Abstract:
A clamping device which uses its own weight to apply pressure during a soldering operation to a solderable part or component for attachment to a circuit board is provided. The clamping device includes a base plate and at least one press block which is configured to be arranged on the base plate and is free to move up or down by gravity relative to the base plate. When the gravitational orientation of the clamping device is correct, the press block moves down relative to the base plate and so presses on the solderable part during soldering.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to Chinese Patent Application No. 201510857353.8 filed on Nov. 30, 2015, the contents of which are incorporated by reference herein. 
       FIELD 
       [0002]    The subject matter herein generally relates to clamping devices, and particularly, to a self-weighted clamping device capable of holding an electronic part for a soldering operation. 
       BACKGROUND 
       [0003]    A clamping device may be employed to press a SIM card onto a circuit board to fix the SIM card in place for soldering it into the circuit board using Surface Mount Technology (SMT). 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    Many aspects of the present disclosure can be better understood with reference to the following 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 several views. 
           [0005]      FIG. 1  is a diagrammatic view showing an exemplary embodiment of a clamping device. 
           [0006]      FIG. 2  is an exploded, isometric view of the clamping device of  FIG. 1 . 
           [0007]      FIG. 3  is another diagrammatic view of the clamping device of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0008]    It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the exemplary embodiments described herein. However, it will be understood by those of ordinary skill in the art that the exemplary embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features. The description is not to be considered as limiting the scope of the exemplary embodiments described herein. 
         [0009]    The term “comprising” means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in a so-described combination, group, series and the like. 
         [0010]    Exemplary embodiments of the present disclosure will be described in relation to the accompanying drawings. 
         [0011]      FIG. 1  illustrates an exemplary embodiment of a clamping device  1 . The clamping device  1  can press a solderable part (not shown) of a circuit board (not shown) onto the circuit board. The clamping device  1  includes a base plate  10 , and at least one press block  20 . The at least one press block  20  is slidably arranged on the base plate  10 , such that the at least one press block  20  can be moved up or down relative to the base plate  10 . The at least one press block  20  can exert pressure on the solderable part of the circuit board by its own weight when the at least one press block  20  moves down relative to the base plate  10 . In at least one exemplary embodiment, the solderable part is a SIM card. 
         [0012]      FIG. 2  also illustrates the clamping device  1  of  FIG. 1 . The at least one press block  20  includes a first cylinder block portion  202  and a second cylinder block portion  204 . The first cylinder block portion  202  and the second cylinder block portion  204  are coaxial to each other. The radius of the first cylinder block portion  202  is greater than the radius of the second cylinder block portion  204 . The height of the first cylinder block portion  202  is less than the height of the second cylinder block portion  204 . In at least one exemplary embodiment, the at least one press block  20  is an integrally formed cylindrical block made of copper. 
         [0013]    The base plate  10  defines at least one first through hole  101 . Each of the at least one first through holes  101  corresponds to one press block  20 . The radius of the first through hole  101  is greater than the radius of the second cylinder block portion  204 , but less than the radius of the first cylinder block portion  202 . The clamping device  1  also includes at least one snap spring  30 . Each press block  20  has an associated snap spring  30 . An end of the second cylinder block portion  204  of the press block  20  that is away from the first cylinder block portion  202  passes through the bottom side of the first through hole  101  and then the snap spring  30  clips around the periphery of the second cylinder block portion  204 , in an annular groove  206  (discussed in more detail below). Accordingly, the snap spring  30  and the first cylinder block portion  202  are on different sides of the base plate  10 . When the second cylinder block portion  204  passes through the first through hole  101 , the second cylinder block portion  204  is restricted both by the first cylinder block portion  202  and the snap spring  30 . 
         [0014]    In this exemplary embodiment, the snap spring  30  includes an annular body  302  and two ends  304  connected to the annular body  302 . The internal diameter of the annular body  302  is slightly less than the diameter of the second cylinder block portion  204 . The external diameter of the annular body  302  is greater than the diameter of the first through hole  101 . The annular groove  206  is defined in the second cylinder block portion  204 . The internal diameter created by the annular groove  206  matches with that of the snap spring  30  for receiving and retaining the annular body  302  of the snap spring  30 . Accordingly, the part of the second cylinder block portion  204  between the first cylinder block portion  202  and the snap spring  30  can freely pass through the first through hole  101  by the self-weighted of the press block  20 . In this exemplary embodiment, the distance between the snap spring  30  and the first through hole  101  is greater than a thickness of the part of the base plate  10 . The weight of the press block  20  can be between about 9 grams and 9.5 grams. In this exemplary embodiment, the numbers of the press blocks  20 , the first through holes  101 , and the snap springs  30  are all four. 
         [0015]    In this exemplary embodiment, the base plate  10  also defines a number of second through holes  40 , some of which may have different sizes from each other. The second through holes  40  are defined around the first through holes  101 . When using Surface Mount Technology to solder the circuit board, the press block  20  of the clamping device  1  can be used to press the solderable part of the circuit board. The soldering heat, which when required, can be transferred to the solderable part by the second through holes  40  around the first through holes  101 . 
         [0016]      FIG. 3  illustrates another view of clamping device  1  of  FIG. 1 . In this exemplary embodiment, the base plate  10  also defines a number of support elements  50 . Each support element  50  is arranged substantially adjacent to a corner of the base plate  10 . The support elements  50  can support the clamping device  1 . The thickness of the support element  50  is less than the distance between the first cylinder block portion  202  and the annular groove  206 . 
         [0017]    The use of the clamping device  1  is as follows: first, the second cylinder block portion  204  of the press block  20  is pushed to pass up through the bottom of the first through hole  101 . Then the annular body  302  of the snap spring  30  is fitted to the annular groove  206  of the second cylinder block portion  204 . When the first cylinder block portion  202  of the press block  20  is placed on the a solderable portion of the solderable part by a user, the first cylinder block portion  202  is able to press the solderable part to the circuit board by its own weight. 
         [0018]    The exemplary embodiments shown and described above are only examples. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the present disclosure is illustrative only, and changes may be made in the detail, including in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including, the full extent established by the broad general meaning of the terms used in the claims.