Patent Document

1. FIELD OF THE INVENTION 
   The present invention generally relates to fixtures for grinding machines, and more particularly to a fixture for grinding machines which prevents ground workpieces from adhering to the fixture. 
   2. DESCRIPTION OF RELATED ART 
   Many kinds of workpieces need to be ground to have a desired shape before use. For example, lenses used in digital camera modules are ground to be round to allow their installation into lens barrels. However, when grinding a plurality of workpieces at the same time, fixtures are used to properly secure the workpieces. 
   Referring to  FIG. 8 , a typical fixture for securing workpieces includes a first base  50  and a second base  60 . The first base  50  is substantially cuboid, a first groove  51  is defined on a surface of the first base  50 , and the first groove  51  has a triangular cross section. The second base  60  is also substantially cuboid, a second groove  61  is defined on a surface of the second base  60 , and the second groove  61  has a semicircular cross section. A diameter of the semicircular cross section of the second groove  61  is equal to a diameter of ground workpieces. 
   When a whole piece of material such as glass (not shown) is cut to be a plurality of rectangular workpieces (not shown), then the workpieces are placed into the first groove  51  of the first base  50 . Two adjacent sides of each workpiece are engaged with the first groove  51 , thus each workpiece is aligned with all other workpieces and pressed close to other workpieces adjacent to itself. Afterwards, some ultraviolet(UV) glue is applied to the workpieces. The ultraviolet glue dries after being irradiated with ultraviolet radiation, thus all workpieces are secured in the first base  50  and form a quadrilateral prism. Two side faces of the quadrilateral prism are exposed from the first groove  51  and the other two face sides of the quadrilateral prism are engaged with the first groove  51 . In this way, the ultraviolet glue prevents the workpieces from moving when the workpieces are being ground. A grinding wheel (not shown) is used to grind the two side faces exposed through the first groove  51 , thus half of the quadrilateral prism is ground to have a semicircular cross section. In this way, each workpiece is ground to have a first portion and a second portion, the first portion is triangular and the second portion is semicircular whose bottom matches (i.e., is shaped so as to conform to) with the bottom of the first portion. The second portion is exposed through the first groove  51 , and the first portion is engaged with the first groove  51 . 
   After grinding the first side, the dried ultraviolet glue is dissolved by water or other kinds of solvent. The second base  60  covers the first base  50 , the second portion of each workpiece is engaged with the second groove  61 . The first base  50  and the second base  60  are turned together, the first base  50  is removed, and all the workpieces are transferred to the second groove  61  of the second base  60 . In this way, the first portion of each workpiece is exposed through the second groove  61 . The workpieces are secured in the second groove  61  in a similar way to that in which the workpieces are secured in the first groove  51  and thus form a column. The column includes a cylinder portion and a prism portion, the prism portion of the first prism is exposed through the second groove  61  and the cylinder portion is engaged with the second groove  61 . The grinding wheel is used to grind the prism portion, thus the prism portion is also ground to have a semicircular portion. In this way, the column is ground to be a cylinder, and each workpiece is ground to have a round shape. 
   However, when the dried ultraviolet glue is dissolved for moving the workpieces from the first base  50  into the second base  60 , a little ultraviolet glue is likely to remain on the first base  50 , particularly in the first groove  51 . Therefore, some workpieces are likely to remain attached to the first base  50  by remaining ultraviolet glue when the first base  50  is turned. Placing these workpieces into the second base  60  and adjusting each of the workpieces to sit in a proper position requires much additional work, thus efficiency of cylindrical grinding is decreased. Additionally, if the number of the workpieces placed into the first groove  51  is too large, the quadrilateral prism formed by the workpieces may be too long, and the quadrilateral prism may become distorted when it is ground or turned, and some workpieces may be damaged. 
   Therefore, a new fixture for grinding machines is desired in order to overcome the above-described shortcomings. 
   SUMMARY OF THE INVENTION 
   In a preferred embodiment, a fixture for grinding machines includes a first base, a second base and a driving component. The first base defines a first working groove therein. The second base defines a second working groove corresponding to the first working groove therein. The driving component is able to slide in the first working groove, and the driving component cooperates with the first base and the second base to releasably hold workpieces. 
   Other advantages and novel features 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 fixture 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 lens module. Moreover, in the drawings, like reference numerals designate corresponding parts through out the several views. 
       FIG. 1  is an isometric view of a first base of a fixture in accordance with a preferred embodiment of the present invention; 
       FIG. 2  is an isometric view of a second base of the fixture in accordance with the preferred embodiment of the present invention; 
       FIG. 3  is an enlarged isometric view of one of partitions of the fixture in accordance with the preferred embodiment of the present invention; 
       FIG. 4  is an enlarged isometric view of a driving component of the fixture in accordance with the preferred embodiment of the present invention; 
       FIG. 5  is an isometric view of workpieces that need to be ground and are placed in the first base of the fixture; 
       FIG. 6  is an isometric view of the workpieces that have been ground in part and are placed in the first base of the fixture; 
       FIG. 7  is an isometric view of turning the fixture; and 
       FIG. 8  is an isometric view of a typical fixture for grinding machines. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to the drawings in detail,  FIG. 1 ,  FIG. 2 ,  FIG. 3  and  FIG. 4  show all components of a fixture for grinding machines in accordance with a preferred embodiment of the present invention. The fixture includes a first base  10 , a second base  20 , a plurality of partitions  30  and a driving component  40 . The fixture can be used to grind workpieces, such as, for example, round lenses. 
   Referring now to  FIG. 1 , the first base  10  is substantially cuboid. The first base includes a first working surface  101  and defines a first working groove  11  on the first working surface  101 . The first working groove  11  runs through the first base  10 . The first working groove  11  defines a grinding groove  111  and a cleaning groove  112  in communication with the grinding groove  111 . The grinding groove  111  has a trapeziform cross section, the cleaning groove  112  has a rectangular cross section, and the grinding groove  111  is parallel to the cleaning groove  112 . A width of the grinding groove  111  at its join with the cleaning groove  112  is less than a width of the cleaning groove  112 , thus two sliding rails  113  are formed beside the first working groove  11 . Two inclined planes  12  positioned corresponding to the grinding groove  111  are formed in the first base  10 , the two inclined places  12  are perpendicular to each other. Additionally, a plurality of grooves similar to the first working groove  11  can be defined on the first working surface  101 . Angle formed by the two inclined planes can be changed to correspond with the workpieces. 
   Referring to  FIG. 2 , the second base  20  is also substantially cuboid. The second base  20  includes a second working surface  201  and defines a second working groove  21  corresponding to the first working groove  11  on the second working surface  201 . The second working groove  21  has a semicircular cross section, a diameter of the semicircular cross section being equal to a diameter of ground workpieces. One end of the second working groove  21  runs through the second base  20 , a confining block  22  is formed on the second working surface  201 , the confining block  22  blocks another end of the second working groove  21 , and size of the confining block  22  is less than a diameter of ground workpieces. Additionally, a plurality of grooves similar to the second working groove  21  can be defined on the second working surface  201  to correspond with the grooves defined on the first working surface  101 . 
   Referring to  FIG. 3 , the partitions  30  are sliding components that can slide in the first working groove  11 . The partitions  30  are made of elastic material such as rubber for preventing adjacent workpieces from being damaged. Each partition  30  includes a sliding portion  31  and an extending portion  32 . The cross section of the sliding portion  31  coincides with the cross section of the first working groove  11 . The extending portion  32  connects with the sliding portion  31 , and size of the extending portion  32  is less than a diameter of ground workpieces. 
   Referring to  FIG. 4 , the driving component  40  includes a pushing board  41  and two driving poles  42 . The pushing board  41  is made of elastic material such as rubber for preventing adjacent workpieces from being damaged. Shape of the pushing board  41  is similar to the partitions  30 , and the pushing board  41  includes a sliding board  411  and an extending board  412 . The shape of the sliding board  411  coincides with the cross section of the first working groove  11 . The extending board  412  connects with the sliding board  411 , and size of the extending board  412  is less than diameter of ground workpieces. The two driving poles  42  each connects with their respective sides of the extending board  412 . 
   In  FIG. 5  and  FIG. 6  the fixture in accordance with the preferred embodiment of the present invention is shown. A material such as glass (not shown) is cut to form a plurality of rectangular workpieces (not shown), the workpieces are then placed in the grinding groove  111  of the first working groove  11 . Two adjacent sides of each workpiece are engaged with the two inclined planes  12  of the first base  10 , each workpiece is aligned with all other workpieces and pressed close to other workpieces adjacent to itself. After a proper quantity of workpieces are placed into the grinding groove  111  of the first working groove  11 , a partition  30  is aligned with one end of the first working groove  11  and the two sliding rails  13  are engaged with the partition  30 . The partition  30  is pushed to slide along the first working groove and pressed against the workpieces. After the partition is properly positioned, some other workpieces are placed in the grinding groove  111 , and another partition  30  is pushed into the first working groove  11 . In this way, workpieces and partitions  30  are placed in the first working groove  11  in turn until the first working groove  11  is filled, and the workpieces in the first working groove  111  are separated into a plurality of groups by the partitions  30 . 
   Ultraviolet glue is applied to the workpieces. The ultraviolet glue dries after being irradiated by ultraviolet radiation, thus all workpieces are secured in the first base  10 , and each group of workpieces forms a quadrilateral prism (not labeled), the partitions  30  separate each quadrilateral prism from the other quadrilateral prisms. Alternatively, the quadrilateral prisms formed by glued workpieces can be formed one by one. Two side faces of each quadrilateral prism are exposed through the first working groove  111  and the other two side faces of each quadrilateral prism are engaged with the first working groove  11 . In this way, the ultraviolet glue prevents the workpieces from moving when the workpieces are being ground. 
   A grinding machine (not shown) with a grinding wheel (not shown) is provided to grind the two side faces exposed through the first working groove  11 , thus half of each quadrilateral prism is ground to have a semicircular cross section. Because size of the extending portion  32  of each partition  30  is less than diameter of ground workpieces, the partitions  30  do not obstruct the grinding wheel while it is grinding the workpieces. In this way, each workpiece is ground to have a first portion and a second portion, the first portion is triangular and the second portion is semicircular with a bottom that conforms to the bottom of the first portion. The second portion is exposed through the first working groove  11 , and the first portion is engaged with the first working groove  11 . 
   Also referring to  FIG. 7 , after each workpiece is ground in part, water or other kinds of solvents are applied to the workpieces to dissolve the dried ultraviolet glue, then the workpieces are released from the first base  10 . The solvent dissolving the ultraviolet glue is allowed to flow out of the first base  10  along the cleaning groove  112  in communication with the grinding groove  111  for removing remaining ultraviolet glue. The second base  20  then covers the first base  10 , the confining block  22  blocks one end of the first working groove  11  and prevents the workpieces from being pushed out of the first base  10 , and the second portion of each workpiece is engaged with the second working groove  21 . The pushing board  41  of the driving component  40  is aligned with another end that is located opposite to the confining block  22  of the first working groove  11 , and the driving component  40  is pushed into the first working groove  11 . The driving poles  42  are pushed towards the confining block  22 , and the driving component  40  is also pushed to slide along the sliding rails  113  to the confining block  22 . In this way, some workpieces that remain attached to the first base  10  by the remaining ultraviolet glue are separated from the first base  10  and fall into the second working groove  21 . 
   The first base  10  and the second base  20  are turned together. The first base  10  is taken away and all workpieces fall into the second working groove  21 . The partitions  30  and the driving component  40  are taken away with the first base  10  due to the sliding portion  31  of each partition  30  and the sliding board  411  of the component  40  engaging with the cleaning groove  112  and being held by the sliding rails  113 . 
   The driving component  40  is taken away from the first base  10  and the extending board  412  of the pushing board  41  is pushed into the second working groove  21 . The driving poles  42  are pushed to the confining block  22 , and the driving component  40  is also pushed to slide towards the confining block  22 , thus all workpieces are pressed against the confining block  22 . The workpieces are adjusted to be placed in the second working groove  21  perpendicularly, ultraviolet glue is applied to the workpieces and irradiated with ultraviolet radiation, thus all workpieces are secured in the second working groove  21  and form a column (not labeled). The column includes a cylinder portion and a prism portion, the prism portion of the first prism is exposed through the second working groove  21  and the cylinder portion is engaged with the second working groove  21 . The grinding wheel is used to grind the prism portion, thus the prism portion is also ground to have a semicircular portion. Because size of the confining block  22  is less than diameter of ground workpieces, confining block  22  does not obstruct the grinding wheel in grinding the workpieces. In this way, the column is ground to be a cylinder, and thus each workpiece is ground to have a round shape. After the workpieces are ground, the ultraviolet glue is dissolved, the workpieces are released and can then be taken away from the second base  20 . 
   It should be understood that when the workpieces are separated by the partitions  30  to form short prisms, the short prisms are less prone to distortion during grinding or turning. Additionally, if the number of workpieces is small, all workpieces can be glued to be a prism without being separated. 
   It is to be understood, however, that even though numerous characteristics and advantages of the present lens module with grating have been set forth in the foregoing description, together with details of the structure and function of the lens module with grating, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the lens module with grating to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.

Technology Category: b