Abstract:
A clamping apparatus for securing a workpiece is provided. The clamping apparatus includes a fixing base and a first and a second clamping device mounted on opposing sides of the fixing base. The first clamping device includes stacked clamping sheets, each of which is moveable and comprises an inclined clamping edge for contacting the workpiece. A support assembly supports the plurality of stacked clamping sheets; and an operating member is slidable relative to the support assembly and contacting the plurality of staked clamping sheets. The operation member is capable of moving at least one of the plurality of stacked clamping sheets relative to another one when the operation member slides relative to the support assembly, and moving at least one of the inclined clamping edge toward or away from the second clamping device to accommodate workpieces of varying sizes.

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure generally relates to clamping apparatus, particularly to a clamping apparatus for small electronic components. 
     2. Description of Related Art 
     Often, clamping apparatus, such as clamping fingers are used to fix electronic components in predetermined positions on a printed circuit board. However, the clamping apparatus is generally provided with a predetermined work range, and can only accommodate electronic components of a predetermined size. If electronic components of varying sizes need to be clamped, accordingly, multiple clamping apparatuses are required, increasing costs and reducing efficiency. 
     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 placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is an isometric view of one embodiment of a clamping apparatus provided with a pair of clamping devices. 
         FIG. 2  is an exploded perspective view of the clamping apparatus shown in  FIG. 1 . 
         FIG. 3  is an isometric view of an operating member of the clamping apparatus of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one. 
     Referring to  FIGS. 1 and 2 , one embodiment of a clamping apparatus  100  can be connected to and operated by a manipulator (not shown). The clamping apparatus  100  is adapted to clamp and position electronic components onto a printed circuit board automatically via control of the manipulator. The clamping apparatus  100  includes a fixing base  10  and a pair of clamping devices  30  mounted on opposite sides of the fixing base  10 . 
     The fixing base  10  includes a main body  11 , two first connection members  12  fixed to the main body  11 , and two second connection members  21  connected to the first connection members  12 , respectively. The main body  11  can be connected to the manipulator. The two first connection members  12  are arranged on opposite sides of the main body  11 , each of which has a connection portion  121  formed thereon. The second connection members  21  may be substantially U-shaped. Each second connection member  21  includes a bottom surface  212  fixed to the connection portion  121 , and two sidewalls  214  substantially perpendicular to the bottom surface  212 . The two sidewalls  214  are spaced from each other, and the clamping device  30  is positioned between the two sidewalls  214 . Each sidewall  214  defines a first hole  216  therein. 
     The clamping device  30  includes a plurality of stacked clamping sheets  13 , each of which is movable along a longitudinal axis, a support assembly  170 , a positioning member  15 , an operating member  19 , and a locking assembly  23 . 
     In this embodiment, each clamping sheet  13  is a substantially thin trapezoid sheet, and includes an engaging portion  131  defining a positioning hole  1311  therein, and a clamping portion  133  extending from the bottom of the engaging portion  131 . The engaging portion  131  and the positioning hole  1311  are substantially rectangular, and the clamping portion  133  is substantially triangular. The clamping portion  133  has an inclined clamping edge  1331  along a longitudinal axis to clamp the electronic component. A top corner of the engaging portion  131  forms a first rounded corner  1313 . The clamping edge  1331  and the rounded corner  1313  are located on the same side of the clamping sheet  13 . Each clamping sheet  13  is provided with a plurality of sawtooth protrusions (not labeled) on the clamping edge  1331  to improve friction. It should be understood that, in other embodiments, two or more clamping sheets  13  can be deployed, with no limitation to seven as shown in  FIG. 2 , and the clamping edge  1331  can be coated with a layer with a higher frication coefficient than the clamping edge  1331 . 
     The positioning member  15  defines a positioning groove  151  in a first end thereof and includes a positioning protrusion  153  extending from a second end opposite to the positioning groove  151 . The positioning groove  151  is substantially V-shaped formed on top surface of the positioning member  15  and passing through two opposite sides  154  thereof. Two inclined and opposite surfaces  1511  cooperatively define the first positioning groove  151 . Each surface  1511  has a plurality of parallel first stepped portions  1512  formed thereon. The positioning protrusion  153  is also substantially V-shaped and defines a second hole  155  therein. 
     The support assembly  170  includes two opposite support members  17 . Opposite surface of the two support members  17  defines a receiving groove  1711 , a guiding groove  1731  and a positioning groove  1733  beneath the guiding groove  1731 . The receiving groove  1711  is formed on the top of the support member  17 , and the locking assembly  23  is received between the receiving grooves  1711  of the two support members  17 . The guiding groove  1731  is perpendicular to and communicates with the receiving groove  1711 . The positioning member  15  is partially received between the guiding grooves  1731  of the two support members  17 . The bottom surface of the positioning groove  1733  defines a third hole  1735  therein corresponding to the first and second holes  216 ,  155 . 
     Referring to  FIG. 3 , the operating member  19  includes a slide bar  191 , a contact portion  193  and an operating portion  195  formed on opposite ends of the slide bar  191 . The slide bar  191  is substantially cuboid, and includes opposite side surfaces  1910  and a top surface  1912  adjoining the side surfaces  1910 . Each of the side surfaces  1910  has a guiding protrusion  1911  formed thereon corresponding to the guiding groove  1731  on the support member  17  (see  FIG. 2 ). The top surface  1912  defines a plurality of locking holes  1914  thereon to receive the locking assembly  23 . In one embodiment, the plurality of locking holes  1914  is arranged in a line at predetermined intervals. 
     The contact portion  193  is a substantially pyramid and includes a first contact surface  1931  and two second contact surfaces  1930  extending from opposite sides of the first contact surface  1931 . The cross section perpendicular to the sliding direction of the contact portion  193  is substantially V-shaped corresponding to the positioning groove  151  of the positioning member  15 . The first contact surface  1931  is inclined toward the end of the slide bar  191  with the operating portion  195 . The inclined angle formed by the first contact surface  1931  and the extending direction of the slide bar  191  is less than 90°. In one embodiment, the inclined angle is about 45°. Each second contact surface  1930  has a plurality of substantially parallel second stepped portions  1933  formed thereon corresponding to the first stepped portions  1512  formed on the positioning member  15 . Each stepped portion  1933  has a rounded corner  1935  in the end adjacent to the contact surface  1931 . 
     The locking assembly  23  includes a sleeve  231  with a top wall (not labeled), a ball  233  partially received in the sleeve  231 , and an elastic member  235  received in the sleeve  231  biasing the ball  233 . In one embodiment, the elastic member  235  is a coil spring. 
     Referring to  FIG. 1 through 3 , to assemble the clamping device  30 , the clamping sheets  13  are stacked, and the positioning member  15  received in the positioning holes  1311  of the clamping sheets  13 , which thus contact the positioning groove  151  of the positioning member  15 . The positioning member  15  is positioned between the two support members  17  and received between the positioning grooves  1733 . The operating member  19  positioned between the two support members  17 , with the guiding protrusions  1911  slidably received in the guiding grooves  1731 , respectively, and the contact portion  193  facing the clamping sheets  13 . The sleeve  231  of the locking assembly  23  is fixed between the two receiving grooves  1711 , and the ball  233  is engaged into a locking hole  1914  to lock the operating member  19 . 
     After assembly, the clamping device  30  is arranged between the two sidewalls  214  of the second connection member  21 , and a fastener (not shown) is received in the first, second and third holes  216 ,  1735 ,  155  in order, to fix the clamping device  30  to the fixing base  10 . 
     Here, an electronic component having a positioning hole (not shown) therein is used as an example to illustrate operation of clamping apparatus  100 . 
     The clamping apparatus  100  is mounted to a manipulator (not shown), and two actuators of the manipulator are connected to the operating portions  195  to control movement thereof. The manipulator moves the clamping apparatus  100  to a position where the clamping portions  133  of the clamping sheets  13  are received in the positioning hole, without contacting the inner sides of the positioning hole. Each actuator slides the operating member  19  along the guiding grooves  1731 . In one embodiment, the two operating portions  195  are moved toward or away form each other via action of corresponding actuators. 
     Since the contact portion  193  of the operating member  19  is a substantially reverse pyramid, and the first contact surface  1931  is inclined, as the operating member  19  slides relative to the support assembly  170 , the contact portion  193  resists the clamping sheets  13  gradually, and accordingly, the clamping sheets  13  are forced to contact the corresponding first stepped portions  1512  of the positioning member  15  via the action of the second stepped portions  1933 . 
     The displacements of the clamping sheets  13  are different corresponding to the position of second stepped portion  1933 . The clamping sheets  13  arranged in the middle have a higher displacement, arranged on two sides having lower placement, thus the clamping edges  1331  of the clamping sheets  13  substantially form a pyramid. The pair of clamping sheets  13  having the highest displacement contact the inner sides of the positioning hole of the electronic component, thus clamping the electronic component. In such a manner, the distance between the two clamping sheets  13  received in the positioning hole in the electronic component can be adjusted by controlling the movement of the operating member  19  to accommodate positioning holes of varying sizes. As the operating member  19  moves to a predetermined position, the clamping sheets  13  are retained in the current position via the engagement of the ball  233  of the locking assembly  23  and a corresponding locking hole  1914  in the operating member  19 . 
     When the operating member  19  is withdrawn and disengages from the staked clamping sheets  13 , the clamping sheets  13  can be moved along a longitudinal direction by external force. So that, when the manipulator moves the bottom end of the clamping sheets  13  to contact a plane, the clamping sheets  13  can be moved and substantially coincide with each other via resisting force. 
     Alternatively, the two clamping devices  30  can be arranged on two sides of the fixing base  10 , and the clamping edges  1331  of the two clamping devices  30  are toward each other. 
     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.