Abstract:
An exemplary test apparatus for a columniform workpiece includes a base plate, a support plate perpendicularly mounted to a top surface of the base plate, a shaft rotatably mounted to the support plate, a contact member mounted the support plate and perpendicularly slidable relative to the support plate, and a test meter. The shaft is configured for mounting the columniform workpiece at a side of the support plate and making the columniform workpiece perpendicularly rotate relative to the support plate. The contact member includes a first end contacting the end surface of the columniform workpiece. The test meter includes a pole with a distal end contacting a second end opposite to the first end of the contact member, the poles&#39; length resiliently adjusting corresponding to the end surface of the columniform workpiece, and a value of the test meter changing corresponding to changes in the length of the pole.

Description:
BACKGROUND 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a test apparatus for gauging radii of columniform workpieces. 
         [0003]    2. Description of Related Art 
         [0004]    Heat sinks are generally used for dissipating heat of electronic components. Heat sinks are easily deformed during punching or other processes, and if that occurs, their heat dissipation ability is diminished. For the heat sink, it is necessary to test planeness of its end surface. 
         [0005]    Typically, a plug gauge is used for testing the planes of an end surface of the heat sink. The heat sink is generally placed on a flat support, with the end surface thereof contacting the flat support, thus a plurality of clearances is formed between different parts of the end surface of the heat sink and the flat support. Attempts are made to insert the plug gauge into each clearance. The end surface of the heat sink is eligible if the plug gauge cannot fit into any of the clearances. However, using the plug gauge to test each clearance is time-consuming. 
       SUMMARY 
       [0006]    An exemplary test apparatus for a columniform workpiece includes a base plate, a support plate perpendicularly mounted to a top surface of the base plate, a shaft rotatably mounted to the support plate, a contact member mounted the support plate and perpendicularly slidable relative to the support plate, and a test meter. The shaft is configured for mounting the columniform workpiece at a side of the support plate and making the columniform workpiece perpendicularly rotate relative to the support plate. The contact member includes a first end thereof contacting the end surface of the columniform workpiece. The test meter includes a pole with a distal end thereof contacting a second end opposite to the first end of the contact member, the poles&#39; length resiliently adjusting corresponding to the end surface of the columniform workpiece, and a value of the test meter changing corresponding to changes in the length of the pole. 
         [0007]    Other advantages and novel features of the present invention will become more apparent from the following detailed description of preferred embodiment when taken in conjunction with the accompanying drawings, in which: 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is an exploded, isometric view of a test apparatus in accordance with an embodiment of the present invention; 
           [0009]      FIG. 2  is an assembled, isometric view of  FIG. 1 , but viewed from another aspect; 
           [0010]      FIG. 3  is an assembled, cross-sectional view of  FIG. 1 ; 
           [0011]      FIG. 4  is another assembled, cross-sectional view of  FIG. 1 ; and 
           [0012]      FIG. 5  is an assembled view of  FIG. 1 , together with a heat sink. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    Referring to  FIG. 1 , a test apparatus in accordance with an embodiment of the present invention includes a base plate  20  with a cutout  22  defined in a side thereof near a corner, a support plate  30  perpendicularly mounted to a top surface of the base plate  20 , a fastening system  60  rotatably mounted to a side  24  neighboring the cutout  22  of the base plate  20 , a shaft  40  (labeled in  FIG. 2 ), and a test system  50  fixed to the support plate  30 . The base plate  20  defines a plurality of through holes therein. 
         [0014]    The support plate  30  includes a first side surface  31  facing the fastening system  60 , and a second side surface  32  (shown in  FIG. 2 ) opposite to the first side surface  31 . The first side surface  31  is plane. A block  321  (shown in  FIG. 2 ) extends from the second side surface  32 . A round through hole  34  is defined in the support plate  30  extending from the first side surface  31  to the block  321 . The support plate  30  defines a stepped slot  36  adjacent the through hole  34 . A plurality of fixing holes perpendicular to the through hole  34  is defined in a bottom of the support plate  30 , corresponding to the through holes of the base plate  20 . A fixing hole  322  of the fixing holes is communicated with the through hole  34 . 
         [0015]    The shaft  40  includes a main body  42  and a rotatable part  48  mounted to the main body  42 . The main body  42  includes a positioning portion  421 , a mounting portion  422  defining a locating slot  46  in a bottom thereof (shown in  FIG. 3 ), and a shoulder  44  protruding from a circumference thereof between the positioning portion  421  and the mounting portion  422 . A slot  43  (labeled in  FIG. 3 ) is defined in the circumference of the positioning portion  421  adjacent the shoulder  44 . 
         [0016]    The test system  50  includes a frame  52 , a test meter  54  fixed to the frame  52 , a support member  56 , and a mounting plate  58 . The frame  52  is generally U-shaped and includes a vertical plate  526 , and two side plates  528  perpendicularly extending from opposite sides of the vertical plate  526 . A holding member  521  is mounted to a lateral surface opposite to the side plates  528 , of the vertical plate  526 . A through hole  523  is defined in the holding member  526  and extends through the vertical plate  526  and the holding member  521 . Each side plate  528  defines a through hole  525  extending from a distal end thereof through the vertical plate  526 . A screw hole  522  is defined in the holding member  526  perpendicular to and communicating with the through hole  523 . The test meter  54  includes a pole  541  extending therefrom and an annular portion  542  ringing the pole  541 . 
         [0017]    The support member  56  is generally rectangular shaped and defines a rectangular through hole  561  through top surface and bottom surfaces thereof. A round hole  562  perpendicular to and communicating with the rectangular through hole is defined in a center of a first side surface of the support member  56 . Two screw holes  563  are defined in the support member  56  extending through the first side surface and a second side surface  564  opposite to the first side surface. A depressed portion  565  is defined in a junction of the top surface and the second side surface  564 . A rectangular hole  567  perpendicular to and communicating with the through hole  561  is defined in the second side surface  564 . The mounting plate  58  defines a rectangular hole  581  in a center thereof corresponding to the rectangular hole  567  of the support member  56 , and two through holes  582  in opposite sides thereof corresponding to the screw holes  563  of the support member  56 . A contact member includes a peg  70  and a test block  72  that are mounted to the support member  56 . The peg  70  includes a column portion  701  and a screw portion  702 . The test block  72  defines a screw hole in an end thereof. 
         [0018]    The fastening system  60  includes an swing arm  62 , a round plate  66 , and a column  68  extending from a central portion of the round plate  66 . The swing arm  62  defines two holes  620 ,  621  in opposite ends thereof. A protruding portion  622  extends up from the swing arm  62  for preventing the swing arm  62  being lower than the base plate  20 . The round plate  66  defines a concavity  61  (shown in  FIG. 2 ) in a side surface thereof. The column  68  extends from an opposite side surface of the round plate  66 . An annular slot  681  is defined in a circumference of a distal end of the column  68 . A fixing hole is defined in the distal end of the column  68  along an axial direction. 
         [0019]    Referring also to  FIG. 2  to  FIG. 4 , in assembly, the support plate  30  is fastened to the base plate  20  by a plurality of screws extending through the through holes of the base plate  20  to engage in the fixing holes of the support plate  30 . A resilient member, such as a spring  37  is fitted in the fixing hole  322  of the support plate  30 , with one end thereof is propped on a distal end of the screw being engaging in the fixing hole  322 . A steel positioning ball  38  is propped on the other end of the spring  37 . The mounting portion  422  of the shaft  40  passes through the through hole  34  from the first side surface  31  of the support plate  30 . The shoulder  44  of the shaft  40  contacts the first side surface  31  of the support plate  30 . The slot  46  of the shaft  40  is engaged with the ball  38 . The rotatable part  48  is mounted to a distal end of the main body  42  by three screws  12 . Thus, the shaft  40  is rotatably mounted to the support plate  30 . The pole  541  of the test meter  54  is extended through the through hole  523  of the frame  52 . A screw  16  is extended through the screw hole  522  of the holding member  521  of the frame  52  to engage with the pole  541  of the test meter  54  via a distal end thereof. A resilient member, such as spring  703 , and a gasket  704  is received in the through hole  561  of the support member  56 , with their through holes aligning with the round hole  562  and the rectangular hole  567  respectively. The test block  72  is inserted into the rectangular hole  567  to contact the gasket  704 . The peg  70  is extended through the round hole  562  of the support member  56 , the spring  703 , and the gasket  704  to engage in the screw hole of the test block  72 . Two screws  121  are respectively extended through the through holes  582  of the mounting plate  58  to be engaged in the screw holes  563  of the support member. The mounting plate  58  is received in the slot  36  of the support plate  30 . An opposite end of the test block  72  passes through the rectangular hole  581 . Thus, the support member  56  and the mounting plate  58  are located at opposite sides of the support plate  30 . Two screws  14  are respectively extended through the through holes  525  of the frame  52  to be engaged in the screw holes  563  of the support member  56 , thus the frame  52  is mounted to the support member  56 . A distal end of the pole  541  of the test meter  54  contacts a distal end of the column portion  701  of the peg  70 . The swing arm  62  is fixed to a side  24  neighboring the cutout  22  of the base plate  20  by a screw  122  extending through the hole  621  to be engaged with the base plate  20 . A resilient member, such as a spring  683  fits about the column  68 . The round plate  66  and the spring  68  are located in the cutout  22  of the base plate  20 . The column  68  is extended through the hole  620  of the swing arm  62  and a clip  682  to make its fixing hole engage with a screw  64 . The clip  682  is engaged in the annular slot  681  of the column  68 . The column  68  is slidably received in the hole  620  of the swing arm  62 . 
         [0020]    Referring also to  FIG. 5 , in use, the heat sink  10  is placed between the shaft  40  and the fastening member  60 . The positioning portion  421  of the shaft  40  is inserted into the hole along an axial direction of the heat sink  10 , with the shoulder  44  contacting a first side surface of the heat sink  10 . The swing arm  62  is rotated up to make the round plate  66  contact a second side surface opposite to the first side surface of the heat sink  10 . The positioning portion  41  of the shaft  40  is accommodated in the concavity  61  of the round plate  66 . Because of the elasticity of the spring  683 , the round plate  66  tightly contacts with the corresponding side surface of the heat sink  10 . At this time, the end surface of the heat sink  10  contacts the test block  72 . The rotatable part  48  is rotated for rotating the heat sink  10 , and changes on radii of the heat sink  10  will drive the test block  72  to extend or retract, thus the pole  541  of the test meter  54  is extended or retracted with a value of the test meter  54  changes. 
         [0021]    The foregoing description of the exemplary embodiments of the invention has been presented only for the purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to explain the principles of the invention and their practical application so as to enable others skilled in the art to utilize the invention and various embodiments and with various modifications as are suited to the particular use contemplated. Alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its spirit and scope. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing description and the exemplary embodiments described therein.