Abstract:
The present disclosure provides a clamp including a base with a holding surface, a first movable element, a second movable element opposite to the first movable element, and a third movable element with two arms opposite to each other. The first, the second, and the third movable elements are mounted on the holding surface of the base, and are slidable relative to the holding surface. Each arm defines a slope face the slope of the other arm. The first and the second movable elements are located between the two arms. The first movable element is resisted one of slope, and the second movable element is resisted the other of the slope. When the third movable element moves, the two slopes move relative to the first and the second movable elements, and the first and the second movable elements move toward or away from each other.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to clamps and, particularly, to a clamp with two opposite movable jaws for holding a workpiece. 
         [0003]    2. Description of Related Art 
         [0004]    A clamp usually has a fixed member and a movable member opposite to the fixed member. The movable member is movable relative to the fixed member. When clamping a workpiece, the movable member is configured to push the workpiece towards the fixed member, and clamp the workpiece together with the fixed member. Because the workpiece is driven to move from one side when the clamp holds a number of workpieces of different sizes, the center of the workpieces will be at different positions relative to the clamp, making machining the workpieces difficult and complicated. 
         [0005]    What is needed, therefore, is a clamp capable of positioning the workpiece while overcoming the above-described problem. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    Many aspects of the present clamp 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 clamp. 
           [0007]      FIG. 1  is an exploded view of a clamp according to an exemplary embodiment. 
           [0008]      FIG. 2  is an assembled, isometric view of the clamp of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    Embodiments of the present disclosure will now be described in detail below, with reference to the accompanying drawings. 
         [0010]    Referring to  FIGS. 1 and 2 , a clamp  100 , according to an exemplary embodiment, is shown. A workpiece  200  is held by the clamp  100 . The clamp  100  includes a base  10 , a first claw assembly  2 , a second claw assembly  4 , and an operation assembly  6 . 
         [0011]    The base  10  includes a holding surface  11 , a first guiding portion  12 , a second guiding portion  13 , a third guiding portion  14 , and a positioning pin  15 . 
         [0012]    The first guiding portion  12  is disposed on the holding surface  11  and defines a first guide hole  120 . In the present embodiment, the first guide hole  120  is a rectangular hole. The second guiding portion  13  is disposed on the holding surface  11 , and is opposite to the first guiding portion  12 . The second guiding portion  13  defines a second guide hole  130 . In the present embodiment, the second guide hole  130  is a rectangular hole. The first guide hole  120  is coaxial to the second guide hole  130 . The third guiding portion  14  includes a main body  14   a  and a cover  14   b . The main body  14   a  is disposed on the holding surface  11 . The cover  14   b  is fixed on the main body  14   a  through a number of screws  141 . The main body  14   a  and the cover  14   b  cooperatively define a third guide hole  140 . The third guide hole  140  is a rectangular hole. The center axis of the third guide hole  140  is perpendicular to that of the first guide hole  120  and the second guide hole  130 . The center axis of the first guide hole  120 , the second guide hole  130 , and the third guide hole  140  are parallel to the holding surface  11 . In the present embodiment, the first guiding portion  12  and the second guiding portion  13  are distributed symmetrically at two opposite sides of the center axis of the third guide hole  140 . 
         [0013]    The positioning pin  15  for positioning the workpiece  200  is disposed on the holding surface  11 . The positioning pin  15  is disposed opposite to the third guiding portion  14 , and is located on the center axis of the third guide hole  140 . 
         [0014]    The first claw assembly  2  includes a first movable element  20 , a first elastic element  24 , a first circlip  25 , and a first gasket  26 . The first movable element  20  is in a T-shaped configuration. The first movable element  20  includes a first pressing portion  21 , a first shaft portion  22 , and a first resisting portion  23 . The first pressing portion  21  is disposed at an end of the first shaft portion  22  facing the second guiding portion  13 . The first pressing portion  21  includes a first pressing surface  21   a  formed at an end away from the first shaft portion  22 . The first pressing surface  21   a  can be a planar surface or a curved surface. In the present embodiment, the first pressing surface  21   a  is a planar surface. The first shaft portion  22  runs through the first guide hole  120 , and is slidable along the first guide hole  120 . The first shaft portion  22  includes a first notch  22   a  formed at an end adjacent to the first resisting portion  23 . The first resisting portion  23  is located at the other end of the first shaft portion  22  away from the second guiding portion  13 . In the present embodiment, the first resisting portion  23  is a cylindrical surface. When the workpiece  200  is clamped between the first claw assembly  2  and the second claw assembly  4 , the first pressing surface  21   a  resists against the workpiece  200 . 
         [0015]    The first elastic element  24  is sleeved around the first shaft portion  22 . In the present embodiment, the first elastic element  24  is a spring. The first elastic element  24  includes a first resisting end  24   a  and a second resisting end  24   b  opposite to the first resisting end  24   a . In the present embodiment, the first circlip  25  is fastened at the first notch  22   a . The first gasket  26  is sleeved around the first shaft portion  22  between the first circlip  25  and the first elastic element  24 . When the first shaft portion  22  is slidably received in the first guide hole  120 , the first resisting end  24   a  resists on the first guiding portion  12 , while the second resisting end  24   b  resists on the first circlip  25  via the first gasket  26 . 
         [0016]    The configuration of the second claw assembly  4  is absolutely same as the configuration of the first claw assembly  2 . The second claw assembly  4  includes a second movable element  40 , a second elastic element  44 , a second circlip  45 , and a second gasket  46 . The second movable element  40  includes a second pressing portion  41 , a second shaft portion  42 , and a second resisting portion  43 . The second pressing portion  41  and the second resisting portion  43  are formed at two end of the second shaft portion  42 . The second pressing portion  41  includes a second pressing surface  41   a  using for resisting against the workpiece  200 . The second shaft portion  42  runs through the second guide hole  130 . The second shaft portion  42  includes a second notch  42   a  near the second resisting portion  43 . 
         [0017]    The second elastic element  44  is sleeved around the second shaft portion  42 . The second elastic element  44  includes a third resisting end  44   a  and a fourth resisting end  44   b  opposite to the third resisting end  44   a . In the present embodiment, the second circlip  45  is fastened at the second notch  42   a . The second gasket  46  is sleeved around the second shaft portion  42  between the second circlip  45  and the second elastic element  44 . 
         [0018]    The operation assembly  6  includes a third slide element  60 , a third elastic element  65 , and a button  63 . The third slide element  60  has a Y-shaped configuration. The third slide element  60  includes a third pressing portion  61  and a third shaft portion  62 . 
         [0019]    The third pressing portion  61  is disposed at an end of the third shaft portion  62  facing the positioning pin  15 . The third pressing portion  61  includes a first arm  610  and a second arm  611  opposite to the first arm  610 . The first arm  610  includes a first slope  610   a  facing the second arm  611 . The first slope  610   a  includes a first end  610   c  adjacent to the third shaft portion  62  and a second end  610   b  away from the first end  610   c . The second arm  611  includes a second slope  611   a  opposite to the first arm  610 . The second slope  611   a  facing the first slope  610   a . The second slope  611   a  includes a third end  611   c  adjacent to the third shaft portion  62  and a fourth end  611   b  opposite to the third end  611   c . When the workpiece  200  is clamped between the first movable element  20  and the second movable element  40 , the first resisting portion  23  resists against the first slope  610   a , while the second resisting portion  43  resists against the second slope  611   a . In the present embodiment, the distance between the first end  610   c  and the third end  611   c  is longer than that of between the second end  610   b  and the fourth end  611   b . The distance between the first end  610   c  and the third end  611   c  can also be shorter than the distance between the second end  610   b  and the fourth end  611   b.    
         [0020]    The third shaft portion  62  runs through the third guide hole  140 , and is slidable along the third guide hole  140 . The button  63  is fixed on a distal end  62   a  of the third shaft portion  62  away from the third pressing portion  61  through a screw  64 . 
         [0021]    The third elastic element  65  is sleeved around the third shaft portion  62 . In the present embodiment, the third elastic element  65  is a spring. The third elastic element  65  includes a fifth resisting end  65   a  and a sixth resisting end  65   b  opposite to the fifth resisting end  65   a . When the third shaft portion  62  runs through the third guide hole  140 , the fifth resisting end  65   a  resists on the third guiding portion  14 , and the sixth resisting end  65   b  resists on the button  63 . The spring force of the third elastic element  65  is more than the total spring force of the first elastic element  24  and the second elastic element  44 . 
         [0022]    Before the workpiece  200  is clamped between the first movable element  20  and the second movable element  40 , the first slope  610   a  slides relative to the first movable element  20 , and the second slope  611   a  slides relative to the second movable element  40 . The first elastic element  24  and the second elastic element  44  will urge the first movable element  20  and the second movable element  40 , because the distance between the first end  610   c  and the third end  611   c  is longer than of the distance between the second end  610   b  and the fourth end  611   b.    
         [0023]    When the workpiece  200  needs to be clamped between the first movable element  20  and the second movable element  40 , the first slope  610   a  slides relative to the first movable element  20 , and the second slope  611   a  slides relative to the second movable element  40 . The first slope  610   a  and the second slope  611   a  will urge the first movable element  20  and the second movable element  40  until the first movable element  20  and the second movable element  40  force against the workpiece  200 , because the distance between the second end  610   b  and the fourth end  611   b  is shorter than that of between the first end  610   c  and the third end  611   c . The first movable element  20  and the second movable element  40  are capable of moving toward each other simultaneously, when the clamp  100  hold a number of workpieces of different sizes, the center of each of the workpieces will be at a stable position relative to the clamp. 
         [0024]    While certain embodiments have been described and exemplified above, various other embodiments will be apparent to those skilled in the art from the foregoing disclosure. The present disclosure is not limited to the particular embodiments described and exemplified, and the embodiments are capable of considerable variation and modification without departure from the scope of the appended claims.