Foaming die device adapted to effect foaming in trim cover assembly integrally to form headrest, and foaming process for forming headrest by effecting foaming in trim cover assembly integrally, using the foaming die device

Abstract

A foaming die device for forming a headrest is provided, which comprises a lower die having a first protrusion and an upper die having a second protrusion. The lower and upper dies are used for accommodating a trim cover assembly with a headrest stay portion extending outwardly through a stay passage hole formed in the trim cover assembly. The first and second protrusions are adapted to press and turn over a projected area created about the stay passage hole into the inside of that trim cover assembly. Also, a foaming process for forming the headrest, using this foaming die device, is provided, in which the projected area is turned over by the first and second protrusions into the trim cover assembly when placing the trim cover assembly in the dies. Hence, conventional preliminary steps using cylindrical stick to turn over the projected area into the trim cover assembly are eliminated.

What is claimed is: 
     
         1 . A foaming process for forming a headrest, comprising the steps of:
 providing a foaming device comprising:
 a lower die having a first cavity region defined therein; 
 an upper die having a second cavity region defined therein; 
   said lower and upper dies being able to be mated with and separated from each other, wherein, when the lower and upper dies are mated with each other, a cavity is defined between said first and second cavity regions;
 a first protrusion provided in said lower die so as to protrude in a direction from an inner wall of the lower die towards said first cavity region; and 
 a second protrusion provided in said upper die so as to protrude in a direction from an inner wall of the upper die towards said second cavity region; 
   providing a headrest stay having at least one stay portion extending therefrom;   providing a trim cover assembly having at least one stay passage hole adapted to allow said at least one stay portion to pass therethrough;   wherein said at least one stay portion is so dimensioned to contact an end of said at least one stay passage hole,   installing said headrest stay within said trim cover assembly, such that said at least one stay portion of the headrest stay passes through said at least one stay passage hole and extends outward from the trim cover assembly, in a sliding, close contact with said end of said at least one stay passage hole, thus causing concurrent stretching of said end of said at least one stay passage hole in an outward direction of the trim cover assembly and resulting in creation of a projected area in said end, said projected area protruding outward from said at least one stay passage hole and being laid on and about a part of the at least one stay portion located exteriorly of the trim cover assembly, so that the projected area is exposed outside of the trim cover assembly;   loading said trim cover assembly with said headrest stay thus installed therein into either of said lower and upper dies;   causing said lower and upper dies to mate together to define said cavity between said first and second cavity regions, with said trim cover assembly being accommodated in the cavity, such that said first and second protrusions are pressed against said projected area towards said at least one stay passage hole and forcibly inserted into between said at least one stay portion and said at least one stay passage hole, to the extent that the first and second protrusions are entered into the inside of the trim cover assembly, thereby causing the projected area itself to turn over at the first and second protrusions in relation to said at least one stay passage hole, thus resulting in reverse folding of the projected area from the at least one stay passage hole into the inside of said trim cover assembly on and along the first and second protrusions being entered into the inside of the trim cover assembly, whereby an entirety of the thus-turned-over projected area is displaced to the inside of the trim cover assembly together with the first and second protrusions, as a result of which, said entirety of the turned-over projected area is positioned within the trim cover assembly and also laid on the first and second protrusions entered in the trim cover assembly;   thereafter, injecting a liquid foaming agent into the inside of said trim cover assembly and curing said liquid foaming agent into an increased mass of foam padding filled in the trim cover assembly, so that said turned-over projected area is sandwiched between said foam padding and both said first and second protrusions, within the trim cover assembly, whereupon a headrest with said at least one stay portion exposed outside thereof is formed in said cavity; and   removing said headrest from said cavity by separating said lower and upper dies, during which, said first and second protrusions, provided in the lower and upper dies, respectively, are both automatically withdrawn outwards through between said at least one stay portion and said turned-over projected area secured to said foam padding and are eventually removed from said at least one stay passage hole, thereby producing a resultant headrest in which said turned-over projected area is retained inside of the resultant headrest, while said at least one stay portion is exposed outside of the resultant headrest.   
     
     
         2 . The foaming process according to  claim 1 , wherein each of said first and second protrusions is provided with:
 a distal end adapted to face said cavity; and   a thickness that becomes small as it proceeds to said distal end, thereby not only facilitating insertion of said first and second protrusions into between said at least one stay passage hole and said at least one stay portion, but also facilitating said reverse folding of said projected area, at said step of causing said lower and upper dies to mate together.   
     
     
         3 . The foaming process according to  claim 1 , wherein each of said first and second protrusions is provided with a toothed end portion that is to face said cavity, said toothed end portion being adapted to reduce a coefficient of friction thereof against said projected area and said at least one stay passage hole, thereby not only facilitating insertion of said first and second protrusions into between said at least one stay passage hole and said at least one stay portion, but also facilitating said reverse folding of said projected area, at said step of causing said lower and upper dies to mate together. 
     
     
         4 . A foaming process for forming a headrest, comprising the steps of:
 providing a foaming device comprising:
 a lower die including:
 a first cavity region; 
 a first mating surface; and 
 a first stay receiving recession formed in said first mating surface; 
 
 an upper die including:
 a second cavity region; 
 a second mating surface adapted to be mated with said first mating surface; and 
 a second stay receiving recession formed in said second mating surface; 
 
   said upper and lower dies being able to be mated with and separated from each other, wherein, when the upper and lower dies are mated with each other, a cavity is defined between said first and second cavity regions;   a first protrusion provided in said lower die at said first mating surface so as to protrude in a direction from an inner wall of the lower die towards said first cavity region, said first protrusion having a first recession communicating with said first stay receiving recession; and   a second protrusion provided in said upper die at said second mating surface so as to protrude in a direction from an inner wall of the upper die towards said second cavity region, said second protrusion having a second recession communicating with said second stay receiving recession;   providing a headrest stay having at least one stay portion extending therefrom;   providing a trim cover assembly having at least one stay passage hole adapted to allow said at least one stay portion to pass therethrough;   wherein said at least one stay portion is so dimensioned to contact an end of said at least one stay passage hole,   installing said headrest stay within said trim cover assembly, such that said at least one stay portion of the headrest stay passes through said at least one stay passage hole and extends outward from the trim cover assembly, in a sliding, close contact with said end of said at least one stay passage hole, thus causing concurrent stretching of said end of said at least one stay passage hole in an outward direction of the trim cover assembly and resulting in creation of a projected area in said end, said projected area protruding outward from said at least one stay passage hole and being laid on and about a part of said at least one stay portion located exteriorly of the trim cover assembly, so that said projected area is exposed outside of the trim cover assembly;   loading said trim cover assembly with said headrest stay thus installed therein into either of said lower and upper dies;   placing said at least one stay portion in either of said first and second stay receiving recessions as well as in either of said first and second recessions;   causing said lower and upper dies to mate together to define said cavity between said first and second cavity regions, with said trim cover assembly being accommodated in the cavity, while said first and second mating surfaces are mated with each other to cause mating of said first and second protrusions together, whereby said first and second stay receiving recessions are mated with each other, thereby embracingly receiving one part of said at least one stay portion therebetween, whereas at the same time, said first and second recessions are mated with each other, thereby embracingly receiving the other part of said at least one stay portion therebetween, such that the thus-mated first and second protrusions are pressed against said projected area towards said at least one stay passage hole and forcibly inserted into between said at least one stay portion and said at least one stay passage hole, to the extent that the mated first and second protrusions are entered into the inside of the trim cover assembly, thereby causing the projected area itself to turn over at the mated first and second protrusions in relation to said at least one stay passage hole, thus resulting in reverse folding of the projected area from the at least one stay passage hole into the inside of said trim cover assembly on and along the mated first and second protrusions being entered into the inside of the trim cover assembly, whereby an entirety of the thus-turned-over projected area is displaced to the inside of the trim cover assembly together with the mated first and second protrusions, as a result of which, said entirety of the turned-over projected area is positioned within the trim cover assembly and laid on and about the mated first and second protrusions entered in the trim cover assembly;   thereafter, injecting a liquid foaming agent into the inside of said trim cover assembly and curing said liquid foaming agent into an increased mass of foam padding filled in the trim cover assembly, so that said turned-over projected area is sandwiched between the foam padding and the mated first and second protrusions, within the trim cover assembly, whereupon a headrest with said at least one stay portion exposed outside thereof is formed in said cavity; and   removing said headrest from said cavity by separating said lower and upper dies, during which, said first and second protrusions, provided in the lower and upper dies, respectively, are both automatically withdrawn outwards through between said at least one stay portion and said turned-over projected area secured to said foam padding and are eventually removed from said at least one stay passage hole, thereby producing a resultant headrest in which said turned-over projected area is retained inside of the resultant headrest, while said at least one stay portion is exposed outside of the resultant headrest.   
     
     
         5 . The foaming process according to  claim 4 , wherein each of said first and second protrusions is provided with:
 a distal end adapted to face said cavity; and   a thickness that becomes small as it proceeds to said distal end thereof, thereby not only facilitating insertion of said mated first and second protrusions into between said at least one stay passage hole and said at least one stay portion, but also facilitating said reverse folding of said projected area, at said step of causing said lower and upper dies to mate together.   
     
     
         6 . The foaming process according to  claim 4 , wherein each of said first and second protrusions is provided with a toothed end portion that is to face said cavity, said toothed end portion being adapted to reduce a coefficient of friction thereof against said projected area and said at least one stay passage hole, thereby not only facilitating insertion of said mated first and second protrusions into between said at least one stay passage hole and said at least one stay portion, but also facilitating said reverse folding of said projected area, at said step of causing said lower and upper dies to mate together. 
     
     
         7 . A foaming process for forming a headrest, comprising the steps of:
 providing a foaming device comprising:
 a lower die having a first cavity region defined therein; 
 an upper die having a second cavity region defined therein; 
 said upper and lower dies being able to be mated with and separated from each other, wherein, when the upper and lower dies are mated with each other, a cavity is defined between said first and second cavity regions; 
 a first substantially-semi-cylindrical protrusion provided in said lower die so as to protrude in a direction from an inner wall of the lower die towards said first cavity region; and 
 a second substantially-semi-cylindrical protrusion provided in said upper die so as to protrude in a direction from an inner wall of the upper die towards said second cavity region; 
   providing a headrest stay having at least one substantially-columnar stay portion extending therefrom;   providing a trim cover assembly having at least one substantially-circular stay passage hole adapted to allow said at least one substantially-columnar stay portion to pass therethrough;   wherein said at least one substantially-columnar stay portion is so dimensioned to contact an entire end of said at least one substantially-circular stay passage hole,   wherein said first and second substantially-semi-cylindrical protrusions are able to be mated with each other to embracingly receive said at least one substantially-columnar stay portion therebetween,   installing said headrest stay within said trim cover assembly, such that said at least one substantially-columnar stay portion of the headrest stay passes through said at least one substantially-circular stay passage hole and extends outward form the trim cover assembly, in a sliding, close contact with said entire end of said at least one substantially-circular stay passage hole, thus causing concurrent stretching of said entire end of said at least one substantially-circular stay passage hole in an outward direction of the trim cover assembly and resulting in creation of a cylindrically projected area in said entire end, said cylindrically projected area protruding outward from said at least one substantially-circular stay passage hole and being laid on and about a part of the at least one substantially-columnar stay portion located exteriorly of the trim cover assembly, so that said cylindrically projected area is exposed outside of the trim cover assembly;   loading said trim cover assembly with said headrest stay thus installed therein into either of said lower and upper dies;   causing said lower and upper dies to mate together to define said cavity between said first and second cavity regions, with said trim cover assembly being accommodated in said cavity, while said first and second substantially-semi-cylindrical protrusions, provided in said lower and upper dies, respectively, are automatically mated with each other, thereby embracingly receiving said at least substantially-columnar stay portion therebetween, such that the thus-mated first and second substantially-semi-cylindrical protrusions are pressed against an entirety of said cylindrically projected area towards said at least one substantially-circular stay passage hole and forcibly inserted into between said at least one substantially-columnar stay portion and said at least one substantially-circular stay passage hole, to the extent that the mated first and second substantially-semi-cylindrical protrusions are entered into the inside of the trim cover assembly, thereby causing the cylindrically projected area itself to turn over at the mated first and second substantially-semi-cylindrical protrusions in relation to said at least one substantially-circular stay passage hole, thus resulting in reverse folding of said cylindrically projected area from the at least one substantially-circular stay passage hole into the inside of said trim cover assembly on and along the mated first and second substantially-semi-cylindrical protrusions being entered into the inside of the trim cover assembly, whereby an entirety of the thus-turned-over cylindrically projected area is displaced to the inside of the trim cover assembly together with the mated first and second substantially-semi-cylindrical protrusions, as a result of which, said entirety of the turned-over cylindrically projected area is positioned within the trim cover assembly and laid on and about the mated first and second substantially-semi-cylindrical protrusions entered in the trim cover assembly;   thereafter, injecting a liquid foaming agent into the inside of said trim cover assembly and curing said liquid foaming agent into an increased mass of foam padding filled in the trim cover assembly, so that the thus-turned-over cylindrically projected area is sandwiched between the foam padding and the mated first and second substantially-semi-cylindrical protrusions, within the trim cover assembly, whereupon a headrest with said at least one substantially-columnar stay portion exposed outside thereof is formed in said cavity; and   removing said headrest from said lower and upper dies by separating said lower and upper dies, during which, said first and second substantially-semi-cylindrical protrusions, provided in the lower and upper dies, respectively, are both automatically withdrawn outwards through between said at least one substantially-columnar stay portion and said turned-over cylindrically projected area secured to said foam padding and are eventually removed from the at least one substantially-circular stay passage hole, thereby producing a resultant headrest in which said turned-over cylindrically projected area is retained inside of the resultant headrest, while said at least one substantially-columnar stay portion is exposed outside of the resultant headrest.   
     
     
         8 . The foaming process according to  claim 7 , wherein each of said first and second substantially-semi-cylindrical protrusions is provided with:
 a distal end adapted to face said cavity; and   a thickness that becomes small as it proceeds to said distal end thereof, thereby not only facilitating insertion of said mated first and second substantially-semi-cylindrical protrusions into between said at least one substantially-circular stay passage hole and said at least one substantially-columnar stay portion, but also facilitating said reverse folding of said cylindrically projected area, at said step of causing said lower and upper dies to mate together.   
     
     
         9 . The foaming process according to  claim 7 , wherein each of said first and second substantially semi-cylindrical protrusions is provided with a toothed end portion that is to face said cavity, said toothed end portion being adapted to reduce a coefficient of friction thereof against said cylindrically projected area and said at least one substantially-circular stay passage hole, thereby not only facilitating insertion of said mated first and second substantially-semi-cylindrical protrusions into between said at least one substantially-circular stay passage hole and said at least one substantially-columnar stay portion, but also facilitating said reverse folding of said cylindrically projected area, at said step of causing said lower and upper dies to mate together.