Abstract:
In an interpose lever ( 60 ) for holding in a tape drive ( 10 ) a tape cartridge ( 20 ) formed with a recess ( 21 ) thereon, a movable base ( 11   a ) has a protrusion ( 614 ) to be engaged with the recess to inhibit the tape cartridge from being released. A release arm ( 63 ) is rotatably attached to the base for releasing engagement between the protrusion and the recess. The release arm is urged by a spring ( 64 ) in a predetermined rotating direction. A shaft ( 617 ) is formed integral with the base to serve as a rotation center member of the release arm.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention relates to a tape drive for use in a linear tape storage system represented by DLT (Digital Linear Tape) or LTO (Linear Tape Open) and, in particular, to an interpose lever for holding a tape cartridge (or a tape cassette) in a tape drive.  
           [0002]    A linear tape storage system of the type has been developed as a backup for a computer system. A variety of linear tape storage systems have heretofore been proposed. For example, a digital linear tape drive as the DLT is disclosed in U.S. Pat. No. 5,862,014.  
           [0003]    The digital linear tape drive is adapted to receive a tape cartridge having a single supply reel. The digital linear tape drive includes a take-up reel in the interior thereof. When the tape cartridge is received in the tape drive, a magnetic tape is pulled out from the tape cartridge to be taken up by the take-up reel through a head guide assembly. The head guide assembly serves to guide to a magnetic head the magnetic tape pulled out from the tape cartridge. The magnetic head exchanges information to and from the magnetic head.  
           [0004]    Typically, a tape drive comprises a generally rectangular housing having a common base as disclosed in U.S. Pat. No. 5,793,574 for example. The base has two spindle motors. The first spindle motor has a permanently mounted spool as a take-up reel permanently mounted to the base and dimensioned to accept a magnetic tape streaming at a relatively high speed. The second spindle motor is adapted to receive a removable tape cartridge.  
           [0005]    The tape cartridge is manually or automatically inserted into the drive via a slot formed on a housing of the drive. When the tape cartridge is inserted into the slot, the cartridge is engaged with the second spindle motor. Prior to rotation of the first and the second spindle motors, the tape cartridge is connected to the permanently mounted spool by means of a mechanical buckling mechanism. A number of guide rollers are positioned between the tape cartridge and the permanently mounted spool and guide the magnetic tape as it streams at a relatively high speed back and forth between the tape cartridge and the permanently mounted spool.  
           [0006]    The tape drive further comprises a head assembly. The head assembly is positioned between the spool and the tape cartridge along a tape path defined by a plurality of rollers. During operation of the tape drive, the magnetic tape streams along the tape path between the spool and the tape cartridge, coming into close proximity to the head assembly while streaming. An example of the head assembly is disclosed in U.S. Pat. No. 5,793,574 mentioned above. Japanese Unexamined Patent Publication No. 2000-149491 (JP 2000-149491 A) discloses an example of the tape cartridge to be received in the digital linear tape drive.  
           [0007]    After the tape cartridge is inserted into the tape drive, it is necessary to hold the tape cartridge at a proper position. For this purpose, the tape drive is provided with an interpose lever for holding the tape cartridge. After completion of information exchange upon the magnetic tape, the magnetic tape is rewound into the tape cartridge. Thereafter, by an eject mechanism operated by an operator, the tape cartridge is ejected from the tape drive. In order to eject the tape cartridge, it is necessary to release holding of the tape cartridge by the interpose lever.  
           [0008]    In view of the above, the interpose lever comprises a movable base having a protrusion to be engaged with a recess formed on the tape cartridge, a release arm for releasing engagement between the protrusion and the recess, and a shaft as a separate component to which the release arm is attached to be rotatable with respect to the base.  
           [0009]    However, the above-mentioned tape drive requires the shaft to be provided as another component separate from the base and the release arm. In addition, an E ring constituting a thrust bearing is also required. Thus, the number of components of the interpose lever is increased so that an assembling efficiency is decreased. As a consequence, it is difficult to reduce the cost of the interpose lever.  
         SUMMARY OF THE INVENTION  
         [0010]    It is therefore an object of this invention to provide an interpose lever which can be reduced in number of components.  
           [0011]    It is another object of this invention to provide an interpose lever which can be reduced in number of assembling steps.  
           [0012]    It is still another object of this invention to provide an interpose lever which can reduced in cost.  
           [0013]    It is yet another object of this invention to provide an inexpensive tape drive which can be reduced in number of components and in number of steps.  
           [0014]    According to this invention, there is provided an interpose lever for holding a removable tape cartridge in a tape drive. The interpose lever comprises a movable base having a protrusion to be engaged with a recess formed on the tape cartridge to inhibit the tape cartridge from being released, a release arm rotatably attached to the base for releasing engagement between the protrusion and the recess, urging means for urging the release arm in a predetermined rotating direction, and a shaft formed integral with the base to serve as a rotation center member for the release arm.  
           [0015]    According to this invention, there is also provided a tape drive which comprises a housing having a slot for receiving a tape cartridge containing a tape, an interpose lever as mentioned above, the interpose lever being assembled to the housing, and a tape driving mechanism assembled to the housing for moving the tape in the tape cartridge loaded in the slot. 
       
    
    
     BRIEF DESCRIPTION OF THE INVENTION  
       [0016]    [0016]FIG. 1 is a perspective view of a part of an existing tape drive in a state where an upper cover is removed;  
         [0017]    [0017]FIG. 2 is a perspective view of an interpose lever used in the tape drive illustrated in FIG. 1;  
         [0018]    [0018]FIG. 3 is an exploded perspective view of the interpose lever illustrated in FIG. 2;  
         [0019]    [0019]FIG. 4 is a plan view of the interpose lever illustrated in FIG. 2;  
         [0020]    [0020]FIG. 5 is a sectional view taken along a line V-V in FIG. 4;  
         [0021]    [0021]FIG. 6 is a perspective view of a part of a tape drive according to one embodiment of this invention in a state where an upper cover is removed;  
         [0022]    [0022]FIG. 7 is a perspective view of an interpose lever used in the tape drive illustrated in FIG. 6;  
         [0023]    [0023]FIG. 8 is an exploded perspective view of the interpose lever illustrated in FIG. 7;  
         [0024]    [0024]FIG. 9 is a plan view of the interpose lever illustrated in FIG. 7;  
         [0025]    [0025]FIG. 10 is a sectional view taken along a line X-X in FIG. 9;  
         [0026]    [0026]FIG. 11 is a plan view for describing the relationship between the interpose lever and a ring cam at the start of insertion of a cartridge (or at the completion of ejection);  
         [0027]    [0027]FIG. 12 is a plan view for describing the relationship between the interpose lever and the ring cam at the completion of insertion of the cartridge;  
         [0028]    [0028]FIG. 13 is a plan view for describing the relationship between the interpose lever and the ring cam at the start of loading;  
         [0029]    [0029]FIG. 14 is a plan view for describing the relationship between the interpose lever and the ring cam at the completion of loading; and  
         [0030]    [0030]FIG. 15 is a plan view for describing the relationship between the interpose lever and the ring cam during an ejecting operation. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0031]    In order to facilitate an understanding of this invention, description will at first be made of an existing tape drive.  
         [0032]    Referring to FIG. 1, a tape drive  10 ′ is adapted to receive a removable tape cartridge (not shown) and contains a take-up reel (not shown) therein. The take-up reel may be called a spool. The tape drive  10 ′ comprises a generally rectangular housing  11 ′ having a common base  11 ′ a . The base  11 ′ a  has two spindle motors (not shown). The first spindle motor has a permanently mounted spool or take-up reel permanently mounted to the base  11 ′ a  and dimensioned to accept a magnetic tape (not shown) streaming at a relatively high speed. The second spindle motor is adapted to receive the tape cartridge. The tape cartridge is manually or automatically inserted into the tape drive  10 ′ via a slot  11 ′ b  formed on the housing  11 ′ of the drive  10 ′ in an inserting direction depicted by an arrow A.  
         [0033]    When the tape cartridge is inserted into the slot  11 ′ b , the cartridge is engaged with the second spindle motor in a known manner. Prior to rotation of the first and the second spindle motors, the tape cartridge is connected to the permanently mounted spool by means of a mechanical buckling mechanism (not shown). A number of guide rollers (not shown) are positioned between the tape cartridge and the permanently mounted spool and guide the magnetic tape as it streams at a relatively high speed back and forth between the tape cartridge and the permanently mounted spool.  
         [0034]    The tape drive  10 ′ further has a right side wall or right receiver  11 ′ c  at which an interpose lever  60 ′ is rotatably attached onto the base  11 ′ a . An existing eject mechanism  30 ′ is attached to the one surface of the right receiver  11 ′ c  of the tape drive  10 ′. Above the interpose lever  60 ′, a write protect arm  42 ′ is rotatably attached to be coaxial with a rotation axis of the interpose lever  60 ′.  
         [0035]    Referring to FIGS. 2 through 5 in addition to FIG. 1, description will be made of the interpose lever  60 ′.  
         [0036]    The interpose lever  60 ′ comprises a base  61 ′ having an upper surface  611 ′ and a lower surface  612 ′, a shaft  62 ′, a release arm  63 ′, a spring  64 ′, and an E ring  65 ′.  
         [0037]    The base  61 ′ is provided with a first cylindrical member  613 ′ formed at its one end  61 ′ a  and extending downward from the lower surface  612 ′ to serve as the rotation axis of the interpose lever  60 ′. Furthermore, the base  61 ′ is provided with a protrusion  614 ′ formed at its the other end  61 ′ b  and protruding towards the right receiver  11 ′ c  (FIG. 1). The base  61 ′ is provided with a rod member  615 ′ formed at its general center near to the other end  61 ′ b  and extending upward from the upper surface  611 ′. The base  61 ′ is provided with a trapezoidal engaging portion  616 ′ formed between its center and the other end  61 ′ b  on the side of the right receiver  11 ′ c  and extending downward from the lower surface  612 ′ to engage one end  64 ′ a  of the spring  64 ′ which will later be described. As illustrated in FIGS. 2 and 4, the trapezoidal engaging portion  616 ′ also serves as a stopper for limiting an operation (rotation) range of the release arm  63 ′ which will later be described. Furthermore, the base  61 ′ is provided with a second cylindrical member  617 ′ formed at its general center, having a through hole  61 ′ c  to receive the shaft  62 ′ (which will later be described) inserted therethrough, and protruding downward from the lower surface  612 ′. Around the second cylindrical member  617 ′, the spring  64 ′ (which will later be described) is arranged. The first cylindrical member  613 ′, the protrusion  614 ′, the rod member  615 ′, the trapezoidal engaging portion  616 ′, and the second cylindrical member  617 ′ are formed integral with the base  61 ′.  
         [0038]    The shaft  62 ′ serves as a rotation axis of the release arm  63 ′ (which will later be described). More in detail, the shaft  62 ′ has one end  62 ′ a  penetrating the through hole  61 ′ c  of the second cylindrical member  617 ′ of the base  61 ′. The shaft  62 ′ has the other end  62 ′ b  forming a head portion having a diameter greater than that of the shaft  62 ′. As illustrated in FIG. 5, the head portion  62 ′ b  serves as a supporting portion for rotatably supporting the release arm  63 ′ (which will later be described) on its lower side. The shaft  62 ′ has a narrow portion  62 ′ c  formed in the vicinity of the one end  62 ′ a  and narrower than the diameter of the shaft  62 ′. The E ring  65 ′ is fitted over the narrow portion  62 ′ c  as illustrated in FIGS. 2 and 5. Thus, a combination of the narrow portion  62 ′ c  and the E ring  65 ′ forms a thrust bearing for the shaft  62 ′.  
         [0039]    The release arm  63 ′ comprises a cylindrical portion  631 ′ having a through hole  631 ′ a  for receiving the shaft  62 ′ inserted therethrough, an arm portion  632 ′ formed at a lower end of the cylindrical portion  631 ′ and extending in a radial direction perpendicular to an extending direction of the shaft  62 ′, and a hook-like protruding portion  633 ′ formed at a general center of the cylindrical portion  631 ′ and protruding in the radial direction. The hook-like protruding portion  633 ′ is engaged with the other end  64 ′ b  of the spring  64 ′ which will later be described.  
         [0040]    As illustrated in FIG. 5, the spring  64 ′ is arranged to cover an outer periphery of the second cylindrical member  617 ′ of the base  61 ′ and an outer periphery of an upper end of the cylindrical portion  631 ′ of the release arm  63 ′. As described above, the one end  64 ′ a  of the spring  64 ′ is engaged with the trapezoidal engaging portion  616 ′ of the base  61 ′ while the other end  64 ′ b  is engaged with the hook-like protrusion  633 ′ of the release arm  63 ′. The spring  64 ′ continuously urges the release arm  63 ′ to rotate the release arm  63 ′ around the shaft  62 ′ in a counterclockwise direction E 1 , as illustrated in FIG. 4. Thus, the spring  64 ′ serves as urging means for urging the release arm  63 ′ around the shaft  62 ′ in the counterclockwise direction E 1 .  
         [0041]    If no external force acts upon an end  632 ′ a  of the arm portion  632 ′ of the release arm  63 ′, the arm portion  632 ′ of the release arm  63 ′ is engaged with the trapezoidal engaging portion  616 ′ of the base  61 ′ as illustrated in FIGS. 2 and 4. Thus, the trapezoidal engaging portion  616 ′ inhibits the rotation of the release arm  63 ′ in the counterclockwise direction E 1 .  
         [0042]    On the other hand, if an external force acts upon the end  632 ′ a  of the arm portion  632 ′ of the release arm  63 ′ in a clockwise direction E 2  as illustrated in FIG. 4, the release arm  63 ′ alone is rotated clockwise around the shaft  62 ′ against the urging force of the spring  64 ′. On the contrary, if an external force acts upon the end  632 ′ a  of the arm portion  632 ′ of the release arm  63 ′ in the counterclockwise direction E 1  as illustrated in FIG. 4, the interpose lever  60 ′ as a whole is rotated around the first cylindrical member  613 ′ of the base  61 ′ in a counterclockwise direction E 3  as depicted in FIG. 4 because the rotation of the release arm  63 ′ in the counterclockwise direction E 1  is inhibited as described above.  
         [0043]    When the tape cartridge (not shown) is inserted into the slot  11 ′ b  of the tape drive  10 ′, the protrusion  614 ′ of the base  61 ′ is engaged with a recess (not shown) formed on the tape cartridge. Furthermore, the end  632 ′ a  of the arm portion  632 ′ of the release arm  63 ′ is applied with a clockwise or a counterclockwise force exerted by a cam surface of a ring cam (not shown).  
         [0044]    The above-mentioned interpose lever  60 ′ requires, as different components separate from the base  61 ′, the shaft  62 ′ serving as the rotation shaft for the release arm  63 ′ and the E ring  65 ′ constituting the thrust bearing. Thus, the interpose lever  60 ′ has an increased number of components so that an assembling efficiency is degraded. As a consequence, it is difficult to reduce the cost of the interpose lever  60 ′ and the tape drive  10 ′.  
         [0045]    Next referring to FIG. 6, description will be made of a tape drive according to one embodiment of this invention.  
         [0046]    The tape drive depicted at  10  in the figure is adapted to receive a cartridge (not shown) and contains a take-up reel (not shown) therein. The take-up reel may be called a spool. The tape drive  10  comprises a generally rectangular housing  11  having a common base  11   a . The base  11   a  has a first spindle motor (not shown) and a second spindle motor (not shown). The first spindle motor has a permanently mounted spool (take-up reel) permanently mounted to the base  11   a  and dimensioned to accept a magnetic tape (not shown) streaming at a relatively high speed. The second spindle motor is adapted to receive a removable cartridge. The removable cartridge is manually or automatically inserted into the tape drive  10  via a slot  11   b  formed on the housing  11  of the drive  10  in an inserting direction depicted by an arrow A.  
         [0047]    When the cartridge is inserted into the slot  11   b , the cartridge is engaged with the second spindle motor in a known manner. Prior to rotation of the first and the second spindle motors, the tape cartridge is connected to the permanently mounted spool by means of a mechanical buckling mechanism (not shown). A number of guide rollers (not shown) are positioned between the tape cartridge and the permanently mounted spool and guide the magnetic tape as it streams at a relatively high speed back and forth between the tape cartridge and the permanently mounted spool.  
         [0048]    The tape drive  10  has a right side wall or right receiver  11   c . An interpose lever  60  is rotatably attached onto the base  11   a  on the side of one surface (i.e. on the side opposite to the slot  11   b ) of the right receiver  11   c . The interpose lever  60  is urged by a spring  70  in the manner which will later become clear. An eject mechanism  30  is attached to the one surface of the right receiver  11   c  of the tape drive  10 . Above the interpose lever  60 , a write protect arm  42  is rotatably attached to be coaxial with a rotation axis of the interpose lever  60 .  
         [0049]    Referring to FIGS. 7 through 10 in addition to FIG. 6, description will be made of the interpose lever  60 .  
         [0050]    The interpose lever  60  comprises a base  61  having an upper surface  611  and a lower surface  612 , a release arm  63 , and a spring  64 .  
         [0051]    The base  61  is provided with a first cylindrical member  613  formed at its one end  61   a  and extending downward from the lower surface  612  to serve as the rotation center member or a shaft of the interpose lever  60 . Furthermore, the base  61  is provided with a protrusion  614  formed at its the other end  61   b  and protruding towards the right receiver  11   c  (FIG. 6). The base  61  is provided with a rod member  615  formed at its general center near to the other end  61   b  and extending upward from the upper surface  611 . The base  61  is provided with an engaging protrusion  616  formed between its center and the other end  61   b  on the side of the right receiver  11   c  and extending downward from the lower surface  612  to engage one end  64   a  of the spring  64  which will later be described. Furthermore, the base  61  is provided with a second cylindrical member  617  formed at its general center to serve as a rotation center member or a shaft of the release arm  63  (which will later be described). Thus, the second cylindrical member  613  is used as the shaft for rotating the release arm  63 . Around the second cylindrical member  617 , a cylindrical portion  631  of the release arm  63  (which will later be described) is arranged.  
         [0052]    The base  61  is provided with a locking portion or stopper  618  formed at its center on the side opposite to the right receiver  11   c  (FIG. 6) and protruding downward from the lower surface  612  to limit a rotation range of the release arm  63  (which will later be described) and to lock the release arm  63 , and a supporting portion  619  formed at an end of the locking portion  618  and perpendicularly bent inward therefrom to rotatably support the release arm  63  (which will later be described).  
         [0053]    The first cylindrical member  613 , the protrusion  614 , the rod member  615 , the engaging protrusion  616 , the second cylindrical member  617 , the locking portion  618 , and the supporting portion  619  are formed integral with the base  11 .  
         [0054]    The release arm  63  comprises the cylindrical portion  631  having a through hole  631   a  for receiving the second cylindrical member  617  inserted therethrough, an arm portion  632  formed at a lower end of the cylindrical portion  631  and extending in a radial direction perpendicular to an extending direction of the second cylindrical member  617 , a semicylindrical portion  633  spaced from the cylindrical portion  631  to cover an outer periphery of the cylindrical portion  631 , and a ring portion  634  formed at a general center of the cylindrical portion  631  and protruding outward in a radial direction to connect the cylindrical portion  631  and the semicylindrical potion  633 . Thus, a half ring groove  63   a  is defined between the cylindrical portion  631  and the semicylindrical portion  633  to receive the spring  64  (which will later be described). The ring portion  634  serves as a bottom of the half ring groove  63   a.    
         [0055]    The release arm  63  further comprises a first flange portion  635  formed at an upper end of the semicylindrical portion  633  and protruding outward in the radial direction, and a second flange portion  636  protruding further outward in the radial direction than the first flange portion  635 . As illustrated in FIG. 5, the first flange portion  635  is supported on the supporting portion  619  of the base  61 . In other words, the first flange portion  635  is located between the supporting portion  619  of the base  61  and the lower surface  612  of the base  61 . Thus, a combination of the first flange portion  63  and the supporting portion  619  of the base  61  forms a thrust bearing for the second cylindrical member  617 . On the other hand, the second flange portion  636  is formed at a position such that the second flange portion  636  is engageable with the locking portion  618  of the base  61  as illustrated in FIGS. 9 and 10.  
         [0056]    As illustrated in FIG. 10, the spring  64  is received in the half ring groove  63   a  on the ring portion  634  of the base  61 . As illustrated in FIG. 9, the one end  64   a  of the spring  64  is engaged with the engaging protrusion  616  of the base  61  as described above. The other end  64   b  is engaged with one end face  633   a  of the semicylindrical portion  633  of the release arm  63  as illustrated in FIGS. 7 and 9. The spring  64  continuously urges the release arm  63  to rotate the release arm  63  around the second cylindrical member  617  in a counterclockwise direction E 1  as illustrated in FIG. 9. Thus, the spring  64  serves as urging means for urging the release arm  63  around the second cylindrical member  617  in the counterclockwise direction E 1 .  
         [0057]    If no external force acts upon an end  632   a  of the arm portion  632  of the release arm  63 , the second flange portion  636  of the release arm  63  is engaged with the locking portion  618  of the base  61  as illustrated in FIG. 9. Thus, the locking portion  618  inhibits the rotation of the release arm  63  in the counterclockwise direction E 1 .  
         [0058]    On the other hand, if an external force acts upon the end  632   a  of the arm portion  632  of the release arm  63  in a clockwise direction E 2  as illustrated in FIG. 9, the release arm  63  alone is rotated clockwise around the second cylindrical member  617  against the urging force of the spring  64 . On the contrary, if an external force acts upon the end  632   a  of the arm portion  632  of the release arm  63  in the counterclockwise direction E 1  as illustrated in FIG. 9, the interpose lever  60  as a whole is rotated around the first cylindrical member  613  of the base  61  in a counterclockwise direction E 3  as depicted in FIG. 9 because the rotation of the release arm  63  in the counterclockwise direction E 1  is inhibited as described above.  
         [0059]    When the tape cartridge is inserted into the slot  11   b  of the tape drive  10 , the protrusion  614  of the base  61  is engaged with a recess (which will later be described) formed on the tape cartridge, as will later be described in detail. Furthermore, the end  632   a  of the arm portion  632  of the release arm  63  is applied with a clockwise or a counterclockwise force exerted by a cam surface of a ring cam (which will later be described).  
         [0060]    In the above-mentioned structure of this embodiment, the base  61  of the interpose lever  60  is integral with the second cylindrical member  617  as the rotation axis of the release arm  63  and the supporting portion  619 . As compared with the existing interpose lever  60 ′, the number of components is reduced so that the number of assembling steps is reduced. This makes it possible to reduce the cost of the interpose lever  60 .  
         [0061]    Next referring to FIGS. 11 through 15, description will be made of the relationship between the interpose lever  60  and the ring cam  50 . FIG. 11 is a plan view showing the relationship between the interpose lever  60  and the ring cam  50  at the start of insertion of the cartridge depicted by  20  in the figure as well as the relationship between the interpose lever  60  and the ring cam  50  at the completion of ejection. FIG. 12 is a plan view showing the relationship between the interpose lever  60  and the ring cam  50  at the completion of insertion of the cartridge  20 . FIG. 13 is a plan view showing the relationship between the interpose lever  60  and the ring cam  50  at the start of loading. FIG. 14 is a plan view showing the relationship between the interpose lever  60  and the ring cam  50  at the completion of loading. FIG. 15 is a plan view showing the relationship between the interpose lever  60  and the ring cam  50  during an ejecting operation. The ring cam  50  may be called a loading ring and comprises a circular disc-shaped member. In FIGS. 11 through 15, the eject mechanism  30  of the tape drive  10  has a preselected ejecting amount or stroke of 30 mm.  
         [0062]    As described above, the interpose lever  60  has the protrusion  614  to be engaged with the recess  21  of the cartridge  20  when the cartridge  20  is inserted into the tape drive  10 , and the release arm  63  having the end  632   a  extending towards the ring cam  50  and attached to the interpose lever  60  to be rotatable around the second cylindrical member  617 . The release arm  63  is continuously urged by the spring  64  counterclockwise around the second cylindrical member  617  but is inhibited by the locking portion  618  from counterclockwise rotation beyond the position illustrated in FIG. 11. However, if the end  632   a  of the release arm  63  is applied with a clockwise rotation force, the release arm  63  is rotatable clockwise around the second cylindrical member  617  against the urging force of the spring  64 .  
         [0063]    On the other hand, the ring cam  50  has a cam groove  51  and a cam surface  52  close to the cam groove  51  in the clockwise direction. Before the cartridge  20  is inserted into the tape drive  10 , the end  632   a  of the release arm  63  is faced to the cam groove  51  as illustrated in FIG. 11.  
         [0064]    At first referring to FIGS. 11 and 12, description will be made of an operation of inserting the cartridge  20  into the tape drive  10 .  
         [0065]    When the cartridge  20  is inserted into the slot  11   b  of the tape drive  10  in the inserting direction A, the interpose lever  60  is rotated around the first cylindrical member  613  counterclockwise against the urging force by urging means such as a spring (not shown). When the cartridge  20  is continuously inserted, a front end face  22  of the cartridge  20  is engaged with an engaging portion  311  of the eject mechanism  30 , as illustrated in FIG. 11.  
         [0066]    When the cartridge  20  is inserted further, the interpose lever  60  is rotated clockwise around the first cylindrical member  613  by the urging force of the spring  70  so that the protrusion  614  is engaged with the recess  21  of the cartridge  20  as illustrated in FIG. 7. At this time, the end  632   a  of the release arm  63  of the interpose lever  60  is slightly inserted into the cam groove  51  of the ring cam  50 . Thus, the cartridge  20  is completely inserted into the slot  11   b  of the tape drive  10 . After completion of insertion of the cartridge  20 , a loading operation is carried out. The loading operation is carried out by rotating the ring cam  50  counterclockwise. The ring cam  50  is driven by driving means, such as a motor and a gear train (not shown). The driving means is controlled in its driving operation by a control unit (not shown).  
         [0067]    Next referring to FIGS. 13 and 14, description will be made of the loading operation. When the control unit is informed of the completion of insertion of the cartridge  20  into the tape drive  10  by a detection signal from any detecting means (not shown), the control unit controls the driving means to drive the rotation of the ring cam  50  in a counterclockwise direction depicted by an arrow D 1  as illustrated in FIG. 8. When the ring cam  50  is rotated in the counterclockwise direction D 1 , the cam surface  52  of the ring cam  50  is engaged with the end  632   a  of the release arm  63  of the interpose lever  60 . Then, following the rotation of the ring cam  50  in the counterclockwise direction D 1 , the release arm  63  is rotated clockwise around the second cylindrical member  617  against the urging force by the spring  64 .  
         [0068]    When the ring cam  50  is continuously rotated in the counterclockwise direction D 1 , the cam surface  52  of the ring cam  50  and the end  632   a  of the release arm  63  are disengaged. The release arm  63  is rotated counterclockwise around the second cylindrical member  617  under the urging force of the spring  64  to be returned to its initial position. When the ring cam  50  is rotated by the driving means over a predetermined angle in the counterclockwise direction D 1 , the loading operation is completed. FIG. 9 illustrates the state where the loading operation is completed.  
         [0069]    Next referring to FIGS. 15 and 11, description will be made of an operation of ejecting the cartridge from the tape drive  10 .  
         [0070]    The tape drive  10  has a front bezel (not shown) provided with an eject button (not shown). When an operator operates or presses the eject button, an ejecting request is transmitted to the control unit. In response to the ejecting request, the control unit controls the driving means to drive the rotation of the ring cam  50  in a clockwise direction depicted by an arrow D 2  as illustrated in FIG. 15 over the predetermined angle from the position illustrated in FIG. 14.  
         [0071]    When the ring cam  50  is rotated in the clockwise direction D 2 , the end  632   a  of the release arm  63  of the interpose lever  60  is engaged with the cam surface  52  of the ring cam  50  as illustrated in FIG. 15. As described above, the release arm  63  is inhibited from the rotation around the second cylindrical member  617  in the counterclockwise direction. Therefore, the release arm  63  can not be rotated around the second cylindrical member  617  in the counterclockwise direction. In this event, as illustrated in FIG. 15, the release arm  63  is not rotated but the end  632   a  climbs up over the cam surface  50  to move in sliding contact therewith. As a consequence, the interpose lever  60  itself is rotated around the first cylindrical member  613  in the counterclockwise direction. Thus, as illustrated in FIG. 15, the protrusion  614  of the interpose lever  60  is disengaged from the recess  21  of the cartridge  20 .  
         [0072]    By the above-mentioned disengagement, the eject mechanism  30  makes the cartridge  20  move or slide in a removing direction or an ejecting direction. As illustrated in FIG. 11, an end of the protrusion  614  of the interpose lever  60  is brought into frictional contact with a right side surface  23  of the cartridge  20 .