1. Field of the Invention
The present invention relates to a headrest which can be mounted via a headrest stay(s) on an automotive seat and is inclinable forwardly and backwardly relative to the headrest stay(s). Hereinafter, this headrest shall be referred to as “inclinable headrest” for simplicity. In particular, the invention is directed to an inclinable headrest of this kind which is formed by a foaming process wherein a liquid foaming agent is injected into an inside of a trim cover assembly preformed to have a predetermined contour of headrest, and then, the liquid foaming agent is cured to form an increased mass of foam padding filled in that trim cover assembly.
2. Description of Prior Art
In most cases, a headrest for use on automotive seat is formed through a foaming process which basically consists of the steps of performing a three-dimensional trim cover assembly in a predetermined shape of headrest by sewing together a plurality of cover materials, then placing a performed headrest frame in that trim cover assembly, together with headrest stays, thereafter, injecting a liquid foaming agent into the inside of the trim cover assembly, and subjecting all those elements to a foaming process by use of a foaming die apparatus. By such foaming process, all the trim cover assembly, headrest frame and headrest stays are formed together integrally into a resulting headrest wherein the liquid foaming agent has been cured into an increased mass of foam padding filled in the trim cover assembly. In this formation of headrest, it has been a common practice to preform an injection hole in a bottom side of the trim cover assembly prior to the foaming process, and in actual foaming operation, a liquid foaming agent is injected through such injection hole into the inside of the trim cover assembly, as known for example from the Japanese Laid-Open Patent Publication No. 9-11252.
Among various kinds of headrests formed in the foregoing foaming process, there has been known an inclinable headrest which allows a headrest body to be inclinable in forward and backward directions relative to a pair of headrest stays for example, wherein such pair of headrest stays are fixedly mounted on a seat back of automotive seat, so that a user can adjust forward and backward inclination of the headrest body to attain his or her preferred head support position. In this particular inclinable headrest, a pair of elongated holes are typically formed in the bottom side of headrest body and the two headrest stays extend outwardly through the respective such pair of elongated holes, thereby permitting the headrest body to be inclinable in the forward and backward directions relative to the two headrest stays.
As stated earlier, even in this inclinable headrest, the aforementioned injection hole is normally formed in a bottom surface of the trim cover assembly that covers the bottom side of headrest body, in order that a liquid foaming agent may be injected through the injection hole into the inside of the trim cover assembly during the foaming process.
As a result thereof, when the headrest is inclined forwardly relative to the headrest stays, the bottom side thereof shows up on a backward side of the seat, thus resulting in such injection hole being clearly viewed from the rear side of vehicle. This undesired problem also arises for backward inclination of the headrest; namely, with the headrest inclined backwardly relative to the headrest stays, the injection hole is then clearly viewed from the front side of vehicle. Such appearance of injection hole is objectionable and impairs the aesthetic appearance of headrest.
In view of the above-stated drawbacks, it is a purpose of the present invention to provide an improved inclinable headrest for automotive seat, which is devoid of the afore-said injection hole in the bottom side of the headrest, to thereby maintain aesthetic appearance of the headrest itself.
In order to achieve such purpose, in accordance with the present invention there is basically provided a headrest inclinable relative to at least one headrest stay, the headrest having at least one elongated hole formed in one side thereof and being formed by a foaming process involving the steps of: providing a three-dimensional trim cover assembly preformed in a predetermined shape conforming to a contour of the inclinable headrest, with the afore-said at least one headrest stay being placed in that particular three-dimensional trim cover assembly such that a part of the former projects outwardly from latter at a point for forming such at least one elongated hole; injecting a liquid foaming agent into the inside of the three-dimensional trim cover assembly, excepting the afore-said point for forming the at least one elongated hole, and then curing the liquid foaming agent into an increased mass of a foam padding filled in the three-dimensional trim cover assembly in integral manner, excepting the at least one elongated hole, the headrest comprising:
the three-dimensional trim cover assembly including a wall disposed on the one side of the headrest;
Another features and advantages of the present invention will become apparent from reading of the description, hereinafter, with reference to the annexed drawings.
The headrest (HR) is depicted in the
As indicated by the dotted lines in
Thus, it is to be seen that the provision of the two elongated holes (1) (1A) and horizontal axis element (S2) allows the headrest (HR) to be free to rotate or incline about that horizontal axis element (S2) in a direction to either of a forward side (F) and a backward side (B) of the seat back (SB) (or of an automotive seat), as indicated by the arrow in
As understandable from
The foam padding (3) is filled in or has been created in the foregoing trim cover assembly (4) through a foaming process to be described later. While not clearly shown, it is to be understandable from
Hence, it is seen that the two cylindrical cover portions (40A) (40B) of trim cover assembly (4) cover the respective two inner surfaces of the afore-said two elongated bores (3H), thus constituting the pair of elongated holes (1) (1A) in the bottom side of the headrest (HR). (See
As previously noted in the description of prior art, due to the forward and backward inclinability of headrest (HR), it is inevitable that the bottom side (at 40) of headrest (HR) has to be clearly viewed from either backward side (B) or forward side (F), and therefore, it is desirable that any injection hole for foaming process purpose should not be formed in that bottom side of headrest (HR), excepting the two elongated holes (1) (1A), in order to maintain aesthetic appearance of the headrest (HR) per se.
In accordance with the present invention, as apparently seen in
Now, a description will be made of a foaming process for forming such inclinable headrest (HR), which uses a novel construction of foaming die apparatus.
As illustrated, the two protrudent die elements (D1) (D2) may be integrally formed on a given vertical wall region (LDa-1) of the lower die (LD). Briefly stated, those two die elements (D1) (D2) are respectively adapted for forming the aforementioned two elongated bores (3B) in a resultant foam pad (3) together with the two cylindrical cover portions (40A) (40B) of trim cover assembly (4) to thereby form the two elongated holes (1) (1A) in a resultant headrest.
As best shown in
In accordance with the present invention, an injection through-hole (7) may be formed in one of the two protrudent die elements (D1) (D2) in a spaced-apart and parallel relation with one of the afore-said headrest stay support through-holes (6) (6A), as can best be seen from
In operation, at first, an incomplete headrest unit (HR′) is provided, which comprises the above-described trim cover assembly (4), the two headrest stays (S) (S1), the horizontal axis element (S2) and any other required element (not shown). As known in the art, in providing such incomplete headrest unit (HR′), those frame elements, i.e. the headrest stays (S and S1) and horizontal axis element (S2), including other required elements, are first inserted through the slit (2) formed in the bottom wall (40) of the trim cover assembly (4) and placed in the inside of that trim cover assembly (4), while passing only the two headrest stays (S) (S1) through the respective two through-holes (1) (1A) to the outside.
The thus-assembled incomplete headrest unit (HR′) is placed in a foaming space defined between the upper and lower dies (UD) (LD) as can be seen from
Then, after having engaged the upper die (UD) with the lower die (LD), an injection nozzle (N) is inserted through the injection through-hole (7) so that the distal end thereof projects in the inside of the engaged dies (UD and LD), followed by injecting a liquid foaming agent (3A) from the nozzle (N) into the inside of the trim cover assembly (4), as in
Subsequent thereto, the upper die (UD) is removed from the lower die (LD) and then the resulting headrest (HR) is taken out from the lower die (LD). As understandable from
As described above, in accordance with the present invention, it is appreciated that the following effects and advantages are attained:
(i) The liquid foaming agent (3A) is injected from the protrudent die element (D1 or D2) into the inside of trim cover assembly (40) at a point where the elongated hole (1 or 1A) is to be formed inside of resultant headrest (HR). Thus, any conventional injection hole for allowing injection of liquid foaming agent is not required in the bottom area (40) of trim cover assembly (4), and therefore, such absence of injection hole effectively keeps an aesthetic appearance of the headrest (HR) and also eliminates conventional troublesome requirement of sealing means to such injection hole to prevent leakage of liquid foaming agent therethrough.
(ii) Additionally, the liquid foaming agent (3A) is injected from a distal end of the protrudent die element (D1 or D2) far into the inside of trim cover assembly (4) at the point for formation of the elongated hole (1 or 1A). This means that the injected point (at P) where the liquid foaming agent (3A) has been injected into the trim core assembly (4) is substantially at an inner base (at 3D) of the elongated hole (1 or 1A) of resultant headrest (HR), or is located in the depth of that elongated hole. Thus, such injected point (P) is not viewed at all from the bottom side (at 40) of headrest (HR) which is to be shown up each time the headrest (HR) is inclined either forwardly or backwardly relative to the stays (S and S1). Further, even though the liquid foaming agent (3A) has been accidentally leaked from the injected point (P) and objectionably cured thereat during the foaming process, the disposition of that injected point (P) in the depth of elongated hole (1 or 1A) insures to completely conceal such objectionably leaked and cured state and make the same invisible from the outside. Accordingly, the present invention provides an aesthetically improved appearance of the inclinable headrest (HR)
Finally, is should be understood that the present invention is not limited to the illustrated embodiment, but any alternation, replacement and addition may be applied thereto without departing from the scopes of the appended claims.