Abstract:
In a cover member attaching structure for putting a flat shaped cover member  3  of a synthetic resin in position in a principal part  1 , a dummy gate  5  serving as an inlet for resin injection from a submarine gate  4  during molding remains uncut after molding and protrudes from the cover member  3 , while the principal part  1  has a portion  6  formed for accommodating the dummy gate  5.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention relates to a cover member attaching structure.  
           [0002]    It is already known that a submarine gate is used for reducing man-hour for cutting off gates for the injection molding of a synthetic resin material. In the event that no port for injection from a submarine gate can be set on a molded product, a dummy gate is set on the product, as described in JP-Y2-2590693.  
           [0003]    In the event, however, that a molten resin is introduced into the cavity of a mold from a submarine gate through a dummy gate, the submarine gate drops off upon opening of the mold after molding, but the dummy gate remains as a part of the product and leaves a problem as the work for its removal is required.  
         SUMMARY OF THE INVENTION  
         [0004]    The present invention has been made to overcome the above drawback. It is an object of the present invention to provide a cover member attaching structure which makes it possible to eliminate the man-hour required for cutting off a dummy gate and thereby achieve a reduction of cost. It is another object of the present invention to provide an inside door handle device for a motor vehicle which can be manufactured with an improved efficiency owing to the use of such an attaching structure.  
           [0005]    According to the present invention, the above object can be accomplished by providing a cover member attaching structure comprising: a principal part  1 ; and a cover member with a flat-shape  3 , made of a synthetic resin, engaged with the principal part; a dummy gate  5 , as an inlet for resin injection from a submarine gate  4  during molding, remaining uncut after molding and protruding from the cover member; and an accommodating portion  6  formed in the principal part  1  for accommodating the dummy gate  5 .  
           [0006]    According to the invention, the flat-shaped cover member  3  put on the principal part  1  is molded by using a mold employing a submarine gate  4  so that the gate may drop off upon opening of the mold after molding.  
           [0007]    In order to employ a submarine gate  4  for molding a flat-shaped cover member  3 , it is necessary to form a dummy gate  5  on the rear side of the cover member  3 , and a separate job is required if the dummy gate  5  should be cut off from the cover member  3 , as stated before.  
           [0008]    The present invention has been made by noting that a member of which only the front side is required, such as the cover member  3 , can be used with the dummy gate  5  left unremoved without causing any functional problem, since the dummy gate  5  protrudes from the rear side of the product and is not exposed on its front side. Therefore, the present invention makes it possible to eliminate the step of cutting off the gate completely by allowing the principal part  1  to absorb the protruding dimensions of the unremoved dummy gate  5 . 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is a front view of an inside door handle device.  
         [0010]    [0010]FIG. 2 is an exploded perspective view of FIG. 1.  
         [0011]    [0011]FIGS. 3A to  3 C are views showing a cover member, wherein FIG. 3A is a top plan view, FIG. 3B is a front view, and FIG. 3C is a perspective view showing its rear side.  
         [0012]    [0012]FIGS. 4A to  4 C are views showing a process for molding a cover member, wherein FIG. 4A is a view showing the state in which a molten resin has been introduced into a cavity, FIG. 4B is a view showing a mold as opened, and FIG. 4C is a view showing a product as removed from the mold.  
         [0013]    [0013]FIGS. 5A to  5 C are views showing a cover member put in position, wherein FIG. 5A is a sectional view taken along the line VA-VA of FIG. 1, FIG. 5B is a sectional view taken along the line VB-VB of FIG. 1, and FIG. 5C is a sectional view taken along the line VC-VC of FIG. 1.  
         [0014]    [0014]FIGS. 6A and 6B are views showing a cover member put in position, wherein FIG. 6A is a sectional view taken along the line VIA-VIA of FIG. 1, and FIG. 6B is an enlarged view of part VIB in FIG. 6A.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0015]    [0015]FIGS. 1 and 2 show an inside door handle device for a motor vehicle to which this invention has been applied. The inside door handle device has an operating handle  7  and a lock lever  11  connected to a handle case as a principal part  1  rotatably about a pivot  12  and the rotation of the operating handle  7  against the reaction force of a spring  13  allows a lock device not shown to work for a door opening operation. The lock lever  11  is operable to cancel the door opening operation for the lock device by the operating handle  7  and thereby prevent the opening of the door during the traveling of the vehicle.  
         [0016]    The handle case  1  is shaped like a frame and the frame is divided by a cover wall  8 A formed at the base ends of the operating handle  7  and the lock lever  11  into a region for accommodating the shaft for the operating handle  7 , etc. and the remaining region which defines a hand-operating recess  9  surrounded by an upstanding wall  8  formed by the side walls of the frame and the cover wall  8 A.  
         [0017]    The attachment of the inside door handle device to a door inner panel P is carried out by fixing to, the door panel P attaching lugs la protruding outwardly from the handle case  1  with the operating handle  7  and the lock lever  11  connected thereto and an attaching lug  9   a  formed in a region facing the hand-operating recess  9 . A bolt for fixing to the door panel P the attaching lug  9   a  in the frame with the operating handle  7 , etc. attached to the handle case  1  has its head (fixing portion  10 ) exposed on the surface, and a cover member  3  is put to cover it, as shown in FIG. 5A.  
         [0018]    In order to prevent the occurrence of any ornamental incompatibility from the covering of only the head  10  of the bolt, the cover member  3  covers substantially the whole of the bottom of the hand-operating recess  9 , is substantially so sized as to form the bottom wall of the hand-operating recess  9  and has a main portion  3   b  in the form of a plate reinforced by ribs  3   a  formed on its rear surface, an engaging leg  14  for a release operation and a second engaging portion  15 .  
         [0019]    The cover member  3  is manufactured by the injection molding of a synthetic resin and a submarine gate  4  not calling for any work to cut it off is used for injecting the resin into the cavity  16   a  of a mold  16 , as shown in FIG. 4A. A dummy gate  5  is set on the rear side of the main portion  3   b  for injecting the resin through the submarine gate  4  for the cover member  3  shaped like a sheet and having a small thickness.  
         [0020]    According to this embodiment, the dummy gate  5  is formed by cutting away a part of the end portion of an ejector pin  16   b  situated in a movable mold  16 A.  
         [0021]    Therefore, according to this embodiment, the opening of the mold after the injection of the molten resin under pressure into its cavity  16   a , as shown in FIG. 4A, and the ejection of the product by the ejector pin  16   b , as shown in FIG. 4B, result in the cutting of the submarine gate  4  off the dummy gate  5  at their boundary with the opening of the mold, and thereby makes the cutting of the gate unnecessary.  
         [0022]    The dummy gate  5  protruding from the rear side of the main portion  3   b  is not removed, but the product is used as it is, as shown in FIG. 4C, so that the work to cut off the gate may be completely eliminated.  
         [0023]    The engaging leg  14  for release operation on the cover member  3  molded as described is formed by folding back upwardly into a U shape a projection  3   c  protruding on the rear surface of the main portion  3   b  from the center of one of its short sides, as shown in FIGS. 6A and 6B. A portion  14   a  engaging an engaging shoulder  1   b  on the handle case  1 , as will be described, is formed at the end of the engaging leg  14  for release operation.  
         [0024]    The second engaging portion  15  is formed at the short side opposite the edge where the engaging leg  14  for release operation is formed. The second engaging portion  15  has its end so positioned as not to project beyond the edge of the cover member  3  as viewed in top plan, so that the second engaging portion  15  may not slide in contact with the upstanding wall  8  and scratch it when the cover member  3  is put in position, as will be described later.  
         [0025]    The cover member  3  is put in the handle case in such a way that it is supported on a supporting shoulder  8   a  formed at the base end of the upstanding wall  8  of the handle case  1 , as shown in FIGS. 5A to  5 C. The handle case  1  has an opening  6   a  for the passage of the dummy gate  5  and the thickness of the handle case  1  is utilized to form an accommodating portion  6  therefore, so that the dummy gate  5  may not prevent the cover member from being put in position in the handle case  1 .  
         [0026]    When the cover member  3  is put in position, the second engaging portion  15  and the engaging portion  14   a  of the engaging leg  14  for release operation are engaged with the handle case  1  to prevent its detachment. When it is put in position, the engaging leg  14  for release operation is slightly flexed to produce an elastic restoring force which urges the whole cover member  3  toward the second engaging portion  15  as shown by an arrow A in FIGS. 6A and 6B. As a result, the second engaging portion  15  is pressed against an engaging wall  1   c  on the handle case  1  and cooperates with the sliding contact of positioning lugs  3   d  formed on the rear surface of the main portion  3   b  near its edges to hold the cover member  3  against irregular movement, as shown in FIG. 5B.  
         [0027]    The removal of the cover member  3  put in position as described can be done easily by inserting a tool  17  having a sharp tip into a gap between a hooking projection  14   b  formed near the engaging portion  14   a  and the surface of the upstanding wall  8  and turning the tool  17 , as shown in FIG. 6B. According to the mode of embodiment under description, the upstanding wall  8  has a recess  8   b  accommodating the hooking projection  14   b , so that no scratch made by the tool  17  during its insertion into the gap, or during its turning is easily visible to the user.  
         [0028]    As is obvious from the foregoing description, this invention makes it possible to eliminate the man-hour for cutting off a dummy gate and thereby reduce the cost of manufacture.