Patent Publication Number: US-7722309-B2

Title: Apparatus for picking and placing workpiece

Description:
TECHNICAL FIELD 
   The present invention generally relates to apparatuses for picking and placing workpieces, and more particularly, to an apparatus for picking and placing a workpiece under suction force. 
   BACKGROUND 
   In the assembling of a product or a semi-finished product, apparatuses for picking and placing workpieces of such products are widely used. A typical such apparatus includes a suction device and at least one hollow body coupled to the suction device. The hollow body may pick a workpiece at an end thereof under a suction force provided by the suction device, and then place the workpiece into a container. Generally, an internal breadth of the hollow body is slightly smaller than an external breadth of the workpiece, thus allowing the workpiece to be picked precisely and steadily. 
   However, when the workpiece is, for example, a lens module, and the container is, for example, a barrel, the internal breadth (diameter) of the hollow body is closely approximate to the external breadth of the workpiece, and an external breadth of the hollow body is closely approximate to an internal breadth of the barrel. As a result, air inside the barrel may be compressed thereby increasing an atmospheric pressure inside the barrel during the workpiece being moved into the barrel, such that pressure imbalance is generated between the exterior of the barrel and the interior of the barrel. This makes it difficult to orient the workpiece precisely. In addition, when the hollow body moves out of the barrel after placing the workpiece, atmospheric pressure inside the barrel may immediately decrease, whereby pressure imbalance is generated between the interior of the barrel and the exterior of the barrel. As a result, it is difficult to move the hollow body out of the barrel. 
   What is needed, therefore, is a device capable of picking and placing a workpiece into a container, which overcomes the above-mentioned problems. 
   SUMMARY 
   In a preferred embodiment, an exemplary apparatus capable of picking and placing a workpiece into a container includes a suction device and a hollow body. The suction device provides a suction force for picking up the workpiece. The hollow body has a picking portion for picking and placing the workpiece into the container under the suction force, wherein a plurality of air slots are defined in an outer wall of the hollow body, the air slots are configured for providing an air passage between an interior of the container and an exterior thereof so as to facilitate movement of the hollow body into and out of the container, whereby the workpiece can be steadily placed in the container. 
   Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Many aspects of the apparatus can be better understood with reference to the following drawings. The components in the drawing are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present apparatus. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
       FIG. 1  is a schematic view of an apparatus capable of picking and placing a workpiece into a container according to a preferred embodiment; 
       FIG. 2  is a second schematic view of a hollow body of the device shown in  FIG. 1 ; 
       FIG. 3  is a third schematic view of a hollow body of the device shown in  FIG. 1 ; 
       FIG. 4  and  FIG. 5  are schematic views of application of the apparatus shown in  FIG. 1  according to a preferred embodiment; and 
       FIGS. 6-8  are schematic views of an apparatus according to another preferred embodiment. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Embodiments of the present apparatus will now be described in detail below and with reference to the drawings. 
   Referring to  FIG. 1 , an exemplary apparatus  100  according to a preferred embodiment includes an elongated hollow body  10  and a suction device  11 , the suction device  11  is configured for providing a suction force to the hollow body  10 . 
   The hollow body  10  may have an exterior shape conforming to an interior shape of a container which is configured for containing a workpiece. For example, the hollow body  10  can be an isometric cylinder (see  FIG. 1 ), a cylinder having a reducer (see  FIG. 2 ), or a cylinder having a distortion (see  FIG. 3 ). An internal breadth of the hollow body  10  can be equal to or slightly smaller than an external breadth of the workpiece, and an external breadth of the hollow body  10  can be approximately equal to an internal breadth of the container. The hollow body  10  defines a first end  102 , a second end  104  opposite to the first end  102 , and a number of air slots  106 . The first end  102  can be used as a picking portion configured for picking and placing the workpiece into the container. Preferably, a rubber ring  105  is mounted on the first end  102 , and the rubber ring  105  can help to contact the workpiece tightly. The second end  104  is configured for coupling to the suction device  11 . The air slots  106  are defined in an outer wall of the hollow body  10  away from an inner wall of the hollow body  10 . In one embodiment, the air slots  106  are evenly distributed in the outer wall of the hollow body  10 . Each of the air slots  106  can extend from the first end  102  or from a position near the first end  102  towards the second end  104 . Each of the air slots  106  can be inclined to a lengthwise direction of the hollow body  10 , and can be generally in the form of part of a helix that winds around the outer wall of the hollow body  10 . A breadth of each of the air slots  106  is preferably 1/15˜ 1/30 of that of the hollow body  10 , and a depth of each of the air slots  106  is ⅕˜⅓ of the wall thickness of the hollow body  10 . 
   The suction device  11  can be a vacuum pump. The suction device  11  pumps out a certain volume of air from the inside of the hollow body  10  (i.e., depressurizes the inside of the hollow body  10 ) thereby providing a suction force for the hollow body  10 , such that the hollow body  10  can pick the workpiece at the first end  102 . When the first end  102  moves in the container, the suction device  11  introduces a certain volume of air to the inside of the hollow body  10  (i.e., partially repressurizes the inside of the hollow body  10 ), such that the first end  102  can place the workpiece in the container. 
   Referring to  FIG. 4  and  FIG. 5 , the apparatus  100  is used for assembling a first workpiece  20  and a second workpiece  30  of a lens module into a container  40  according to a preferred embodiment. The apparatus  100  can be integrally formed with an apparatus for assembling lens modules, which may have other members, for example, trays for carrying the workpieces  20 ,  30  and the containers  40 , belts for conveying the trays, motors for driving the apparatus  100  and so on. In the present preferred embodiment, the hollow body  10  is an isometric pipe, an internal diameter of the hollow body  10  is equal to or slightly smaller than an external size of the workpiece  20 ,  30 , and an external diameter of the hollow body  10  is approximately equal to an internal diameter of the container  40 . The container  40  is a barrel having a bottom opening  41 . 
   Firstly, the hollow body  10  picks the first workpiece  20  at the first end  102  under the suction force provided by the suction device  11 , moves to a bottom position of the container  40  (air inside the container  40  can escape through the bottom opening  41  thereof or through the air slots  106 ), and places the workpiece  20  in the bottom position. Then the hollow body  10  moves back, and at the same time air outside the container  40  enters the container  40  through the air slots  106  thereby balancing atmospheric pressure between an interior of the container  40  and an exterior of the container  40 . This facilitates the hollow body  10  to easily move out of the container  40  and the workpiece  20  to be steadily received in the container  40 . 
   Secondly, the hollow body  10  picks the second workpiece  30  at the first end  102  under the suction force provided by the suction device  11 , moves in the container  40 , and places the workpiece  30  in position. Then the hollow body  10  moves back. 
   It is understood that the apparatus  100  is not limited to assembling lens modules, and can be applied in other apparatuses for precisely and steadily placing a small and light workpiece into a container. 
   Referring to  FIGS. 6-8 , an apparatus  200  according to another preferred embodiment is similar to the apparatus  100  of  FIGS. 1-3 , except that air slots  206  are substantially parallel to a lengthwise direction of a hollow body  20 . The hollow body  20  may be an isometric cylinder (see  FIG. 6 ), a cylinder having a reducer (see  FIG. 7 ), or a cylinder having a distortion (see  FIG. 8 ). 
   It is understood that the above-described embodiment are intended to illustrate rather than limit the invention. Variations may be made to the embodiments and methods without departing from the spirit of the invention. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.