Abstract:
An adjustable cassette ( 1 ) for accommodating substrates includes a frame ( 10 ), a pair of supporting plate ( 20 ) with a plurality of retaining members ( 208 ) facing each other, and an adjusting means for joining of the supporting plates to the frames and thereby forming the cassette. At least one supporting plate can slide away from or close to another supporting plate and be fixed by means of the adjusting means.

Description:
BACKGROUND OF INVENTION 
   1. Field of the Invention 
   The present invention relates to a storage cassette, and more particularly to a cassette which can be adjusted to adapt to substrates having different sizes. 
   2. Description of Related Art 
   In handling substrates such as glass substrates for LCDs, cassettes are useful for holding and stowing the substrates and keeping them from contacting each other. The substrates are thus protected from damaging each other. In a manufacturing plant, substrates having different sizes may be produced. Thus, a cassette which can be used to hold or stow different substrates is more versatile and reduces costs. 
   A conventional adjustable cassette is described in Japan Yodogawa Kasei publication number H03-273664. The cassette comprises a pair of frames and a group of supporting columns. Each supporting column is provided with a plurality of annular slots defined in a rod made from resin, and defines a threaded hole in each of two opposite ends thereof. 
   For adapting to different sized substrates, the frames are panels which define a plurality of holes in different places for joining of the frames to the supporting columns using screws and thereby forming the cassette. According to the size of the substrates to be stowed, the supporting columns are locatable at different positions to form different spaces for accommodating different substrates. To adjust the cassette, a tool such as a screwdriveris needed to unfasten and refasten the screws. In addition, every part must be disassembled and then reassembled. The disassembly and reassembly are troublesome and timeconsuming. Moreover, the unfastened screws are liable to be lost. 
   For the above reasons, a new cassette which is readily adjusted to adapt to different sized substrates is desired. 
   SUMMARY OF INVENTION 
   An object of the invention is to provide a cassette which is readily adjusted to adapt to different sized substrates. 
   In order to achieve the object set forth above, the present invention provides an adjustable cassette for accommodating substrates includes a frame, a pair of supporting plate with a plurality of retaining members facing each other, and an adjusting means for joining of the supporting plates to the frames and thereby forming the cassette. At least one supporting plate can slide away from or close to another supporting plate and be fixed by means of the adjusting means. 
   The adjusting means comprises two guiding slots and two positioning slots with keyways defined in each of two opposite sides of the frame, two threaded holes and two through holes defined in each of opposite end portions thereof corresponding to the guiding slots and the positioning slots respectively, a plurality of screw bolts passed through the guiding slots and engaged in corresponding threaded holes, and a plurality of positioning pins located in the through holes and positioning slots. 
   Further, the present invention provides a method for adjusting an adjustable cassette, the method comprising:
         providing a cassette comprising upper and lower supports with guiding slots and keyways, supporting plates, positioning pins having coil springs therearound, and screw bolts; unscrewing screw bolts slightly so that they are slidable along guiding slots; pressing heads of positioning pins so that stoppers are disengaged from keyways; sliding one supporting plate along upper and lower supports until the distance between supporting plates corresponds to the size of the substrate; releasing pressure on the heads so that coil springs decompress and drive the stoppers to engage in appropriate selected keyways; and tightening the screw bolts.       

   When the size of a substrate is larger or smaller than the distance between the two opposing supporting plates, the cassette can be adjusted to fit the substrate. In the adjusting process, only one of the two supporting plates needs to be repositioned, and no part need be detached from the cassette. The risk of misplacing loose parts is eliminated, and the adjusting process is simple and speedy. 
   Other objects, advantages and novel features of the invention will become more apparent from the following detailed description of the preferred embodiment of the invention as illustrated in the accompanying drawings, in which: 

   
     BRIEF DESCRIPTION OF DRAWINGS 
       FIG. 1  is an isometric view of a cassette according to the present invention; 
       FIG. 2  is an enlarged view of a portion of the cassette of  FIG. 1 , showing a screw bolt partly unscrewed and a stopper disengaged from a corresponding pair of keyways; 
       FIG. 3  is an enlarged, isometric view of another portion of the cassette of  FIG. 1 , showing a screw bolt screwed in and a stopper engaged in a corresponding pair of keyways; 
       FIG. 4  is an enlarged, exploded, isometric view of some of the parts shown in  FIG. 2 ; and 
       FIG. 5  is similar to  FIG. 2 , but viewed from another aspect. 
   

   DETAILED DESCRIPTION 
   Reference will be made to the drawings to describe the invention in detail. 
   Referring to  FIG. 1 , a cassette  1  comprises a frame  10 , two pairs of supporting plates  20 , a plurality of positioning pins  30 , a plurality of coil springs  50 , and a plurality of screw bolts  40 . The frame  10  and the supporting plates  20  define a space therebetween for accommodating substrates, and further define an entrance for inserting the substrates into the space. 
   The frame  10  is generally box-shaped, and comprises a group of upper supports  101  and a group of lower supports  102  at two opposite sides thereof respectively. The upper supports  101  and the lower supports  102  have a same structure. Referring also to  FIGS. 2 and 3 , each lower support  102  defines a longitudinal guiding slot  105  and a longitudinal positioning slot  104  therein, the guiding slot  105  and the positioning slot  104  being parallel to each other. Furthermore, the positioning slot  104  comprises a plurality of pairs of keyways  106  at an outer surface of the lower support  102 . Each pair of keyways  106  is at opposite sides of the positioning slot  104  respectively. The pairs of keyways  106  are spaced apart from one another at predetermined distances. 
   Each supporting plate  20  comprises an upper sliding support  202 , a lower sliding support  204 , and a supporting body  206  therebetween. The upper sliding support  202  and the lower sliding support  204  have a same structure. Therefore, only the lower sliding support  204  is described in detail herebelow. Referring also to  FIG. 4 , only a part of the lower sliding support  204  is shown. The lower sliding support  204  defines a through hole  242  and a threaded hole  244  in each of opposite end portions thereof. A lateral displacement between the through hole  242  and the threaded hole  244  is the same as a distance between the guiding slot  105  and the positioning slot  104 . The supporting body  206  is generally plate-shaped, and comprises a plurality of parallel retaining ribs  208  on an inner face thereof. Thus two of the supporting plates  20  face each other, with the retaining ribs  208  thereof being symmetrically opposite each other. The retaining ribs  208  cooperate with each other to retain a plurality of substrates therebetween. 
   Referring also to  FIG. 5 , each positioning pin  30  comprises a head  32  at one end, a main body  34  defining a stopper hole  342  in an end thereof distal from the head  32 , and a stopper  60  received in the stopper hole  342 . A diameter of the head  32  is larger than that of the through hole  242 , and a diameter of the main body  34  is slightly less than the diameter of the through hole  242 . One coil spring  50  is engaged around the main body  34  between the head  32  and the stopper hole  342 . The coil spring  50  is compressed to enable the stopper  60  to be received in the stopper hole  342  below the lower sliding support  204 . 
   Each screw bolt  40  comprises a head (not labeled) and a main body (not labeled). A diameter of the head is larger than a width of the guiding slot  105 , and a diameter of the main body is slightly less than the width of the guiding slot  105 . 
   The positioning pins  30  and the screw bolts  40  are used for assembling the frame  10  and the supporting plates  20  together and thereby forming the cassette  1 . 
   In assembly, one pair of the supporting plates  20  is placed in the space of frame  10 , with the retaining ribs  208  thereof facing inwardly toward each other. The through holes  242  and the threaded holes  244  of the upper and lower sliding supports  202 ,  204  are aligned with the corresponding positioning slots  104  and guiding slots  105  respectively. Eight screw bolts  40  are passed through the guiding slots  105  from an outside of the frame  10  and engaged in corresponding threaded holes  244 . The main bodies  34  of the positioning pins  30  are passed through the corresponding through holes  242  and the positioning slots  104  from an inside of the frame  10 , and the stoppers  60  are engaged in the stopper holes  342 . The coil springs  50  are thereby compressed, and the stoppers  60  are engaged in selected keyways  106 . Finally, the supporting plates  20  can be even further secured by tightening the screw bolts  40 . Thus the frame  10  and both pairs of the supporting plates  20  are firmly joined together. 
   Mounting each positioning pin  30  in the above-described assembly procedure comprises the following steps. First, the main body  34  with the coil spring  50  engaged therearound is extended into the through hole  242 . Second, the head  32  is pressed to expose the stopper hole  342  beyond an outer side of the corresponding upper or lower sliding support  202 ,  204 , and the stopper  60  is inserted into the stopper hole  342 . The coil spring  50  is also thereby compressed. Third, pressure on the head  32  is released, so that the coil spring  50  decompresses and drives the stopper  60  to engage in a selected pair of keyways  106 . 
   When the size of a substrate is larger or smaller than the distance between the two opposing supporting plates  20 , the cassette  1  can be adjusted to fit the substrate. Normally only one of the two supporting plates  20  needs to be repositioned, as follows. The screw bolts  40  are unscrewed slightly so that they are slidable along the guiding slots  105 . The heads  32  are pressed so that the stoppers  60  are disengaged from the keyways  106 . The supporting plate  20  is slid along the upper and lower supports  101 ,  102  until the distance between the supporting plates  20  corresponds to the size of the substrate. Pressure on the heads  32  is released, so that the coil springs  50  decompress and drive the stoppers  60  to engage in appropriate selected keyways  106 . Finally, the screw bolts  40  are tightened. 
   The cassette  1  of the present invention provides the above-described sliding and fixing means, which essentially comprise the positioning pins  30 , the screw bolts  40 , the positioning and guiding slots  104 ,  105 , and the through and threaded holes  242 ,  244 . The sliding and fixing means enable easy adjustment of the distance between two opposite supporting plates  20 . In the adjusting process, no part need be detached from the cassette  1 . The risk of misplacing loose parts is eliminated, and the adjusting process is simple and speedy. 
   It is to be understood, however, than even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, 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 invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.