Patent Publication Number: US-6668697-B2

Title: Automatic cutting device for an adhesive-tape holder

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to an automatic cutting device for an adhesive-tape holder, particularly to one having a blade sandwiched by a blade slide base and a blade holder and actuated to cut off an adhesive tape with precision when a press plate is pressed. 
     A conventional adhesive-tape holder, as disclosed in the Taiwan Patent No. 5641377, 5906705, 5849144, titled “RETRACTABLE BLADE HAND HELD TAPE APPLICATORS”, has its flat plate and its blade connected by a spring and then pressed by a press plate having positioning member serving as a fulcrum to push the blade forward to cut off adhesive tape. 
     However, the spring in the foresaid conventional device is provided dangling between the flat plate and the blade, therefore it is likely to be contracted to an unexpected position and hard to recover its position as anticipated. 
     In addition, a fixing plate has to be additionally provided on the rear side of the press plate and positioning members have to be respectively provided on opposite sides of the fixing plate to be respectively inserted in the positioning grooves of an adhesive-tape holder and of a side plate to make up two pivotal shafts, thus complicating its structure and increasing its cost. 
     SUMMARY OF THE INVENTION 
     This invention has been devised to offer an automatic cutting device for an adhesive-tape holder, having a blade sandwiched by a blade slide base and a blade holder to be guided and restricted to move forward to cut off an adhesive tape precisely when a press plate is pressed. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     This invention will be better understood by referring to the accompany drawings, wherein: 
     FIG. 1 is an exploded perspective view of an automatic cutting device for an adhesive-tape holder in the present invention: 
     FIG. 2 is a side cross-sectional view of the automatic cutting device for an adhesive-tape holder in the present invention: 
     FIG. 3 is a side cross-sectional view of the automatic cutting device for an adhesive-tape holder in an operating condition in the present invention: 
     FIG. 4 is a perspective view of the automatic cutting device for an adhesive-tape holder in the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A preferred embodiment of an automatic cutting device for an adhesive-tape holder in the present invention, as shown in FIGS. 1 and 2, includes a blade holder  20 , a blade  30 , a blade slide base  40  and a press plate  50  as main components combined together. 
     The blade holder  20  is L-shaped and has its left side formed integral with a side plate  11  while its right side end formed with a fixing member  21 . The fixing member  21  is directly inserted in the inner side edge of the side plate  12  of a handle  10 . The blade holder  20  is provided on top with two fixing studs  22  protruding upward and respectively having a female thread for receiving a bolt  25 . Further, a receiving groove  23  is formed between two fixing studs  22 , and a slide groove  24  is respectively provided at the left and the right of the receiving groove  23 . 
     The blade  30  is mounted on the blade holder  20  and provided with two oval holes  31  corresponding to and for receiving two fixing studs  22  of the blade holder  20 . The blade  30  further has two position holes  32  to match with two slide grooves  24  of the blade holder  20 . 
     The blade slide base  40  is L-shaped, fitted on the blade  30  to activate the blade  30  to shift. The blade slide base  40  is provided on top with two oval holes  41  conforming to the oval holes  31  of the blade  30 , and a projecting stud  42  and a spring  43  on the inner wall of the lateral side. The spring  43  has one end fitted around the projecting stud  42  and the other end inserted in the receiving groove  23  of the blade holder  20  so as to enable the blade slide base  40  recover by the resilient force of the spring  43 . In addition, the blade slide base  40  is provided with two position studs  44  protruding downward and corresponding to the position holes  32  of the blade  30  to be inserted through the position holes  32 , and then get and shift in the slide grooves  24  to shift therein. 
     The press plate  50  curved in a  shape, provided with a pivotal stud  51  at a corner of opposite sides to be axially pivoted at a proper position of the side plate  11 . The press plate  50  has a push plate  52  formed on the lower end for pushing against the lateral side of the blade slide base  40 . 
     In assembling, as shown in FIGS. 2 and 3, firstly, the blade  30  is positioned on the blade holder  20 , letting the oval holes  31  of the blade  30  fitted around the fixing studs  22  of the blade holder  20 . Thus, the oval holes  31  are restricted to move back and forth along the fixing studs  22 , and the blade  30  can only shift back and forth on the blade holder  20 . 
     Next, the blade slide base  40  is mounted on the blade  30 , letting the oval holes  41  fitted around the fixing studs  22  to be restricted to move to and fro therein, so that the blade  30  can simply shift back and forth along the fixing studs  22 . At the same time, the position studs  44  are inserted through the position holes  32  and then get in the slide grooves  24  of the blade holder  20  to shift therein together with the blade  30 . Then, fit one end of the spring  43  around the projecting stud  42  of the blade slide base  40  and insert the other end in the receiving groove  23  of the blade holder  20 . 
     Subsequently, the press plate  50  is positioned on the rear side of the blade slide base  40 , letting its push plate  52  push against the lateral side of the blade slide base  40 , and lastly the whole device is sandwiched between the side plates  11  and  12  and secured by means of the fixing member  21  of the blade holder  20 , with the press plate  50  capable to sway with the pivotal studs  51 . 
     In using, an adhesive-tape roll is fitted on the adhesive-tape base  13  and the adhesive tape is pulled out to pass through a roller  14  and get onto the press plate  50 . Then, hold the handle  10  to let the adhesive tape glued on the article to be adhered and pulled out by rotating the roller  14  with the adhesive tape flattened by the end edge of the press plate  50 . 
     In case the adhesive tape is expected to be cut off, just forcefully press the handle  10  on the article being adhered to force the upper end of the press plate  50  sway backwards by leverage produced by the pivotal studs  51 , and at the same time the push plate  52  is activated to push forward the blade slide base  40  together with the blade  30  as shown in FIGS. 2 and 3. Since the blade  30  is restricted to move back and forth along the fixing studs  22  inserting and moving in the oval holes  31 , and sandwiched between the blade holder  20  and the blade slide base  40  to be guided and restricted in shifting, therefore the blade  30  can cut off adhesive tape on a level and with precision. 
     When the handle  10  is no longer pressed on the article, the blade slide base  40  together with the blade  30  and the press plate  50  will quickly recover their positions by the resilient force of the spring  43 . 
     Evidently, this invention has some advantages described below. 
     1. The blade  30  is sandwiched between the blade holder  20  and the blade slide base  40  to be guided and restricted in shifting, therefore it can cut an adhesive tape on a level and with precision. 
     2. The press plate  50  is provided with pivotal studs on opposite sides as fulcrums, so one end of the press plate  50  can flatten the adhesive tape and the other end by leverage can push the blade  30  forward to cut off an adhesive tape. 
     3. When flattening the adhesive tape, the swaying force of the press plate  50  is smaller than the resilient force of the spring  43  so the blade  30  is impossible to protrude out, ensuring safety in using. 
     4. The blade  30  can automatically cut off an adhesive tape simply by pressing or releasing the handle  10 , convenient in handling. 
     While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications that may fall within the spirit and scope of the invention.