means which has a whole length smaller than a whole length of said first cover section material means;
• reversing said first and second cover material means, with their respective reverse sides being exposed outwardly;
• sewing said second cover section material means with the inward opened side of said first cover section material means, such as to define a pair of inward openings adjacent to said pair of outward openings of said first cover section material means, to thereby provide a first cover unit which is of generally inverted-U-shaped, cylindrical configuration and is in a reversed state;
• turning over said first cover unit in a direction from one of said pair of inward openings as well as one of said pair of outward openings towards another of said pair of inward openings as well as another of said outward openings, so that the first cover unit is turned over completely into a normal state of the first cover unit in which all outer sides of said first and second cover section material means opposite to the reverse sides respectively of them are exposed outwardly;
• providing a second cover unit;
• bending said second cover unit in a generally "U" shaped fashion with the outer side thereof exposed outwardly, such as to define an outward opening at one side thereof;
• sewing the thus-bent second cover unit with said pair of inward openings associated with said normal state of the first cover unit, such that said pair of outward openings associated with said first cover unit and said outward opening associated with said second cover unit cooperate with one another to define an annular end therealong, whereupon a normal state of said first and second cover units having said annular end is provided, with all their respective outer sides exposed outwardly;
• providing a third cover unit which has, formed therein, an opening for allowing a headrest frame to be passed therethrough;
• and
• widening said opening of the third cover unit;
• and
• then effecting a direct sewing of the third cover unit, via the thus-widened opening, to said normal state of the first and second cover units in such manner that a peripheral end of said third cover unit is sewn along said annular end associated with said normal state of the first and second cover units.