Abstract:
A tape cartridge includes a single tape reel around which a length of magnetic tape is wound and which is turnably held within a housing. The beginning of the tape is drawn out through an opening formed in the housing by a tape drawing-out member of a recorder. The drawing-out member has an engaging member at the outer end. The housing has a cell in which a hook member to catch an engaging end of a leader tape, when the leader tape holding the beginning of the magnetic tape is used, is detachably fitted and a cell in which a leader member to hold the beginning of the magnetic tape, when the leader member is used, is contained. The housing is made using a mold which forms a cell having a leader member holding the beginning of the magnetic tape or which forms the cell without the leader member.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a single-reel type tape cartridge for use with magnetic recording-reproducing apparatus and, more particularly, to improvements in the tape leader of a tape cartridge of this type. 
     Single-reel type tape cartridges are extensively used in computer backup and other data storage applications for safekeeping. With a tape cartridge of this type, a leader tape or leader member attached to the outer end of a magnetic tape is drawn out by drawing-out means provided in a magnetic recording-reproducing apparatus (hereinafter referred to as a “recorder”) or drive, the tape is led through passages in the recorder, and the tape end is fixed to the hub of another reel normally held within the recorder. On conclusion of recording or playback operation the tape is driven backward and withdrawn into the cartridge, until the leader tape is reset in the original position in the cartridge. 
     Typical of leader members for conventional single-reel type tape cartridges is one (disclosed, e.g., in Japanese Patent Application Kokai No. 58-169380) which comprises a pin, block, etc. secured to a tape end to be caught by a tape drawing-out member of a recorder. Another type uses a leader tape of relatively tough, elastic material which is connected to a magnetic tape end and has a hole at its own outer end adapted to be engaged with a corresponding hook of a drawing-out member of a recorder which too is formed of a relatively tough, elastic material (Japanese Patent Application Kokai No. 10-188520). When the cartridge incorporating the latter is not in use, the leader tape is held within the cartridge housing and the engaging hole of the leader tape is engaged with a hook inside the housing. 
     FIG. 10 is an exploded view of a conventional single-reel type cartridge  103  described in the specification of the above-mentioned Patent Application Kokai No. 10-188520. A housing of the cartridge including an upper casing  101  and a lower casing  102  is shown containing a single tape reel  107  which has an upper flange  104  and a lower flange  105 , the tape reel  107  being normally biased toward the lower door lock member  102  by a compression spring  108 . A leader tape  109  is spliced to the outer end of a length of magnetic tape  106  wound round a hub (not shown) of the upper flange  104  of the tape reel  107 . The tape reel  107  has a bearing (not shown) on a ring which is press fitted in an annular recess (not shown) formed in the center of the upper flange  104 . With a reel shaft (not shown) fitted in the bearing, the reel can revolve around the shaft. The upper flange  104  of the tape reel  107  has a serration  114  formed along its circumference. On the other hand, a pair of brake members  112 ,  113  are provided on the inner surface  101   a  of the upper casing  101  and are normally biased toward the serration  114  by torsion coil springs  110 ,  111 , with cogs  115 ,  116 , respectively, of the brake members  112 ,  112  adapted to be in mesh with the serration to keep the tape reel from revolution when the cartridge is not in use. When the cartridge is on standby the magnetic tape  106  is wound up on the tape reel  107 , and an engaging hole formed at the end of the leader tape  109  is engaged with a hook  117  located close to a side wall of the cartridge housing  103 . An opening through which the magnetic tape  106  is drawn out from the cartridge housing  103  is normally closed by a lid  118  which is openable with respect to the cartridge housing. 
     For use, the cartridge is loaded into a recorder, and the brake members  112 ,  113  are automatically set free and the tape reel  107  is lifted against the urging of the compression spring  108  to a position free to turn. At the same time, the lid  118  is opened by means provided for that purpose in the recorder. 
     The tape drawing-out member on the part of the recorder then enters the housing through the opening to be engaged with the hole of the leader tape  109  and draws out the magnetic tape together with the leader tape  109  in the manner described above, so that the tape is threaded in the route within the recorder. When the cartridge is not in use, the magnetic tape is housed within the cartridge and the leader tape is wound up too, with its engaging hole engaged with the hook  117 . 
     The leader tape  109  is made using a thick spring sheet of tough synthetic resin such as polyethylene terephthalate (PET). As FIGS.  11 ( a ) to  11 ( c ) indicate, a hole  128  is formed at the end of the tape so as to be engaged with a tab  121  (serving as a hook) formed at the end of a tape drawing-out member  122  of the recorder. The hole  128  has an angular cutout  123  to ensure positive engagement with the tab  121 , with a neck of the drawing-out member that supports the tab  121  fitted in the cutout. FIGS.  11 ( a ) to  11 ( c ) show a sequence of the stages in which the drawing-out member  122  is progressively engaged with the leader tape  109  as the drawing-out member enters the cartridge. 
     The tape drawing-out mechanism of the prior art causes the following problem. The tape drawing-out member  122  of the recorder, as shown in FIGS.  11 ( a ) to  11 ( c ), is in the form of a tape connected to a reel provided in the recorder, with the tape end having the tab  121  adapted to be engaged with the hole  128  of the leader tape in the tape cartridge. Since the end portions of the leader tape and the drawing-out member  122  of the recorder are both tape-shaped, they are susceptible to curling. When they both curl, it becomes sometimes impossible for the tape drawing-out member  122  of the recorder to engage the leader tape  109  of the cartridge loaded in the recorder. 
     On the other hand, direct coupling of the end of a magnetic tape to a tough leader member without the aid of a leader tape would stabilize the actions of drawing out and drawing in of the magnetic tape. Such a leader member, as illustrated in FIG. 1, comprises a center pin member  91  in the form of a pin on which a tape end is wound and secured in place by clamping, and a pair of engaging members  92 ,  92  fixed at one ends to the upper and lower end of the pin member  91 . On the sides of the engaging members  92 ,  92  facing each other, there are formed engaging recesses  92 - 1 ,  92 - 2  in mirror symmetry (see FIG. 9) adapted to engage a pin or casing of a recorder. The center pin member  91  is made of metal and the engaging members  92 ,  92  are made of plastic. 
     Users generally desire to enjoy recording and playback with both tape cartridges using a leader tape and a leader member on one and the same drive device. On the other hand, tape cartridge manufacturers commonly desire to minimize the investment in equipment to manufacture the two types of tape cassettes. 
     BRIEF SUMMARY OF THE INVENTION 
     The tape cartridge according to the present invention is one including a single tape reel around which a length of magnetic tape is wound and which is turnably held within a housing in such a manner that the beginning of the tape is drawn out through an opening formed in the housing by a tape drawing-out member of a recorder, said drawing-out member having an engaging means at the outer end, characterized in that the housing has both a cell in which a hook member to catch an engaging end of a leader tape, when the leader tape holding the beginning of the magnetic tape is used, is detachably fitted and a cell in which a leader member to hold the beginning of the magnetic tape, when the leader member is used, is contained. 
     In another aspect the tape cartridge according to the invention includes a single tape reel around which a length of magnetic tape is wound and which is turnably held within a housing in such a manner that the beginning of the tape is drawn out through an opening formed in the housing by a tape drawing-out member of a recorder, said drawing-out member having an engaging means at the outer end, said housing having a cell in which a hook member to catch an engaging end of a leader tape holding the beginning of the magnetic tape is detachably fitted, characterized in that the housing is made using a mold equipped with either a first replaceable mold part for forming a cell in which a leader member holding the beginning of the magnetic tape is contained or a second replaceable mold part that can replace the first mold part but does not form the cell to contain the leader member. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 is an exploded view of a tape cartridge embodying the present invention; 
     FIG. 2 is a plan view of a combined-type upper casing according to the invention; 
     FIG. 3 is a plan view of a combined-type upper casing of the invention, with a hook member fitted in place; 
     FIG. 4 shows, in perspective, a combined-type upper casing of the invention with a hook member,  4 ( a ) as an exploded view and  4 ( b ) as an assembled view; 
     FIG. 5 is a plan view of a combined-type upper casing of the invention, accommodating a leader member; 
     FIG. 6 shows, in perspective, a combined-type upper casing of the invention with a leader member,  6 ( a ) as an exploded view and  6 ( b ) as an assembled view; 
     FIG. 7 is a perspective view of an upper casing made by a mold including a first replaceable mold part according to the invention; 
     FIG. 8 is a perspective view of an upper casing made by a mold including a second replaceable mold part according to the invention; 
     FIG. 9 shows, in perspective, relations between a tape drawing-out member of a recorder of combined type to which the present invention is applicable and the leader tape and the leader member of two different tape cassettes,  9 (   1   ) showing the relation of the drawing-out member to the leader tape and  9 ( b ) the relation to the leader member; 
     FIG. 10 is an exploded view of a conventional tape cartridge; and 
     FIGS.  11 ( a ) to  11 ( c ) show ordinary relations between a conventional leader tape and drawing-out member of a recorder, FIGS.  11 ( a ) to  11 ( c ) showing a sequence of movements of the two members into mutual engagement. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention will be described in detail below in conjunction with some preferred embodiments thereof. 
     FIG. 1 is an exploded view of an embodiment of the invention. 
     Referring to FIG. 1, a tape cartridge according to the invention is shown upside down. It illustrates how the parts look in actual assembled operation. A complete cartridge is loaded, in the regular unreversed posture, in a recorder. The cartridge is similar in construction to the cartridge shown in FIG. 4 excepting the leader member and associated parts. 
     An upper casing  1  and a lower casing  2  are joined close to their comers using setscrews  23  to form a cartridge housing. A reel  3  on which a length of magnetic tape is wound is accommodated in the space inside the housing composed of the upper and lower casings. 
     The reel  3  consists of an upper flange  31 , a hub  33  formed in one piece with the upper flange, and a lower flange  32 . The underside of the hub  33  inward of the core on which the tape is wound is closed and is provided with an annular toothed part  34 . The upper side of the hub  33  constitutes an open recess which contains a rotational reel support  5  composed of a bearing  4  that smoothens the rotation of the reel, a ball  51  in contact with the center of the bearing  4 , and a support member  52  recessed at top to receive the ball. The upper end of the support member  52  is received by a blind hole in the upper casing  1 , and a coiled compression spring  6  loosely fitted around the support member normally urges the bearing  4  and the rotational reel support  5  toward the reel. 
     An irregular surface  35  is formed along the circumference of the upper flange  31 , and there are provided two brake mechanisms each composed of one of a pair of pins  13 ,  14  held upright on two diagonal comers inside the housing, a coiled torsion spring  72 , and a brake member  71  with a bore, the spring and brake member being fitted on the pin. When the cartridge is not in use, the two brake mechanisms co-act to engage the brake members  71  with the irregular surface  35  on the circumference of the upper flange  31  so as to keep the reel from unwanted rotation. 
     The outer end of the tape is fixed to a leader member  9 . The leader member  9  is made up of a center pin  91 , a pair of engaging members  92  fixed at one end to the upper and lower ends of the pin member, and a clamp  93  for clamping the tape end to the pin  91 . The tape end is wound round the center pin  91  and is secured in place with the clamp  93  fitted onto it. The leader member  9  is housed in a recess  11  formed near the inner surface of an opening formed on one side of the housing. 
     On the outer side of the leader member is fitted a turnable door member  81 . The door member  81  is pivotally supported by a pin  15  of the upper casing  1  and is normally biased to a closing position by a torsion coil spring  84  fitted around the pin  15 . When the cartridge is not in use, it is locked by a door lock member  82  under downward urging by a compression spring  83 . A record defeat member  12  is held in a part of one side of the housing, slidably along that side. 
     For a better understanding of the present invention, the description of the cartridge housing according to the invention will be preceded by an explanation of a leader tape type and a leader member type with reference to FIG.  9 . In the illustrated example a tape drawing-out member  122  of a recorder, as shown in FIG.  9 ( a ), has a tab  121  adapted to engage a hole  128  of a leader tape  109 . It also has a pin  125 , as in FIG.  9 ( b ), which has flanges  124  at both ends adapted to fit in engaging recesses  92 - 1 ,  92 - 2  of engaging members  92  of a leader member  9 . The recorder sometimes may use only one of the two leader types. 
     FIG.  9 ( a ) shows the relation between a tape cartridge of the leader tape type and a drawing-out member. The leader tape  109  has a hole  128  formed at its outer end for engagement purposes, and while it is withdrawn in the tape cartridge, the hole  128  receives a hook member  17  (FIGS. 3 and 4) that comes in the passage for the leader tape  109  (as well as the magnetic tape ). When the drawing-out member  122  of the recorder gains entrance into the cartridge to draw out the magnetic tape, the tab  121  formed at the end of the drawing-out member  122  as shown engages the hole  128  of the leader tape  109  to draw out the leader tape  109 . 
     FIG.  9 ( b ) shows the relation between a tape cartridge of the leader member type and a drawing-out member. Here no leader tape is used, and the outer end of the magnetic tape is wound round the center pin member  91  of the leader member  9  and is clamped ( 93  in FIG. 1) securely. While the tape is withdrawn in the tape cartridge, the leader member  9  is housed in the recess  11  provided for that purpose as indicated in FIGS. 5 and 6. When the drawing-out member  122  enters the cartridge to draw out the magnetic tape, the flanges  124  of the pin  125  provided at the end of the drawing-out member as shown engage the recesses  92 - 1 ,  92 - 2  of engaging members  92  of the leader member type, whereby the leader member  9  is pulled out. 
     Now, in connection with FIGS. 2 to  6 , a housing of a tape cartridge embodying the invention will be explained. 
     Referring to FIG. 2, an upper casing  1  is shown with a guide wall  19  formed close to one side wall to draw out a magnetic tape. A hook cell  16  to hold a hook member  17  is formed opposite to the guide wall. A leader member-containing cell  11  into which one of the engaging members  92  of the leader member  9  fits is formed contiguous to an end of the guide wall. The hook member  17  and the leader member-containing cell  11  are alternatively used, depending on the structure of the member of the recorder that draws out the tape from the cartridge. The combined system thus far described in conjunction with FIG. 9 is applicable to tape cartridges using either the leader tape type or leader member type. The tape cartridge itself has an indication of which type it is designed for. 
     The hook cell  16  comprises a continuous surrounding wall forming a generally triangular space in which the hook member  17  fits snugly. When the housing is to be assembled as a leader tape type, as illustrated in FIGS. 3 and 4, the hook member  17  is fitted securely in the cell. A hook  17 - 1  at the end of the hook member  17  projects toward the guide wall  19 , exposing itself partly in the path of the leader tape. 
     On the other hand, the leader member-containing cell  11  is formed contiguous to the guide wall  19 . It is formed away from the path in which the tape travels, lest the cell interfere with the running of the magnetic tape and the movement of the tape drawing-out member of a recorder. The adjoining end of the guide wall  19  extends over a part of the leader member-containing cell  11  to constitute a part of the wall of the cell. When the housing is to be built as one of the leader member type, as shown in FIGS. 5 and 6, one of the engaging members  92  of the leader member  9  that clamps an end of the magnetic tape on its center pin member  91  is fitted in the cell  11 . 
     According to the present invention, as described above, both the cells for the hook member and the leader member are arranged along the path in which the tape travels. Thus one and the same housing serves the combined purpose of the leader member type and the leader tape type. This adds to the economy of cartridge manufacture, since a single mold can be utilized in making cartridges of the two types. 
     Next, referring to FIGS. 7 and 8, another embodiment of the invention will be described. In these figures the identical parts, excepting the portions surrounded by broken lines  200 ,  201 , are the parts of two upper casings molded of plastic by mold parts common to both. 
     In FIG. 7, the portion surrounded by the broken line  201  is a portion formed using a first replaceable mold part. This means that the upper casing  1  shown was made by a mold combining a common mold part and the first replaceable mold part. The first replaceable mold part has a mold cavity contour for forming a leader member-containing cell  11 . In this manner a tape cartridge that can incorporate both the leader tape type and leader member type is provided. 
     Referring to FIG. 8, the portion surrounded by the broken line  200  is a portion formed using a second replaceable mold part. In other words the upper casing  1  shown was made by a mold combining a common mold part and the second replaceable mold part. The second replaceable mold part does not have a mold cavity contour for forming a leader member-containing cell; it simply forms a side wall as an uninterrupted extension of the guide wall. In this manner the upper casing permits the manufacture of a tape cartridge of the leader tape type. 
     Although the construction of the mold is not illustrated, the cavity surface of the mold has a shape complimentary to that of the molded product, and therefore the mold construction should be obvious to those skilled in the art from the foregoing description as well as from the illustrations. 
     As has been described, the present invention renders it possible to manufacture tape cassettes at lower cost than heretofore because it advantageously permits the production of cartridge housings with alternate tape drawing-out types, (1) housings combining the leader tape type and the leader member type and (2) housings that selectively use the leader tape type alone or combine the leader tape and leader member types.