Abstract:
A positioning apparatus includes a base plate and a deflection mechanism mounted upon the base plate. The deflection mechanism includes a stationary platform, a rocker assembly and a deflection platform. The stationary platform is mounted over the base plate for placing and positioning a workpiece. The deflection platform is tiltably mounted over the stationary platform via the rocker assembly and the height of the stationary platform itself is adjustable. The rocker assembly comprises a first rocker and a second rocker of different lengths.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to positioning apparatus and, particularly, to a positioning apparatus used for positioning a workpiece during a mechanical manufacturing process. 
         [0003]    2. Description of Related Art 
         [0004]    Positioning apparatus are widely applied in many manufacturing fields, such as welding processes, milling processes, and the like, for positioning the workpiece. A commonly used positioning apparatus generally is large in size and has low precision. In use, the workpiece is fixedly placed on the positioning apparatus manually or by a manipulator, the position and angle of the workpiece cannot be adjusted during the manufacturing process, thus, the operator needs to process or handle the workpiece from different directions and angles thereby decreasing the manufacturing efficiency and requiring to have unnecessary widened tolerances in the quality specification of the workpiece. 
         [0005]    Therefore, there is room for improvement within the art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    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 views. 
           [0007]      FIG. 1  is an isometric view of an embodiment of an assembled positioning apparatus. 
           [0008]      FIG. 2  is similar to  FIG. 1 , but viewed from another aspect. 
           [0009]      FIG. 3  is an isometric, exploded view of the positioning apparatus of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    Referring to  FIGS. 1 through 3 , an embodiment of a positioning apparatus  100  is shown for positioning a workpiece (not shown) during a mechanical manufacturing process. The positioning apparatus  100  includes a base plate  10 , an elevating mechanism  30 , and a deflection mechanism  50  mounted on the elevating mechanism  30 . The base plate  10  is a substantially H-shaped plate in the illustrated embodiment, and is configured for supporting the elevating mechanism  30  and the deflection mechanism  50 . 
         [0011]    The elevating mechanism  30  is mounted on the base plate  10 , and positioned under the deflection mechanism  50 . The elevating mechanism  30  is connected to the deflection mechanism  50  and is configured for adjusting the height of the deflection mechanism  50  relative to the base plate  10 . The elevating mechanism  30  includes an elevating board  31 , an elevating driver  33 , a guiding assembly  35  and at least one limiting rod  37 . The elevating board  31  is mounted over the base plate  10 , and above the elevating driver  33 , the guiding assembly  35  and the limiting rod  37 . The elevating board  31  is capable of being adjusted upward and downward, and is thereby capable of achieving a preset height relative to the base plate  10 . In the illustrated embodiment, the elevating board  31  is a substantially H-shaped board. Four limiting slots  311  are oppositely defined through the elevating board  31 , and are positioned in pairs adjacent to the two ends of the elevating board  31 . An accommodating slot  313  is defined in the middle of one side of the elevating board  31 . 
         [0012]    The elevating driver  33  is mounted on the base plate  10  and is connected with the elevating board  31  to drive the elevating board  31  upward or downward, thereby adjusting the height of the elevating board  31 . The elevating driver  33  can be a hydraulic cylinder, an electric motor, or the like. In the illustrated embodiment, the elevating driver  33  is a hydraulic cylinder. 
         [0013]    The guiding assembly  35  is also mounted on the base plate  10  and is connected to the elevating board  31 , for guiding the elevating board  31  to move up and down in a strictly perpendicular fashion relative to the base plate  10  and thereby preventing any lateral movement. In the illustrated embodiment, the guiding assembly  35  includes four cylindrical guiding rods  351  and four guiding sleeves  353 . The four guiding rods  351  are perpendicularly fixed to the base plate  10 , and each guiding rod  351  is positioned adjacent to a corner of the base plate  10 . The four guiding sleeves  353  are substantially hollow cylinders, and each guiding sleeve  353  is fixed adjacent to a corner of the elevating board  31 . The guiding sleeves  353  form a precise sliding fit on the guiding rods  351 , respectively. Thus, the elevating board  31  is capable of sliding upward and downward and maintaining a precise and constant alignment to the base plate  31 . 
         [0014]    The limiting rod  37  is mounted on the base plate  10  and limits the up and down movement of the elevating board  31 . In the illustrated embodiment, there are four limiting rods  37  to engage with the four limiting slots  311  of the elevating board  31 . Each limiting rod  37  includes a support portion  371  fixed to the base plate  10 , a limiting portion  373  and a connecting portion  375  creating a neck between the support portion  371  and the limiting portion  373 . The diameter of the connecting portion  375  is substantially the same as or less than that of the limiting slot  311  of the elevating board  31 , such that the connecting portion  375  may slide into the limiting slot  311  of the elevating board  31 . The support portion  371  and the limiting portion  373  both have a diameter substantially greater than the width of the limiting slot  311  of the elevating board  31 . The support portion  371  and the limiting portion  373  are configured for keeping the elevating board  31  to stay within bounds. 
         [0015]    The deflection mechanism  50  includes a stationary platform  51 , a deflection platform  53 , a rocker assembly  55 , a deflection driver  57  and a limiting member  59 . The stationary platform  51  is fixed on the elevating board  31 , and includes a substantially rectangular base body  511  and two positioning posts  513  formed on the top surface of the base body  511 , being equidistant from the ends of the base body  511 . A mounting hole  515  is defined through in the middle of one side of the base body  511  of the stationary platform  51 , and is arranged above the nominal center point of the accommodating slot  313 . 
         [0016]    The deflection platform  53  is a substantially rectangular board and is adjustably mounted over the stationary platform  51  via the rocker assembly  55 . The deflection platform  53  is used for positioning and securing the workpiece. In one embodiment, the deflection platform  53  may include a holding member, such as a latching arm, a suction disc, and the like for holding the workpiece. In the illustrated embodiment, there are two rocker assemblies  55 , one at each end of the stationary platform  51 , thereby attaching the stationary platform  51  and the deflection platform  53  together. Each rocker assembly  55  is a bar with a pivot at each end thereof, and includes a first rocker  551  and a second rocker  553 , in which one side of the stationary platform  51  supports a pair of the first rockers  551  and the other side of the stationary platform  51  supports a pair of the second rockers  553 . The first rocker  551  and the second rocker  553  are of different lengths. 
         [0017]    The deflection driver  57  is mounted to the stationary platform  51  and partially accommodated within the corresponding accommodating slot  313  of the elevating board  31 . One end of the deflection driver  57  passes through the corresponding mounting hole  515  of the stationary platform  51  and connects with the deflection platform  53 , for driving the deflection platform  53  to tilt up or down on one or more lengthwise axis (relative to the stationary platform  51 ) or axes, to stay within the limits of range of movement defined by the rocker assembly  55 . The deflection driver  57  may be a hydraulic cylinder, an electric motor, or the like. In the illustrated embodiment, the deflection driver  57  is a hydraulic cylinder. 
         [0018]    In this embodiment, a limiting member  59  is mounted at each end of the deflection platform  53 , to impose tilting angle limits for the deflection platform  53  relative to the stationary platform  51 . The limiting member  59  includes a main body  591  fixed to the deflection platform  53 , and a limiting portion  593  extending from one end of the main body  591 . 
         [0019]    Also referring to  FIGS. 1 and 2 , as in use, the workpiece (not shown) is positioned and secured on to the deflection platform  53 . The deflection platform  53  together with the workpiece can be driven to lift upward or descend downward until they are finally positioned at a particular (preset if required) height relative to the base plate  10 , within the range of movement allowed by the connecting portion  375  to the elevating board  31 . Further, the deflection platform  53  and the workpiece can be tilted to any desired (preset if required) angle relative to the stationary platform  51 , within the tilting limits set by the limiting members  59 . 
         [0020]    The stationary platform  51 , the two first rockers  551 , the deflection platform  53  and the two second rocker  553  cooperatively form a pair of four bar linkage mechanisms, which are lengthwise symmetrical but not laterally symmetrical. The positioning apparatus  100  has a simple structure and is easy to operate. In use, the workpiece is mounted on the deflection platform  53 . The deflection platform  53  together with the workpiece can be adjusted to any preset position, and during the entire mechanical manufacturing process, the workpiece needs not be detached from the deflection platform  53 . 
         [0021]    Although numerous characteristics and advantages of the disclosure have been set forth in the foregoing description, together with details of the structure and function of the embodiment, the disclosure is illustrative only, and changes may be made in detail, especially in the matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.