Plastic and nonmetallic article shaping or treating: processes – Pore forming in situ – Composite article making
Reexamination Certificate
1999-12-10
2001-03-13
Kuhns, Allan R. (Department: 1732)
Plastic and nonmetallic article shaping or treating: processes
Pore forming in situ
Composite article making
C264S046700, C264S276000
Reexamination Certificate
active
06200506
ABSTRACT:
BACKGROUND OF INVENTION
1. Field of the Invention
The present invention relates to a method for forming a headrest adapted for use on an automotive seat, and more particularly to the method of this kind wherein the headrest is formed by injecting a liquid foaming base material into the interior of a preformed three-dimensional trim cover assembly having a predetermined headrest outer shape and then subjecting both liquid foaming base material and trim cover assembly to foaming integrally together.
2. Description of Prior Art
According to a typical known foaming process for producing a headrest, a three-dimensional trim cover assembly of a predetermined headrest shape is firstly provided by sewing together required separate cover sections, with an opening defined therein, then a generally U-shaped headrest frame having a pair of headrest stay portions is inserted through the opening into the interior of the trim cover assembly, and thereafter, a liquid base foaming material is injected and cured in the trim cover assembly, so as to produce a foamed resultant headrest with the pair of headrest stay portions projecting therefrom.
This foaming process has encountered the problem that the liquid base foaming material is leaked through the opening to the outside of trim cover assembly, leaving an objectionable spot thereon. Conventionally, in an attempt to prevent the leakage of liquid base foaming material, typical solution is for example found in the Japanese Granted Patent Pub. No. 6-45149 and Japanese Laid-Open Patent Pub. No. 7-31759, wherein a pair of extensions are formed in the portion of trim cover assembly corresponding to that opening such as to extend inwardly from the opening into the trim cover assembly, and a flattened tubular film piece is fitted between the pair of extensions, so that an injection nozzle can be inserted through the flattened tubular piece into the interior of trim cover assembly, and, during the foaming process, the liquid base foaming material being injected from the nozzle is prevented by those two extensions and film from the opening in question.
However, such conventional method requires cutting of an externally exposed part of the film which projects outwards from the opening, subsequent to the foaming process, thus resulting in a troublesome labor on the part of worker and also in the high likelihood of a cut, tear or undesired damage being given to the trim cover assembly when the worker cuts off the film.
SUMMARY OF THE INVENTION
In view of the above-stated drawbacks, it is therefore a primary purpose of the present invention to provide an improved method for forming a headrest which eliminates the foregoing various troubles and effectively prevents a liquid base foaming material against leakage from the opening of trim cover assembly during a foaming process.
In order to achieve such purpose, in accordance with the present invention, there is basically provided the steps of:
pre-assembling an incomplete headrest unit comprising a three-dimensional trim cover assembly of a predetermined headrest configuration, which has an opening formed therein and an extension means extending therefrom via said opening into an interior of the three-dimensional trim cover assembly and a headrest frame means having a stay portion, wherein the headrest frame means has been inserted via the opening into and placed in the interior of three-dimensional trim cover assembly, with the stay portion projecting outwardly therefrom;
providing an injection nozzle means having a catching means for catching the extension means associated with the three-dimensional trim cover assembly;
inserting the injection nozzle means through the opening in a first direction toward the interior of three-dimensional trim cover assembly, while locating the catching means at the extension means therewithin;
drawing the injection nozzle means in a second direction opposite to such first direction, to thereby catch the extension means;
drawing further the injection nozzle means in such second direction, thereby causing the opening to be closed positively by the extension means and catching means
thereafter, injecting a liquid base foaming material through the injection nozzle means into the interior of trim cover assembly;
curing the liquid base foaming material to form a foam padding integrally with the interior of trim cover assembly and headrest frame means; and
thereafter, removing the injection nozzle means from the trim cover assembly, whereby the headrest is formed.
Accordingly, a positive closing of the opening is attained via the catching means to insure avoiding creation of any loosen point or clearance at the opening through which the liquid base foaming material will invade or will be leaked. Further, an increased mass of the liquid base foaming material being cured presses the extension means against an inner side of the trim cover assembly to thereby positively close the opening against leakage of the liquid base foaming material therethrough.
In one aspect of the present invention, the trim cover assembly and extension means are formed from a material having an elastic property, and a through-hole be formed in the extension means, thus having an elastic property for allowing its elastic deformation and recovery to its original diameter. In that instance, both injection nozzle means and catching means can be inserted through that through-hole while elastically deforming the same, at the step of inserting the injection nozzle means, and also removed via the through-hole from the trim cover assembly at the step of removing the injection nozzle means therefrom.
In another aspect of the present invention, the extension means may comprise first and second extensions which are resiliently biased to contact with each other to normally close the opening, wherein the first extension is greater in length than the second extension, with a projected part defined continuously from the first extension. In that instance, at the step of drawing further the injection nozzle means in the second direction, the projected part of the first extension is bent toward the free end of second extension, thereby causing a tight contact of such projected part with the end of second extension, so that the opening is positively closed by the first and second extensions. Further, the projected part of first extension is folded about the end of said second extension by a pressure applied from an increased mass of said liquid base foaming material being cured, rendering more positive the closing of the opening to insure preventing the liquid base foaming material from the opening;
Other various features and advantages of the present invention will become apparent from reading of the descriptions hereinafter with reference to the annexed drawings.
REFERENCES:
patent: 4738809 (1988-04-01), Storch
patent: 4908170 (1990-03-01), Kurimoto
patent: 5004572 (1991-04-01), Kurimoto
patent: 5135593 (1992-08-01), Quirin
patent: 5478136 (1995-12-01), Takeuchi et al.
patent: 5730917 (1998-03-01), Ishikawa et al.
patent: 5855831 (1999-01-01), Takei
patent: 5984414 (1999-11-01), Adachi et al.
patent: 6120100 (2000-09-01), Palazzolo et al.
patent: 9-108066 (1997-04-01), None
Browdy and Neimark
Kuhns Allan R.
Tachi-Co., LTD
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