Abstract:
A manipulator includes a support arm, a grasping member, and a connecting assembly. The connecting assembly connects the support arm with the grasping member. A base is fixed to the support arm, and the holder is fixed to the base. The holder defines an assembling hole, and a perimeter of the assembling hole increases along a direction towards the base. The connecting member has a first assembling portion received in the assembling hole of the holder. The elastic member is positioned between the base and the connecting member, thus producing an elastic force to drive the connecting member to resist the holder.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates generally to manipulators and, more particularly, to a manipulator used in manufacturing. 
         [0003]    2. Description of Related Art 
         [0004]    Manipulators are widely used in the manufacturing industry to increase production efficiency. The manipulator generally moves in a predetermined path according to machining programs stored in a controller, to assemble or combine workpieces. However, the manipulator may experience positioning errors caused by inner components with insufficient precision, such as gears. Therefore, the manipulator may deviate from the predetermined path, resulting in unsatisfactory assembly standards. 
         [0005]    Therefore, a manipulator which overcomes the described limitations is desirable. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
           [0007]      FIG. 1  is a cross-section of an embodiment of a manipulator, the manipulator including a support arm, a grasping member, and a connecting assembly. 
           [0008]      FIG. 2  is an assembled, isometric view of the connecting assembly of  FIG. 1 . 
           [0009]      FIG. 3  is an exploded, isometric view of the connecting assembly of  FIG. 1 . 
           [0010]      FIG. 4  is similar to  FIG. 3 , but viewed from another aspect. 
           [0011]      FIG. 5  is a cross-section of the manipulator of  FIG. 1 , illustrating a process of attaching a first workpiece to a second workpiece. 
           [0012]      FIG. 6  is similar to  FIG. 5 , but shows the first workpiece attached to the second workpiece. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Referring to  FIG. 1 , an embodiment of a manipulator  100  includes a support arm  10 , a grasping member  30 , and a connecting assembly  20  connecting the support arm  10  with the grasping member  30 . 
         [0014]    Referring also to  FIGS. 2 through 4 , the connecting assembly  20  includes a base  21 , an elastic member  22 , a connecting member  23 , an engaging member  24 , a holder  25 , a flange  26 , an adjusting member  27 , a fastening member  28 , and a plurality of fasteners (not shown). 
         [0015]    The base  21  is substantially cylindrical. A cylindrical protrusion  212  (shown in  FIG. 1 ) is formed on a bottom surface thereby defining a receiving groove  211 . The base  21  further defines a through hole  213  in the cylindrical surface communicating with the receiving groove  211 . The elastic member  22  is a compression spring in this embodiment. 
         [0016]    The connecting member  23  includes a first assembling portion  231  and a second assembling portion  232 . The first assembling portion  231  decreases in size with distance from the second assembling portion  232 . In the illustrated embodiment, the first assembling portion  231  is a frusto-conical shaped, and the second assembling portion  232  is cylindrical. The first assembling portion  231  defines a receiving groove  2313  in a center portion. A positioning protrusion  2311  extending towards the second assembling portion  232  is formed on a bottom wall, thereby defining an assembling groove  2323  in a center portion. The positioning protrusion  2311  defines a through hole  2315  communicating with the receiving groove  2313 . An engaging groove  2312 , partially receiving the engaging member  24 , is defined in the sidewall defining the receiving groove  2313 . The second assembling portion  232  defines a positioning cutout  2321  in the cylindrical surface. 
         [0017]    The holder  25  defines an assembling hole  251  in a center portion. A fixing portion  253  is formed on an end of the holder  25 . A perimeter of the assembling hole  251  increases with distance from the fixing portion  253 . The fixing portion  253  defines a plurality of fixing holes  2532  arranged regularly, and a plurality of cutouts  2531  corresponding to the fixing holes  2532 . 
         [0018]    The flange  26  includes a main portion  261  and a connecting portion  262  formed on an end of the main portion  261 . In the illustrated embodiment, both the main portion  261  and the connecting portion  262  are cylindrical. The main portion  261  defines an assembling groove  2611  in a center portion. The connecting portion  262  defines a restricting groove  2621  in the cylindrical surface to partially receive the engaging member  24 . The connecting portion  262  further defines a threaded hole  2622  communicating with the assembling groove  2611 . 
         [0019]    In assembling the connecting assembly  20 , the holder  25  sleeves on the first assembling portion  231  of the connecting member  23 . The engaging member  24  partially engages with the engaging groove  2312  of the connecting member  23 . The connecting portion  262  is received in the receiving groove  2313  of the connecting member  23 , and the engaging member  24  is partially received in the restricting groove  2621  of the flange  26 , thus preventing the connecting member  23  from rotating relative to the flange  26 . A fastener extends through the through hole  2315  of the connecting member  23 , and engages with the threaded hole  2622  of the flange  26 , thus fixedly connecting the connecting member  23  with the flange  26 . One end of the elastic member  22  partially sleeves on the positioning protrusion  2311 . The connecting member  23  is received in the receiving groove  211  of the base  21 , and an opposite end of the elastic member  22  partially sleeves on the protrusion  212 . The fixing portion  253  of the holder  25  is fixed to the base  21  via fasteners. The adjusting member  27  extends through the through hole  213  of the base, and the positioning cutout  2321  of the connecting member  23 , to prevent the connecting member  23  from rotating relative to the base  21 . The fastening member  28  engages with the adjusting member  27 . After the connecting assembly  20  is assembled, the connecting member  23  can move axially relative to the holder  25   
         [0020]    Referring to  FIG. 5 , in use, the connecting assembly  20  is assembled to the support arm  10 . The grasping member  30  partially engages with the assembling groove  2611  of the main portion  261 . A first workpiece  50  is grasped by the grasping member  30 . A second workpiece  60  is mounted on a worktable or grasped by another manipulator. The manipulator  100  moves to place the first workpiece  50  in a connecting hole  61  of the second workpiece  60 . Since a real moving path of the manipulator  100  deviates slightly from a predetermined path, the axis of the first workpiece  50  cannot be aligned perfectly with the axis of the connecting hole  61 . That is, the first workpiece  50  cannot be placed in the connecting hole  61  as previously designed, and resists a guiding portion  611  of the connecting hole  61 . 
         [0021]    Referring to  FIG. 6 , the manipulator  100  moves closer towards the second workpiece  60 . If the first workpiece  50  is not perfectly aligned with the second workpiece  60 , the connecting member  23  can slide along the holder  25  thereby compressing the elastic member  22 , due to the first workpiece  50  resisting the guiding portion  611 . Thus, a space is formed between the connecting member  23  and the holder  25 , and the connecting member  23  deviates at an angle relative to the holder  25 , so that the axis of the first workpiece  50  can align with the axis of the connecting hole  61 . Therefore, the first workpiece  50  can be aligned to the second workpiece  60  with low friction, depending on the stored elastic force in the elastic member  22 , thereby preventing the first workpiece  50  from damage. 
         [0022]    After the first workpiece  50  is placed in the connecting hole  61  of the second workpiece  60 , the connecting member  23  returns to the original position, driven by the restoring elastic force of the elastic member  22 . Since the elastic member  22  is a compression spring, the connecting member  23  again tightly engages the holder  25 . 
         [0023]    It should be pointed out that the first assembling portion  231  may be other shapes, such as hemispherical. The engaging member  24  can be integrally formed with the first assembling portion  231 . The connecting assembly  20  may not include the adjusting member  27  and the fastening member  28 , rather, a positioning pole can be formed on the inner surface of the base  21 , engaging the assembling groove  2323  of the connecting member  23 . In addition, the flange  26  can be integrally formed with the first assembling portion  231 , and the connecting member  23  can be integrally formed with the base  21 . 
         [0024]    It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its material advantages.