Abstract:
A mold assembly for manufacturing a trim component of an automotive vehicle. The mold assembly comprises a first mold half having a contoured first mold surface and an outer peripheral edge and a second mold half having a contoured second mold surface and an outer peripheral edge. The mold halves pivotal about a hinge between an open position providing access to the respective mold surface and a closed position with the outer peripheral edge of the first mold half aligned with an abutting the outer peripheral edge of the second mold surface. A cutting ridge is formed around the outer peripheral edge of the first mold half for engaging a bulbous projection formed around the outer peripheral edge of the second mold halves in the closed position whereby upon the injection of a urethane material onto the mold halves, the cutting ridge abuts against the projection and perforates any oversprayed material extending outside of the mold surfaces when the mold halves are moved to the closed position.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1) Field of the Invention  
         [0002]     The subject invention relates to an automotive trim component, such as a headrest, armrest or the like. Further, the subject invention also relates to a mold assembly and method for manufacturing the aforementioned automotive trim component.  
         [0003]     2) Description of the Related Art  
         [0004]     Automotive trim components, such as headrests and armrests, and their general method of manufacture are known in the art. For example, a conventional method for making headrests includes the following steps. Initially, a plurality of trim cover pieces are manually, either by machine or by hand, sewn together to form a trim cover envelope, also known in the art as an outer shell of the headrest. The outer shell includes sewn seams throughout. Next, the sewn outer shell is positioned into cavity of a mold assembly. Foam is then injected into the sewn outer shell while in the mold assembly to form the headrest. Such conventional methods for making headrests have a number of deficiencies. In particular, upon injecting foam into the sewn outer shell, foam may leak through the sewn seams in the headrest and result in a defective headrest. Further, automotive seating headrests with the sewn seams are prone to tearing, ripping, snagging, and opening during repeated use over the life of an automobile.  
         [0005]     Illustrative of another example, an alternative method of making a headrest is disclosed in U.S. Pat. No. 5,116,557 wherein the outer shell or layer of the headrest is synthetically made of an elastomer within a mold tool. The mold tool includes a pair of mold halves which form a hermetic seal when closed together. The method as disclosed in the &#39;557 patent requires that the elastomer be in a substantially liquid state during the closing of the mold halves in order to press the elastomer which may have been oversprayed onto the mold halves out from between the mold halves. This method is overly sensitive to the specific curing times of the elastomer and outside factors such as humidity, temperature and the like.  
       SUMMARY OF THE INVENTION  
       [0006]     According to one aspect of the invention, a mold assembly is provided for manufacturing a trim component of an automotive vehicle. The mold assembly comprises a first mold half having a contoured mold surface and an outer peripheral edge and a second mold half having a contoured mold surface and an outer peripheral edge. The mold halves are movable between an open position providing access to the respective mold surfaces and a closed position with the outer peripheral edge of the first mold half aligned with and abutting the outer peripheral edge of the second mold surface. A cutting ridge is formed around the outer peripheral edge of one of the mold halves for engaging the other of the mold halves in the closed position whereby upon the injection of a urethane material onto at least one of the mold halves, the cutting ridge perforates any oversprayed material extending outside of the mold surfaces when the mold halves are moved to the closed position.  
         [0007]     According to another aspect of the invention, a method is provided for manufacturing a trim component for an automotive vehicle with a mold assembly having a first mold half having a first mold surface and a cutting ridge surrounding the first mold surface and a second mold half having a second mold surface and a projection surrounding the second mold surface, wherein the mold halves are moveable relative to each other between an open position having the cutting ridge disengaged from the projection and a closed position having the cutting ridge engage the projection. The method comprises the steps of applying an in-mold coat to each of the mold halves when the mold halves are in the open position; applying a skin coat to each in-mold coat when the mold halves are in the open position, whereby the skin coat in the first mold half bonds with the respective in-mold coat to form a first structural skin coat in the second mold half bonds with the respective in-mold coat to form a second structural skin; moving the mold halves to the closed position whereby the cutting ridge abuts the projection to cut any overspray of in-mold coat and skin coat extending outside of the first and second mold surfaces; injecting a foam into the mold halves after applying the skin coat to expand and cure between the first and second structural skins forming the trim component; moving the mold halves to the open position after forming the trim component; and removing the trim component from the mold assembly after moving the mold halves to the open position.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     Advantages of the present invention will be readily appreciated as the same becomes understood by reference to the following detailed description when considered in connection with the accompanying wherein:  
         [0009]      FIG. 1  is a sectional view of a mold assembly for manufacturing a trim component shown in an open position; and  
         [0010]      FIG. 2  is a sectional view of the mold assembly shown in a closed position. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0011]     Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, a mold assembly for making an automotive trim component is generally shown at  10  in  FIGS. 1 and 2 . For illustrative purposes only, the mold assembly  10  is depicted as a mold assembly for making a headrest. It should be appreciated that the mold assembly  10  may be configured to make any other suitable trim components, such as armrests or the like.  
         [0012]     Referring to  FIG. 1 , the mold assembly  10  includes a first mold half  11  and a second mold half  12 . The mold halves  11 ,  12  are movable relative to each other between an open position, as shown in  FIG. 1 , and a closed position, as shown in  FIG. 2 . The first and second mold halves  11 ,  12  include first and second contoured mold surfaces  14 ,  16 , respectively. The mold surfaces  14 ,  16  are concave and complimentary to each other such that the molded surfaces  14 ,  16  define a substantially enclosed mold cavity  18  when the mold assembly  10  is in the closed position. The surfaces of the mold surfaces  14 ,  16  defining the mold cavity  18  correspond to an outer contour of the headrest (not shown in the Figures). The mold surfaces  14 ,  16  preferably include a textured surface that forms a final surface texture of the headrest. It should be appreciated that while the mold surfaces  14 ,  16  are illustrated as concave, the mold surfaces  14 ,  16  may be of any suitable shape so as to define a cavity commensurate with the desired shape of the headrest.  
         [0013]     The mold halves  11 ,  12  further include first and second receiving recessed channels  15 ,  17 , respectively, and a hinge  19 , such as a piano-type hinge, interconnecting the mold halves  11 ,  12  opposite the channels  15 ,  17  for providing pivotal movement of the mold halves  11 ,  12  between the open and closed positions. The operation of these components will be described further hereinbelow. Additionally, a filler port  9 ,  13  is disposed within each of the first  11  and second  12  mold halves, respectively, to receive an injection funnel  40 , as will be described in greater detail below.  
         [0014]     The second mold half  12  includes a peripheral cutting ridge  21  surrounding the circumference of the opening defined by the second mold surface  16 . The size of the cutting ridge  21  is exaggerated in the Figures. The cutting ridge  21  is shown as a substantially triangular barb having a sharp leading edge. Alternatively, the cutting ridge  21  may have any shape or configuration suitable for performing a cutting operation described below.  
         [0015]     The first mold half  11  includes a projection or lip  26  extending from and surrounding the circumference of the opening defined by the first mold surface  14 . The projection  26  acts as cutting board for the cutting ridge  21  as further described below. Additionally, the projection  26  provides an indentation in the completed headrest so to convey the appearance of headrest being formed of two pieces. Preferably, the first mold surface  14  is slightly deeper than the second mold surface  16  such that the projection  26  is centered on the completed headrest. In other words, the first  14  and second  16  mold surfaces are preferably designed such that when the mold halves  11 ,  12  are closed, the projection  26  is in the center of the headrest. The projection  26  is shown as having a bulbous semi-circular configuration. It should be appreciated that the projection  26  may have any suitable configuration depending upon the desired effect for the trim component being manufactured.  
         [0016]     In forming the headrest, the mold assembly  10  is initially placed in the open position as shown in  FIG. 1 . An in-mold coat  20  is then applied to each of the mold surfaces  14 ,  16 . It is optional that a mold-release coat is applied to each of the mold surfaces  14 ,  16  prior to the in-mold coating  20  to promote efficient removal of the headrest from the mold assembly  10  after the forming process is complete. The in-mold coat  20  is preferably applied in a generally uniform manner to promote consistent gloss, texture, and color of the outer contour of the seating headrest. Preferably, the in-mold coat  20  is a waterborne urethane coating, which can be applied by an air-atomized coating applicator such as a spray gun or bell applicator. Alternatively, the composition and means of applying the in-mold coat  20  may be of any suitable type. A skin coat  22  is next applied to the in-mold coat  20  in a manner similar to application of the in-mold coat  20 . The composition of the skin coat  22  is preferably a two component polyurethane elastomer including a polyol component and an isocyanate component as disclosed and described in U.S. Pat. No. 5,885,662 which is incorporated herein by reference in its entirety. The in-mold coat  20  applied to each mold half  11 ,  12  bonds to the respective skin coat  22  to form a structural skin  29 .  
         [0017]     During the application of the in-mold coat  20  and the skin coat  22 , a certain amount of overspray  24  can accumulate on the mold halves  11 ,  12  outside of the mold surfaces  14 ,  16  and outside of the cutting ridge  21  and projection  26 . For illustrative purposes, the overspray  24  is exaggerated in the Figures.  
         [0018]     A pair of elongated headrest armatures  30 , which function as a support of the headrest to an automotive seat, are then inserted into the respective receiving channels  15 ,  17  of a designated one of the mold halves  11 ,  12  such that the armature  30  extend into the mold cavity  18 . The headrest armatures  30  are preferably connected to a cross member  31  to form a U-shaped support. The U-shaped support may be an integral U-shaped tube having a solid or hollow construction. Alternatively, the U-shaped support may have a pair of separate armature posts  30  connected to a separate cross member by any suitable attachment means. In addition, there may be two separated armatures  30  without a cross member or even a single armature  30 . Each armature  30  has at least one air channel  32  formed longitudinally therein that is in fluid communication with the mold cavity  18  for venting the mold cavity  18  as further discussed below. The air channels  32  may be notches formed in the outer surfaces of the armatures  30  or may be vent holes formed in armatures  30  that are hollow. The armatures  30  are held in place by a clamp, toggle, or the like. It should be appreciated that the armatures  30  may be placed in the designated mold half  11 ,  12  prior application of the mold-release coat, the in-mold coat  20  or the skin coat  22 .  
         [0019]     Once the in-mold  20  and skin coat  22  are applied and with the armatures  30  held in the respective receiving channels  15 ,  17 , the injection funnel  40  is then inserted into the filler port  9 ,  13  of a designated one of mold halves  11 ,  12 .  
         [0020]     The mold assembly  10  is then placed in the closed position as shown in  FIG. 2  by rotating the second mold half  12  about the hinge  19  (the movement of which is represented by Arrow A). As the mold assembly  10  is placed in the closed position, the armatures  30  and the funnel  40  are received in the other receiving channel  15 ,  17  and the other filler port  9 ,  13 , respectively, thereby enabling complete closure of the second mold half  12  relative to the first mold half  11 . It should be appreciated that the hinge  19  is optional, and that the mold assembly  10  may alternatively be placed in the closed position by moving the mold halves  11 ,  12  relative to each other in any suitable manner including linear movement, arcuate movement or a combination linear and arcuate movements.  
         [0021]     As the mold halves  11 ,  12  are moved to the closed position, the peripheral cutting ridge  21  cuts through the overspray  24  of the coats  20 ,  22  on the mold halves  11 ,  12  and into abutment with the projection  26 . The cutting ridge  21  and projection  26  extend around the entire perimeter of the mold cavity  18  such that any overspray  24  on the mold halves  11 ,  12  will be cut by the ridge  21 . When the cutting ridge  21  abuts the projection  26 , the mold assembly  10  is in the closed position.  
         [0022]     Before the mold halves  11 ,  12  are moved to the closed position, the coats  20 ,  22  are allowed to at least partially harden to a non-liquid or gel state. The non-liquid or gel state of the coats  20 ,  22  promotes the cutting of the overspray  24  during the closing of the mold halves  11 ,  12 .  
         [0023]     Once the mold halves  11 ,  12  have reached, or just prior to reaching, the closed position, the mold halves  11 ,  12  are mechanically clamped or locked together to ensure that the mold assembly is properly placed and held in the closed position.  
         [0024]     When in the closed position, the coats  20 ,  22  of the first mold half  11  bond with the coats  20 ,  22  of the second mold half  12  at the junction between the mold halves  11 ,  12 . That is, the portion of the coats  20 ,  22  around the perimeter the first mold surface  14  bond with the portion of the coats  20 ,  22  around the perimeter of the second mold surface  16 . The bond between the coats  20 ,  22  of the mold halves  11 ,  12  is more durable than a conventional headrest having sewn seams because the bonding of the subject invention is particularly resistant to tearing, ripping, snagging and opening during repeated use over the life of the headrest.  
         [0025]     A cellular foam filler  42  is then injected through the funnel  40  placed in fluid communication with the mold cavity  18 . Alternatively, provided that the armatures  30  are hollow, the foam filler  42  may be injected through an opening formed in either or both of the armatures  30 . An advantage of injecting the foam filler  42  through the armatures  30  is that the foam filler  42  has additional time to blend into a proper mixture.  
         [0026]     The cellular foam filler  42  expands in the mold cavity  18  and bonds with the armatures  30  and the structural skin  29 , formed by the coats  20 ,  22 , to form the headrest.  
         [0027]     The foam filler  42  is preferably urethane and may be manufactured of a color that is complementary to the color of the structural skin  29 , which provides the advantage of partially concealing any tears, cuts or breakage in the structural skin  29  that may occur during the life of the headrest.  
         [0028]     The air channels  32  formed in the armatures  30  allow gases to escape from the cavity  18  as the foam filler  42  occupies the cavity  18 . Alternatively, gases may be vented through one or more vent holes formed in the armatures  30 . As a further alternative, provided that the armatures  30  utilize the U-shaped cross member  31  that is hollow, one of the armatures  30  may have inlet opening external to the cavity  18  and one or more fill holes in fluid communication with the cavity  18  for facilitating the injection of the foam filler  42 . The other armature  30  may have an outer opening external to the cavity  18  and one or more vent holes in fluid communication with the cavity  18  for facilitating the venting of gases. In this embodiment, the foam filler  42  is injected into the cavity  18  trough the inlet opening via the fill holes, and gases escape the cavity  18  through outlet opening via the vent holes. It should be further appreciated that the injecting and venting may be further facilitated through apertures formed in the cross member having a hollow construction.  
         [0029]     Preferably, the mold halves  11 ,  12  are manipulated 90 degrees before the injection of the foam filler  42  such that the armature  30  extends upwardly (as shown in  FIG. 2 ). The 90 degree rotation assists in venting the mold cavity  18  during the foam injection.  
         [0030]     The structural skin  29  is allowed to expand in the mold cavity  18  and cure and then the mold halves  11 ,  12  are opened to remove the completed headrest. Finally, if necessary, the subject invention may include a step of deflashing excess structural skin  29  at the bonding line created between the mold halves  11 ,  12 .  
         [0031]     As stated above, the completed headrest conveys the appearance of being formed of two pieces as provided by the indentation formed by the projection  26 . Such a headrest may be regarded as a more aesthetically pleasing than a conventional headrest having sewn seams.  
         [0032]     An alternative embodiment of the subject invention proceeds as follows. With the mold halves  11 ,  12  in the open position, the in-mold coat  20  and the skin coat  22  are applied as introduced and described above. Further, the armature  30  is inserted into the receiving channel  15  of the first mold half  11  as described above. However, prior to rotating the second mold half  12  about the hinge  19  to close upon the first mold half  11 , the cellular foam filler  42  is injected over the skin coat  22  and the in-mold coat  20  in the first mold half  11 . That is, the semi-rigid cellular foam filler  42  is injected into one of the mold halves in the open position. Next, the second mold half  12  is rotated about the hinge  19  to close upon the first mold half  11 , and the first  11  and second  12  mold halves are locked together. In this alternative embodiment of the subject invention, all reactions described above occur simultaneously. That is, the in-mold coat  20  and the skin coat  22  bond to establish the structural skin  29  of the headrest, and simultaneously, the cellular foam filler  42  expands in the structural skin  29  to bond with the structural skin  29  thereby forming the complete headrest. In this embodiment, the cutting ridge  21  may remove excess, or overspilled, foam filler  42  as well as the oversprayed coats  24 .  
         [0033]     As appreciated, the use of the funnel  40  is eliminated from this alternative embodiment. One disadvantage to using the funnel  40  is that residue or overspill can be formed on the exterior of the headrest when the funnel  40  is removed. This alternative embodiment therefore eliminates any residue or overspill occurring in this manner.  
         [0034]     The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that the invention may be practiced otherwise as specifically described.