Patent Publication Number: US-2010117278-A1

Title: Vacuum sucker for workpiece having through holes

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a vacuum sucker, and more particularly to a vacuum sucker for workpiece having through holes. 
     2. Description of the Prior Art 
     With the rapid development of science and technology industry, automatic equipments which is applied to simulate human activities have been improved continually, such as, the application of mechanical arms for simulating human arms. However, due to different using states of the workpieces, the automatic equipments are divided into two types, that is, non-contact type and contact type. As far as the strict environment for processing control tubes is concerned, the non-contact type automatic equipments can prevent the equipments from contacting the workpieces directly, therefore, a vacuum sucker appeared in the market. 
     Referring to  FIG. 1 , a conventional vacuum sucker  10  comprises a vacuum cup  11  having a suction portion  111  and a vacuum accessory  12  having a suction passage  121 . The vacuum accessory  12  is inserted in the vacuum cup  11 , the suction passage  121  of the vacuum accessory  12  is in communication with the suction portion  111  of the vacuum cup  11 , and the suction passage  121  of the vacuum accessory  12  is connected to a vacuum generator which is used to vacuum the suction portion  111  of the vacuum cup  11 , so as to make the suction portion  111  of the vacuum cup  11  form a negative pressure state, so that the vacuum sucker  10  can suck the workpiece. When the vacuum sucker  10  sucks the workpiece having through holes as shown in  FIG. 2 , although the vacuum sucker  10  continually produces negative pressure suction to the workpiece, the positive pressure air from outside can also continually enter the through holes of the workpiece, such that the vacuum sucker  10  cannot suck the workpiece successfully. As a result, it will not only affect the manufacturing speed, but also waste the manpower and costs. 
     The present invention has arisen to mitigate and/or obviate the afore-described disadvantages. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a vacuum sucker for workpiece having through holes which can suck the workpiece successfully by preventing air from outside from entering the vacuum sucker. 
     To achieve the objective of the present invention, the vacuum sucker for workpiece having through holes comprises a vacuum cup and a vacuum accessory. One end of the vacuum cup is formed with a combining section, and the other end of the vacuum cup is formed with a vacuum chamber. One end of the vacuum accessory is formed with an assembling section, and the other end of the vacuum accessory is provided with a suction head having an abutting surface. The vacuum accessory is axially defined with a first passage which penetrates from the assembling section to the suction head. The assembling section of the vacuum accessory is screwed with the combining section of the vacuum cup, so that the suction head of the vacuum accessory is located in the vacuum chamber of the vacuum cup. 
     It is apparent from the above-mentioned descriptions that the present invention has the advantages described as follows: the vacuum sucker utilizes the suction head of the vacuum accessory to seal through holes of the workpiece so as to prevent air from outside from entering the vacuum sucker, and the passage of the vacuum accessory to cooperate with the vacuum chamber to produce vacuum suction to the workpiece, so as to suck the workpiece by the vacuum sucker successfully. Thereby, it can not only quicken the manufacturing speed, but also can save manpower and costs. 
     The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiments in accordance with the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of a conventional vacuum sucker; 
         FIG. 2  is an illustrative showing an operation of the conventional vacuum sucker; 
         FIG. 3  is an exploded view of a vacuum sucker for workpiece having through holes in accordance with the present invention; 
         FIG. 4  is an assembly perspective view of the vacuum sucker for workpiece having through holes in accordance with the present invention; and 
         FIG. 5  is an illustrative showing an operation of the vacuum sucker for workpiece having through holes in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 3 , a vacuum sucker  20  for workpiece having through holes in accordance with the present invention comprises a vacuum cup  21  and a vacuum accessory  22 . 
     The vacuum cup  21  is flexible, one end of the vacuum cup  21  is axially formed with a cylindrical combining section  211 , and the other end of the vacuum cup  21  is axially formed with a cylindrical vacuum chamber  212 . The combining section  211  is in communication with the vacuum chamber  212  and is screwed with the vacuum accessory  22 . 
     On an outer surface of one end of the vacuum accessory  22  is axially formed a column-shaped assembling section  221  having outer threads to be screwed with the combining section  211  of the vacuum cup  21 , and the other end of the vacuum accessory  22  is axially provided with a column-shaped suction head  222 . One end of the suction head  222  is provided with an abutting surface  223 . The cross section of the suction head  222  of the vacuum accessory  22  is smaller than that of the vacuum chamber  212  of the vacuum cup  21 . The vacuum accessory  22  is axially defined with a first passage  224  which penetrates from the assembling section  221  to the suction head  222 . One end of the first passage  224  towards the assembling section  221  is an open end, and the other end of the first passage  224  towards the suction head  222  is a close end. In the outer surface of the suction head  222  of the vacuum accessory  22  are radially defined a second passage  225 , a third passage  226 , a fourth passage  227  and a fifth passage  228 , respectively, which extends towards the close end of the first passage  224 . The first passage  224  is in communication with the second, third, fourth and fifth passages  225 ,  226 ,  227  and  228  for airflow circulation, respectively, and these passages,  225 ,  226 ,  227  and  228  are radially arranged. 
     Referring to  FIGS. 3 and 4 , the assembling section  221  of the vacuum accessory  22  is screwed with the combining section  211  of the vacuum cup  21 , so that the suction head  222  of the vacuum accessory  22  is located in the vacuum chamber  212  of the vacuum cup  21 , thus forming an airflow distance A between the outer wall of the suction head  222  of the vacuum accessory  22  and the vacuum chamber  212  of the vacuum cup  21 . 
     The open end of the first passage  224  of the vacuum accessory  22  is connected to a vacuum generator which is used to vacuum the vacuum chamber  212  of the vacuum cup  21  via the first, second, third, fourth and fifth passages  224 ,  225 ,  226 ,  227  and  228 , so as to make the vacuum chamber  212  of the vacuum cup  21  form a negative pressure state, so that the vacuum sucker  20  can suck the workpiece. When the vacuum sucker  20  sucks the workpiece having through holes as shown in  FIG. 5 , it will seal the through holes of the workpiece with the abutting surface  223  of the suction head  222 , so as to prevent the positive pressure air from outside from entering the vacuum chamber  212  of the vacuum cup  21  continuously, thus sucking the workpiece by the vacuum cup  21  successfully. 
     While we have shown and described various embodiments in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.