Patent Publication Number: US-6702491-B2

Title: Film transfer apparatus

Description:
The following disclosure is based on Japanese Patent Application No. 2001-249348, filed on Aug. 20, 2001, which is incorporated into this application by reference. 
     FIELD OF AND BACKGROUND OF THE INVENTION 
     This invention relates to a film transfer apparatus and more particularly to an improvement in a non-return mechanism for a take-up reel of a film transfer apparatus of a type which is formed by combining a cartridge unit and a case body with each other. A feed reel and a take-up reel around which a transfer tape adapted to be reversed on a transfer head is wound are supported by the apparatus so that the two reels can be rotated relatively and smoothly irrespective of an increase and a decrease in the amounts of the transfer tape wound around the reels. 
     FIG. 8 is a perspective view of a typical conventional film transfer apparatus, and FIG. 9 an exploded view in perspective of the film transfer apparatus shown in FIG.  8 . 
     The conventional film transfer apparatus  01  is provided with a cartridge unit  01  and a case body  03 . 
     The cartridge unit  02  serves as a cover and is slightly laterally elongated, i.e., elliptic in a front elevation. The cartridge unit  02  is provided at one lateral end of a front side-opened, flat, case member  04  thereof with a cutout hole  05  as a window-like hole, from which a transfer head  06  is projected. In the case member  04 , a feed reel  07  and a take-up reel  08  are provided laterally spaced from each other. A portion of a coiled transfer tape  09  wound around the feed reel  07  and drawn out therefrom is reversed at a tip  06   a  of the transfer head  06  and then taken up around the take-up reel  08 . 
     The case body  03  is formed of a front-side opened, flat case member  010  having substantially the same contour in a front elevation as the cartridge unit  02 , but the contour of the case body being slightly larger than that of the cartridge unit. The case member  010  is provided at one lateral end thereof with a cutout hole  011  as a window-like hole. In the interior of the case member, a feed gear  012  and a take-up gear  013  are arranged laterally spaced from each other, both meshing with an intermediate gear  014 . These gears  012 ,  013  are adapted to be rotated in the same direction. 
     The positions, shapes and sizes of the two cutout holes  05 ,  011  are determined so that the cutout holes are aligned with each other when the cartridge unit  02  and the case body  03  are engaged with each other as will be described later. 
     To obtain the assembled film transfer apparatus  01 , the cartridge unit  02  and case body  03  are disposed the open sides thereof opposite to each other, and a shaft  015  in the center of the feed gear  012  is inserted into a shaft cylinder  016  in the center of the feed reel  07  with a shaft  017  in the center of the take-up gear  013  into a shaft cylinder  018  in the center of the take-up reel  08 . The transfer head  06  projects out from the cutout holes  05 ,  011  of the mutually aligned cartridge unit  02  and case body  03 , and the cartridge unit  02  and case body  03  are thereby engaged with each other for forming one body. 
     In this film transfer apparatus  01 , the shaft  015  in the center of the feed gear  012  and the shaft  017  in the center of the take-up gear  013  are inserted into the shaft cylinders  016 ,  018  of the feed reel  07  and take-up reel  08  respectively. The film transfer apparatus is operated as follows. 
     When the film transfer apparatus is moved rightward in FIG. 8 as the transfer head  06  is pressing against a surface of a sheet, the transfer tape  09  slides on the tip  06   a  of the transfer head  06  and a portion of the transfer tape  09  which is wound like a coil around the feed reel  07  is turned. A turning force is transmitted to the feed gear  012  via the shaft  015  inserted in the shaft cylinder  016  of the feed reel  07 , and further to the take-up gear  013  operatively connected to the feed reel  07 . 
     The turning force is then transmitted to the take-up reel  08  via the shaft  017  in the center of the take-up gear  013  and the shaft cylinder  018  in which the shaft  17  is inserted. 
     Owing to the turning force thus transmitted, the portion of the coiled transfer tape  09  on the feed reel  07  which is drawn therefrom is reversed at the tip  06   a  of the transfer head  06  and then taken up around the take-up reel  08 . 
     To be precise, in an initial stage of a film transfer operation, the diameter of the coiled transfer tape  09  on the feed reel  07  is large, and that portion thereof taken up around the take-up reel  08  is small. However, as the transfer tape is used, the diameters of the coiled transfer tape on the feed reel  07  and take-up reel  08  are gradually reversed. 
     A compensation of the differing rotation ratio of the feed reel  07  to the take-up reel  08  is made by interposing a resistance member, for example, a suitable spring and a ring-shaped material between the shaft cylinder  016  of the feed reel  07  and the shaft  015  in the center of the feed gear  012 , or between the shaft cylinder  018  of the take-up reel  08  and the shaft  017  in the center of the take-up gear  013  so that the shafts  015 ,  017  and shaft cylinders  016 ,  018  are rotated relatively with a low resistance generated therebetween. 
     In order that an operator cannot move the film transfer apparatus reversely, a reverse rotation preventing mechanism is usually provided on the take-up reel  08  so that the transfer tape  09  is not drawn from the take-up reel  08 , and shaking of the apparatus during a transfer tape operation does not cause the transfer tape  09  on the take-up reel  08  to be turned back. 
     As a device for preventing a reverse rotation of the take-up reel  08 , a ratchet mechanism is disclosed, for example, in the Japanese patent laid-open document No. 104563/1997. 
     Namely, in the conventional apparatus according to FIGS. 8 and 9, a reverse rotation preventing annular toothed member  019  coaxial with the take-up gear  013  combined in one body with the shaft  017  supporting the take-up reel  013 , and an elastic plate type claw member  020  directed from a suitable portion of the take-up gear  013  toward the annular toothed member  019  are provided on an inner surface of the case body  03 , the claw member  020  being engaged with the annular toothed member  019  in a reverse rotation preventing manner. 
     However, when the annular toothed member  019  or the plate type claw member  020  of this conventional reverse rotation preventing mechanism are worn out or bent as these parts are used, resulting in that the functions thereof becoming incomplete, it is necessary to remove the cartridge unit  02  from the case body  03 , renew the case body  03  combined with the annular toothed member  019  in one body, or the take-up gear  013  provided with the claw member  020 , and then put the case body  03  and cartridge unit  02  together again. 
     Such operations are troublesome and need delicate carefulness, and various parts scatter and move. Therefore, a user cannot carry out such operations easily at all. 
     OBJECTS OF THE INVENTION 
     The present invention has been made to overcome the above-mentioned inconveniences. Namely an object of the invention is to provide a film transfer apparatus having a mechanism which is adapted to prevent a reverse rotation of a transfer tape-wound take-up reel and includes a check claw and check teeth, in which the check claw and one of the check teeth can be engaged with each other firmly and reliably. Another object of the invention is to provide a film transfer apparatus in which only the check claw member-carrying parts need to be renewed which can be done easily by a simple operation when the check claw should be broken or deformed resulting in that the functions thereof become incomplete. 
     SUMMARY OF THE INVENTION 
     These and other objects are solved in accordance with the present invention by a film transfer apparatus which comprises a cartridge unit and a case body adapted to be combined with said cartridge unit, and including a feed reel and a take-up reel supported on the case body, around which a transfer tape adapted to be reversed on a transfer head is wound, these reels can be rotated relatively and smoothly irrespective of an increase and a decrease in the amounts of the transfer tape wound around the two reels, and a reverse rotation preventing mechanism. Said mechanism comprises a check pin inserted from the outer side of the cartridge unit into a cylindrical retainer shaft on which the take-up reel is rotatably mounted, combined in one body rotationally with the take-up reel, and engaged in a reverse rotation preventing manner in a tightly winding direction with respect to the cartridge unit. 
     According to an embodiment of the invention the check pin can be provided on an outer circumferential portion of a free end thereof with a slip-off preventing projection capable of being engaged with a shaft hole of the take-up reel supported rotatably on the case body. 
     According to another embodiment of the invention an outer circumferential surface of the check pin and an inner circumferential surface of the shaft hole of the take-up reel can be provided with axially extending locking ribs engageable with each other in a rotational direction thereof. 
     Still according to another embodiment of the invention the cylindrical retainer shaft on which the take-up reel in the cartridge unit is rotatably mounted can be provided on an inner circumferential surface thereof with teeth extending in one circumferential direction thereof, the check pin being provided at the portion of an outer circumferential surface thereof which is opposed to the teeth with a check or locking claw engageable with one of the teeth in a predetermined direction only. 
     Finally according to another embodiment of the invention the check pin can be withdrawn from the cartridge unit by a screw driver. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention as well as embodiments and advantages thereof will now be described with greater detail with reference to the drawings, in which: 
     FIG. 1 is an external view in perspective showing a film transfer apparatus according to an embodiment of the present invention; 
     FIG. 2 is a perspective view showing the film transfer apparatus according to FIG. 1 with a cartridge unit and a case body thereof separated from each other; 
     FIG. 3 is an exploded perspective view of the cartridge unit and case body shown in FIG. 2; 
     FIG. 4 is a longitudinal sectional view taken along the line IV—IV in FIG. 1; 
     FIG. 5 is an enlarged view of a principal portion of what is shown in FIG. 4; 
     FIG. 6 is a horizontal sectional view taken along the line VI—VI in FIG. 5; 
     FIG. 7 is a perspective view of a check pin shown in each of the above drawings; 
     FIG. 8 is a perspective view showing an example of a conventional film transfer apparatus; and 
     FIG. 9 is a perspective view showing a cartridge unit and a case body in a separated state of the conventional apparatus of FIG.  8 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIGS. 1-7 show an embodiment of the present invention. A basic portion of this embodiment does not fundamentally differ from that of the conventional apparatus shown in FIGS. 8 and 9, except for a mechanism for preventing a reverse rotation of a take-up reel. Therefore, the parts of the present embodiment which are identical with those shown in FIGS. 8 and 9 are designated by same reference numerals but numeral  “ 0” has been omitted. 
     In this embodiment, a feed gear  12  has a cylindrical shaft  15  in the center thereof. The cylindrical shaft  15  is fitted rotatably around a cylindrical support shaft  16  projecting from rather the left-of-center of an inner surface of a case member  4  of a case body  3 . 
     An intermediate cylinder  17  is fitted around the cylindrical shaft  15 , and a feed reel  7  is fitted around and supported on the intermediate cylinder  17 . An outer end portion is supported rotatably on a support shaft  18  projecting from the inner surface of the case member  10  of the cartridge unit  2 . 
     A front end portion of a shaft hole  8   a  of a take-up reel  8  is fitted around a short cylindrical shaft  19  projecting from rather the right-of-center of the inner surface of the case member  4  of the case body  3 , while an outer end portion of the shaft hole is fitted around and supported on a retainer shaft  20  projecting from the inner surface of the case member  4  cartridge unit  2 . 
     An intermediate gear  14  is fitted around a mount shaft  21  projecting from the portion of the inner surface of the case member  4  which is between the cylindrical support shaft  16  and the retainer shaft  20 . The intermediate gear  14  meshes with the feed gear  12  and take-up gear  13 . 
     The feed reel  7  is adapted to be rotated with a low resistance with respect to the support shafts  16 ,  18  in the same manner as that of the conventional apparatus. Since details of the feed reel are not in a direct relation with the present invention, a detailed description thereof is omitted. 
     A mechanism for preventing a reverse rotation of the take-up reel  8 , which constitutes the characteristic feature of the present invention will now be described. 
     According to the present invention, the reverse rotation preventing mechanism is formed of number of check teeth provided on the inner surface of the take-up gear, and a check pin capable of being inserted into and withdrawn from the case body, instead of, for example, the plate type claw member  020  projected from the take-up gear  013 , and the annular tooth  019  provided on the case body  03  according to the conventional mechanism. The reverse rotation mechanism in the present invention is designed so as to solve the above-mentioned problems involved with the conventional reverse rotation preventing mechanism. 
     A front end portion of the take-up reel  8  is fitted rotatably around the short cylindrical shaft  19  of the case body  3 , and the cartridge unit  2  in the case body  3 , the case body and cartridge unit being then combined with each other suitably by screws. The retainer shaft  20  in the cartridge unit  2  is thereby opposed coaxially with a front end surface of the short cylindrical shaft  19 . 
     A check pin  23  is then inserted from a stepped hole  22 , which is provided in the cartridge unit  2  coaxially with the retainer shaft  20 , and a diametrically enlarged head portion  24  of the check pin is engaged with the stepped hole  22  with an outwardly directed claw  25  at a front end of the check pin  23  engaging a lower surface of a slip-off preventing projection  26  provided on an inner surface of the take-up reel  8 . 
     Owning to this arrangement, the take-up reel  8  is retained in the cartridge  2  via the check pin  23  in a slip-off preventing manner. 
     In this structure, axially extending locking ribs  27  provided on a required portion of an outer circumferential surface of the check pin  23  are engaged with axially extending locking ribs  28  provided one an inner circumferential surface of the take-up reel  8 , and these two sets of locking ribs are thereby united rotationally. A check claw  29  provided on a neck portion of the outer circumferential surface of the check pin  23 , projecting in the radial direction and extending in one circumferential direction is meshed with one of the cylindrically arranged teeth  30  provided on the whole inner circumferential surface of the retainer shaft  20  of the cartridge unit  2 , and the check pin  23  is thereby held so that the check pin cannot be reversely rotated. 
     Accordingly, the take-up reel  8  is held non-reversely-rotatably via the check pin  23  with respect to the cartridge unit  2  and case body  3 . 
     The objects and effects obtained by the construction mentioned above will be described as follows. 
     After the cartridge unit and case body are combined with each other, or, when these parts are combined with each other, the check pin  23  is inserted from the stepped hole  22 , which is provided in the cartridge unit  2 . The front end portion of the check pin  23  is thereby engaged in a slip-off preventing manner with the take-up reel  8  supported rotatably in the case body. In addition, the axially extending locking ribs  29  provided, for example, on the check pin  23  and in the shaft hole of the take-up reel  8  are engaged with one another, thereby the check pin and the take-up reel are united rationally. Therefore, incorporating the reverse rotation preventing mechanism into the film transfer apparatus can be done simply. 
     An outwardly extending slip-off preventing projection is provided on the front end of the check-pin  23 , and the check pin  23  is inserted from the outer side of the cartridge toward the case body  3 . As a result, the slip-off preventing projection is engaged automatically with the locking projection provided in the shaft hole of the take-up reel supported rotatably on the case body, and the cartridge unit and case body are held in a combined state. The front end portion of the take-up reel is also supported firmly and stably owing to the check pin. 
     Since the outer circumferential surface of the check pin and the inner circumferential surface of the shaft hole of the take-up reel are provided with axially extending locking ribs respectively which can be engaged with one another in the circumferential direction, the check pin and the take-up reel are united rotationally by only inserting the former into the latter. Therefore, it becomes simple to carry out the assembling and disassembling of these parts. 
     Since the reverse rotation preventing check teeth extending in a predetermined direction are provided on the inner circumferential surface of the retainer shaft with the check claw provided on the outer circumferential surface of the check pin, the contact areas of one of these teeth and the check claw become remarkably large as compared with those of the conventional combination shown in FIGS. 8 and 9 of the locking claw, which is formed of the front end portion of the bent member, and annularly arranged teeth. Accordingly, the engagement of a check tooth with the check claw becomes firm and reliable, and the durability of these parts high. This minimizes a fear of the occurrence of a breakage of these parts. 
     When the degree of engagement or the shape of each locking part is determined in advance so that the check pin is disengaged from the retainer shaft and the shaft hole of the take-up reel by inserting a free end portion of a screw driver under a lower surface of the diametrically enlarged head portion of the check pin and then forcing up the same head portion, the check pin can be renewed easily when the locking parts are worn out or deformed. 
     The above description of the preferred embodiments has been given by way of example. From the disclosure given, those skilled in the art will not only understand the present invention and the attendant advantages, but will also find apparent various changes and modifications to the structures disclosed. It is sought, therefore, to cover all such changes and modifications as fall within the spirit and scope of the invention, as defined by the appended claims, and equivalents thereof.