Abstract:
An arrangement for loading a tape from a removable tape cartridge into a take-up reel has a hub filler that is frictionlessly guided from a removable tape cartridge to a take-up reel utilizing a roller element attached to the bottom of the hub filler. The roller element prevents the wearing down of the guide pin and allows for accurate and reliable picking up and dropping off of tape at the tape cartridge.

Description:
This application claims priority from U.S. Provisional Application Ser. No. 60/221,223, filed Jul. 25, 2000, incororated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a method and apparatus for loading and unloading tape from a removable tape cartridge in a tape drive. 
     DESCRIPTION OF RELATED ART 
     Single reel tape cartridges are used to transport and store tape for reel-to-reel tape drives. A single reel tape cartridge is inserted into a tape drive and a mechanism is used to load the end of the tape into a take-up reel from the tape cartridge. Once the end of the tape is loaded into the take-up reel, the tape drive operates as a reel-to-reel tape drive. A motor is coupled to the take-up reel to rotate the take-up reel about the take-up reel axis and another motor is coupled to the single reel tape cartridge to rotate the reel of the tape cartridge about its axis. 
     The tape drive loading mechanism attaches to a tape leader pin, located at the end of the tape contained in the single reel tape cartridge. The hub filler uses a slot in the hub filler for receiving the tape leader pin. The hub filler is coupled to a guide arm that drives the hub filler along a guide rail between the single reel tape cartridge and the take-up reel. An example of a mechanism for driving the hub filler between the tape cartridge and the take-up reel is disclosed in U.S. Pat. No. 6,034,839. 
     FIG. 1 is a view of the tape drive loading mechanism disclosed in U.S. Pat. No. 6,034,839. The hub filler  300  enters into the removable cartridge  210  and attaches to the end of the tape. The hub filler  300  then moves along a guide rail  247 , driven by the guide arm  250 . Typically, the hub filler  300  attaches to the end of a tape in the tape cartridge  210  and the guide arm  250  moves the hub filler  300  along the guide rail  247 , trailing the tape across the read/write head  222  and into the take-up reel  242 . The hub filler  300  comprises a pin (not shown) fixedly attached to the bottom of the hub filler  300  that is in contact with the guide rail  247 . More particularly, the hub filler  300  rides on the top of the guide rail  247  and is guided in the horizontal direction from the removable cartridge  210  to the hub  245  of the take-up reel  242 . When the hub filler  300  enters the removable cartridge  210  to attach the end of the tape, the pin moves snuggly within the guide rail  247  at the cartridge to precisely control the position of the hub filler  300  during pick up of the tape. The tape is attached to the hub filler  300  and the hub filler  300  travels along the guide rail  247  between the removable cartridge  210  and the hub  245 . During this movement, the pin is in contact with the inner surface of the guide rail  247 . The hub filler  300  enters the take-up reel  245  through a channel  244  and into the hub  245  of the take-up reel  242 . 
     FIG. 2 is a top view of the tape drive, depicting the hub filler  300  in the take-up reel  242  with the tape  216  attached. The tape  216  passes across the read/write head  222  and the end of the tape  216  is secured to the take-up reel  242 . The tape drive is then operated by rotation of the take-up reel  242  and the single reel of the cartridge  210  about their respective axes to move the tape  216  across the read/write head  222 . Motors are used to rotate the take-up reel  242  and the single reel of the cartridge  210 , controlling the speed of the tape  216  as it moves across the read/write head  222 . The hub filler  300  pivots on an axle  252  that is coupled to the guide arm  250 . This pivoting is necessary for the hub filler  300  to be guided on the guide rail  247  into the take-up reel  242 . Once the hub filler  300  is in the take-up reel  242 , with the tape  216  attached, the take-up reel  242  rotates to thereby unload the tape from the cartridge  210 . The hub filler  300  rotates with the take-up reel  242  on the axle  252 . The loading mechanism attempts to align the axle  252  axis and the take-up reel  242  axis perfectly. 
     There are some concerns regarding the conventional tape drive loading mechanism described above. As the hub filler moves along the guide rail, only a small surface area of the pin is in contact with the inner surface of the guide rail. Consequently, there may be substantial friction between the guide rail and the pin. As a result, the pin becomes worn down as it travels repeatedly between the tape cartridge and the take-up reel. 
     The wearing down of the pin is a source of several problems in the conventional tape drive loading mechanism. One problem is that the wearing down of the pin reduces the accuracy with which the hub filler can pick up and drop off tape at the removable tape cartridge. The portion of the guide rail that is proximate to the removable cartridge needs to be arranged so the pin fits snugly in the guide rail. This is necessary so that the hub filler is tightly controlled and can accurately and repeatedly pick up the tape from the tape cartridge. However, if the pin is worn down, the pin will not fit snugly in this portion of the guide rail and the accuracy of the hub filler picking up the tape from the cartridge is diminished. This diminished accuracy increases the instances of the tape drive failing to load tape from removable cartridges, which compromises the reliability of the tape drive. Those skilled in the art will appreciate that the reliability of the tape pick-up and tape drop-off mechanism is an important characteristic of tape loading devices. 
     SUMMARY OF THE INVENTION 
     There is a need for a tape drive loading mechanism that guides a hub filler between a removable tape cartridge and a take-up reel substantially without friction. 
     These and other needs are met by embodiments of the present invention, which provide the implementation of a roller in place of the conventional pin at the bottom of the hub filler. More particularly, the present invention relates to a tape loading device for loading tape from a tape cartridge to a take-up reel. The device comprises a hub filler and a means for frictionless guiding of the hub filler between the tape cartridge and the tape-up reel. The hub filler is driven independent of the take-up reel. 
     With the present invention, the roller on the bottom of the hub filler substantially eliminates friction between the hub filler and the guide rail. As a result of this reduced friction, the roller experiences reduced wear. The roller is able to snugly fit within the portion of the guide rail proximate to the removable tape cartridge. The hub filler of the present invention can therefore more accurately pick up and drop off tape from the tape cartridge. 
    
    
     The foregoing and other features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the present invention, taken in conjunction with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a view of a prior art tape drive loading mechanism. 
     FIG. 2 is a top view of the prior art tape drive loading mechanism of FIG.  1 . 
     FIG. 3 is a view of the tape drive loading mechanism of the present invention. 
     FIG. 4 is a view of the hub filler on the guide rail. 
     FIG. 5 is a top view of the tape drive loading mechanism of the present invention. 
     FIG. 6 is a side view of the hub filler entering the take-up reel. 
     FIG. 7 is a side view of the hub filler entering the take-up reel and decoupling from the guide arm. 
     FIG. 8 is a side view of the hub filler completely lodged in the take-up reel. 
     FIG. 9 is a side view of the hub filler in the take-up reel and decoupled from the guide arm. 
     FIG. 10 is a side view of the axle. 
     FIG. 11 is a side view of the shaft in the hub filler for receiving the axle. 
     FIG. 12 is a view of the ramp. 
     FIG. 13 is a bottom oblique view of the hub filler depicting a roller element. 
     FIG. 14 is a cross-sectional view of the hub filler and roller element. 
     FIG. 15 is a cross-sectional view of the roller element. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention relates to an apparatus for loading a take-up reel with tape from a tape cartridge. The tape cartridge of the present invention is a single reel cartridge. Accordingly, it is necessary for the tape drive to load the end of the tape from the cartridge into the take-up reel. A hub filler, which is part of the tape drive, receives the end of the tape from the cartridge. After the hub filler has attached to the end of the tape in the cartridge, usually by attaching to a leader pin that is connected to the end of the tape, the hub filler moves along a guide rail pulling the tape out of the cartridge, across the read/write head, and to the take-up reel. The hub filler is driven independent of the take-up reel. The hub filler comprises a roller element which is in contact with the guide rail and provides for substantial frictionless guiding of the hub filler between the cartridge and the take-up reel. The hub filler enters the take-up reel, with the tape attached, and brings the hub filler to the hub of the take-up reel. Upon the hub filler attaching to the take-up reel, the tape is connected to both the single reel of the cartridge and the take-up reel. The rotation of the two reels controls the movement of the tape across the read/write head and consequently, the reading of the tape. A guide arm moves the hub filler from the cartridge to the take-up reel. The hub filler pivots on an axle as it is driven by the guide arm. As the hub filler enters the take-up reel, the axle decouples from the hub filler. 
     FIG. 3 is a view of the tape drive loading mechanism of the present invention. A single reel tape cartridge  610  is shown in a loaded position in the tape drive. The tape  613  is wound on a reel inside the cartridge  610 . The end of the tape  613  is attached to a leader pin  618 . A hub filler  616  moves along a guide rail  624 , driven by a guide arm  626 , from the cartridge  610  to a take-up reel  614 . The hub filler  616  pivots on an axle  620 . The hub filler  616  is held to the guide rail  624  by pressure from a spring  622  as the hub filler  616  moves along the guide rail  624  between the tape cartridge  610  and the take-up reel  614 . The hub filler  616  also includes a notch  617  that attaches to the leader pin  618  when entering the cartridge  610 . As the hub filler  616  enters the take-up reel  614 , the axle  620  is lifted from the hub filler  616  by a ramp  612 . 
     Other mechanisms can be used to de-couple the axle  620  from the hub filler  616  within the scope of the invention. For example, one embodiment that may be used to de-couple the axle  620  from the hub filler  616  is a spring mechanism that manipulates spring tensions at the take-up reel  614  to lift the axle  620  out of the hub filler  616 . Other embodiments include a snap coupling arrangement and a latch and release arrangement. Still another embodiment that may be used to de-couple the axle  620  is a motor lifting the axle  620  out of the hub filler  616 . The above-described embodiments for lifting the axle  620  out of the hub filler  616  are not exclusive. 
     FIG. 4 is a view of the hub filler  616  on the guide rail  624  between the tape cartridge  610  and the take-up reel  614 . The hub filler  616  is held to the guide rail  624  by the spring  622  disposed around the axle, creating tension between the hub filler  616  and the guide arm  626 . The axle  620  can move in the vertical direction and rotates in a bore of the guide arm  626 . The top of the axle  620  has a portion that is larger than the bore of the guide arm  626 . The guide arm  626  moves in a horizontal plane during travel between the cartridge  610  and the take-up reel  614 . The spring  622  between the guide arm  626  and the hub filler  616  exerts downward pressure (as viewed in FIG. 4) on the hub filler  616 , pressing the hub filler  616  against the guide rail  624 . This ensures that the hub filler  616  stays on the guide rail  624  during travel from the cartridge  610  to the take-up reel  614 . The spring  622  is attached to a notch in the axle  620  and pushes the axle  620  into the hub filler  616 . When the axle  620  is pulled out of the hub filler  616 , the tension of the spring  622  is increased. 
     FIG. 5 is a top view of the tape drive loading mechanism. The single reel tape cartridge  610  is shown inserted in the tape drive. The hub filler  616  is shown entering the take-up reel  614 , but not fully inserted. The axle  620  is shown at the entering position of the ramp  612 . The hub filler  616  travels from the cartridge  610  to the take-up reel  614  along the guide rail  624 , pulling tape from the cartridge  610  across a read/write head  619 . 
     FIG. 6 is a side view of the hub filler  616  entering the take-up reel  614 . The side view of the hub filler  616  shows the axle  620  in a sheath  628  of the hub filler  616 . Since the sheath  628  and the axle  620  are cylindrical, the hub filler  616  is able to pivot about the axle  620  as the hub filler  616  moves along the bends of the guide rail  624 . A small shaft  621  of the axle  620  and a small bore  623  of the sheath  628  fit snugly together, such that the hub filler  616  pivots about the axle  620  and is tightly controlled by the movement of the guide arm  626 . The spring  622  is attached to the axle  620  at a notch  625  in the axle  620 . The other end of the spring  622  presses against the guide arm  626 , creating tension and pushing the axle  620  into the sheath  628  of the hub filler  616 . The axle axis  630  is the axis about which the hub filler  616  pivots during travel along the guide rail  624 . 
     As will be explained in more detail with respect to FIGS. 7-9, the axle  620  is decoupled from the hub filler  616  by the ramp  612 , so that the hub filler  616  can rotate freely on the axis of the take-up reel  614  during winding and unwinding of the tape. The large shaft  627  of the axle  620  is rotatable inside the bore of the guide arm  626 . Above the large shaft  627  of the axle  620  is a top section  629  of the axle  620 . As the hub filler  616  enters the take-up reel  614 , the axle top section  629  contacts the ramp  612  and the axle  620  is lifted out of the hub filler  616 . When the hub filler  616  is not in the take-up reel  614 , the axle  620  is in the hub filler  616  and the hub filler  616  is tightly pivoting on the axle  620 . A small spherical stop  631  interacts with the top of a large bore  635  to limit movement of the axle  620  into the sheath  628 . 
     FIG. 7 is a side view of the hub filler  616  entering the take-up reel  614 . The axle top section  629  and the axle  620  are lifted up the ramp  612  as the hub filler  616  moves into the take-up reel  614  driven by the guide arm  626 . This causes the axle  620  to partially lift out of the hub filler  616 . The small shaft  621  is almost, but not completely, removed from the small bore  623 . The axis  630  of the axle  620  is now closer to the axis  632  of take-up reel  614  than shown in FIG.  6 . 
     FIG. 8 is a side view of the hub filler  616  in the take-up reel  614 . The hub filler  616  is fully inserted in the take-up reel  614  due to the continued movement of the arrangement by the motor and linkage. In the illustrated embodiment, the axle  620  is lifted up by the ramp  612 . A main shaft portion  633 , of larger diameter than small shaft  621 , pushes the hub filler  616  completely into the take-up reel  614  by pushing against one side of the large bore  635 . The small shaft  621  has been completely lifted out of the small bore  623  to de-couple the small shaft  621  from the small bore  623 . This allows some freedom of movement of the axle  620  in the hub filler  616 . The main shaft portion  633  is only able to push the hub filler  616  through contact with the large bore  635  when the small shaft  621  is not de-coupled from the small bore  623 . At this point, the guide arm  626  has pushed the hub filler  616  to the extreme end of the channel in the take-up reel  614 . The axle  620  is still in contact with the hub filler  616  and is therefore not fully de-coupled from the hub filler  616 . The axis  630  of the axle  620  is not aligned with the axis  632  of the take-up reel  614 . In certain embodiments of the invention, the take-up reel  614  will rotate several times while the main shaft portion  633  is still in contact with the large bore  635 . 
     FIG. 9 is a side view of the hub filler  616  in the take-up reel  614  when it is fully decoupled from the guide arm  626 . The axle  620  is now centered in the sheath  628  such that the axis  630  of the axle  620  and the axis  632  of the take-up reel  614  are aligned. Since the guide arm  626  is fully de-coupled from the hub filler  616 , the take-up reel  614  is able to rotate freely around the axis  632 , immune from any small misalignments between the axle axis  630  and the take-up reel axis  632 . This relative immunity helps prevent small speed variations and wearing down of the bearings. 
     In certain embodiments of the invention, the guide arm  626  is driven by a motor (not shown) with an encoder. The motor has encoded positions for positioning of the guide arm  626  throughout the loading and unloading of the tape; such positioning can include attachment of the tape  613  at the cartridge  610 , movement along the guide rail  624  into the take-up reel  614 , the de-coupling movements in the take-up reel  614 , recoupling movements of the guide arm  626  with the hub filler  616 , return of the tape to the cartridge, and detachment movements of the tape from the hub filler  616 . Small misalignments due to the encoded motor position or other mechanical tolerations are immune in the take-up reel  614 , as the axle  620  is de-coupled from the hub filler  616  during rotation of the take-up reel  614  during the reading and writing of the tape  613  in the tape drive. 
     FIG. 10 is a side view of the axle  620 . The axle top section  629  is above the large shaft  627  which is above the notch  625  for the spring. The notch  625  for the spring is above the small spherical stop  631 . The small spherical stop  631  is above the medium shaft  633 . The medium shaft  633  is above the small shaft  621 . The small shaft  621  is above the axle point  637 . 
     FIG. 11 is a side view of the sheath  628  of the hub filler  616 . The large bore  635  is above the small bore  623 . The small bore  623  is above the axle&#39;s point receiver  639 . 
     FIG. 12 is a top perspective view of the ramp  612 . The ramp  612  has a first bore  640  and a second bore  642  for attachment of the ramp  612  above the take-up reel  614 . The ramp  612  has diagonal regions  646  and a plateau region  644 . A channel  648  in the ramp  612  is disposed in the plateau region  644  and between the diagonal regions  646 . As the axle  620  enters the channel  648  of the ramp  612 , the top section  629  of the axle  620  is positioned between the diagonal regions  646  to catch on the ramp  612 . The large shaft  635  travels inside the channel  648  as the axle  620  is lifted out of the hub filler by the ramp  612 . 
     FIG. 13 is an oblique view of hub filler  616  that comprises a roller  652 . The notch  656  of hub filler  616  picks up and drops off tape  613  from a removable tape cartridge  610  that is to be loaded into a take-up reel. The tape  613  in the removable tape cartridge  610  normally comprises a pin attached to the end of the tape  613  to which the notch  656  attaches. The bottom surface  650  of the hub filler  616  rides on top of the guide rail and the roller  652  and roller pin  654  ride inside the guide rail  624  to guide the hub filler  615  smoothly between the removable tape cartridge  610  and the take-up reel  614 . The roller pin  654  couples the roller  652  to the hub filler  616  and also serves as an axis about which the roller  652  rotates. 
     FIG. 14 is a cross-sectional view of the hub filler  616 . Sheath  628  is shown and can be adapted to accommodate an axle  620 , such as shown in FIG. 6, which may de-couple from the hub filler  616  when the hub filler  616  enters into the take-up reel  614 . FIG. 14 also illustrates that the roller  652  surrounds and attaches to the roller pin  654 . The roller pin  654  is fixedly attached to the hub filler  616 . 
     FIG. 15 is an enlarged view of the roller  652  and the roller pin  654  inside guide rail  624 . The roller pin comprises a main shaft  660  and a bottom section  662 . The main shaft  660  serves as an axis about which the roller  652  can rotate. The bottom section  662  serves to attach the roller  662  to the hub filler  616 , without preventing the roller  652  from rotating around the roller pin  654 . One of ordinary skill in the art can appreciate other embodiments of a substantially frictionless guide. Examples are a ball bearing arrangement, a lubricating arrangement, a roller ball arrangement, and other low friction guiding mechanisms. 
     The present invention provides an improved implementation of a hub filler for substantial frictionless guiding the hub filler between a tape cartridge and a take-up reel. In certain embodiments, the roller is attached to the bottom of the hub filler by a roller pin. As the hub filler travels between the tape cartridge and the take-up reel, the hub filler is guided by a guide rail. The hub filler rides on top of the guide rail and the roller is in contact with the inside of the guide rail. The present invention also provides an improve method of loading a tape from a single reel cartridge into a take-up reel. This is accomplished, in part, by a guide arm being de-coupled from a hub filler as it enters a take-up reel. The de-coupling mitigates problems of conventional tape drive mechanisms that result from small misalignments of the axis of the hub filler axle with the axis of the take-up reel. The axle and drive arm are fully de-coupled from the hub filler by the axle by being lifted out of the hub filler, allowing for the take-up reel to rotate freely during winding and unwinding of the tape without interference from the axle. 
     Although the present invention has been described and illustrated in detail, it is to be clearly understood that the same is by way of illustration and example only, and is not to be taken by way of limitation. The scope of the present invention being limited only by the terms of the appended claims.