Ulllted States Patent
`[19]
`[11] Patent Number:
`5,927,633
`
`McAllister
`[45] Date of Patent:
`Jul. 27, 1999
`
`U5005927633A
`
`[54] RESILIENTLY BIASED PARKING SEAT FOR
`RECEIVING THE LEADER PIN OF A
`SINGLE REEL TAPE CARTRIDGE
`.
`.
`Jeffrey 8' McAlllster, B01se, ld~
`
`Inventor:
`
`l75l
`
`[73] Assignee: Hewlett-Packard Company, Palo Alto,
`Calif.
`
`[21l APPI- NOJ 09/121,273
`[22]
`Filed‘
`Jul 22 1998
`'
`I
`’
`Int. Cl.6 ................................................... GllB 23/037
`[51]
`[52] US. Cl.
`...................................... 242/3482; 242/3324
`[58] Field of Search ................................. 242/348, 348.2,
`242/2483, 332.4, 332.7, 332.8
`
`[56]
`
`References Cited
`
`US' PATENT DOCUMENTS
`6/1981 Anagnostopoulos.
`4,273,454
`10/1984 Dalziel et a1.
`....................... 242/3324
`4,477,851
`9/1985 Hart .
`4,542,864
`8/1989 McGee .
`4,852,825
`FOREIGN PATENT DOCUMENTS
`
`1 547 015
`
`10/1969 Germany ............................ 242/3324
`
`Primary Examiner—John P. Darling
`
`[57]
`
`ABSTRACT
`
`A resilient parking seat for the leader device of a single reel
`tape cartridge is provided which works in combination with
`a tape supply reel lock having discrete, evenly-spaced lock-
`ing positions. The parking seat includes a cradle assembly,
`which is shaped to receive the leader device. The cradle
`assembly, mounted in a recess within a tape access port in
`the cartridge housing,
`is linearly slidable between two
`limiting positions along a path that is approximately coin-
`cident with that of the tape as it enters or exits the cartridge
`housing. The cradle assembly is biased with at least one
`biasing spring in a tape exiting direction, so that when the
`tape is completely rewound into the cartridge, the leader
`device enters the access port, makes contact with the cradle
`assembly, causing the cradle assembly to slide within the
`recess and compress the biasing spring(s). Compression of
`the biasing spring(s) is maintained by a rewind mechanism
`of a tape drive as the reel lock is engaged. Linear travel of
`the cradle assembly is sufficient to overcome any slack that
`might ordinarily be introduced into the tape by disengaging
`the cartridge from the rewind mechanism. The resilient
`parking seat also reduces the shock forces to which the tape
`is subjected as the leader device slams into the parking seat
`at the end of a rewind operation. A large portion of the
`momentum of the spinning supply reel
`loaded with the
`rewound tape and of the leader device is absorbed by
`compressing the biasing Spring(S), momentum which would
`otherwise be absorbed by stretching the tape.
`
`20 Claims, 6 Drawing Sheets
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`SONY Exhibit 1008
`SONY Exhibit 1008
`SONY v. FUJI
`SONY V. FUJI
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`5,927,633
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`1
`RESILIENTLY BIASED PARKING SEAT FOR
`RECEIVING THE LEADER PIN OF A
`SINGLE REEL TAPE CARTRIDGE
`
`This application is related to US. utility patent applica-
`tion Ser. No. 09/033,352, filed on Mar. 2, 1998, and to US.
`design patent application Ser. No. 29/084,903, filed on Mar.
`11, 1998.
`
`FIELD OF THE INVENTION
`
`This invention relates to data storage tape cartridges and,
`more specifically, to the parking of a data storage tape in a
`single reel cartridge before the tape cartridge is removed
`from the tape drive.
`BACKGROUND OF THE INVENTION
`
`The evolution of tape backup systems is similar to that of
`many computer components. At first, reel-to-reel systems
`(somewhat similar to old reel-to-reel audio tape recorders)
`were used to store data. In 1972, more than a decade before
`the introduction of the first IBM-PC,
`the 3M Company
`introduced the first quarter-inch tape cartridge designed for
`data storage. This pioneering cartridge from 3M was a
`dual-reel design. Somewhat more than a decade later, the
`first single reel tape cartridges and single reel cartridge tape
`drives were introduced.
`
`Most single reel cartridges include a housing which
`encloses a single supply reel onto which a magnetic tape is
`wound. A terminator, or leader, device is generally attached
`to the free end of the magnetic tape. The leader device has
`a cross section that is larger than that of the tape, allowing
`it to be captured by a leader device seat within the housing
`whenever the tape is rewound onto the supply reel. The
`leader device may be in the shape of a block, a sphere, a
`spheroid, a rod or even a T-shaped tab. The reel has a central
`drive hub which is exposed by a central aperture within the
`housing. When the cartridge is inserted in a tape drive, a
`drive spindle engages the drive hub, and a priming mecha-
`nism within the drive captures a free end of the tape and
`either directly or indirectly threads the tape over the tape
`drive’s read/write head and attaches the tape to a take-up reel
`located within the tape drive. The tape is then accessed (i.e.,
`read and written to) in a conventional manner. After the tape
`has been accessed by the drive, the magnetic tape is rewound
`onto the cartridgc’s singlc supply rccl and detached from the
`take-up reel so that the cartridge may be removed from the
`drive. This is in contrast to the dual reel tape cartridges
`which have both a supply reel and a take up reel incorpo—
`rated therein.
`
`Single reel tape cartridges are becoming a popular alter-
`native to dual reel cartridges because the single reel car-
`tridges are less expensive to manufacture and require less
`storage space. In fact, single reel cartridge drives are rapidly
`becoming the preferred design for high-capacity tape-based
`data backup solutions for data processing systems. Using
`600 meters of 12.7 mm-wide tape wound on an 100 mm
`diameter rccl, a single rccl cartridgc can store approximately
`100 gigabytes of uncompressed data and approximately 200
`gigabytes if compressed.
`There are several disadvantages associated with the use of
`single reel tape cartridges. One disadvantage is increased
`tape drive complexity. Unlike a dual reel cartridge in which
`the magnetic tape is permanently attached to both reels, a
`single reel cartridge must be “primed”, just like the reel-to-
`reel audio tape player/recorders that were popular forty
`years ago. That is,
`the leader device must somehow be
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`grasped, and the attached magnetic tape threaded over the
`read/write head, and attached to the take-up reel. Whereas
`for the reel-to-reel machines, this process was accomplished
`by human dexterity, the process for single reel cartridges is
`performed automatically by a priming mechanism. The
`operation of a priming mechanism used for a preferred
`embodiment of a single reel cartridge will subsequently be
`briefly described. Because of the non-trivial nature of these
`tasks, the priming mechanism is a complex device which
`increases the cost of the tape drive and adds another failure
`mode to the tape system.
`Another problem single reel drives have is that they place
`stress on the tape when it is rewound and the leader device
`is parked. This is because the cartridge reel when completely
`loaded with the rewound tape has considerable angular
`momentum. Thus, when the leader device is caught as the
`tape becomes fully rewound with the cartridge reel spinning,
`the magnetic tape may be stretched or broken by the shock
`loading. Consequently, most single reel tape drives currently
`in production dramatically reduce rewind speed as the tape
`approaches the fully rewound condition in order to reduce
`the angular momentum to safe levels which will not break or
`permanently stretch the tape.
`Another problem related to the use of single reel tape
`cartridges involves the need to maintain tension on the tape
`after the cartridge has been removed from the tape drive
`mechanism]. Although reel
`locking mechanisms have
`reduced the amount of slack that can be introduced, tension
`cannot be maintained because the locking mechanisms gen-
`erally in use are not rotationally continuous, but have a
`plurality of discreet
`locking positions.
`If tension is not
`maintained, the outer layers of tape will become loose and
`may slip. Not only will this slippage result in a certain
`amount of tape feed misalignment, but contact between tape
`edges and the supply reel flange may cause increased tape
`wear and some additional friction as the tape is unwound
`from the supply reel.
`A single reel tape cartridge 10 is depicted in FIGS. 1 and
`2. The cartridge 10 includes a housing 11 which encloses a
`tape supply reel. A sliding door 12 covers the tape access
`port and leader device parking place (neither of which are
`shown in this view). The door 12 slides to the side in order
`to expose the tape access port when the single reel tape
`cartridge 10 is inserted in a tape drive. A driven gear (also
`referred to herein as a driven coupler) 21 is incorporated in
`the central hub of the tape supply reel (the tape reel itself is
`enclosed by the housing 11 and is not visible in this view).
`The driven gear 21 engages a driver gear (also referred to
`herein as a driver coupler) which is part of the tape drive (the
`driver gear is not shown). It will be noted that the driven gear
`has a central aperture 22 through which a reel
`locking
`mechanism within the cartridge 10 may be released.
`Although driver and driven gears are utilized for imparting
`rotary motion to the supply reel other types of couplers using
`splines or friction may be substituted for the geared type.
`A reel locking mechanism 30 is depicted in a cut-away
`view of the single reel cartridge of FIGS. 3 and 4. The driven
`gear 21 is rigidly affixed to the reel 31. The backside of the
`driven gear 21 (i.e., the side which does not engage the
`driver gear) has a first locking gear 32 rigidly affixed thereto.
`The first locking gear 32, which has a first set of teeth 33, is
`centered about the reel’s axis of revolution 38, and rotates
`with the reel 31 and driven gear 21. The first set of teeth 33
`of the first locking gear 32 engage a second set of teeth 34
`on a second locking gear 35 when the driven gear 21 is
`decoupled from the driver gear 36 of the tape drive. The
`second locking gear 35, which is non-rotatable and slidably
`
`

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`5,927,633
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`3
`mounted on a pedestal 37 rigidly affixed to the drive housing
`11, is resiliently biased toward the first locking gear 32 along
`the rotational axis 38 of reel 31. Resilient biasing of the
`second locking gear may be provided by a coil spring (not
`shown) within the pedestal 37 which is compressed between
`the pedestal and the second locking gear 35. When the driver
`gear 36 of the tape drive engages the driven gear 21, a
`projection 39 on the top of the driver gear 36 passes through
`a center aperture in the driven gear 21, lifting the second
`locking gear 35 a distance at least sufficient to disengage its
`teeth from those of the first locking gear 32. Each tooth of
`the first and second sets of teeth (33 and 34, respectively) are
`preferably ramp shaped so that when the teeth of both
`locking gears are engaged, rotation of the reel 31 in an
`unwind direction is blocked. At least one of the locking
`gears must have a full complement of equally-spaced teeth.
`As there are a finite number of teeth on each locking gear,
`the reel 31 may be locked in a plurality of positions equal to
`the number of teeth on a locking gear having a full-
`complement of teeth. The angular distance between each
`locking position will be equal to 360 degrees divided by the
`total number of locking positions. For example, if each of
`the locking gears has a total of 60 teeth, the reel may be
`locked in 60 difierent angular positions, six degrees apart, as
`it is rotated. Thus, when the tape is rewound completely and
`still taught, that same degree of tautness will remain only if
`the teeth of both locking gears are perfectly aligned with one
`another. If the gears are not perfectly aligned, up to six
`degrees of slack are possible. The linear slack in the tape
`may be readily calculated. For example,
`the maximum
`amount of slack in a tape on a reel having an outermost loop
`with a diameter of 100 mm and a circumference of approxi-
`mately 314 mm will be about 314/60, or about 5 mm.
`Although the amount of tape slack will average half that
`amount, or about 2 mm, the system must be able to cope with
`the worst-case scenario of 5 mm. Tape slack of 5 mm may
`cause significant
`tape slippage. One might reasonably
`assume that by increasing the number of teeth on the locking
`gear, tape slack could be reduced. Although this is theoreti-
`cally correct,
`there is a limit
`to the number of teeth
`(particularly plastic teeth) that may be placed on the locking
`gear before the teeth are likely to strip and become useless
`with repeated use.
`What is needed is an improved tape leader device parking
`mechanism which will not only reduce stresses on the
`magnetic tape or on a leader tape attached to the magnetic
`tape when the leader device is captured in its parking place
`under rewind conditions, but which will also maintain
`tension on the tape after it has been rewound into the
`cartridge, removed from the tape drive, subjected to han-
`dling which may be not particularly gentle, and stored for
`extended periods of time in varying temperature conditions.
`SUMMARY OF THE INVENTION
`
`The present invention provides a resilient parking seat for
`the leader device of a single reel tape cartridge. The inven-
`tion works in combination with a reel lock having discrete
`evenly-spaced locking positions. For a preferred embodi-
`ment of the invention, the leader device is a pin shaped like
`a dumbbell, and the parking seat includes a cradle assembly
`that is shaped to receive the ends of the pin, and which is
`slidably mounted in a recess within a tape access port in the
`cartridge housing. The cradle assembly is slidable between
`two limiting positions along a path that is largely coincident
`with movement of the tape as it enters or exits the cartridge
`housing. The cradle assembly is biased with at least one
`biasing spring in a tape exiting direction, so that when the
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`tape is completely rewound into the cartridge, the leader pin
`makes contact with the cradle assembly, causing the cradle
`assembly to slide within the recess so that
`the biasing
`spring(s) is (are) compressed.
`During a rewind operation, the resilient parking seat is in
`a state of compression when the tape is fully rewound and
`the leader pin is seated in the cradle assembly. Before the
`coupler of the cartridge is disengaged from the rewind
`mechanism, the reel lock is engaged while the parking seat
`is in a compressed state. The travel of the parking seat is
`sufficient to overcome any slack that might ordinarily be
`introduced into the tape by the disengaging the coupler from
`the rewind mechanism.
`
`In addition to preventing the rewound tape from becom-
`ing slack, the resilient parking seat has the added advantage
`of cushioning the shock to which the leader tape is subjected
`as the leader pin slams into the parking seat at the end of a
`rewind operation. A large portion of the momentum of the
`spinning supply reel loaded with the rewound tape and of the
`leader pin is transferred to the biasing spring(s) as they
`compress rather than to the leader tape as it stretches, and the
`kinetic energy associated with the reel, tape and leader pin
`is dissipated by friction as the cradle assembly slides within
`the recess. Although some bounce is inevitable as the leader
`pin enters the cartridge recess and slams into the resilient
`seat, the bouncing effect assists in the frictional dissipation
`of the kinetic energy. This shock absorbing feature greatly
`reduces the tendency of the tape to break and stretch during
`rewind operations, and permits higher tape leader parking
`speeds.
`
`DESCRIPTION OF THE DRAWINGS
`
`The items depicted in the drawings have been simplified,
`and may not be drawn to scale. The drawing figures are
`intended to show mainly those features associated with the
`invention. For the sake of clarity, many features required for
`tape cartridge functionality have been omitted. However,
`those having ordinary skill in the art of tape cartridge design
`and manufacture should have little difficulty incorporating
`the invention into existing single reel tape cartridge designs.
`FIG. 1 is a perspective view of a single reel tape cartridge,
`showing the top and sides thereof;
`FIG. 2 is a perspective view of a single reel tape cartridge,
`showing the bottom and sides thereof;
`FIG. 3 is a perspective cut-away view of a single reel tape
`cartridge having an internal reel locking mechanism which
`is engaged to lock the reel;
`FIG. 4 is a perspective cut-away view of the single reel
`tape cartridge of FIG. 3, but with the internal reel locking
`mechanism disengaged to free the reel;
`FIG. 5 is a cut-away top plan view of a single reel tape
`cartridge drive having a single reel tape cartridge inserted
`therein;
`FIG. 6 is a cut-away top plan view of a single reel tape
`cartridge which incorporates the invention;
`FIG. 7 is a front elevational view of a cradle assembly in
`which is seated a leader pin;
`FIG. 8 is a top plan view of a cradle assembly in which
`is seated a leader pin and a primer block about to be attached
`to the leader pin,
`FIG. 9 is a side elevational View of both a primer block
`and cradle assembly in which is seated a leader pin that is
`attached to an end of the magnetic tape; and
`FIG. 10 is a close-up view of the region of FIG. 6 which
`incorporates the invention.
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`

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`5,927,633
`
`5
`DETAILED DESCRIPTION OF THE
`IN VEN 'I‘ION
`
`FIGS. 1 through 4 depict a single reel tape cartridge which
`was developed by the Hewlett-Packard Company, and which
`is the subject of the pending patent applications referenced
`at the beginning of this document.
`The present invention provides a resilient parking seat for
`the leader pin of a single reel tape cartridge. The resilient
`parking seat, which includes a resiliently-biased leader pin
`cradle assembly linearly movable between two positions,
`works in combination with a reel
`lock having discrete
`evenly-spaced locking positions,
`to prevent slack in the
`rewound tape during storage. The resilient parking seat also
`reduces stress on the tape as the leader pin enters the leader
`pin storage recess in the cartridge housing during rewind
`operations.
`As the present invention can be readily incorporated into
`the single-reel tape cartridge of FIGS. 1 through 4, common
`numbering of like components in FIGS. 1 through 6 and 10
`has been employed.
`Referring now to FIG. 5, a single reel tape cartridge 10
`which incorporates the invention has been inserted in a tape
`drive 51. It should be understood that no attempt has been
`made to show all the features of either the tape drive 51 or
`the tape cartridge 10. The purpose of this drawing, which is
`primarily a schematic diagram, is to show the path of the
`tape 53, which leads from the supply reel 31 of the cartridge
`10, around a first idler pulley 52, over a read/write head 54,
`around a second idler pulley 55, to the take-up reel 56 of tape
`drive 51. The take-up reel 56 has a hub 57. The hub 57 is
`generally cylindrically shaped, but having a flattened side.
`The flattened side is shaped to receive a primer block 59
`which has both a locator pin 60 and a leader pin 61 clipped
`thereto. The flanges 58 of take-up reel 56 has locating
`grooves 62 which guide the ends of the locator pin 60 and
`the ends of the leader pin 61, directing the primer block 59
`to its proper location against the flattened side of hub 57 as
`the tape is wound onto the take-up rel 56. The primer block
`59 is shaped so that it completes the cylindrical shape of hub
`57 when attached to the flattened side thereof. Because this
`
`drawing figure may be considered a schematic diagram, the
`driven gear 21 is depicted as though made of transparent
`material. Ordinarily, it would appear as shown only in a
`bottom view. No attempt has been made to depict the tape
`priming mechanism, the tape drive electronics, the controls,
`the driver gear 36 which engages the driven gear 21, or many
`other hardware features essential for tape drive operation.
`The central aperture 22 in the driven gear 21, through which
`the projection 39 on the driver gear 36 lifts the second
`locking gear 35 (please refer to FIGS. 3 and 4) and thereby
`disengages the reel locking mechanism 30, is clearly visible
`in this view.
`
`Referring now to FIGS. 6, 7 and 10, the single reel tape
`cartridge 10 of FIG. 5 is shown separate from the tape drive
`51. The cartridge 10 has a supply reel 31 with a driven gear
`21 centrally and axially incorporated therein. Also visible in
`this view are the reel lock release aperture 22, a leader
`device (in this case a leader pin) 61, and a tape access port
`63 within the cartridge housing 11. The access port 63,
`which is a passage way in the cartridge housing roughly
`within the confines of a polygon having apices A, B, C, and
`D, has a slidable access door 12 across the opening 64 of
`access port 63. The cartridge 10 may have a leader tape
`which connects the leader pin 61 to the magnetic tape 53
`(see FIG. 5), which is in turn anchored to the tape supply reel
`31. For a preferred embodiment of the invention, no leader
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`tape is utilized between the magnetic tape 53 and the leader
`pin 61. The leader pin 61 is seated in a cradle assembly 65
`which is linearly movable within a cradle recess 66 between
`a first position 67A and a second position 67B within access
`port 63. The cradle assembly 65 is resiliently biased by a pair
`of compressible coil springs 68 (only one is visible in this
`view) toward the tape access port opening 64. The springs 68
`are compressed between the cradle assembly 65 and the
`cartridge housing 11. It will be noted that the cradle assem-
`bly 65 is notched to receive the leader pin 61. The notches
`69 (only one is visible in this top plan View) prcvcnt sidc
`movement of the leader pin 61.
`For a preferred embodiment of a single -reel tape cartridge
`10 which incorporates the invention, a brief explanation of
`how the priming mechanism works is in order. Referring
`now to FIGS. 7, 8 and 9, the leader pin 61 is generally rod,
`or cylindrically, shaped, having a central portion 71A to
`which the magnetic tape 53 is attached, two reduced diam-
`eter portions 72 on either side of the central portion 71A, and
`two end portions 71B, which are of the same diameter as the
`central portion 71A. Leader devices other than leader pin 61
`are contemplated by this invention. For example, the leader
`device may be block shaped, or the free end of the magnetic
`tape 53 may be reinforced with a capturable T—shaped
`laminar tab. In the latter case, the tape would be attached to
`the vertical portion of the “T”, and the cradle assembly 65
`would capture the horizontal portions of the “T” as the tape
`53 is rewound. A first end of a leader tape 74 is anchored to
`the take—up reel 56 of the tape drive 51 and passes over the
`read/write head 54 of tape drive 51 (see FIG. 5). A second
`end of the leader tape 74 is attached to a primer block 59 that
`has a pair of grooves 77 which are adapted to clip around the
`narrow portions 72 of leader pin 61 as the leader pin 61 is
`being held at both ends 71B by the cradle assembly 65. The
`length of the leader tape 74 is indexed to the diameter of
`take-up reel hub 58 so that as the primer tape 74 winds onto
`the take-up reel 56, the primer block 59 and attached leader
`pin 61 will fit against the flattened side of the reel hub 57.
`After the primer block 59 and attached leader pin 61 are
`fitted to the flattened side of reel hub 57, the magnetic tape
`53 winds around the hub 57 and primer block 59. The
`priming mechanism captures the primer block 59 and
`detaches it from the leader pin 61 whenever the magnetic
`tape 53 is fully rewound into the cartridge 10. When a new
`cartridge is inserted into the tape drive, the priming mecha—
`nism attaches the primer block 59 to the leader pin 61. The
`priming mechanism attaches and detaches the primer block
`59 to and from the leader pin 61 in a direction that is
`generally perpendicular to the tape exit path, as lateral
`movement of the cradle assembly 65 is constrained by the
`cradle recess 66. Lateral movement of the leader pin 61 in
`that direction is constrained by notches 68 in cradle assem-
`bly 65. As the priming mechanism is not the focus of this
`disclosure, it is not graphically depicted herein. Each of the
`biasing springs 68 fits into a recess 76 in cradle assembly 65.
`Referring now to FIG. 10,
`the details of the cradle
`assembly 65, the tape access port 63 and cradle recess 66 are
`more clearly visible. The cradle assembly 65, when viewed
`along the tape exit path, is C-shaped in order to provide
`clearance for the tape 53 as the tape’s exit angle changes as
`it is unwound from the tape supply reel 31. As the angle at
`which the tape 53 enters the cradle assembly 65 varies
`depending on the amount of tape which has been unwound
`from the cartridge tape supply reel 31, the cradle assembly
`65 must be open on one side. The access door 12 is held in
`a normally shut position with a door closing spring (not
`shown). When inserted within the tape drive, the door 12 is
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`5,927,633
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`7
`pushed rearward into a door recess 70, opening the tape
`access port 63.
`Although only one embodiment of the invention has been
`described herein, it will be obvious to those having ordinary
`skill in the art of tape cartridge design and manufacture, that
`changes and modifications may be made thereto without
`departing from the scope and spirit of the invention as
`hereinafter claimed. For example, as explained in the back-
`ground section of this disclosure, the couplers which impart
`rotational movement to the tape supply reel, though dis-
`closed as geared devices, may also be any other type of
`couplcr known in the art. That is, they may be splincd or be
`friction coupled. In addition, other types of biasing devices
`may be used in place of the coil springs 68. One or more leaf
`or torsion springs might be substituted for the coil springs.
`In addition, one or more compressible pads made of resilient
`foam might also be substituted for springs. Although open-
`pore foam material might provide energy absorbing action
`as the air is forced out of the pores as the foam collapses,
`foam manufactured from polymeric compounds may lose its
`ability to expand to its original dimensions if compressed for
`extended periods.
`What is claimed is:
`1. In combination with a single reel tape cartridge having
`a tape supply reel enclosed within a cartridge housing
`having a tape access port, a data storage tape having a first
`end thereof coupled to the supply reel and a second end
`thereof coupled to a leader device, a resilient parking seat for
`the leader device, said parking seat comprising:
`a cradle assembly slidably movable within said access
`port along a path taken by said tape as it enters and exits
`said cartridge, said cradle assembly having at least one
`notch which receives said leader device when said tape
`is fully rewound onto said supply reel;
`means for biasing said cradle assembly in a tape exiting
`direction.
`
`2. The parking seat of claim 1, wherein said means for
`biasing comprise at
`least one coil spring compressible
`between said cradle assembly and said cartridge housing.
`3. The parking seat of claim 1, wherein said cradle
`assembly has a C-shaped cross section and a channel formed
`by the C-shaped cross section through which said path is
`directed.
`
`4. The parking seat of claim 3, wherein said means for
`biasing comprises a pair of coil springs, one of which is
`positioned above the tape path,
`the other of which is
`positioned below the tape path.
`5. The parking seat of claim 1, wherein said cradle
`assembly is linearly slidable between first and second posi-
`tions.
`6. The parking seat of claim 5, wherein the distance
`between said first and second positions is greater than any
`amount of slack that may be present in said tape when, after
`said tape is rewound on said tape supply reel, further rotation
`of said reel is prevented by the engagement of a reel locking
`device.
`
`7. A single reel tape cartridge for insertion within a tape
`drive unit, said cartridge comprising:
`a cartridge housing having a tape access port;
`a tape supply reel enclosed within said housing, said reel
`rotatable about a rotational axis;
`a driven coupler axially affixed to said reel, said driven
`coupler being adapted to engage a rotatable powered
`driver coupler of said tape drive unit and thereby
`couple rotary motion of the driver coupler to said reel;
`a magnetic tape having a first end permanently attached to
`said supply reel and a second end coupled to a leader
`
`10
`
`15
`
`20
`
`30
`
`35
`
`40
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`45
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`50
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`55
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`60
`
`65
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`8
`device, said tape and leader device being extricable
`from said cartridge by said tape drive;
`a first locking gcar affixed to and rotatablc with said
`driven coupler, said first locking gear having a first set
`of teeth and a center coincident with said rotational
`axis;
`a second locking gear non-rotatably affixed to said
`housing, said second locking gear being movable along
`said rotational axis and having a second set of teeth and
`a center coincident with said rotational axis, said non-
`rotatable locking gear second set of teeth adapted to
`engage said first set of teeth and prevent unwinding of
`said tape from said reel;
`a cradle asscmbly slidably movablc within said access
`port along a path by which said tape enters and exits
`said housing, said cradle receiving said leader device
`and restraining lateral movement of said leader device
`when said tape is fully rewound onto said supply reel;
`means for biasing said assembly in a tape—exiting direc—
`tion.
`
`8. The tape cartridge of claim 7, wherein said means for
`biasing comprise at
`least one coil spring compressible
`between said cradle assembly and said cartridge housing.
`9. The tape cartridge of claim 7, wherein said cradle
`assembly is linearly slidable between first and second posi-
`tions.
`10. The tape cartridge of claim 9, wherein said supply reel
`is lockable at a plurality locations within said housing, each
`location being equiangularly spaced from adjacent locations.
`11. The tape cartridge of claim 10, wherein the distance
`between said first and second positions is greater than the
`circumference of an outmost loop of said tape when fully
`rewound, divided by the number of locations at which said
`reel is lockable.
`12. The parking seat of claim 7, wherein said cradle
`assembly has a C-shaped cross section and a channel formed
`by the C-shaped cross section through which said path is
`directed.
`
`13. The parking seat of claim 12, wherein said means for
`biasing comprises a pair of coil springs, one of which is
`positioned above the tape path,
`the other of which is
`positioned below the tape path.
`14. A single reel tape cartridge for insertion within a tape
`drive unit, said cartridge comprising:
`a cartridge housing having a tape access port;
`a tape supply rccl enclosed within said housing, said rccl
`rotatable about a rotational axis;
`a driven coupler axially affixed to said reel, said driven
`coupler being adapted to engage a rotatable powered
`driver coupler of said tape drive unit and thereby
`couple rotary motion of the driver coupler to said reel;
`a magnetic tape having a first end permanently attached to
`said supply reel and a second end coupled to a leader
`device, said tape and leader device being extricable
`from said cartridge by said tape drive;
`a reel lock adapted to lock said supply reel at any one of
`a plurality locations within said housing;
`a cradle assembly slidably movable within said access
`port along a path by which said tape enters and exits
`said housing, said cradle assembly receiving said leader
`device and restraining lateral movement of said leader
`device when said tape is fully rewound onto said supply
`reel;
`means for biasing said cradle assembly in a tape exiting
`direction.
`
`

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`5,927,633
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`15. The tape cartridge of claim 14, wherein said means for
`biasing comprise at
`least one coil spring compressible
`between said cradle assembly and said cartridge housing.
`16. The tape cartridge of claim 14, wherein said cradle
`assembly is linearly slidable between first and second posi-
`tions.
`
`17. The tape cartridge of claim 14, wherein each of said
`plurality of locations at which said reel
`is lockable are
`equiangularly spaced from adjacent locations.
`18. The tape cartridge of claim 17, wherein the distance
`between said first and second positions is