Abstract:
In a coating film transfer tool, a tape supply core rotation limiter predetermines the amount of coating film laid down on a receiving surface, to enable erasure of small areas. The permitted rotation of the supply core can be selected from a group of different choices by the use of an adjusting member, releasably engageable with the teeth of a toothed wheel rotatable with the supply core, and movable with the wheel when engaged therewith until engaged with a stop. A spring pawl, engageable with the teeth of the wheel, prevents reverse rotation of the supply core. The adjusting member can be disabled by holding it out of engagement with the toothed wheel, so that the instrument can be used as a conventional coating film transfer tool.

Description:
FIELD OF THE INVENTION 
   This invention relates to coating film transfer tools for transferring correction films, adhesives, decorative coating films, or the like, onto a receiving surface. 
   BACKGROUND OF THE INVENTION 
   A conventional coating film transfer tool comprises a supply core and a take-up core, both rotatably supported within a case having a transfer head. A coating film on a base tape is supplied as a winding on the supply core. The base tape is unwound from the supply core, passes over the transfer head, and is wound onto the take-up core as the transfer head moves over a receiving surface. As the transfer head move over the receiving surface, the coating film is transferred from the base tape onto the receiving surface 
   A coating film transfer tool functions efficiently when erasing relatively long sections of print, for example, a section containing more than ten letters. However, when a small section of written matter, consisting of only one or a few letters is to be erased, it is difficult to adjust the length of the transfer tape to the length of the section to be erased. Consequently, the coating film is commonly transferred to an area that does not need to be erased, or the length of the transferred film is insufficient to cover section to be erased. In such case, it is necessary to remove, or add, coating film, and excessive time is consumed in effecting erasure of the unwanted written matter. 
   Unexamined Japanese Patent Publications Nos. 264588/2002, 227386/1999, and 19914/2001 disclose stamp-type coating film transfer tools, which transfer a coating film onto a receiving surface by pressing a transfer head downwards to correct a single letter or a small, well-defined area. The coating film transfer tools disclosed in Japanese patent publications 227386/1999, and 19914/2001 not only transfer the coating film onto the receiving surface by pressing, but also transfer the coating film by moving the tool parallel to the receiving surface as in the case of a conventional coating tape transfer tool. The stamp-type pressing transfer tool can securely erase letters within a fixed area, since the width of the transfer head corresponds to that of a coating film transfer surface. 
   Because the stamp-type pressing transfer tool has a large transfer surface area, it is difficult to apply pressing force evenly over the receiving surface, and it is difficult, and often impossible, to achieve fine transfer resolution. In addition, since the transfer head is in the shape of a box, corresponding to the size of the transfer surface which transfers the coating film onto the receiving surface, it is difficult to check whether the transfer head is over the targeted letters or area until the transfer head is pressed down onto the receiving surface. Moreover, when using a stamp-typed pressing transfer tool as a conventional transfer tool, which transfers a coating film by moving parallel to a receiving surface, it is difficult to cut the coating film cleanly by raising the transfer head, because of the large cohesive forces acting on the coating film. As a result, the coating film can be dragged to an area of the receiving surface to which the transfer head was not applied. In order to avoid undesired dragging of the coating film, it is necessary to control the breaking strength and elongation rate of the coating film, as disclosed, for example in Japanese patent publication 19914/2001. However, controlling the breaking strength and elongation rate of a coating film leads to manufacturing complications and excessive manufacturing cost. 
   An object of this invention is to provide a coating film transfer tool in which a coating film is transferred by pressing the transfer head onto a receiving surface and moving the tool parallel to the receiving surface, and which is capable of erasing written matter over a predetermined distance, and which is capable of erasing very small sections of written matter easily and securely. 
   SUMMARY OF THE INVENTION 
   The coating film transfer tool in accordance with the invention, comprises a rotatable tape supply core, a transfer head, and a rotatable take-up core. A transfer tape, comprising a base tape and a coating film, is wound on the supply core. The base tape extends from the supply core, past the transfer head, to the take-up core, for transfer of the coating film from the base tape to a receiving surface as the transfer tape is unwound from the supply core and pressed by the transfer head against the receiving surface while the transfer head is moved parallel to the receiving surface. The improvement comprises a tape supply length limiter for limiting the rotation of the supply core, and thereby predetermining the amount of base tape that moves past the transfer head in a single coating film transfer operation. 
   Preferably, the tape supply length limiter is adjustable to allow selection from a set of different, and preferably discrete, choices, the predetermined amount of base tape that moves past the transfer head in a single coating film transfer operation. 
   In a preferred embodiment, the tape supply length limiter comprises a toothed wheel, rotatable with the supply core, an adjusting member releasably engageable with the teeth of the wheel, and movable with the wheel when engaged therewith, and a stop engageable by the adjusting member. 
   To avoid inadvertent unreeling of the tape from the supply core as the supply length limiter is reset, a means, such as a spring pawl having both sloping and non-sloping tooth faces engageable with the teeth of the wheel, is provided for preventing reverse rotation of the supply core in a direction opposite to the direction in which the core rotates as transfer tape is unwound therefrom. 
   A mechanism is preferably provided for disabling the operation of the tape supply length limiter so that the instrument can be used as a conventional coating film transfer tool. 
   The coating film transfer tool according to the invention makes it possible to transfer a coating film to a pinpointed area by presetting the range of rotation of the transfer tape supply core and forcing the supply core to stop at a predetermined position in order to prevent more than a predetermined length of coating film from being applied to a receiving surface in a given coating film transfer operation. With a preferred embodiment of the transfer tool in accordance with the invention, it is also possible to select the predetermined amount of coating film to be applied from a set of choices. The invention allows the amount of coating film applied to a receiving surface to be accurately controlled, making it possible to erase small amounts of written matter, such as one or two printed letters, without erasing adjacent written matter. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
       FIG. 1  is a side elevational view of a coating film transfer tool according to the invention, with the cover removed to reveal the internal mechanism of the transfer tool; 
       FIG. 2  is a cross sectional view taken on section plane  2 - 2  of  FIG. 1 ; 
       FIG. 3  is right side elevational view of the tool, as seen along the direction indicated by arrow a in  FIG. 1 ; 
       FIG. 4  is perspective view of the tape supply length adjusting mechanism; 
       FIG. 5  is an enlarged, fragmentary, perspective view showing the components in the vicinity of the tape supply length adjusting mechanism; 
       FIG. 6  is an enlarged, fragmentary, perspective view showing details of an anti-reverse member; and 
       FIG. 7  is a partial plan view showing the tape supply length adjusting mechanism in its released condition. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   As shown in  FIGS. 1 and 2 , the coating film transfer tool  10  according to the invention comprises a case  21   a , having shafts  22   a  and  22   b , a transfer head  30  at the end of the case, the transfer head having a transfer tip  34 , a supply core  24   b  and a take-up core  24   a  which are rotatably supported by shafts  22   a  and  22   b  respectively, and a transfer tape T comprising a coating film on a base tape. The coating film transfer tool  10  also includes a tape supply length adjusting mechanism  20 . 
   The supply core  24   b  and the take-up core  24   a  are connected by an endless rubber belt BT. The belt drives the take-up core, with some slippage, when the supply core rotates as transfer tape T is pulled from the supply core. In the operation of the transfer tool, the transfer tape T is drawn off the supply core. The coating film is separated from the base tape at the transfer tip  34 , where the coating film is transferred onto a receiving surface. The base tape, from which the coating film has been separated, is wound onto the take-up core  24   a.    
   The tape supply adjusting mechanism  20  allows a predetermined length of transfer tape to be supplied, by adjustably limiting the range of rotation of the supply core  24   b , causing the supply core to stop at a predetermined position. The tape supply length adjusting mechanism  20  comprises a toothed wheel  25 , which rotates with the supply core  24   b , a tape supply length adjusting member  26  engageable with the toothed wheel  25 , and an opening  28  in the case  21   a  through which the adjusting member  26  extends. One end of the opening  28  (the upper end in  FIGS. 1 and 3 , engages the adjusting member  26  to limit its range of movement, thereby limiting rotation of the tape supply core  25   b.    
   As seen in  FIG. 4 , the adjusting member  26  includes an arc-shaped spring  29  is provided on the adjusting member  26  at a location approximately midway between its inner and outer ends. The spring engages an inner wall of the case  21   b , urging the adjusting member inward toward the toothed wheel  25 . A projection  31 , which enters a space between adjacent teeth of wheel  25 , is provided on the adjusting member  26  adjacent the center of spring  29 . An elongated hole  32  is provided in the adjusting member near its inner end, and a U-shaped groove  33  is provided in the side of a flat gripping section  34  at the outer end of the adjusting member for, so that the user can grasp and pull the adjusting member, and thereby disengage the projection  31  from the toothed wheel  25 . 
   As shown in  FIGS. 1 and 2 , the shaft  22   b  on the case extends through the elongated hole  32  of the adjusting member  26 , thereby supporting the adjusting member while allowing rotation of the adjusting member about the axis of the toothed wheel, and also allowing longitudinal movement of the adjusting member for disengagement of its projection  31  from the teeth of wheel  25 . The adjusting member rotates with the toothed wheel when its projection  31  is engaged with the toothed wheel, and can be rotated independently of the toothed wheel, when, by pulling on gripping section  34 , the user disengages projection  31  from the toothed wheel, against the action of spring  29 . In each case, however, the ends of opening  28  establish limits for the rotation of the adjusting member. 
   As shown in  FIG. 5 , the adjusting member  26  can move between a starting point A and an ending point B at the respective ends of opening  28 . In  FIG. 5 , the adjusting member  26  is in contact with the ending point B, and projection  31  is in contact with the teeth of toothed wheel  25 . When the adjusting member is in contact with ending point B as shown, the transfer tape can no longer be unreeled from the supply core. 
   The adjusting member  26  may be pulled manually to disengage its projection  31  from the toothed wheel  25 . The adjusting member  26  may then be rotated clockwise, and its projection  31  re-engaged with the toothed wheel  25  at an appropriate position between the starting point A and the ending point B. Then, when the coating film transfer tool  10  is pressed onto, and moved over a receiving surface, the toothed wheel  25  and the adjusting member  26  rotate with the supply core in the direction of the arrow in  FIG. 5  until the adjusting member once again contacts point B at an end of opening  28 . When the adjusting member  26  reaches the ending point B, rotation of the supply core  24   b  is stopped, and consequently, the feed of transfer tape T is also stopped. 
   The amount of transfer tape to be supplied can be adjusted by aligning a triangular marking on the adjusting member  26  (see  FIG. 4 ) with one of the markings adjacent opening  28 , as shown in  FIG. 3 . In this case, the markings “2”, “4” and “6” indicate the length, in millimeters, of transfer tape T that will be fed. The distance between the markings on the scale correspond to the pitch of the teeth of the toothed wheel  25 . Thus, if the projection of the adjusting member is re-engaged with the toothed wheel at scale position “2”, the adjusting member  26  will allow the supply core  24   b  to rotate through an angle of 12 degrees, supplying approximately 2 mm of tape until the adjusting member  26  contacts ending point B to stop the rotation of the supply core. The length of tape supplied will vary depending on the amount of tape wound on the supply core. However, the diameter of the supply core and the diameter of the outer winding of tape on the core differ by only a small amount, and therefore variations in the length of tape supplied for a given setting of the adjusting member are inconsequential. The scales shown in  FIG. 3  are merely examples, and it is possible to provide for smaller or larger feed lengths by providing a toothed wheel having a suitable pitch and changing the scales on the case accordingly. 
   To prevent the toothed wheel from being rotated in the reverse direction when the adjusting member is pulled outward and moved clockwise to adjust the length of the transfer tape to be supplied, an anti-reverse pawl  27  is provided, as shown in  FIG. 6 . The anti-reverse pawl  27  comprises a flat spring, having a tooth at one end, the tooth having a sloping face  27   a  and a non-sloping face  27   b . When the toothed wheel  25  rotates in the direction to feed tape toward the transfer head, the teeth of wheel  25  push against the sloping face  27   a  of the tooth, and the pawl is elastically deformed so that the teeth of wheel  25  can move over the sloping face of tooth  27   a . On the other hand, if an attempt is made to rotate the toothed wheel in the reverse direction, engagement of a tooth of the wheel with the non-sloping surface  27   b  of the pawl tooth, will prevent reverse rotation. Ratchets, and other suitable anti-reverse mechanisms can, of course, be used as alternatives to the anti-reverse pawl mechanism shown in  FIG. 6 . 
   In  FIG. 7 , the tape supply length adjusting mechanism is taken out of service by a disabling mechanism  40 . The flat section  34  of the adjusting member  26  may be grasped manually, pulled against the force exerted by spring  29  to disengage the projection  31  from the teeth of wheel  25 , and then the adjusting member may be rotated counterclockwise about the axis of the toothed wheel and supply core so that the U-shaped groove  33  is engaged with the ending point B of opening  28 . When the U-shaped groove is engaged with the ending point B of the opening  28 , the projection  31  will remain disengaged from the toothed wheel, and the instrument can be used as an ordinary coating film transfer tool, in which the transfer tape T is supplied continuously. The elastic deformation of the spring  29  maintains the U-shaped groove  33  engaged with the ending point B of the opening  28 . 
   The invention enables a coating film transfer tool, of the kind having a relatively sharp transfer tip which moves parallel to a receiving surface, to erase small areas, for example, one or two letters of print, reliably and without difficulty. In addition, since the tape supply length adjusting mechanism can be easily disabled, the transfer tape can be supplied continuously as in the case of a conventional coating film transfer tool.