Patent Publication Number: US-9849396-B2

Title: Shoulder joint structure of doll body

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     The present invention contains subject matter related to Japanese Patent Application No. 2015-209680 filed in the Japan Patent Office on Oct. 26, 2015, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a shoulder joint structure of a doll body. 
     2. Description of the Related Art 
     A shoulder joint structure of a doll body described in Japanese Registered Utility Model No. 3185443 is configured such that a joint member provided at one end of an arm is connected to a shoulder of a trunk through a ring-like cover member made of a soft material. The cover member covers a gap between the shoulder and the arm. When the arm is moved, the cover member is appropriately deformed between the arm and the shoulder, and covers the gap between the shoulder and the arm without limiting the range of motion of the arm. 
     In the shoulder joint structure of a doll body described in Japanese Registered Utility Model No. 3185443, the position of the shoulder at the base of the arm is almost fixed. For example, when moving the arm in front of the chest of the trunk, the arm abuts on the front or chest side edge of the shoulder of the trunk, and the arm cannot be moved such that the arm overlaps the chest of the trunk. If the shoulder of the trunk is hollowed out to expand the range of motion of the arm, the cover member becomes large and unnaturalness stands out. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in consideration of such circumstances, and an object of the present invention is to provide a shoulder joint structure of a doll body the range of arm motion of which can be expanded. 
     In an aspect of the present invention, a shoulder joint structure of a doll body includes a first joint member housed inside a trunk of the doll body and connected to the trunk, a second joint member housed inside the trunk and connected to the first joint member, and a third joint member connected to the second joint member and an arm of the doll body through an opening formed in a shoulder of the trunk. The first joint member is capable of rotating about a first connecting portion where the trunk and the first joint member are connected, so as to move the third joint member away from a trunk axis of the trunk in a shoulder width direction. The second joint member is capable of rotating about a second connecting portion where the first joint member and the second joint member are connected, so as to move the third joint member away from the trunk axis in the shoulder width direction. 
     The first joint member may be capable of rotating about the first connecting portion, so as to move the second joint member and the third joint member in front of the trunk in a chest depth direction. 
     The first connecting portion may be a ball joint. 
     The first connecting portion may be disposed below the opening of the shoulder of the trunk in an axial direction of the trunk axis. 
     The first connecting portion may be disposed in front of the opening of the shoulder of the trunk in the chest depth direction. 
     The first connecting portion may be disposed inside a breast or a pectoralis major muscle of the doll body. 
     The shoulder joint structure of a doll body may further include an annular cover member that is inserted into the opening of the shoulder of the trunk so as to be protrudable and retractable and that covers the third joint member. 
     The present invention can provide a shoulder joint structure of a doll body the range of arm rotation of which can be expanded. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the upper body of a doll body for illustrating an embodiment of the present invention; 
         FIG. 2  is an exploded perspective view of the upper body of the doll body of  FIG. 1 ; 
         FIG. 3  is a perspective view of a shoulder joint structure of the doll body of  FIG. 1 ; 
         FIG. 4  is a side view of the shoulder joint structure of the doll body of  FIG. 1 ; 
         FIG. 5  is a front view showing the operation of the shoulder joint structure of the doll body of  FIG. 1 ; and 
         FIG. 6  is a plan view showing the operation of the shoulder joint structure of the doll body of  FIG. 1 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  and  FIG. 2  show the configuration of the upper body of a doll body for illustrating an embodiment of the present invention. 
     The doll body  1  shown in  FIG. 1  includes a trunk  2  and a pair of left and right arms  3 . The pair of left and right arms  3  are each provided with a first joint member  6 , a second joint member  7 , and a third joint member  8  that form a shoulder joint, and a cover member  9 . 
     The trunk  2  includes a frame member  11  disposed on the trunk axis A of the trunk  2 , a chest member  12 , and a back member  13 . The chest member  12  and the back member  13  are assembled together. The frame member  11  is housed in the inside space of the trunk  2  surrounded by the chest member  12  and the back member  13 . The back member  13  is fixed to the frame member  11  with a screw or the like, and the chest member  12  assembled to the back member  13  is also fixed to the frame member  11 . 
     Each arm  3  includes a shoulder member  14  serving as the base of an upper arm. Members (not shown) that form parts beyond the shoulder, such as an upper arm and a forearm, are assembled to the shoulder member  14 . 
     The first joint member  6  and the second joint member  7  are housed inside the trunk  2 . The first joint member  6  is connected to the frame member  11  inside the trunk  2 , and the second joint member  7  is connected to the first joint member  6 . 
     The third joint member  8  is connected to the shoulder member  14  of the arm  3 . An opening  15  is formed in each shoulder of the trunk  2 , and the third joint member  8  is connected through the opening  15  to the second joint member  7 . 
     The cover member  9  is formed in an annular shape, and is inserted into the opening  15  of the shoulder of the trunk  2  so as to be protrudable and retractable. The third joint member  8  connected through the opening  15  to the second joint member  7  and the shoulder member  14  is passed through the cover member  9 , and the cover member  9  covers the connecting portion between the third joint member  8  and the shoulder member  14 . 
       FIG. 3  and  FIG. 4  show a shoulder joint structure of the doll body  1 , and  FIG. 5  and  FIG. 6  show the operation of the shoulder joint structure of the doll body  1 . 
     The connecting portion  20  between the frame member  11  and the first joint member  6  is disposed below the opening  15  (see  FIG. 1 ) of the shoulder of the trunk  2  in the axial direction of the trunk axis A, and in front of the opening  15  in the chest depth direction. The connecting portion  22  between the second joint member  7  and the third joint member  8  is disposed in the shoulder of the trunk  2  facing the opening  15 . The connecting portion  21  between the first joint member  6  and the second joint member  7  is disposed between the connecting portion  20  and the connecting portion  22 . 
     The connecting portion  20  between the frame member  11  and the first joint member  6  is configured as a so-called ball joint consisting of a socket  30  provided in the frame member  11  and a ball  31  provided at one end of the first joint member  6 . The first joint member  6  is capable of rotating with respect to the frame member  11  in a precession-like motion. The frame member  11  may be provided with a ball, and the first joint member  6  may be provided with a socket. 
     The connecting portion  20  between the first joint member  6  and the second joint member  7  consists of a shaft portion  32  provided at the other end of the first joint member  6 , and a bearing portion  33  provided at one end of the second joint member  7 . The second joint member  7  is capable of rotating with respect to the first joint member  6  about the shaft portion  32 . The first joint member  6  may be provided with a bearing portion, and the second joint member  7  may be provided with a shaft portion. 
     The connecting portion  22  between the second joint member  7  and the third joint member  8  is configured as a so-called ball joint consisting of a socket  34  provided at the other end of the second joint member  7  and a ball  35  provided at one end of the third joint member  8 . The third joint member  8  is capable of rotating with respect to the second joint member  7  in a precession-like motion. The second joint member  7  may be provided with a ball, and the third joint member  8  may be provided with a socket. 
     The connecting portion  23  between the third joint member  8  and the shoulder member  14  of the arm  3  consists of a bearing portion  36  provided at the other end of the third joint member  8  and a shaft portion  37  provided on the shoulder member  14 . The shoulder member  14  is capable of rotating with respect to the third joint member  8  about the shaft portion  37 . The third joint member  8  may be provided with a shaft portion, and the shoulder member  14  may be provided with a bearing portion. 
     The arm  3  is swung with respect to the trunk  2  back and forth and up and down by the rotation of the shoulder member  14  relative to the third joint member  8  and the rotation of the third joint member  8  relative to the second joint member  7 . 
     As shown in  FIG. 5  and  FIG. 6 , the first joint member  6  is capable of rotating with respect to the frame member  11  about the connecting portion  20  with the frame member  11 , which is configured as a ball joint, so as to move the connecting portion  21  with the second joint member  7  away from the trunk axis A of the trunk  2  in the shoulder width direction. By such rotation of the first joint member  6 , the third joint member  8  is moved away from the trunk axis A in the shoulder width direction. 
     The second joint member  7  is also capable of rotating with respect to the first joint member  6  about the connecting portion  21  with the first joint member  6 , so as to move the connecting portion  22  with the third joint member  8  away from the trunk axis A of the trunk  2  in the shoulder width direction. By such rotation of the second joint member  7 , the third joint member  8  is moved further away from the trunk axis A in the shoulder width direction. 
     Since the third joint member  8  is moved away from the trunk axis A in the shoulder width direction, the connecting portion  23  between the third joint member  8  and the shoulder member  14  of the arm  3  moves away from the opening  15  of the shoulder of the trunk  2 . Thereby, the upper arm part of the arm  3  extending beyond the shoulder member  14  is made less likely to interfere with the trunk  2  or the edge of the opening  15 , and the range of motion of the arm  3  is expanded. For example, when moving the arm  3  in front of the chest of the trunk  2 , the arm  3  can be moved such that the arm  3  overlaps the chest of the trunk  2 . 
     The first joint member  6  is capable of rotating with respect to the frame member  11  about the connecting portion  20  with the frame member  11 , which is configured as a ball joint, so as to move the third joint member  8  forward in the chest depth direction. By such rotation of the first joint member  6 , the connecting portion  23  between the third joint member  8  and the shoulder member  14  of the arm  3 , that is, the part about which the arm  3  swings is disposed close to the front edge of the opening  15  of the shoulder of the trunk  2 . Thereby, the upper arm portion of the arm  3  extending beyond the shoulder member  14  is made less likely to interfere with the trunk  2  or the front edge of the opening  15 , and the range of motion of the arm  3  is further expanded. That is, the range of motion when moving the arm  3  in front of the trunk  2  is expanded. 
     Since the connecting portion  20 , about which the first joint member  6  rotates, is disposed on the front side of the opening  15  in the chest depth direction, the arm  3  can be moved in front of the trunk  2  to a greater extent than in a case where the connecting portion  20  is at the back of the chest in the chest depth direction. Since the connecting portion  20 , about which the first joint member  6  rotates, is disposed below the opening  15  of the shoulder of the trunk  2  in the axial direction of the trunk axis A, the radius of rotation of the third joint member  8  can be increased. The first joint member  6  is rotated in a limited space inside the trunk  2 , and the rotation angle of the first joint member  6  is naturally limited. However, since the radius of rotation of the third joint member  8  is increased, the amount of displacement of the third joint member  8  can be increased despite the predetermined rotation angle of the first joint member  6 . 
     If the connecting portion  20 , about which the first joint member  6  rotates, is provided above the opening  15  of the shoulder of the trunk  2  in the axial direction of the trunk axis A, the upper part of the trunk  2  (the position near the collarbone in a human body) becomes thick in the chest depth direction in order to secure a space for the connecting portion  20 , and therefore the appearance is impaired. By disposing the connecting portion  20 , about which the first joint member  6  rotates, in the chest of the trunk  2 , a space for housing the connecting portion  20  can be secured inside the breast, utilizing the swell of the breast, without providing the appearance of the trunk  2  with an unnatural bulge. 
     During the movement of the third joint member  8 , the cover member  9  is dragged by the third joint member  8  and protrudes from the opening  15  of the shoulder of the trunk  2 , or comes into contact with the third joint member  8  and is thereby retracted into the opening  15 , and a state where the connecting portion  23  between the third joint member  8  and the shoulder member  14  is covered by the cover member  9  is maintained. Thereby, the naturalness of appearance can be kept while expanding the range of motion of the arm  3  of the doll body  1 . 
     Although in the embodiment of the present invention described above, the connection between the first joint member  6  and the frame member  11  and the connection between the second joint member  7  and the third joint member  8  are ball joints, and the connection between the first joint member  6  and the second joint member  7  and the connection between the third joint member  8  and the shoulder member  14  are shaft and bearing joints, the structures of the connecting portions of the shoulder joint structure of the present invention are not limited to those set forth above.