Abstract:
A tape drive wherein a tape leader from a tape cartridge is urged through a tape path, into a take-up reel, and secured therein without the use of a buckling mechanism or a take-up leader. The take-up reel includes a locking slot defined along the central hub for receiving and locking the leader thereto. As the tape cartridge is inserted into the tape drive, an idle roller moves into position to push the leader against a motorized roller, pinching the tape leader therein between. As the motorized roller rotates, friction between the leader and rollers urges the leader through the tape path and into the take-up reel locking slot. A slight predetermined rotation of the take-up reel secures the leader with a locking member further defined within the locking slot.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to magnetic tape recording. More particularly, it relates to a tape drive having an assembly that eliminates the conventional buckling process, including a buckling mechanism and a take-up leader. 
     BACKGROUND OF THE INVENTION 
     The constantly increasing operational speeds of digital computers are creating a demand for corresponding increases in the data storage capacities of magnetic tape recording and reproducing systems, while maintaining the special requirements of high speed digital tape systems. As shown in FIG. 1, a typical single reel magnetic tape drive  10  includes a baseplate  11 , a take-up reel  15 , a take-up leader  50  attached thereto, a read/write head  16 , control circuits (not shown), and an opening  17  defined in a face plate  12  for receiving a tape cartridge  20 . In FIG. 1, the tape drive  10  is shown with the tape cartridge  20  and the take-up leader  50  being buckled to a tape leader  30 . In addition, an enclosure covering the top of the drive  10  is removed in FIG. 1 to show the internal components described above. 
     By way of example, a section of a typical take-up leader  50  is shown in FIG. 2 b . The take-up leader  50  includes a nose  51  and neck  55  defined at one end while the other end of the take-up leader  50  is attached to the take-up reel  15 . 
     A typical tape cartridge includes a housing, a supply reel, and a fixed length of magnetic data storage tape attached thereto. A tape leader  30  is attached at one end of the data storage tape while the other end of the tape is attached to the supply reel hub. The cartridge is inserted into the tape drive to store the desired information thereon, and removed and stored in a secure location. A tape cartridge is typically four and one-tenth inches square and one inch high. FIG. 2 a  shows a typical tape leader  30  including a tape leader hoop  39 . The hoop  39  includes a notch area  32 . The hoop  39  is dimensioned to enable the take-up leader nose  51  and a take-up leader neck  55  to pass therethrough. The notch area  32  is further dimensioned to enable the neck  55  to pass therethrough, but prevent the nose  51  from passing therethrough. Thus, in a “buckled” position, the nose  51  is locked against the notch area  32 . 
     As an example, FIG. 3 represents a typical buckling process wherein, as a cartridge  20  is inserted into a tape drive, the tape leader  30  and take-up leader  50  are buckled by a buckling mechanism  25 . The process of buckling/unbuckling the take-up leader  50  with the tape leader  30  is described in detail in commonly assigned U.S. patent application Ser. No. 08/666,854 and is incorporated herein by reference. In addition, commonly assigned U.S. Pat. Nos. 4,662,049 and 4,720,913 provide examples of prior tape buckling arrangements and structures. The contents of which are also incorporated herein by reference. 
     Unsuccessful buckling is a costly source of drive failure. Two of the more common buckling failure modes are “leader runaway” and “half-buckling”. Leader runaway occurs when the leaders are not completely locked, and the take-up leader unbuckles before the tape leader has been pulled into the take-up reel. Half-buckling occurs when only one ear of the take-up leader nose engages and locks to the tape leader hoop and often results in leader runaway. Leader runaway is a failure that cannot be fixed by the end user and requires the tape drive to be returned to the drive manufacturer for repair. Causes of buckling related drive failures are commonly related to the buckling mechanism design and/or the integrity of the take-up leader. 
     Thus, there exits a hitherto unsolved need for an improved, simple and cost efficient tape drive assembly for coupling a tape leader to a tape drive take-up leader that eliminates the use of a buckling mechanism and take-up leader, thereby eliminating the possibility of buckling related drive failures. 
     SUMMARY OF THE INVENTION WITH OBJECTS 
     A general object of the present invention is to provide an improved tape drive that overcomes limitations and drawbacks of the prior art by eliminating the use of a conventional take-up leader and buckling mechanism. 
     More specifically, it is an object of the present invention to provide a tape drive with a take-up reel having features enabling a tape leader to be coupled and locked thereon as well as features enabling the tape leader to be transferred from a tape cartridge to the take-up reel. 
     It is also an object of the present invention to provide a method for urging a tape cartridge tape leader through a tape drive tape path and into locking engagement with a tape drive take-up reel without the use of conventional take-up leader and conventional buckling mechanism. 
     In accordance with principles of the present invention, a leaderless tape drive includes a take-up reel having a locking slot for locking a tape leader thereon and rollers for feeding the tape leader from the cartridge through an enclosed tape path and into a locking position with the take-up reel. A leader guide end member and the enclosed tape path ensure that the tape leader is transferred from the cartridge to the take-up reel despite the possibility of leader curl. As a cartridge is inserted into the tape drive, the tape leader is presented in position to be pinched between a motorized roller and an idle roller. As the motorized roller rotates, the idle roller rotates in concert to urge tape leader through the tape path and into the locking slot of take-up reel. Motorized roller stops when a sensor, located adjacent the leader guide end member, senses an indicator (e.g. magnetic indicator), signifying that the tape leader is in position to be locked with take-up reel. A predetermined rotation of take-up reel engages a locking member, defined on the take-up reel hub, with tape leader. 
     These and other advantages of the present invention will become apparent upon reading the following detailed descriptions and studying the various figures of the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of a prior art tape drive. 
     FIG. 2 a  is a top view in elevation of a section of a prior art tape leader. 
     FIG. 2 b  is a top view in elevation of a section of a prior art take-up leader. 
     FIG. 3 represents a prior art buckling mechanism buckling a take-up leader to a tape leader as a tape cartridge is inserted into a tape drive. 
     FIG. 4 a  represents a leaderless tape drive in accordance with principles of the present invention. 
     FIG. 4 b  is a top view in elevation of the take-up reel shown in FIG. 4 a.    
     FIG. 5 represents the tape drive of FIG. 4 a  showing the tape leader prior to insertion into take-up reel. 
     FIG. 6 represents the tape drive of FIG. 4 a  showing a preferred position of the leader guide end after the take-up reel locking member engages take-up leader. 
     FIG. 7 represents the tape drive of FIG. 4 a  showing an alternative position of the leader guide end after the take-up reel locking member engages take-up leader. 
     FIG. 8 represents the tape drive of FIG. 4 a  showing the position of the tape leader prior to rotation of take-up reel. 
     FIG. 9 represents the tape drive of FIG. 4 a  showing the position of a spring loaded arm as tape is wound onto take-up reel. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention described herein relates to a tape drive. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present inventions may be practiced without some or all of these specific details. In other instances, well known structures and/or process steps have not been described in detail in order not to unnecessarily obscure the present invention. 
     FIG. 4 a  is a simplified representation of a tape drive, illustrating the components that are particularly significant to the present invention, including a tape cartridge  20  inserted therein. 
     As shown, the present invention includes a take-up reel  44 , a plurality of roller tape guides  12 , a read/write head  16 , leader feeding rollers  41  and  42 , tape guides  43   a  and  43   b  and tape guide end  47 . 
     As shown in the cutout view of FIG. 4 b , take-up reel  44  includes radial flanges  45 , which extend radially from each end of a central hub  46 . Take-up reel motor  71  engages and drives take up reel  44  in the direction shown by arrow A to transfer the tape from tape cartridge  20  to take-up reel  44  once a cartridge has been inserted. In addition, a supply reel motor (not shown) engages and drives a supply reel in tape cartridge  20  to transfer the tape from the take-up reel  44  back into the cartridge  20 . Proper balance of the opposing torque of the two motors produces the required tension and also produces tape motion either in or out of cartridge  20 . The motors associated with reels are driven by a motor control circuit (not shown) such as the circuit described in commonly assigned U.S. Pat. No. 5,216,656 for “Method for Optimized Tape Tension Adjustment for a Tape Drive”, the disclosure thereof being incorporated herein by reference. 
     A spring loaded arm  48  pivots about a pivot point  48   a , located on hub  46 . Arm  48  is shown in an unbiased (“home”) position. As will be explained below, arm  48  is biased into a “closed” position as tape is wound around take-up reel  44 . Take-up reel  44  also includes a locking slot  66  defined on the hub  46  and adjacent arm  48 . Locking slot  66  is dimensioned to receive tape leader  30 , enabling a leader-locking member  65 , defined preferably as shown in FIG. 4 b , to engage and lock onto leader hoop  39 . 
     In the embodiment of FIG. 4 a , a tape path  62  is defined by six-roller tape guides  12   a,b,c,d,e,f  and tape guide end  47  which provide the path for the tape to travel from the cartridge supply reel, across the read/write head  16 , and onto take-up reel  44 . It is conventionally necessary to constrain the tape  35  against lateral movement as it traverses a face of the read/write head  16  in order to keep the parallel data tracks defined on tape  35  in alignment with transducing elements defined about the head  16 . Accordingly, a preferred embodiment of six roller tape guides is used to constrain 0.5 inch wide tape (of predetermined thickness) in place across the head  16 . Presently preferred embodiments of the rollers  12   a,b,c,d,e,f  are set forth in commonly assigned U.S. Pat. No. 5,173,828 for “Compact Multiple Roller Tape Guide Assembly” and in commonly assigned U.S. Pat. No. 5,414,585 for “Rotating Tape Edge Guide”, the disclosures thereof being incorporated herein by reference. 
     As shown in FIG. 4 a , the tape path  62  is further defined by a plurality of tape path guides  49   a,b,c,d,e . Each of the tape path guides  49   a,b,c,d,e  is defined between adjacent roller tape guides  12   a,b,c,d,e,f  on the opposite side of the tape leader guides  43   a  and  43   b . Thus, tape path guides  49   a,b,c,d,e , leader guides  43   a  and  43   b  and tape guide end  47 , together, provide an enclosed tape path which prevents the tape leader from straying away from the tape path  62  during tape loading. Typically, leader guides  43   a  and  43   b  as well as tape path guides  49   a,b,c,d,e  may be made from polycarbonate or other suitable material and are rigidly attached to the drive  10  using conventional means such as screws, or other suitable means. Those skilled in the art will understand that the shape of leader guides  43   a,b  and the number of tape path guides  49   a,b,c,d,e  will depend on drive design factors such as the number of roller tape guides and the actual layout of the roller tape guides. 
     Since tape leader  30  may curl in the manner shown in FIG. 5, from being wound and stored in tape cartridge  20 , it is possible that leader  30  may veer away from tape path  62  during tape loading, after passing roller tape guide  12   f . Accordingly, leader guide end  47  is provided to prevent such an occurrence and enable tape leader  30  to be successfully fed into take-up reel locking slot  66  during the loading operation. Tape guide end  47  is pivotably biased about one end  47   a  and includes a roller  47   b  rotatably defined about the other end. Roller  47   b  rests on arm  48  when tape is removed from take-up reel  44 , as shown in FIG.  5 . As tape is wound onto take-up reel  44 , leader guide end  47  preferably is biased into a position shown in FIG. 6, i.e. away from the take-up reel hub  46 . Those skilled in the art will understand that the leader guide end  47  may be biased into this position by various known methods e.g. a mechanical arm or a motor coupled to end  47   a . Alternatively, roller  47   b  may remain in biased contact against the tape as the tape is wound on take-up reel  44 , as shown in FIG.  7 . As tape is unwound from take-up reel  44 , leader guide end  47  is driven back to the “home” position shown in FIG.  5 . 
     As shown in FIG. 4 a , motorized roller  41  and idle roller  42  provide mechanical means for urging the tape leader  30  from the cartridge  20  to take-up reel  44 , once the cartridge  20  is inserted into tape drive  10 . Preferably, but not necessarily, a motor (not shown) drives roller  41  while roller  42  remains idle. As shown in FIG. 4 a , roller  42  moves between a first (“home”) position (represented by a dotted line) and a second position (represented by a solid line). When tape cartridge  20  is inserted into tape drive, roller  42  moves from the first position to the second position, pushing tape leader  30  against roller  41 , such that tape leader  30  is pinched therein between. As roller  41  is driven into rotation in the direction shown by the arrow R 1 , idle roller  42  correspondingly rotates in an opposite direction, as shown by arrow R 2 , to urge tape leader  30  through tape path  62  and into take-up reel  44 . 
     As tape leader  30  enters locking slot  66 , a magnetic sensor located in proximity to leader guide end  47  senses an indicator (not shown) defined on the leader  30 . The motor driving roller  41  is then turned off, stopping further advancement of the tape leader  30 , thereby enabling the tape leader  30  to always stop at the same position (represented in FIG. 8) relative to the take-up reel  44 . At this point, roller  42  returns to the home position and roller  41  is freely rotatable. Take-up reel motor  71  then drives take-up reel  44  to rotate a predetermined radian, in the direction shown by the arrow of FIG. 6, such that locking member  65  engages and locks onto leader hoop  39 . As take-up reel  44  continues to wind tape thereon, the tension of the tape  35  overcomes the spring constant of arm  48  such that arm  48  is pivoted against hub  46  as shown in FIG.  9 . 
     In general, the tape  35  may be driven in either forward direction or backward direction to write data onto selected track locations, or to read data from selected data track locations. 
     During an unloading process, supply reel motor (not shown) drives supply reel and transfers the tape  35  from take-up reel  44  back onto the supply reel. As tape leader  30  unwinds from take-up reel, arm  48  and tape guide end  47  return to their respective “home” positions. During the unload process, roller  41  remains idle while roller  42  remains in the “home” position, i.e. away from the tape  35 . The tape  35  is rewound back onto the supply reel before tape cartridge  20  may be released and withdrawn from the tape drive  10 . 
     To those skilled in the art, many changes and modifications will be readily apparent from consideration of the foregoing description of a preferred embodiment without departure from the spirit of the present invention, the scope thereof being more particularly pointed out by the following claims. The descriptions herein and the disclosures hereof are by way of illustration only and should not be construed as limiting the scope of the present invention which is more particularly pointed out by the following claims.