Abstract:
A test probe for testing an object electrically includes a main body, a first probe pin mounted to and protruding out of the main body, and at least one second probe pin coupled to the main body. The at least one second probe pin is changeable from a first state of being folded into the main body to a second state of being unfolded to protrude out of the main body. When the at least one second probe pin is in the first state, the first probe pin is used to contact the object, and when the at least one second probe pin is in the second state, the at least one second probe pin takes the place of the first probe pin in making electrical connection with the object.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to test probes. 
         [0003]    2. Description of Related Art 
         [0004]    A typical test probe for testing resistance, for example in semiconductor circuits, often includes a probe pin for making electrical contact with the object. However, the probe pin is generally made of hard metal, such as tungsten or its alloys, and is always tined. Thus, the surface of some objects (for example the copper coated pathways on PCBs) may very easily be scraped by the tined end of the probe pin. 
         [0005]    Therefore, there is room for improvement in the art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    Many aspects of the embodiments can be better understood with references 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 embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the five views. 
           [0007]      FIG. 1  is a perspective view of a test probe in accordance with an embodiment; the test probe is be used in a first state. 
           [0008]      FIG. 2  is a disassembled perspective view of the test probe of  FIG. 1 . 
           [0009]      FIG. 3  is similar to  FIG. 2 , but viewed from another aspect. 
           [0010]      FIG. 4  is a perspective view showing the test probe of  FIG. 1  being used in a second state. 
           [0011]      FIG. 5  is a cross-sectional view taken along line V-V of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    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. 
         [0013]    Referring to  FIG. 1 , a test probe  100  in accordance with an embodiment is shown. The test probe  100  includes a main body  10 , a conductive post  20  mounted to the main body  10 , a first probe pin  30  mounted to an end of the conductive post  20  and protruding out of the main body  10 , and a number of second probe pins  40  electrically connected to the conductive post  20 . The second probe pin  40  are rotatably coupled to the main body  10 , are arranged circumferentially around the main body  10 , and are capable of being rotated outwards approximately one hundred and eighty degrees from a first position within the main body  10  to a second extended or protruded position out of the main body  10 . The manner of operation of each of the second probe pins  40  is similar to that of a flick-knife. In the embodiment, the conductive post  20 , the first probe pin  30  and the second probe pins  40  are conductors, and are made of conductive metal such as copper. 
         [0014]    Referring to  FIGS. 2-3 , the main body  10  includes a cylindrical portion  120  and a head portion  140  mounted to the cylindrical portion  120 . The cylindrical portion  120  is hollow and has an axis A (see  FIG. 1 ). An end of the cylindrical portion  120  adjacent to the head portion  140  recesses to define a receiving space  121  extending along the axis A, and the other end of the cylindrical portion  120  defines a fixing hole  122  extending along the axis A and communicating with receiving space  121 . The fixing hole  122  is used to mount the conductive post  20  thereinto. The outer surface of the cylindrical portion  120  defines a number of receiving slots  124  extending in a direction parallel to the axis A. The receiving slots  124  are arranged evenly at the end of the cylindrical portion  120  adjacent to the head portion  140 , and are used for receiving and containing the second probe pins  40  respectively. An end of each receiving slot  124  adjacent to the head portion  140  includes a receiving portion  126 . The receiving portions  126  are substantially spherical in cross section. One end of each second probe pin  40  is rotatably received in a corresponding receiving portion  126 , such that the second probe pins  40  are rotatably coupled to the main body  110 . 
         [0015]    The cylindrical portion  120  further defines a guiding slot  127 . The guiding slot  127  is substantially L-shaped and is arranged radially in the main body  10  between two adjacent receiving slots  124 . The guiding slot  127  includes a guiding portion  128  parallel to the axis A and a limiting portion  129  communicating with the guiding portion  128 . The limiting portion  129  extends in a direction perpendicular to the axis A. 
         [0016]    The head portion  140  is substantially in the shape of a frustum in the embodiment, and is coaxial with the cylindrical portion  120 . The head portion  140  is mounted to an end of the cylindrical portion  120  defining the receiving space  121 . The head portion  140  defines a guiding hole  142  along the axis A. The diameter of the guiding hole  142  is larger than that of the conductive post  20 , but is less than that of the receiving space  121 . The head portion  140  defines a number of latching slots  143  respectively corresponding to the receiving slots  124 . The latching slots  143  are arranged evenly at the outer surface of the head portion  140 , and are used to limit the movement of the second probe pins  40  when the second probe pins  40  rotate outwards to the second position. 
         [0017]    The conductive post  20  is cylindrical and is fixed coaxially to the main body  10  by means of the fixing hole  122 . A portion of the conductive post  20  is received in the main body  10 . An end of the conductive post  20  is received in the guiding hole  142  and is substantially coplanar with the end of the head portion  140  farthest from the cylindrical portion  120 , and the other end of the conductive post  20  protrudes out of the cylindrical portion  120 . 
         [0018]    The tine of the first probe pin  30  is substantially conical. An end of the first probe pin  30  is mounted coaxially to the end of the conductive post  20  received in the guiding hole  142 , and the other end of the first probe pin  30  protrudes from the head portion  140 . The extension of the first probe pin  30  from the end of the conductive post  20  is integral in this embodiment. 
         [0019]    The second probe pins  40  are electrically connected to the conductive post  20 . The length of the second probe pins  40  when protruding out of the main body  10  is less than that of the first probe pin  30  protruding out of the main body  10 . Each second probe pin  40  includes a rotating portion  410  and an end portion  420  opposite to the rotating portion  410 . The rotating portion  410  is substantially spherical, and is rotatably received in the corresponding receiving portion  126  of the receiving slots  124 . The end portion  420  is blunt, and is used to make contact with the object to be tested (as shown in  FIG. 2 ). A magnetic member  430  is arranged at an end of each second probe pin  40  adjacent to the end portion  420 . 
         [0020]    The test probe  100  further includes a sliding member  50 , an elastic element  60 , and an operating member  70 . The sliding member  50  is slidably received in the main body  10 . The elastic element  60  is received in receiving space  121  and resists the sliding member  50  to provide an elastic force between the sliding member  50  and the cylindrical portion  120  when pressed by the sliding member  50 . The operating member  70  is fixed to the sliding member  50  and is slidably received in the guiding slot  127 . The operating member  70  is used to drive the sliding member  50  to slide relative to the main body  10 . 
         [0021]    Referring to  FIG. 2  again, the sliding member  50  includes a sleeve  510 , a first magnet  520 , and a second magnet  530 . The sleeve  510  is hollow and may slide along the conductive post  20 . The first magnet  520  is substantially in the shape of a frustum in the embodiment, and defines a round hole  522  extending along an axis thereof. The first magnet  520  sleeves on an end of the sleeve  510  via the round hole  522 . The second magnet  530  is substantially in the shape of a disk, and sleeves on an end of the sleeve  510  opposite to the first magnet  520 . The diameter of the first magnet  520  is larger than that of the guiding hole  142 . The diameter of the second magnet  530  is larger than that of the guiding hole  142 , but is less that that of the receiving space  121 . 
         [0022]    Furthermore, the test probe  100  includes a plurality of weights  80 . The weights  80  are substantially cylindrical and are made of insulation material or covered with insulation material. Each weight  80  defines a hole  810  extending in an axis thereof. The hole  810  is used to receive the conductive post  20 , whereby the weights  80  sleeve on the conductive post  20 . 
         [0023]    In assembly, the conductive post  20  is fixed to the cylindrical portion  120 . The elastic element  60 , the second magnet  530  and the sleeve  510  are sleeved on the conductive post  20  in order and are further received in the receiving space  121 . The rotating portions  410  are received in the corresponding receiving portion  126 , and the head portion  140  is mounted to the cylindrical portion  120 , thus, the second probe pins  40  are rotatably coupled to the main body  10 . The first probe pin  30  is mounted to the conductive post  20 . The first magnet  520  sleeves on an end of the sleeve  510  opposite to the second magnet  530 . Finally, the operating member  70  extends through the guiding slot  124  and is mounted to the sleeve  510 . 
         [0024]    Referring to  FIG. 1  again, the test probe  100  in a first state is shown. In the first state, the second probe pins  40  are folded and are resting in their corresponding receiving slots  124 , the operating member  70  is at an end of the sliding portion  128  opposite to the limiting portion  129  of the guiding slot  127 , and the sliding member  50  is in the main body  10  with the first magnet  520  resisting against the head portion  140  and the second magnet  520  at an end of the receiving space  121  away from the head portion  140 . The attractive force of the second magnet  530  on the magnetic members  430  causes the second probe pins  40  to remain retracted in the receiving slots  124 , and the first probe pin  30  protruding out of the main body  10  is capable of being used to test an object. In the first state, the elastic element  60  may be in an original state. 
         [0025]    Referring to  FIGS. 4-5 , the test probe  100  in a second state is shown. In the second state, the operating member  70  slides to the limit imposed by the limiting portion  129  (as shown in  FIG. 3 ), the sliding member  50  slides toward the first probe pin  30  with the first magnet  520  sliding away from the head portion  140  and covering the first probe pin  30 , the second magnet  530  slides to a position adjacent to the head portion  140 , and the elastic element  60  is stretched by the sliding member  50 . The movement of the second magnet  530  to a position adjacent to the head portion  140  decreases the force of magnetic attraction between the second magnet  530  and the magnetic members  430 . Thus, if the first probe pin  30  is pointing vertically downwards, the second probe pins  40  may be driven by gravity to rotate approximately one hundred and eighty degrees outwards towards the head portion  140  and be received in the limiting slots  143 , and the second probe pins  40 , experiencing the magnetic force of the first magnet  520 , may then remain in place. Therefore, the second probe pins  40  having blunt ends can substitute for the first probe pin  30  in making electrical contact with the object to be tested, thereby protecting the object from scrape-damage caused by the first probe pin  30 . 
         [0026]    By virtue of the test probe  100 , the second probe pins  40 , of various materials, types, and profiles, are individually selectable in substituting for the first probe pin  30 . 
         [0027]    It is to be understood, even though information and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the present embodiments, the disclosure is illustrative only; and that changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the present embodiments to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.