Patent Publication Number: US-2012032385-A1

Title: Clamping mechanism

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates generally to robotics, and especially to a clamping mechanism used on a robot. 
     2. Description of Related Art 
     A commonly used clamping mechanism includes a plurality of claws for holding a workpiece. The claws are generally standardized, and substantially the same, such that the claws can hold a regular shaped workpiece securely. However, if the workpiece is irregularly shaped, such secure retention may be difficult. 
     Therefore, there is room for improvement within the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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 views. 
         FIG. 1  is an isometric view of an embodiment of a clamping mechanism including a plurality of claws and a contact member. 
         FIG. 2  is an exploded, isometric view of the clamping mechanism of  FIG. 1 . 
         FIG. 3  is similar to  FIG. 2 , but shown in another aspect. 
         FIG. 4  is an exploded, isometric view of a claw shown in  FIG. 1 . 
         FIG. 5  is an exploded, isometric view of the contact member shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 through 3 , an embodiment of a clamping mechanism  200  includes a pair of clamping boards  20 , an end executor  21 , a first boot  22 , a second boot  23 , a contact member  24 , a fixing board  25 , a driving member  26 , a holder  27 , a housing  28 , and a connecting member  29 . The first boot  22  and the second boot  23  are positioned on the end executor  21 , providing protection thereto. The driving member  26  is received in the housing  28 . The connecting member  29  includes two parts mounted on both sides of the housing  28  adjacent to an end of the housing  28 , connecting to a robot arm (not shown). 
     Each clamping board  20  includes a first clamping portion  201  and a second clamping portion  203  at an end of the first clamping portion  201 . The first clamping portion  201  is used for clamping the contact member  24  and the fixing board  25 , and the second clamping portion  203  is used for holding the first boot  22  and the second boot  23 . 
     As shown in  FIG. 4 , the end executor  21  includes a plurality of claws  211  arranged in a matrix. Each claw  211  includes a rectangular main body  2111 , an extending portion  2113  formed at an end of the main body  2111 , an elastic member  2115 , and a tube  2117 . The elastic member  2115  is sleeved on the extending portion  2113 . The tube  2117  forms a flange  2118  at an end for resisting the elastic member  2115  when the tube  2117  is sleeved on the extending portion  2113 . 
     The first boot  22  is substantially rectangular, and forms a stopping board  221  at an end. The stopping board  221  defines a plurality of through holes  2211 . A diameter of the through hole exceeds that of the tube  2117 , but is less than that of the flange  2118 , allowing the tube  2117  to pass through the through hole  2211 . The flange  2118  may be blocked by the stopping board  211  to limit the tube  2118 . 
     The second boot  23  is similar to the first boot  22 , and forms a stopping board  231  at an end. The stopping board  231  defines a plurality of through holes  2311 . A diameter of the through holes  2311  exceeds that of the tube  2117 , but is less than that of the main body  2111  of the claw  211 , allowing the tube  2117  to pass therethrough. 
     As shown in  FIG. 5 , the contact member  24  includes a substantially rectangular mounting board  241 , a plurality of contact sleeves  243  and four positioning posts  245 . The four positioning posts  245  are fixed at four corners of the mounting board  241  respectively. The mounting board  241  defines a plurality of mounting holes  2411  corresponding to the contact sleeves  243  respectively and each contact sleeve  243  is mounted in one of the mounting holes  2411 . Some of the contact sleeves  243  may be of varying height to form a shaped matrix according to a workpiece to be clamped. In the illustrated embodiment, the mounting board  241  is made of iron. Alternatively, the mounting board  241  may be made of cobalt, nickel, or other magnetic materials. 
     The fixing board  25  defines a positioning groove  251  at each corner corresponding to the positioning post  245  of the mounting board  241 . In the illustrated embodiment, the fixing board  25  is a magnet for attracting the mounting board  241 . The driving member  26  includes a cylinder  261  and an output shaft  263  at an end of the cylinder  261 . The output shaft  263  may extend out of the cylinder  261  and driven by the cylinder  261 . The fixing board  25  defines a shaft hole  253  at a center thereof, allowing the output shaft  263  of the driving member  26  to pass through and resist the contact member  24 . The holder  27  is substantially rectangular and defines a receiving hole  271  therein for receiving the cylinder  261 . 
     In assembly, each claw  211  passes through one of the through holes  2211  and protrudes out of the first boot  22 . The first boot  22  receives the main body  2111  of the claws  211 , and arranges the claws  211  in matrix. Then, one end of the tube  2117  of the end executor  21  away from the flange  2118  passes the through hole  2311  of the second boot  23 , and protrudes out of the second boot  23 . The stopping board  231  of the second boot  23  abuts the stopping board  221  of the first boot  22 . The tube  2117  is capable of sliding on the extending portion  2113 , compressing the elastic member  2115 . The first clamping portion  201  is mounted on a side of the first boot  22  and the second boot  23 , thus to interconnect the firs boot  22  and the second boot  23 . The fixing board  25  is attracted by the mounting board  241 , and fixed on the mounting board  241 . Each positioning post  245  is mounted in one of the positioning groove  251 , to slidably position the mounting board  25  and the contact member  24  between the two clamping board  20 . The cylinder  261  is fixed in the receiving hole  271 . The holder  27  is fixed in the housing  28 , and the housing  28  is fixed on the clamping board  20 . The output shaft  263  of the driving member  26  passes the shaft hole  253  of the fixing board  25 , and urges the mounting board  241  of the contact member  24 , thus the contact member  24  may slide between the two clamping boards  20 , driven by the contact member  26 . The connecting member  29  is mounted on a side surface of the housing  28  away from the end executor  21 . The connecting member  29  may be connected to the robot arm. 
     In use, a plurality of contact sleeves  243  with different heights may be prepared and arranged on the mounting board  241  of the contact member  24  according to a shape of the workpiece. The output shaft  263  extends and contacts the mounting board  241 , driven by the cylinder  261 , whereby the contact sleeves  243  can move the tubes  2117  respectively, to push the claws  211  out of the first boot  22  and fix the workpiece securely. The extending portion  2113  of the claw  211  may partially extend into the contact sleeve  243 . 
     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.